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Office of Scientific and Technical Information
Gas Powered Air Conditioning Absorption vs. Engine-Drive
E-Print Network (OSTI)
It used to be that the only alternative to costly electric air conditioning was the double-effect gas-fired absorption chiller/heaters. Beginning in the 1980's, they were the "star" equipment promoted by gas companies throughout the nation. Although not a new technology at the time, neither was the gas engine. But now in the 19901s, gas engine-drive (GED) chillers have "hit" the air conditioning market with a "bang". In the Lone Star Gas Company area in 1995, GED chillers are now being considered in as many projects as are Absorption. units. Where once the only studies being analyzed were absorption vs. electric chiller operation costs. Now, the choice is: Why, Where, and How to choose between gas fired Absorption and GED chillers. WHY Absorption or Engine ? . Absorption uses the most environmentally friendly refrigerant - water. . Absorption chillers are chiller/heaters Absorption chillers are manufactured by the four US major manufacturers Absorption chillers have few moving parts . Engine chillers provide "free" hot water Engine chillers retrofit with DX systems . Engine chillers use less gas per ton WHERE Do Absorption And Engine Chillers Belong? . Absorption: Office buildings, restaurants, industries, churches, universities . Engine: Hospitals, universities, hotels, apartments, industries HOW To Choose Between Absorption And Engine Chillers? Energy cost Operation and maintenance costs Equipment cost Environmental concerns Thermal requirements . Space requirements Staff experience
Phillips, J. N.
LiCl Dehumidifier LiBr absorption chiller hybrid air conditioning system with energy recovery
SciTech Connect
This invention relates to a hybrid air conditioning system that combines a solar powered LiCl dehumidifier with a LiBr absorption chiller. The desiccant dehumidifier removes the latent load by absorbing moisture from the air, and the sensible load is removed by the absorption chiller. The desiccant dehumidifier is coupled to a regenerator and the desiccant in the regenerator is heated by solar heated hot water to drive the moisture therefrom before being fed back to the dehumidifier. The heat of vaporization expended in the desiccant regenerator is recovered and used to partially preheat the driving fluid of the absorption chiller, thus substantially improving the overall COP of the hybrid system.
Ko, Suk M. (Huntsville, AL)
Cascade Reverse Osmosis Air Conditioning System: Cascade Reverse Osmosis and the Absorption Osmosis Cycle
BEETIT Project: Battelle is developing a new air conditioning system that uses a cascade reverse osmosis (RO)-based absorption cycle. Analyses show that this new cycle can be as much as 60% more efficient than vapor compression, which is used in 90% of air conditioners. Traditional vapor-compression systems use polluting liquids for a cooling effect. Absorption cycles use benign refrigerants such as water, which is absorbed in a salt solution and pumped as liquid�replacing compression of vapor. The refrigerant is subsequently separated from absorbing salt using heat for re-use in the cooling cycle. Battelle is replacing thermal separation of refrigerant with a more efficient reverse osmosis process. Research has shown that the cycle is possible, but further investment will be needed to reduce the number of cascade reverse osmosis stages and therefore cost.
The absorbent's solution flow process, non-parametric identification into an absorption chiller for air conditioning
Science Conference Proceedings (OSTI)
The lithium bromide chillers supplied from solar collectors are used to provide proper environmental conditions into industrial and civil buildings. To maintain the appropriate values for the temperature into the chiller's boiler, a control unit is introduced ... Keywords: absorption chiller, flow process, system identification
Adrian Danila
The Study of Heat and Mass Transfer In The Generator For an Absorption Air Conditioning System.
??This thesis is aimed to study the heat and mass transfer performance of a generator for the absorption cooling system. Both aqueous lithium bromide (LiBr)� (more)
Hsu, Yu-lien
Air Conditioning and lungs
NLE Websites -- All DOE Office Websites (Extended Search)
Air Conditioning and lungs Name: freeman Status: NA Age: NA Location: NA Country: NA Date: Around 1993 Question: What affect does air conditioning have upon the lungs of the...
Movements in air conditioning.
??Movements in Air Conditioning is a collection of poems that explores the obstacles inherent in creating a new sense of home in a country that� (more)
Hitt, Robert D. (Robert David)
Split-flow regeneration in absorptive air separation
DOE Patents (OSTI)
A chemical absorptive separation of air in multiple stage of absorption and desorption is performed with partial recycle of absorbent between stages of desorption necessary to match equilibrium conditions in the various stages of absorption. This allows reduced absorbent flow, reduced energy demand and reduced capital costs. 4 figs.
Weimer, R.F.
Solar air conditioning
DOE Green Energy (OSTI)
Development of a hybrid solar-assisted air conditioning system that combines a vapor compression section for sensible cooling with a desiccant section for dehumidification and that uses both solar energy and condenser waste heat to drive the dehumidifier has been under way for the last two years (1981 and 1982). The results of this research are included in this report: utilizing solar energy in an economical way has proven quite difficult.
Robison, H.
Performance of an air-cooled ammonia-water absorption air conditioner at low generator temperatures
An ammonia--water absorption air conditioning system has been tested to investigate the stability of operation near the cut-off conditions. Circulation ratios were from 8 to 30. Relations for the estimation of the coefficient of performance and for the prediction of operating temperatures were derived and verified experimentally. Possible operating conditions for an air-cooled ammonia--water air conditioning system were concluded.
Dao, K.; Simmons, M.; Wolgast, R.; Wahlig, M.
Air Conditioning | Department of Energy
Energy.gov (U.S. Department of Energy (DOE)) Indexed Site
Conditioning Conditioning Air Conditioning July 1, 2012 - 6:28pm Addthis Air conditioners cost U.S. homeowners more than $11 billion each year, and regular maintenance can keep your air conditioner running efficiently. | Photo courtesy of ©iStockphoto/JaniceRichard Air conditioners cost U.S. homeowners more than $11 billion each year, and regular maintenance can keep your air conditioner running efficiently. | Photo courtesy of ©iStockphoto/JaniceRichard How does it work? An air conditioner uses energy -- usually electricity -- to transfer heat from the interior of your home to the relatively warm outside environment. Two-thirds of all homes in the United States have air conditioners. Air conditioners use about 5% of all the electricity produced in the United States, at an annual cost of more than $11 billion to homeowners. As a
Optimization of Air Conditioning Cycling.
??Systems based on the vapor compression cycle are the most widely used in a variety of air conditioning applications. Despite the vast growth of modern� (more)
Seshadri, Swarooph
Computer controlled air conditioning systems
This patent describes an improvement in a computer controlled air conditioning system providing for circulation of air through an air conditioned house in contact with concrete walls requiring a humidity within a critical range. The improvement consists of: a computer for processing sensed environmental input data including humidity and oxygen to produce output control signals for affecting the humidity of the air in the house; provision for an air flow circulation path through the house in contact with the concrete walls; sensing responsive to the amount of oxygen in the house for providing input signals to the computer; mixing for combining with the air in the house a variable amount of fresh atmospheric air to supply fresh oxygen; and humidity modifying means for modifying the humidity of the air flowing in the flow path responsive to the control signals.
Dumbeck, R.F.
Air conditioning: Impact on the built environment
The topics discussed in this book are: Introduction. 1. Air Conditioning - An Ever Expanding Market. 2. Building Envelope Design and Air Contitioning. 3. Air Conditioning and Energy - The CIBSE Building Energy Code. 4. Thermal Storage in Air Conditioning Systems. 5. Good Practice in the Design and Construction of Air Conditioning Systems. 6. Software for Air Conditioning Load Analysis and Design. 7. Lloyd's of London - The Architecture of Air Conditioning - Prediction of the Environment.
Sherratt, A.F.C.
Central Air Conditioning | Department of Energy
Central Air Conditioning Central Air Conditioning Central Air Conditioning May 30, 2012 - 8:01pm Addthis Central air conditioners circulate cool air through a system of supply and return ducts. | Photo courtesy of ©iStockphoto/DonNichols. Central air conditioners circulate cool air through a system of supply and return ducts. | Photo courtesy of ©iStockphoto/DonNichols. What does this mean for me? Central air conditioning systems are thermostatically controlled and convenient to use. Central air conditioning systems must be installed properly to operate efficiently. Central air conditioning systems can share ductwork with your heating system. Central air conditioners circulate cool air through a system of supply and return ducts. Supply ducts and registers (i.e., openings in the walls,
Alternative non-CFC mobile air conditioning
Concern about the destruction of the global environment by chlorofluorocarbon (CFC) fluids has become an impetus in the search for alternative, non-CFC refrigerants and cooling methods for mobile air conditioning (MAC). While some alternative refrigerants have been identified, they are not considered a lasting solution because of their high global warming potential, which could result in their eventual phaseout. In view of this dilemma, environmentally acceptable alternative cooling methods have become important. This report, therefore, is aimed mainly at the study of alternative automotive cooling methodologies, although it briefly discusses the current status of alternative refrigerants. The alternative MACs can be divided into work-actuated and heat-actuated systems. Work-actuated systems include conventional MAC, reversed Brayton air cycle, rotary vane compressor air cycle, Stirling cycle, thermoelectric (TE) cooling, etc. Heat-actuated MACs include metal hydride cooling, adsorption cooling, ejector cooling, absorption cycle, etc. While we are better experienced with some work-actuated cycle systems, heat-actuated cycle systems have a high potential for energy savings with possible waste heat applications. In this study, each altemative cooling method is discussed for its advantages and its limits.
Mei, V.C.; Chen, F.C.; Kyle, D.M.
An overview of solar assisted air-conditioning system application in small office buildings in Malaysia
In many regions of the world especially tropical weather in Malaysia, the demand for cooling of indoor air is growing due to increasing comfort expectations and increasing cooling loads. Air-conditioning, the most common cooling mechanism for providing ... Keywords: Malaysian climatic conditions, absorption chiller, evacuated tube solar collector, high energy consumption, peak load demand, solar assisted air conditioning system, solar energy
Lim Chin Haw; Kamaruzzaman Sopian; Yusof Sulaiman
Air-Conditioning Basics | Department of Energy
Air-Conditioning Basics Air-Conditioning Basics Air-Conditioning Basics August 16, 2013 - 1:59pm Addthis Air conditioning is one of the most common ways to cool homes and buildings. How Air Conditioners Work Air conditioners employ the same operating principles and basic components as refrigerators. Refrigerators use energy (usually electricity) to transfer heat from the cool interior of the refrigerator to the relatively warm surroundings; likewise, an air conditioner uses energy to transfer heat from the interior space to the relatively warm outside environment. An air conditioner uses a cold indoor coil called the evaporator. The condenser, a hot outdoor coil, releases the collected heat outside. The evaporator and condenser coils are serpentine tubing surrounded by aluminum fins. This tubing is usually made of copper.
environment. An air conditioner uses a cold indoor coil called the evaporator. The condenser, a hot outdoor coil, releases the collected heat outside. The evaporator and...
Investigation of residential central air conditioning load shapes in NEMS
of Residential Central Air Conditioning Load Shapes in NEMSof Residential Central Air Conditioning Load Shapes in NEMSof Residential Central Air Conditioning Load Shapes in NEMS
Hamachi LaCommare, Kristina; Marnay, Chris; Gumerman, Etan; Chan, Peter; Rosenquist, Greg; Osborn, Julie
Development of solar driven absorption air conditioners and heat pumps
The objective of this project is the development of absorption refrigeration systems for solar active heating and cooling applications. The approaches being investigated are those using air-cooled condenser-absorbers and those leading to coefficient of performances (COP) that increase continuously with heat source temperature. This is primarily an experimental project, with the emphasis on designing, fabricating and testing absorption chillers in operating regimes that are particularly suited for solar energy applications. The first phase of this project has been concluded and has experimentally demonstrated that the conventional single-effect ammonia-water absorption cycle can be used (with minor modifications) for solar cooling. The second phase of this project explores the commercial potential of the single-effect (SE) NH/sub 3//H/sub 2/O absorption air conditioner. (WHK)
Dao, K.; Wahlig, M.; Wali, E.; Rasson, J.; Molishever, E.
Heating, Ventilation and Air Conditioning Efficiency
Presented By: WALTER E. JOHNSTON, PE Presented By: WALTER E. JOHNSTON, PE CEM, CEA, CLEP, CDSM, CPE Air Conditioning (HVAC) system is to provide and maintain a comfortable environment within a building for the occupants or for the process being conducted Many HVAC systems were not designed with energy efficiency as one of the design factors 3 Air Air is the major conductor of heat. Lack of heat = air conditioning OR 4 Btu - Amount of heat required to raise one pound of water 1 F = 0.252 KgCal 1 Pound of Water = About 1 Pint of Water ~ 1 Large Glass 1 Kitchen Match Basics of Air Conditioning = 1 Btu 5 = 6 Low Cost Cooling Unit 7 8 Typical Design Conditions 75 degrees F temperature 50% relative humidity 30 - 50 FPM air movement
Lab Breakthrough: Desiccant Enhanced Evaporative Air Conditioning |
Desiccant Enhanced Evaporative Air Conditioning Desiccant Enhanced Evaporative Air Conditioning Lab Breakthrough: Desiccant Enhanced Evaporative Air Conditioning May 29, 2012 - 5:22pm Addthis This breakthrough combines desiccant materials, which remove moisture from the air using heat, and advanced evaporative technologies to develop a cooling unit that uses 90 percent less electricity and up to 80 percent less total energy than traditional air conditioning. This solution, called the desiccant enhanced evaporative air conditioner (DEVAP), also controls humidity more effectively to improve the comfort of people in buildings. View the entire Lab Breakthrough playlist. What are the key facts? Recent materials advances and liquid desiccant advances to design the compact and cost-effective DEVAP system. DEVAP uses 90 percent less electricity and up to 80 percent less
Lab Breakthrough: Desiccant Enhanced Evaporative Air Conditioning Lab Breakthrough: Desiccant Enhanced Evaporative Air Conditioning Lab Breakthrough: Desiccant Enhanced Evaporative Air Conditioning May 29, 2012 - 5:22pm Addthis This breakthrough combines desiccant materials, which remove moisture from the air using heat, and advanced evaporative technologies to develop a cooling unit that uses 90 percent less electricity and up to 80 percent less total energy than traditional air conditioning. This solution, called the desiccant enhanced evaporative air conditioner (DEVAP), also controls humidity more effectively to improve the comfort of people in buildings. View the entire Lab Breakthrough playlist. What are the key facts? Recent materials advances and liquid desiccant advances to design the compact and cost-effective DEVAP system.
Solar air-conditioning-active, hybrid and passive
After a discussion of summer air conditioning requirements in the United States, active, hybrid, and passive cooling systems are defined. Active processes and systems include absorption, Rankine cycle, and a small variety of miscellaneous systems. The hybrid solar cooling and dehumidification technology of desiccation is covered as well as evaporative cooling. The passive solar cooling processes covered include convective, radiative and evaporative cooling. Federal and state involvement in solar cooling is then discussed. (LEW)
Yellott, J. I.
Zoned heating and air conditioning system
This patent describes a zoned heating and air conditioning system comprising: a central air handling system with an air heating means and an air cooling means and a blower connected to an air duct system; thermostats each have heating and cooling set points, respectively associated with and located in different zones of a building; dampers respectively associated with each building zone positioned in the air duct system. Each damper has an open position allowing air into the respective zone from the duct system and a closed position; relay means for connecting one thermostat to the air handling system upon a call for heating or cooling by one thermostat and disconnecting all other thermostats by connecting one thermostat's connections between the thermostat and air handling system. Only one thermostat is connected to the air handling system at a time and the relay means disconnects one thermostat from the air handling system after one thermostat is satisified; and damper actuating means for unlocking each damper in one building zone responsive actuated by a respective zone thermostat connected to the air handling system by the relay means. The damper actuates means including a damper solenoid for each damper located adjacent each damper and connected to a respective zone thermostat. It unlocks each damper in one building zone responsive to being actuated by the respective zone thermostat and unlocks the dampers in one building zone when one thermostat is actuated while preventing the dampers in another thermostat's building zone from unlocking.
Beachboard, S.A.
Troubleshooting the residential air conditioning system
In order to effectively diagnose problems in a residential air conditioning system, the technician should develop and follow a logical step-by-step troubleshooting procedure. A list of problems, along with possible causes and solutions, that a technician may encounter when servicing a residential air conditioner is presented.
Puzio, H. [Sussex County Vocational Technical School, Sparta, NJ (United States)
A study of membrane properties on air conditioning performance.
??Energy consumption due to heating, ventilation, and air conditioning amounts to 10-20% of global electrical energy usage. Air conditioning alone uses one trillion kilowatt hours� (more)
Boyer, Elizabeth J.
Does the Air-Conditioning Engineering Rubric Work in Residences...
Does the Air-Conditioning Engineering Rubric Work in Residences? Title Does the Air-Conditioning Engineering Rubric Work in Residences? Publication Type Conference Paper LBNL...
Automobile air-conditioning unit. Final report
In this study the refrigerant in the automobile air-conditioner is compressed by thermal energy in a unique compression system rather than by work in a standard compressor. The compression uses an intermittent compression process with a solid absorbent. The vapor is absorbed by an absorbent at relatively low temperature and ejected as the absorbent temperature is raised. A set of one way valves limits flow to one direction. Major contributions are heat transfer requirements, molecular sieve-refrigerant matching, minimizing non-producing mass, solving thermal fatigue and shock problems, and applying this to automobile air-conditioning. The performance study shows energy savings up to fifty percent are possible, depending on engine load. A twenty percent energy savings with the vehicle tested with the air-conditioner in operation is average. The study also showed that less fuel is used with the windows open than with the air-conditioner operating.
Schaetzle, W.J.
Rotating heat pipe for air-conditioning
A unique rotary hermetic heat pipe is disclosed for transferring heat from an external source to an external heat sink. The heat pipe has a tapered condensing surface which is curved preferably to provide uniform pumping acceleration, the heat pipe being rotated at a velocity such that the component of centrifugal acceleration in an axial direction parallel to the tapered surface is greater than lG and so that the condensing surface is kept relatively free of liquid at any attitude. The heat pipe may be incorporated in an air conditioning apparatus so that it projects through a small wall opening. In the preferred air conditioning apparatus, a hollow hermetic air impeller is provided which contains a liquefied gaseous refrigerant, such as freon, and means are provided for compressing the refrigerant in the evaporator region of the heat pipe.
Gray, V.H.
Importance of Design Conditions for Sizing Air-Conditioning Plant
Design conditions based on the meteorological data collected at two weather stations located less than 10 km away from each other within Kuwait City are presented for dry-bulb temperature (DBT) and web-bulb temperature (WBT) prioritization. The proposed design conditions specific to the location and the application are drastically different than currently used single design conditions for all application and locations. Cooling load estimates fro two building located in Kuwait have been analyzed for the proposed and the current design conditions to highlight over- or under-sizing the air-conditioning (A/C) plant capacity. Finally, a number of recommendations are made for architects and designers to use proper design conditions to ensure year-round comfort and energy conservation.
Shaban, N.; Maheshwari, G. P.; Suri, R. K.
Seminar 14 - Desiccant Enhanced Air Conditioning: Desiccant Enhanced Evaporative Air Conditioning (Presentation)
This presentation explains how liquid desiccant based coupled with an indirect evaporative cooler can efficiently produce cool, dry air, and how a liquid desiccant membrane air conditioner can efficiently provide cooling and dehumidification without the carryover problems of previous generations of liquid desiccant systems. It provides an overview to a liquid desiccant DX air conditioner that can efficiently provide cooling and dehumidification to high latent loads without the need for reheat, explains how liquid desiccant cooling and dehumidification systems can outperform vapor compression based air conditioning systems in hot and humid climates, explains how liquid desiccant cooling and dehumidification systems work, and describes a refrigerant free liquid desiccant based cooling system.
Kozubal, E.
Lithium bromide absorption chiller passes gas conditioning field test
A lithium bromide absorption chiller has been successfully used to provide refrigeration for field conditioning of natural gas. The intent of the study was to identify a process that could provide a moderate level of refrigeration necessary to meet the quality restrictions required by natural-gas transmission companies, minimize the initial investment risk, and reduce operating expenses. The technology in the test proved comparatively less expensive to operate than a propane refrigeration plant. Volatile product prices and changes in natural-gas transmission requirements have created the need for an alternative to conventional methods of natural-gas processing. The paper describes the problems with the accumulation of condensed liquids in pipelines, gas conditioning, the lithium bromide absorption cycle, economics, performance, and operating and maintenance costs.
Lane, M.J.; Huey, M.A. [Nicol and Associates, Richardson, TX (United States)
Keeping Cool Without Air Conditioning | Department of Energy
Keeping Cool Without Air Conditioning Keeping Cool Without Air Conditioning August 2, 2013 - 9:50am Addthis Trees can save you energy by blocking sunlight in the summer and letting...
Air-Conditioning, Heating, and Refrigeration Institute (AHRI...
Conditioning, Heating, and Refrigeration Institute (AHRI) Regulatory Burden RFI Air-Conditioning, Heating, and Refrigeration Institute (AHRI) Regulatory Burden RFI These comments...
Solar liquid-desiccant air-conditioning system. Final report
A design for a closed, diurnal, intermittent absorption chiller for passive solar air-conditioning using liquid sorbents has been constructed and tested. LiBr-H/sub 2/O will not work with this design because of its low vapor pressure at the temperature available. The approach has possibilities using the 2 LiBr-ZrBr-CH/sub 3/OH or H/sub 2/O-NH/sub 3/ sorbent refrigerant pairs. The use of H/sub 2/O-NH/sub 3/ appears to be the better candidate because of the lower solution viscosity and less cycle weight, through tank volumes and collector requirements are similar. Further study of other refrigerant pairs such as S-Thiocyanate-ammonia is indicated, however, the difficulties encountered in construction and low potential coefficient of performance, and thus large collection area needed, makes commercialization of such a system doubtful in the foreseeable future.
Not Available
A method to correct IACT data for atmospheric absorption due to the Saharan Air Layer
Using the atmosphere as a detector volume, Imaging Air Cherenkov Telescopes (IACTs) depend highly on the properties and the condition of the air mass above the telescope. On the Canary Island of La Palma, where the Major Atmospheric Gamma-ray Imaging Cherenkov telescope (MAGIC) is situated, the Saharan Air Layer (SAL) can cause strong atmospheric absorption affecting the data quality and resulting in a reduced gamma flux. To correlate IACT data with other measurements, e.g. long-term monitoring or Multi-Wavelength (MWL) studies, an accurate flux determination is mandatory. Therefore, a method to correct the data for the effect of the SAL is needed. Three different measurements of the atmospheric absorption are performed on La Palma. From the determined transmission, a correction factor is calculated and applied to the MAGIC data. The different transmission measurements from optical and IACT data provide comparable results. MAGIC data of PG 1553+113, taken during a MWL campaign in July 2006, have been analyzed using the presented method, providing a corrected flux measurement for the study of the spectral energy distribution of the source.
Daniela Dorner; Kari Nilsson; Thomas Bretz
The Technical and Economical Analysis of the Air-conditioning System Usage in Residential Buildings in Beijing
In this paper, we show that the air-conditioning usage in residential buildings in Beijing grows rapidly in relation to the development of civil construction. More and more people are not satisfied with the current style of only using split air-conditioning units in residential buildings, and are using the central air-conditioning system in residential buildings. To determine the best air conditioning mode, a residential tower building with 22 layers was chosen for analysis. The advantages and disadvantages of the central air-conditioning system and the residential multi-unit air-conditioning equipment system and the LiBr absorption chiller were compared based on calculating the first-cost and the annual cost (according to providing cooling 90 days annually). The predicted results show the economical feasibility of using the refrigerating units in air-conditioning systems in Beijing region, and point out the developing directions for the future.
Sheng, G.; Xie, G.
Innovative Systems for Solar Air Conditioning of Buildings
Solar air conditioning is an attractive technology to achieve comfortable room conditions, especially in hot and sunny climates. In particular air conditioning systems based on sorption technologies offer several advantages as they can be designed for a high efficient utilization of solar thermal energy. To show the today's and near future potential innovative solar cooling and air conditioning systems are discussed which are well adapted to the utilization of solar energy. The system performance of each air conditioning system is evaluated under Abu Dhabi design conditions.
Kessling, W.; Peltzer, M.
A heuristic predictive logic controller applied to hybrid solar air conditioning plant
This paper shows the development of a heuristic predictive logic controller (HPLoC) applied to a solar air conditioning plant. The plant uses two energy sources, solar and gas, in order to warm up the water. The hot water feeds a single-effect absorption ...
Darine Zambrano; Winston Garc�a-Gab�n; Eduardo F. Camacho
Proceedings of the 1993 non-fluorocarbon insulation, refrigeration and air conditioning technology workshop
Sessions included: HFC blown polyurethanes, carbon dioxide blown foam and extruded polystyrenes, plastic foam insulations, evacuated panel insulation, refrigeration and air conditioning, absorption and adsorption and stirling cycle refrigeration, innovative cooling technologies, and natural refrigerants. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.
SOLERAS - Saudi University Solar Cooling Laboratories Project: University of Riyadh. Solar air conditioning. Final report
Research on solar air conditioning at the University of Riyadh in Riyhadh, Saudi Arabia is presented. Topics relevant to the university's proposed solar cooling laboratory are discussed: absorption systems and various contingencies, photovoltaic solar collectors and thermoelectric elements, measuring instruments, solar radiation measurement and analysis, laboratory specifications, and decision theories. Dual cycle computations and equipment specifications are included among the appendices.
Investigation of Residential Central Air Conditioning Load Shapes in
LBNL-52235 Investigation of Residential Central Air Conditioning Load Shapes in NEMS Kristina Laboratory is an equal opportunity employer. #12;#12;LBNL-52235 Investigation of Residential Central Air;#12;Investigation of Residential Central Air Conditioning Load Shapes in NEMS i Table of Contents Acronyms
Heating, ventilation and air conditioning systems
A study is made of several outstanding issues concerning the commercial development of environmental control systems for electric vehicles (EVs). Engineering design constraints such as federal regulations and consumer requirements are first identified. Next, heating and cooling loads in a sample automobile are calculated using a computer model available from the literature. The heating and cooling loads are then used as a basis for estimating the electrical consumption that is to be expected for heat pumps installed in EVs. The heat pump performance is evaluated using an automobile heat pump computer model which has been developed recently at Oak Ridge National Laboratory (ORNL). The heat pump design used as input to the model consists of typical finned-tube heat exchangers and a hermetic compressor driven by a variable-speed brushless dc motor. The simulations suggest that to attain reasonable system efficiencies, the interior heat exchangers that are currently installed as automobile air conditioning will need to be enlarged. Regarding the thermal envelope of the automobile itself, calculations are made which show that considerable energy savings will result if steps are taken to reduce {open_quote}hot soak{close_quote} temperatures and if the outdoor air ventilation rate is well controlled. When these changes are made, heating and cooling should consume less than 10% of the total stored electrical energy for steady driving in most U.S. climates. However, this result depends strongly upon the type of driving: The fraction of total power for heating and cooling ({open_quote}range penalty{close_quote}) increases sharply for driving scenarios having low average propulsion power, such as stop-and-go driving.
Kyle, D.M. [Oak Ridge National Lab., TN (United States); Sullivan, R.A. [Dept. of Energy, Washington, DC (United States)
Alternative Air Conditioning Technologies: Underfloor Air Distribution (UFAD)
is defined as any space conditioning system that allowsor by a separate space conditioning system, but in eitherenergy use - As with any space conditioning system, a poorly
Webster, Tom
An Analysis of Price Determination and Markups in the Air-Conditioning and Heating Equipment Industry
of Commercial and Residential Air Conditioning and HeatingOF COMMERCIAL AND RESIDENTIAL AIR-CONDITIONING AND HEATINGand residential air-conditioning and heating equipment.
Comparison of Zone Cooling Load for Radiant and All-Air Conditioning Systems
Load for Radiant and Air Conditioning Systems. ProceedingsRefrigerating and Air Conditioning Engineers Inc. Babiak,of European Heating ahd Air-Conditioning Associations. CEN (
Feng, Jingjuan; Schiavon, Stefano; Bauman, Fred
Using Modelica for Physical Modeling of Air-Conditioning Systems
Using Modelica for Physical Modeling of Air-Conditioning Systems Using Modelica for Physical Modeling of Air-Conditioning Systems Speaker(s): Jonas Eborn Date: August 23, 2007 - 12:00pm Location: 90-4133 Seminar Host/Point of Contact: Michael Wetter The Air Conditioning library is a commercial Modelica library for the steady-state and transient simulation of air conditioning systems using both compact micro-channel heat exchangers as well as fin-and-tube type heat exchangers. Currently it is mostly used by automotive OEMs and suppliers that need high-accuracy system level models to evaluate energy efficiency of systems developed under the pressure of reduced design cycle times. The library also has applications in other areas, including aircraft cooling systems and residential air-conditioning. The Air Conditioning library contains published correlations for heat and mass transfer and
Seawater Air Conditioning for Downtown Engineering Project Manager
of energy use in typical office and hotel buildings in Hawaii. Hawaii relies on imported fossil fuels electricity usage by 75 percent compared to conventional air conditioning systems. This renewable energy conditioning. Conventional air conditioning systems are energy intensive and represent close to 50 percent
Frandsen, Jannette B.
Modeling and construction of a computer controlled air conditioning system.
??As energy efficient devices become more necessary, it is desired to increase the efficiency of air conditioning systems. Current systems use on/off control, where the� (more)
Frink, Brandon S.
and ready-to-use models for all relevant components of automotive air conditioning systems like condenser, evaporator, compressor, expansion devices and accumulatorreceiver...
New and Underutilized Heating, Ventilation, and Air Conditioning...
8, 2013 - 2:56pm Addthis The following heating, ventilation, and air conditioning (HVAC) technologies are underutilized within the Federal sector. These technologies have been...
2001 Consumption and Expenditures -- Electric Air-Conditioning ...
U.S. Energy Information Administration (EIA)
CE3-1c. Electric Air-Conditioning Energy Consumption in U.S. Households by Climate Zone, 2001 : 2: CE3-2c. ...
Effect of Air Bubbles on Absorption of Solar Radiation by Water Droplets
It was suggested that absorption by a weakly absorbing droplet may be increased substantially by the presence of air bubbles within a droplet. The authors use an exact solution of the scattering of electromagnetic waves by a spherical particle ...
Petr Ch�lek; Gorden Videen; Dat Ngo
Electrospun Polyurethane Fibers for Absorption of Volatile Organic Compounds from Air
Electrospun polyurethane fibers for removal of volatile organic compounds (VOC) from air with rapid VOC absorption and desorption have been developed. Polyurethanes based on 4,4-methylenebis(phenylisocyanate) (MDI) and ...
Scholten, Elke
Variables optimization of building air conditioning system
A heating and climatizer system based on selective absorption of solar energy by a selective collector. The experimental study shows that the performance of this system depends on several variables: the nature of the colporteur fluid, the flow of the ... Keywords: heating and climatisation, modelation and optimization, solar energy
Marius-Constantin Popescu; Cornelia Aida Bulucea; Gheorghe Manolea; Cristian Vladu
Date | 1Refrigeration and Air Conditioning EMA Education and Training Date | 2Refrigeration and Air Conditioning EMA Education and Training
Date | 1Refrigeration and Air Conditioning EMA Education and Training #12;Date | 2Refrigeration Flow Coil Design etc. Finger Print Relationship Every evaporator is unique Unstable Region * = examples
Oak Ridge National Laboratory
Performance of an experimental solar-driven absorption air conditioner. Annual report, July 1975--September 1976
An important pathway for the use of solar energy for space conditioning of buildings is the development of a heat-actuated air conditioner that can operate with the temperatures available from flat-plate solar collectors and use air cooling for disposal of the waste heat. The solar heating and cooling program of the Lawrence Berkeley Laboratory is exploring the use of the ammonia-water absorption cycle for this purpose. Results of the initial tests of an experimental system that has been fabricated to provide basic engineering data on the operation of the ammonia-water absorption cycle under such conditions are presented. A nominal three-ton, continuous operation, heat-actuated water chiller has been fabricated by drastic modification of a commercial gas-fired unit. The major modifications included designing a new water-heated generator, adding a preheater to the solution circuit, and increasing the flow rate of solution by a factor of about three. The unit was instrumented for measurement of temperatures, pressures, and solution concentrations at points in the circuit. Twenty-two experimental runs have been made and the results analyzed. An analysis of the thermodynamic cycle which includes the finite effectiveness of heat transfer at various points in the cycle is shown to predict with good accuracy the measured values of COP. The measured coefficient of performance agreed with the calculated values over the range 0.4 to 0.75 as the conditions of individual runs were varied. The agreement with the calculated values was within about 5 percent.
Design of Air-cooled Microchannel Condensers for Mal-distributed Air Flow Conditions .
??Air-cooled condensers are routinely designed for a variety of applications, including residential air-conditioning systems. Recent attempts at improving the performance of these heat exchangers have� (more)
Subramaniam, Vishwanath
Air Conditioning Load Prediction Based on DE-SVM Algorithm
Based on SVM (Support Vector Machine) theory, and the model to predict air conditioning load was established. In order to optimize the behavior of SVM, the DE (Differential Evolution) algorithm was introduced into classic SVM. The DE-SVM model is applied ... Keywords: Air Conditioning load, DE-SVM, Prediction
Zhonghai Chen; Yong Sun; Guoli Yang; Tengfei Wu; Guizhu Li; Longbiao Xin
The Feasibility Analysis of a New Air-Conditioning System
This paper presents a new modular solar refrigeration and liquid desiccant air conditioning system composed by adsorption refrigeration system, liquid desiccant system and roof cold radiation. The feasibility and beneficial of this new system are analyzed ... Keywords: liquid desiccant, modular solar refrigeration, new air conditioning system, roof cold radiation, technical and economic feasibility analysis
Jinggang Wang; Meixia Du; Xiaoxia Gao; Jin Zhao; Zhenjiang Yin; Yi Man
Air conditioning system with supplemental ice storing and cooling capacity
The present air conditioning system with ice storing and cooling capacity can generate and store ice in its pipe assembly or in an ice storage tank particularly equipped for the system, depending on the type of the air conditioning system. The system is characterized in particular in that ice can be produced and stored in the air conditioning system whereby the time of supplying cooled air can be effectively extended with the merit that the operation cycle of the on and off of the compressor can be prolonged, extending the operation lifespan of the compressor in one aspect. In another aspect, ice production and storage in great amount can be performed in an off-peak period of the electrical power consumption and the stored ice can be utilized in the peak period of the power consumption so as to provide supplemental cooling capacity for the compressor of the air conditioning system whereby the shift of peak and off-peak power consumption can be effected with ease. The present air conditioning system can lower the installation expense for an ice-storing air conditioning system and can also be applied to an old conventional air conditioning system.
Weng, Kuo-Lianq (Taichung, TW); Weng, Kuo-Liang (Taichung, TW)
BEETIT: Building Cooling and Air Conditioning
BEETIT Project: The 14 projects that comprise ARPA-E�s BEETIT Project, short for �Building Energy Efficiency Through Innovative Thermodevices,� are developing new approaches and technologies for building cooling equipment and air conditioners. These projects aim to drastically improve building energy efficiency and reduce greenhouse gas emissions such as carbon dioxide (CO2) at a cost comparable to current technologies.
NREL: Vehicle Ancillary Loads Reduction - Air Conditioning and Emissions
Conditioning and Emissions Conditioning and Emissions Air conditioning and indirect emissions go together in the sense that when a vehicle's air conditioning system is in use, fuel economy declines. When more petroleum fuel is burned, more pollution and greenhouse gases are emitted. An additional, "direct" source of greenhouse gas emissions is the refrigerant used in air conditioning. Called HFC-134a, this pressurized gas tends to seep through tiny openings and escapes into the atmosphere. It can also escape during routine service procedures such as system recharging. NREL's Vehicle Ancillary Loads Reduction team applied its vehicle systems modeling expertise in a study to predict fuel consumption and indirect emissions resulting from the use of vehicle air conditioning. The analysis
Neural network control for an intelligent air handler in an air-conditioning system.
??Many commercial air-conditioning systems in hot and humid areas like Singapore are operated throughout the year. There are two main classifications for these systems: the� (more)
Zhang, Qi.
Direct Digital Control in Air Conditioning Systems for Energy Efficiency
With the rapid development of Intelligent Buildings (IB), the Building Automation System (BAS) has come to control and manage the equipment in the building more and more scientifically, economically and rationally, which can not only raise the function and the level of the building, but also save energy. At present, air-conditioning design in internal commercial buildings is becoming more complex and enormous. The proportion of air conditioning systems in the whole building is getting larger. In order to control and manage the air-conditioning systems effectively and take full use of energy-saving technology, we apply computer control to the system of air automation control. This paper discusses direct digital control (DDC) in the air conditioning system in buildings.
Liu, W.; Ye, A.; Li, D.
Heating, Ventilation, and Air Conditioning Renovations | Department of
Heating, Ventilation, and Air Conditioning Renovations Heating, Ventilation, and Air Conditioning Renovations Heating, Ventilation, and Air Conditioning Renovations October 16, 2013 - 4:49pm Addthis Renewable Energy Options for HVAC Renovations Geothermal Heat Pumps (GHP) Solar Water Heating (SWH) Biomass Passive Solar Heating Biomass Heating Solar Ventilation Air Preheating Federal building renovations that encompass the heating, ventilation, and air conditioning (HVAC) systems in a facility provide a range of renewable energy opportunities. The primary technology option for HVAC renovations is geothermal heat pumps (GHP). Other options include leveraging a solar water heating (SWH) system to offset heating load or using passive solar heating or a biomass-capable furnace or boiler. Some facilities may also take
Desiccant Enhanced Evaporative Air Conditioning: Parametric Analysis and Design; Preprint
This paper presents a parametric analysis using a numerical model of a new concept in desiccant and evaporative air conditioning. The concept consists of two stages: a liquid desiccant dehumidifier and a dew-point evaporative cooler. Each stage consists of stacked air channel pairs separated by a plastic sheet. In the first stage, a liquid desiccant film removes moisture from the process (supply-side) air through a membrane. An evaporatively-cooled exhaust airstream on the other side of the plastic sheet cools the desiccant. The second-stage indirect evaporative cooler sensibly cools the dried process air. We analyze the tradeoff between device size and energy efficiency. This tradeoff depends strongly on process air channel thicknesses, the ratio of first-stage to second-stage area, and the second-stage exhaust air flow rate. A sensitivity analysis reiterates the importance of the process air boundary layers and suggests a need for increasing airside heat and mass transfer enhancements.
Woods, J.; Kozubal, E.
Residential Air-Conditioning System with Smart-Grid Functionality.
??This thesis sets forth a novel intelligent residential air-conditioning (A/C) system controller that provides optimal thermal comfort and electricity cost trade-offs for a household resident� (more)
Thomas, Auswin George
Intelligent Control of Heating, Ventilating and Air Conditioning Systems
This paper proposed a simulation-optimization energy saving strategy for heating, ventilating and air conditioning (HVAC) systems' condenser water loop through intelligent control of single speed cooling towers' components. An analysis of system components ...
Patrick Low Kie; Lau Bee Theng
Approaches to Selecting Design Temperatures for Air-Conditioning
Approaches to Selecting Design Temperatures for Air-Conditioning Speaker(s): Eric Peterson Date: July 7, 2005 - 12:00pm Location: 90-3122 Seminar HostPoint of Contact: Philip...
Dynamic performance testing of prototype 3 ton air-cooled carrier absorption chiller
The performance of a prototype 3 ton cooling capacity air-cooled lithium bromide/water absorption chiller was tested using an absorption chiller test facility which was modified to expand its testing capabilities to include air-cooled chillers in addition to water-cooled chillers. Temperatures of the three externally supplied fluid loops: hot water, chilled water, and cooling air, were varied in order to determine the effects this would have on the two principal measures of chiller performance: cooling capacity and thermal coefficient of performance (COP). A number of interrelated factors were identified as contributing to less than expected performance. For comparison, experimental correlations of other investigators for this and other similar absorption chillers are presented. These have been plotted as both contour and three-dimensional performance maps in order to more clearly show the functional dependence of the chiller performance on the fluid loop temperatures.
Borst, R.R.; Wood, B.D.
Report on field experiment program lithium bromide absorption chiller: Field gas conditioning project, Grayson County, Texas. Topical report, May 1991-December 1994
The primary objective of the project was to determine the applicability of using commercial absorption air conditioning technology in an oil and gas field environment to condition natural gas to meet contractual limitations. Operational and maintenance requirements were documented throughout the test period of 1992 through 1994.
Lane, M.J.; Kilbourn, R.A.; Huey, M.A.
Reducing Air-Conditioning System Energy Using a PMV Index
The control system of central air-conditioning, based on PMV, not only improves thermal comfort but also reduces system energy consumption. A new thermal comfort degree softsensor model is built via use of the CMAC neural network nonlinear calibration function. It can realize on-line detection of thermal comfort. At the same time it can also realize real-time control of central air-conditioning system based on PMV. Simulation results demonstrate the simplicity and effectiveness of the presented method.
Li, H.; Zhang, Q.
Understanding Sulfur Poisoning and Regeneration of Nickel Biomass Conditioning Catalysts using X-Ray Absorption Spectroscopy
The production of biofuels can proceed via a biomass gasification to produce syngas, which can then undergo catalytic conditioning and reforming reactions prior to being sent to a fuel synthesis reactor. Catalysts used for biomass conditioning are plagued by short lifetimes which are a result of, among other things, poisoning. Syngas produced from biomass gasification may contain between 30-300 ppm H2S, depending on the feedstock and gasification conditions, and H2S is a key catalyst poison. In order to overcome catalyst poisoning, either an H2S-tolerant catalyst or an efficient regeneration protocol should be employed. In this study, sulfur K-edge X-ray absorption near edge spectroscopy (XANES) was used to monitor sulfur species on spent catalyst samples and the transformation of these species from sulfides to sulfates during steam and air regeneration on a Ni/Mg/K/Al2O3 catalyst used to condition biomass-derived syngas. Additionally, nickel K-edge EXAFS and XANES are used to examine the state of nickel species on the catalysts. Post-reaction samples showed the presence of sulfides on the H2S-poisoned nickel catalyst and although some gaseous sulfur species were observed to leave the catalyst bed during regeneration, sulfur remained on the catalyst and a transformation from sulfides to sulfates was observed. The subsequent H2 reduction led to a partial reduction of sulfates back to sulfides. A proposed reaction sequence is presented and recommended regeneration strategies are discussed.
Yung, M. M.; Cheah, S.; Kuhn, J. N.
Approaches to Selecting Design Temperatures for Air-Conditioning Approaches to Selecting Design Temperatures for Air-Conditioning Speaker(s): Eric Peterson Date: July 7, 2005 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Philip Haves Edward A. Arens The presentation will describe and compare the methods of determining cooling design conditions used by ASHRAE and the Australian Institute of Refrigeration, Air-Conditioning and Heating. A case study based on weather data for Brisbane will be used to illustrate the issues that arise. One issue is the usefulness of the 3-hourly temperature observations archived in International Weather Office records compared to the hourly observations required by the ASHRAE method. Another issue is the use of daily maxima, which have been archived for over 100 years at many Australian locations. Daily data can easily be used to find trends
Room Air Conditioning Energy Efficiency and Demand Response Potential
Room or window air conditioners are a common appliance in parts of the United States residential sector for providing summertime cooling. The technology is based on the same vapor compression cycle common in central air conditioning and refrigeration applications, but with all system components in one enclosure, which is generally small and comparatively inexpensive. The systems are simple and modular enough to be installed by the homeowner, and can be installed in windows without major modification, or ...
Commentary: Air-conditioning as a risk for increased use of health services
55476 Commentary: Air-conditioning as a risk for increased5-14-04 Commentary: Air-conditioning as a risk for increasedof office buildings with air-conditioning systems (e.g. ,
Mendell, Mark J.
Energy Conservation of Air Conditioning Systems in Large Public Buildings
Analyzing the actuality of the large-scale public buildings' energy consumption, we know that most of them run not only in low efficiency, but also in high energy consumption. According to the characteristics of the building, we should proceed with the heating characteristics of the exterior -protected construction, the set value of the temperature of the air-conditioning, the lectotype of the Central air-conditioning system, the regulation and the modification of the transmission and distribution system, the use of the new energy and the daily management or the method of adjustment and control, and so on , so we can make the air-conditioning system run efficiently. Analyzing and comparing the large-scale public buildings' energy consumption with each other, some pointed improvement measures are proposed further. According to the study and analysis, even though large-scale public buildings consume a great of energy, there exists a huge potential for energy conservation.
Liu, P.; Li, D.
Non-CFC air conditioning for transit buses
In the United Sates, more than 80% of transit city buses are air conditioned. Vapor compression refrigeration systems are standard for air conditioning buses and account for up to 25% of fuel consumption in the cooling season. Vapor compression devices use chlorofluorocarbons (CFCs), chemicals that contributes to Earths`s ozone depletion and to global warming. Currently, evaporative cooling is an economical alternative to CFC vapor compression refrigeration for air conditioning buses. It does not use CFCs but is restricted in use to arid climates. This limitation can be eliminated by dehumidifying the supply air using desiccants. We studied desiccant systems for cooling transit buses and found that the use of a desiccant-assisted evaporative cooling system is feasible and can deliver the required cooling. The weight and the size of the desiccant system though larger than vapor compression systems, can be easily accommodated within a bus. Fuel consumption for naming desiccant systems was about 70% less than CFC refrigeration system, resulting in payback periods of less than 2.5 years under most circumstances. This preliminary study indicated that desiccant systems combined with evaporative cooling is a CFC-free option to vapor compression refrigeration for air conditioning of transit buses. The concept is ready to be tested in a fun prototype scale in a commercial bus.
Pesaran, A.A.; Parent, Y.O.; Bharathan, D.
In the United Sates, more than 80% of transit city buses are air conditioned. Vapor compression refrigeration systems are standard for air conditioning buses and account for up to 25% of fuel consumption in the cooling season. Vapor compression devices use chlorofluorocarbons (CFCs), chemicals that contributes to Earths's ozone depletion and to global warming. Currently, evaporative cooling is an economical alternative to CFC vapor compression refrigeration for air conditioning buses. It does not use CFCs but is restricted in use to arid climates. This limitation can be eliminated by dehumidifying the supply air using desiccants. We studied desiccant systems for cooling transit buses and found that the use of a desiccant-assisted evaporative cooling system is feasible and can deliver the required cooling. The weight and the size of the desiccant system though larger than vapor compression systems, can be easily accommodated within a bus. Fuel consumption for naming desiccant systems was about 70% less than CFC refrigeration system, resulting in payback periods of less than 2.5 years under most circumstances. This preliminary study indicated that desiccant systems combined with evaporative cooling is a CFC-free option to vapor compression refrigeration for air conditioning of transit buses. The concept is ready to be tested in a fun prototype scale in a commercial bus.
Table HC4-12a. Air Conditioning by West Census Region, Million U.S ...
Table HC4-12a. Air Conditioning by West Census Region, Million U.S. Households, 2001 Air Conditioning Characteristics RSE Column Factor: Total U.S.
Table HC4-9a. Air Conditioning by Northeast Census Region, Million ...
Table HC4-9a. Air Conditioning by Northeast Census Region, Million U.S. Households, 2001 Air Conditioning Characteristics RSE Column Factor: Total
Table AC1. Total Households Using Air-Conditioning Equipment, 2005 ...
Table AC1. Total Households Using Air-Conditioning Equipment, 2005 Million U.S. Households Type of Air-Conditioning Equipment (millions) Central System
Table AC7. Average Expenditures for Air-Conditioning by Equipment ...
Central System 5 Table AC7. Average Expenditures for Air-Conditioning by Equipment Type, 2005 Dollars per Household Type of Air-Conditioning Equipment
Ventilation and air-conditioning concept for CNGS underground areas
The aim of the CNGS project is to prove the existence of neutrino oscillation by generating an intense neutrino beam from CERN in the direction of the Gran Sasso laboratory in Italy, where two large neutrino detectors are built to detect the neutrinos. All the components for producing the neutrino beam will be situated in the underground tunnels, service galleries and chambers. The ventilation and air-conditioning systems installed in these underground areas have multiple tasks. Depending on the operating mode and structure to be air-conditioned, the systems are required to provide fresh air, cool the machine, dehumidify areas housing sensible equipment or assure the smoke removal in a case of a fire. This paper presents the technical solutions foreseen to meet these requirements.
Lindroos, J
Solutions for Summer Electric Power Shortages: Demand Response and its Applications in Air Conditioning and Refrigerating Systems
LBNL-63806 Refrigeration, Air Conditioning, & Electric Powerand its Applications in Air Conditioning and Refrigeratingand its applications in Air Conditioning and refrigerating
Han, Junqiao; Piette, Mary Ann
Study of long term options for electric vehicle air conditioning
There are strong incentives in terms of national energy and environmental policy to encourage the commercialization of electrically powered vehicles in the U.S. Among these incentives are reduced petroleum consumption, improved electric generation capacity utilization, reduced IC engine emissions, and, depending on the primary fuel used for electric power generation, reduced emissions of carbon dioxide. A basic requirement for successfully commercializing any motor vehicle in the US is provision of adequate passenger comfort heating and air conditioning (cooling). Although air conditioning is generally sold as optional equipment, in excess of 80% of the automobiles and small trucks sold in the US have air conditioning systems. In current, pre-commercial electric vehicles, comfort heating is provided by a liquid fuel fired heater that heats water which is circulated through the standard heater core in the conventional interior air handling unit. Air conditioning is provided by electric motor driven compressors, installed in a system having, perhaps, an [open quotes]upsized[close quotes] condenser and a standard evaporator (front and rear evaporators in some instances) installed in the conventional interior air handler. Although this approach is adequate in the near term for initial commercialization efforts, a number of shortcomings of this arrangement, as well as longer range concerns need to be addressed. In this project, the long term alternatives for cooling and heating electric vehicles effectively, efficiently (with minimum range penalties), and without adverse environmental impacts have been examined. Identification of options that can provide both heating and cooling is important, in view of the disadvantages of carrying separate heating and cooling systems in the vehicle.
Dieckmann, J.; Mallory, D. (Little (Arthur D.), Inc., Cambridge, MA (United States))
There are strong incentives in terms of national energy and environmental policy to encourage the commercialization of electrically powered vehicles in the U.S. Among these incentives are reduced petroleum consumption, improved electric generation capacity utilization, reduced IC engine emissions, and, depending on the primary fuel used for electric power generation, reduced emissions of carbon dioxide. A basic requirement for successfully commercializing any motor vehicle in the US is provision of adequate passenger comfort heating and air conditioning (cooling). Although air conditioning is generally sold as optional equipment, in excess of 80% of the automobiles and small trucks sold in the US have air conditioning systems. In current, pre-commercial electric vehicles, comfort heating is provided by a liquid fuel fired heater that heats water which is circulated through the standard heater core in the conventional interior air handling unit. Air conditioning is provided by electric motor driven compressors, installed in a system having, perhaps, an {open_quotes}upsized{close_quotes} condenser and a standard evaporator (front and rear evaporators in some instances) installed in the conventional interior air handler. Although this approach is adequate in the near term for initial commercialization efforts, a number of shortcomings of this arrangement, as well as longer range concerns need to be addressed. In this project, the long term alternatives for cooling and heating electric vehicles effectively, efficiently (with minimum range penalties), and without adverse environmental impacts have been examined. Identification of options that can provide both heating and cooling is important, in view of the disadvantages of carrying separate heating and cooling systems in the vehicle.
Dieckmann, J.; Mallory, D. [Little (Arthur D.), Inc., Cambridge, MA (United States)
Solar powered desiccant air conditioning system. Final report
A solar-powered desiccant air conditioning system using silica gel has been developed, and modifications to the existing unit and additional testing are proposed to demonstrate the feasibility of the unit. Conversion from a rotating bed to a fixed bed of silica gel is proposed. Some general plans for commercialization are briefly discussed. (LEW)
Solar air conditioning system using desiccant wheel technology
The electrical energy consumption in Malaysia has increased sharply in the past few years. Modern energy efficient technologies are desperately needed for the national energy policy. In this paper, a new design of desiccant cooling is being developed ... Keywords: air-conditioning, desiccant cooling, solar thermal energy, solid desiccant
Arfidian Rachman; Sohif Mat; Taib Iskandar; M. Yahya; Azami Zaharim; Kamaruzzaman Sopian
Research on Fuzzy Regulation Strategies in the Constant Air Volume Air Conditioning System
The energy consumption of the constant air volume (CAV) system largely depends on the regulation strategies. Although some air conditioning systems are equipped with automatic regulation devices, others lack effective regulation strategies. To avoid wasting energy and presenting simple regulation methods, fuzzy regulation strategies for CAV systems are studied in this research. A CAV system of an office building is modeled and simulated with the Designer's Simulation Toolkit (DeST). The operating parameters are calculated based on the instantaneous load obtained from simulation. The operation of the system is divided into five stages according to different conception of �cold� or �hot� in different seasons. The relationship between the outdoor air temperature and the fresh air volume, and the supply air temperature is presented in the form of fuzzy rules. Then the building is simulated under different load conditions and the operating parameters are obtained from fuzzy reasoning. Finally, the effect of fuzzy strategies on energy consumption is analyzed and compared with the effects of the operating parameters obtained from simulation. The results show that energy consumption using a fuzzy regulation strategy is close to the energy consumption of knowing the exact load of the building, while the fuzzy regulation strategy can largely simplify the regulation of the air conditioning system.
Bai, T.; Zhang, J.; Ning, N.; Tong, K.; Wu, Y.; Wang, H.
Performance assessment on continuous air monitors under real operating conditions
In the nuclear industry, workers may be exposed to artificial radioactive aerosols. These aerosols are generally composed of particles with a diameter measuring between 0.1 {mu}m and 10 {mu}m. To protect workers in nuclear facilities, monitors that continuously measure radioactivity in the air are used. The main function of the monitor is to provide real-time measurement of activity concentration. Measurement of aerosol activity concentration can be affected by a number of factors specific to the aerosols and the instrument. The first part of the article will present the general operating principles of continuous air monitors (CAMs) and inherent measurement difficulties, as well as the main standard tests. The second section describes the experimental ICARE facility The ICARE facility generates standard artificial and natural radioactive aerosols for calibrating continuous air monitors under real operating conditions. (authors)
Monsanglant-Louvet, C.; Liatimi, N.; Gensdarmes, F. [Inst. of Radioprotection and Nuclear Safety- IRSN, Saclay (France)
Thermal storage HVAC system retrofit provides economical air conditioning
This article describes an EMS-controlled HVAC system that meets the ventilation and cooling needs of an 18,000-seat indoor ice hockey arena. The Buffalo Memorial Auditorium (affectionately referred to as the Aud) was built in 1937 under the Works Project Administration of the federal government. Its original configuration included a 12,000-seat arena with an ice skating rink. By the late 1980s, the city was unsuccessfully attempting to attract events and tenants to the auditorium, which lacked air conditioning and other modern amenities. Thus, it was decided to renovate the facility to make it marketable. The first phase of the renovation included installing an air-conditioning system in the arena and repairing the existing building systems that were inoperable because of deferred maintenance. After considering the existing conditions (such as size of the space, intermittent usage, construction restrictions, operating budgets and the limited operations staff), the engineering team designed an innovative HVAC system. The system's features include: a carbon dioxide monitoring device that controls the intake of outside air; an ice storage system that provides chilled water and shifts electrical demand to off-peak hours; and a design that uses the building mass as a heat sink. A new energy management system (EMS) determines building cooling needs based on the type of event, ambient conditions and projected audience size. Then, it selects the most economical method to obtain the desired arena temperature.
Smith, S.F. (Wendel Engineers, P.C., Buffalo, NY (United States))
Magnetic Refrigeration Technology for High Efficiency Air Conditioning
Magnetic refrigeration was investigated as an efficient, environmentally friendly, flexible alternative to conventional residential vapor compression central air conditioning systems. Finite element analysis (FEA) models of advanced geometry active magnetic regenerator (AMR) beds were developed to minimize bed size and thus magnet mass by optimizing geometry for fluid flow and heat transfer and other losses. Conventional and magnetocaloric material (MCM) regenerator fabrication and assembly techniques were developed and advanced geometry passive regenerators were built and tested. A subscale engineering prototype (SEP) magnetic air conditioner was designed, constructed and tested. A model of the AMR cycle, combined with knowledge from passive regenerator experiments and FEA results, was used to design the regenerator beds. A 1.5 Tesla permanent magnet assembly was designed using FEA and the bed structure and plenum design was extensively optimized using FEA. The SEP is a flexible magnetic refrigeration platform, with individually instrumented beds and high flow rate and high frequency capability, although the current advanced regenerator geometry beds do not meet performance expectations, probably due to manufacturing and assembly tolerances. A model of the AMR cycle was used to optimize the design of a 3 ton capacity magnetic air conditioner, and the system design was iterated to minimize external parasitic losses such as heat exchanger pressure drop and fan power. The manufacturing cost for the entire air conditioning system was estimated, and while the estimated SEER efficiency is high, the magnetic air conditioning system is not cost competitive as currently configured. The 3 ton study results indicate that there are other applications where magnetic refrigeration is anticipated to have cost advantages over conventional systems, especially applications where magnetic refrigeration, through the use of its aqueous heat transfer fluid, could eliminate intermediate heat exchangers or oil distribution issues found in traditional vapor compression systems.
Boeder, A; Zimm, C
Improving Glass Walls Thermal Resistance In Air-Conditioned Buildings
The solar radiation through an air conditioned building depends on what is called the building envelope. Building envelope consists of the surfaces that separate the inside from the building outdoors. Area, direction, and specifications of glass walls; as one of envelope surfaces; has an important impact on solar radiation. Design and construction of glass walls have significant effects on building comfort and energy consumption. This paper describes methods of improving glass walls thermal resistance in air conditioned buildings. Effect of glass wall radiation temperature on the indoor temperature distribution of building rooms is also investigated. Heat gain through various types of glass is discussed. Optimization and testing of these types are carried out theoretically and experimentally as well. A series of experiments on different types of glass with special strips is performed.
Galal, T.; Kulaib, A. M.; Alajmi, R.; Al-Ansary. A; Abuzaid, M.
High-throughput liquid-absorption air-sampling apparatus and methods
A portable high-throughput liquid-absorption air sampler [PHTLAAS] has an asymmetric air inlet through which air is drawn upward by a small and light-weight centrifugal fan driven by a direct current motor that can be powered by a battery. The air inlet is so configured as to impart both rotational and downward components of motion to the sampled air near said inlet. The PHTLAAS comprises a glass tube of relatively small size through which air passes at a high rate in a swirling, highly turbulent motion, which facilitates rapid transfer of vapors and particulates to a liquid film covering the inner walls of the tube. The pressure drop through the glass tube is <10 cm of water, usually <5 cm of water. The sampler's collection efficiency is usually >20% for vapors or airborne particulates in the 2-3.mu. range and >50% for particles larger than 4.mu.. In conjunction with various analyzers, the PHTLAAS can serve to monitor a variety of hazardous or illicit airborne substances, such as lead-containing particulates, tritiated water vapor, biological aerosols, or traces of concealed drugs or explosives.
Zaromb, Solomon (95706 William Dr., Hinsdale, IL 60521)
Service center to test solar air-conditioning system
Field testing of an advanced solar-powered air-conditioning system developed under the joint Saudi Arabia-US Agreement for Cooperation in the Field of solar Energy (SOLERAS) will be conducted in Arizona over a three-phase 34-month perod. Participants in the program and their contribution are cited. The solar-Rankine alternative to conventional systems using electricity or fossil fuels. (DCK)
Fetz Plumbing, Heating & Air Conditioning | Open Energy Information
Open Energy Info (EERE)
Fetz Plumbing, Heating & Air Conditioning Fetz Plumbing, Heating & Air Conditioning Jump to: navigation, search Name Fetz Plumbing, Heating & Air Conditioning Address 115 Washington Street - P.O. Box 516 Place Urbana, Ohio Zip 43078 Sector Efficiency, Geothermal energy, Services, Solar Product Installation; Maintenance and repair Phone number 937-652-1136 Website http://fetzphc.com Coordinates 40.108862°, -83.757291° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":40.108862,"lon":-83.757291,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
High Technology Centrifugal Compressor for Commercial Air Conditioning Systems
R&D Dynamics, Bloomfield, CT in partnership with the State of Connecticut has been developing a high technology, oil-free, energy-efficient centrifugal compressor called CENVA for commercial air conditioning systems under a program funded by the US Department of Energy. The CENVA compressor applies the foil bearing technology used in all modern aircraft, civil and military, air conditioning systems. The CENVA compressor will enhance the efficiency of water and air cooled chillers, packaged roof top units, and other air conditioning systems by providing an 18% reduction in energy consumption in the unit capacity range of 25 to 350 tons of refrigeration The technical approach for CENVA involved the design and development of a high-speed, oil-free foil gas bearing-supported two-stage centrifugal compressor, CENVA encompassed the following high technologies, which are not currently utilized in commercial air conditioning systems: Foil gas bearings operating in HFC-134a; Efficient centrifugal impellers and diffusers; High speed motors and drives; and System integration of above technologies. Extensive design, development and testing efforts were carried out. Significant accomplishments achieved under this program are: (1) A total of 26 builds and over 200 tests were successfully completed with successively improved designs; (2) Use of foil gas bearings in refrigerant R134a was successfully proven; (3) A high speed, high power permanent magnet motor was developed; (4) An encoder was used for signal feedback between motor and controller. Due to temperature limitations of the encoder, the compressor could not operate at higher speed and in turn at higher pressure. In order to alleviate this problem a unique sensorless controller was developed; (5) This controller has successfully been tested as stand alone; however, it has not yet been integrated and tested as a system; (6) The compressor successfully operated at water cooled condensing temperatures Due to temperature limitations of the encoder, it could not be operated at air cooled condensing temperatures. (7) The two-stage impellers/diffusers worked well separately but combined did not match well.
Ruckes, John
Effect of Intake Air Filter Condition on Vehicle Fuel Economy
The U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy and the U.S. Environmental Protection Agency (EPA) jointly maintain a fuel economy website (www.fueleconomy.gov), which helps fulfill their responsibility under the Energy Policy Act of 1992 to provide accurate fuel economy information [in miles per gallon (mpg)] to consumers. The site provides information on EPA fuel economy ratings for passenger cars and light trucks from 1985 to the present and other relevant information related to energy use such as alternative fuels and driving and vehicle maintenance tips. In recent years, fluctuations in the price of crude oil and corresponding fluctuations in the price of gasoline and diesel fuels have renewed interest in vehicle fuel economy in the United States. (User sessions on the fuel economy website exceeded 20 million in 2008 compared to less than 5 million in 2004 and less than 1 million in 2001.) As a result of this renewed interest and the age of some of the references cited in the tips section of the website, DOE authorized the Oak Ridge National Laboratory (ORNL) Fuels, Engines, and Emissions Research Center (FEERC) to initiate studies to validate and improve these tips. This report documents a study aimed specifically at the effect of engine air filter condition on fuel economy. The goal of this study was to explore the effects of a clogged air filter on the fuel economy of vehicles operating over prescribed test cycles. Three newer vehicles (a 2007 Buick Lucerne, a 2006 Dodge Charger, and a 2003 Toyota Camry) and an older carbureted vehicle were tested. Results show that clogging the air filter has no significant effect on the fuel economy of the newer vehicles (all fuel injected with closed-loop control and one equipped with MDS). The engine control systems were able to maintain the desired AFR regardless of intake restrictions, and therefore fuel consumption was not increased. The carbureted engine did show a decrease in fuel economy with increasing restriction. However, the level of restriction required to cause a substantial (10-15%) decrease in fuel economy (such as that cited in the literature) was so severe that the vehicle was almost undrivable. Acceleration performance on all vehicles was improved with a clean air filter. Once it was determined how severe the restriction had to be to affect the carbureted vehicle fuel economy, the 2007 Buick Lucerne was retested in a similar manner. We were not able to achieve the level of restriction that was achieved with the 1972 Pontiac with the Lucerne. The Lucerne's air filter box would not hold the filter in place under such severe conditions. (It is believed that this testing exceeded the design limits of the air box.) Tests were conducted at a lower restriction level (although still considerably more severe than the initial clogged filter testing), allowing the air filter to stay seated in the air box, and no significant change was observed in the Lucerne's fuel economy or the AFR over the HFET cycle. Closed-loop control in modern fuel injected vehicle applications is sophisticated enough to keep a clogged air filter from affecting the vehicle fuel economy. However for older, open-loop, carbureted vehicles, a clogged air filter can affect the fuel economy. For the vehicle tested, the fuel economy with a new air filter improved as much as 14% over that with a severely clogged filter (in which the filter was so clogged that drivability was impacted). Under a more typical state of clog, the improvement with a new filter ranged from 2 to 6%.
Norman, Kevin M [ORNL; Huff, Shean P [ORNL; West, Brian H [ORNL
Identifying Efficiency Degrading Faults in Split Air Conditioning Systems
Studies estimate that as much as 50% of packaged air conditioning systems operate in faulty conditions that degrade system efficiency. Common faults include: under- and over-charged systems (too much or too little refrigerant), faulty expansions valves (stuck valves, valve hunting, poorly tuned valve controllers), and fouled evaporators and condensers. Furthermore, air conditioning systems can often be adjusted to improve efficiency while continuing to meet cooling loads (adjusting system pressures, decreasing superheat setpoints). This study presents the design of a low cost device that can non-invasively measure system operating conditions, diagnose faults, estimate potential energy savings, and provide recommendations on how the system should be adjusted or repaired. Using eight external temperature measurements, the device potentially can detect and diagnose up to ten faults commonly found in HVAC systems. Steady state temperatures are compared to threshold values obtained from literature and HVAC manufacturers to detect and determine the severity of faults and subsequent reductions in coefficient of performance. Preliminary tests reveal the potential for the device to detect and diagnose common efficiency-degrading faults in HVAC systems.
Terrill, T. J.; Brown, M. L.; Cheyne, R. W. Jr.; Cousins, A. J.; Daniels, B. P.; Erb, K. L.; Garcia, P. A.; Leutermann, M. J.; Nel, A. J.; Robert, C. L.; Widger, S. B.; Williams, A. G.; Rasmussen, B. P.
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the top of the tower An (earlier) alternative is to use a spray pond to cool water; disadvantages. Air conditioning, cooling towers7. Air conditioning, cooling towersg, gg, g Ron Zevenhoven �?�?bo, is the hi htemperature at which condensation begins when air is cooled at constant pressurecooled
Zevenhoven, Ron
Vehicle Transient Air Conditioning Analysis: Model Development& System Optimization Investigations
The National Renewable Energy Laboratory (NREL) has developed a transient air conditioning (A/C) system model using SINDA/FLUINT analysis software. It captures all the relevant physics of transient A/C system performance, including two-phase flow effects in the evaporator and condenser, system mass effects, air side heat transfer on the condenser/evaporator, vehicle speed effects, temperature-dependent properties, and integration with a simplified cabin thermal model. It has demonstrated robust and powerful system design optimization capabilities. Single-variable and multiple variable design optimizations have been performed and are presented. Various system performance parameters can be optimized, including system COP, cabin cool-down time, and system heat load capacity. This work presents this new transient A/C system analysis and optimization tool and shows some high-level system design conclusions reached to date. The work focuses on R-134a A/C systems, but future efforts will modify the model to investigate the transient performance of alternative refrigerant systems such as carbon dioxide systems. NREL is integrating its transient air conditioning model into NRELs ADVISOR vehicle system analysis software, with the objective of simultaneously optimizing A/C system designs within the overall vehicle design optimization.
Hendricks, T. J.
Commissioning and Diagnosis of VAV Air-Conditioning Systems
This paper presents a fault detection and diagnosis (FDD) strategy based on system knowledge, qualitative states and object-oriented statistical process control (SPC) models for typical pressure-independent variable air volume (VAV) air-conditioning systems. Eight FDD schemes are built to detect the eleven pre-defined VAV faults using the qualitative and quantitative FDD approaches within the strategy at two steps. The ten hard faults, which would affect the system operation, are analyzed at Step 1. The soft fault, which would not affect the basic system operation but would impact the supervisory controls, is analyzed at Step 2. The strategy is tested and validated on typical VAV systems involving multiple faults, both in simulation and in-situ tests. A software package is developed as a BMS-assisted automatic commissioning tool based on the FDD strategy. Off-line tests were conducted in both the simulated building and the real building.
Qin, J.; Wang, S.; Chan, C.; Xiao, F.
Reducing air conditioning waste by signalling it is cool outside
This experiment looked at the effects on residential energy consumption of providing homeowners with (1) a signalling device that indicated a conservation opportunity and (2) information feedback about their rate of energy use. The signalling device operated when the outside temperature was below 68F and the air conditioner was on. Homeowners were told that the signalling device indicated when they could cool their house effectively by opening the windows and turning off their air conditioner. Forty households were randomly assigned to one of four conditions: signalling device only, feedback only, both, neither. The results showed a significant 15.7% decrease in energy use for those households with the signalling devices. Neither the feedback nor interaction effect was significant. The advantages and disadvantages of having people in the control cycle were discussed. 4 references, 1 table.
Becker, L.J.; Seligman, C.
A cost-effective and fuel-conserving nonelectric air conditioner that combines engine-driven compression and absorption cycles
A natural-gas-fueled electricity-producing condensing furnace with the potential of being mass produced at a cost of less than $1000 and providing a cost-effective and highly fuel-conserving alternative to virtually every residential gas furnace in the world has been developed. While this is a new system, it completely consists of existing mass-produced components including single-cylinder air-cooled engines, induction motors/generators, and control devices. Thus, timely commercialization can be expected and an important new energy technology and industry can result. However, all the benefits of this electricity-producing furnace occur during the winter. This has stimulated the search for a new system that can provide comparable benefits in terms of fuel conservation, the environment, and electric utility peak reduction during the summer, along with the prospects of a new and efficient new use for the natural gas surpluses that occur during the summer. The resulting system, which can use existing component equipment, is a commercial-size nonelectric air conditioner that consists of an automobile-type engine converted to natural gas, or possibly a diesel or combustion turbine, driving a Freon compression cycle, with virtually all of the engine reject heat from the exhaust and from the engine cooling system driving a conventional absorption air conditioning cycle.
Wicks, F.
Liquid over-feeding air conditioning system and method
A refrigeration air conditioning system utilizing a liquid over-feeding operation is described. A liquid refrigerant accumulator-heat exchanger is placed in the system to provide a heat exchange relationship between hot liquid refrigerant discharged from condenser and a relatively cool mixture of liquid and vaporous refrigerant discharged from the evaporator. This heat exchange relationship substantially sub-cools the hot liquid refrigerant which undergoes little or no evaporation across the expansion device and provides a liquid over-feeding operation through the evaporator for effectively using 100 percent of evaporator for cooling purposes and for providing the aforementioned mixture of liquid and vaporous refrigerant.
Mei, Viung C. (Oak Ridge, TN); Chen, Fang C. (Knoxville, TN)
A refrigeration air conditioning system utilizing a liquid over-feeding operation is described. A liquid refrigerant accumulator-heat exchanger is placed in the system to provide a heat exchange relationship between hot liquid refrigerant discharged from condenser and a relatively cool mixture of liquid and vaporous refrigerant discharged from the evaporator. This heat exchange relationship substantially sub-cools the hot liquid refrigerant which undergoes little or no evaporation across the expansion device and provides a liquid over-feeding operation through the evaporator for effectively using 100 percent of evaporator for cooling purposes and for providing the aforementioned mixture of liquid and vaporous refrigerant. 1 figure.
Mei, V.C.; Chen, F.C.
Weatherking Heating & Air conditioning | Open Energy Information
Page Page Edit with form History Facebook icon Twitter icon » Weatherking Heating & Air conditioning Jump to: navigation, search Name Weatherking Heating & Air conditioning Address 51 Meadow Lane Place Northfield, Ohio Zip 44067 Sector Buildings, Efficiency, Geothermal energy, Renewable Energy, Services Product Business and legal services; Energy audits/weatherization; Energy provider: power production;Energy provider: wholesale;Engineering/architectural/design;Installation;Investment/finances;Maintenance and repair; Retail product sales and distribution Phone number 330-908-0281 Website http://www.weatherking1.com Coordinates 41.3340869°, -81.530299° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":41.3340869,"lon":-81.530299,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}
Evaluation of air-conditioning compressor performance for assessment of load management potential
Residential air-conditioning contributes heavily to the electrical utilities' summer peak demand. Cycling programs in which utilities turn off air-conditioning compressors a certain percentage of each hour through remotely-controlled switches can help ...
Jerry R. Harber; Aileen Henson
Regression Forecasting of the Onset of the Indian Summer Monsoon with Antecedent Upper Air Conditions
It is shown that the recorded onset dates of the summer monsoon in southwestern India can be closely related functionally to the antecedent upper air conditions. The antecedent upper air conditions are represented by April mean values of the ...
Ernest C. Kung; Taher A. Sharif
Table HC2.6 Air Conditioning Characteristics by Type of Housing ...
Table HC2.6 Air Conditioning Characteristics by Type of Housing Unit, 2005 Million U.S. Housing Units Air Conditioning Characteristics Attached 2 to 4 Units 5 or More
Prediction of Air Conditioning Load Response for Providing Spinning Reserve - ORNL Report
This report assesses the use of air conditioning load for providing spinning reserve and discusses the barriers and opportunities. Air conditioning load is well suited for this service because it often increases during heavy load periods and can be curtailed for short periods with little impact to the customer. The report also provides an appendix describing the ambient temperature effect on air conditioning load.
Kueck, John D [ORNL; Kirby, Brendan J [ORNL; Ally, Moonis Raza [ORNL; Rice, C Keith [ORNL
Assessment of thermal swing absorption alternatives for producing oxygen enriched combustion air
It has been established that oxygen enriched combustion (OEC) can substantially improve the thermal efficiency and productivity of a furnace. An OEC performance study by the Union Carbide Corporation found that in furnaces with flue gas temperatures above 2,000{degree}F, a high level of oxygen (O{sub 2}) enrichment (50% to 100% O{sub 2}) will result in a 40% to 60% fuel savings. The US DOE's (Department of Energy) Office of Industrial Programs (OIP) has sponsored several research development projects and engineering assessments relevant to the production of oxygen enriched air (OEA) and its use in combustion systems. In an OIP-sponsored assessment of research and development opportunities for combustion technologies, Taratec Corporation indicated that thermal swing absorption (TSA) offers a potentially viable option for producing low-cost oxygen enriched combustion air (OECA). In fact, an integrated, TSA-based oxygen enriched air production system driven by waste heat from furnace exhaust may be more energy- and cost-efficient than the alternative technologies. The study presented in this document further investigates and assesses TSA alternatives for producing low-cost OECA. 7 refs., 4 figs., 5 tabs.
Electrical applications for air conditioning and refrigeration systems
Electrical troubleshooting is possibly the most neglected area of maintaining air conditioning and refrigeration equipment. This text explains and illustrates methods for troubleshooting the full spectrum of electrical or electronic circuits of these systems. Comprehensive sections offer coverage of electrical fundamentals, single-phase electric motors, three-phase motors, control devices, electrical control circuits, use of schematic diagrams in troubleshooting, ice makers, solid state electronics, and basic electronic controls. The author`s clear, concise coverage of controls enables one to quickly understand both how a specific type of control works, and how it is used in the system. The reader will find a wealth of useful instructions for making operational checks and troubleshooting for proper operation. The book is conveniently divided into application-specific units, making it easy to quickly find information specific to a particular job at hand.
Langley, B.C.
This memo explains what Berkeley Lab has learned about how the residential central air-conditioning (CAC) end use is represented in the National Energy Modeling System (NEMS). NEMS is an energy model maintained by the Energy Information Administration (EIA) that is routinely used in analysis of energy efficiency standards for residential appliances. As part of analyzing utility and environmental impacts related to the federal rulemaking for residential CAC, lower-than-expected peak utility results prompted Berkeley Lab to investigate the input load shapes that characterize the peaky CAC end use and the submodule that treats load demand response. Investigations enabled a through understanding of the methodology by which hourly load profiles are input to the model and how the model is structured to respond to peak demand. Notably, it was discovered that NEMS was using an October-peaking load shape to represent residential space cooling, which suppressed peak effects to levels lower than expected. An apparent scaling down of the annual load within the load-demand submodule was found, another significant suppressor of the peak impacts. EIA promptly responded to Berkeley Lab's discoveries by updating numerous load shapes for the AEO2002 version of NEMS; EIA is still studying the scaling issue. As a result of this work, it was concluded that Berkeley Lab's customary end-use decrement approach was the most defensible way for Berkeley Lab to perform the recent CAC utility impact analysis. This approach was applied in conjunction with the updated AEO2002 load shapes to perform last year's published rulemaking analysis. Berkeley Lab experimented with several alternative approaches, including modifying the CAC efficiency level, but determined that these did not sufficiently improve the robustness of the method or results to warrant their implementation. Work in this area will continue in preparation for upcoming rulemakings for the other peak coincident end uses, commercial air conditioning and distribution transformers.
Effectiveness of Shading Air-Cooled Condensers of Air-Conditioning Systems
In air-conditioning (A/C) systems with air-cooled condensers, the condensing unit has to be kept in the open for easy access to outdoor air in order to efficiently dissipate heat. During daytime, the solar radiation falling on the surfaces of the condenser and the high ambient temperatures can be detrimental for the energy performance. The effectiveness of shading the condensing unit to mitigate this adverse impact is investigated in this paper. A limiting analysis compares the performance of several A/C systems with ideal shade to those with ideal solar heat gain. The comparison is based on a theoretical model and data from equipment catalogs. The theoretical increase in the coefficient of performance (COP) due to shading is found to be within 2.5%. Furthermore, this small improvement in ideal efficiency decreases at higher ambient temperatures, when enhancements to efficiency are more needed. The actual efficiency improvement due to shading is not expected to exceed 1%, and the daily energy savings will be lower.
ElSherbini, A.; Maheshwari, G. P.
Optimization of a solar powered absorption cycle under Abu Dhabi's weather conditions
In order for the solar absorption air conditioners to become a real alternative to the conventional vapour compression systems, their performance has to be improved and their total cost has to be reduced. A solar powered absorption cycle is modeled using the Transient System Simulation (TRNSYS) program and Typical Meteorological Year 2 data of Abu Dhabi. It uses evacuated tube collectors to drive a 10 kW ammonia-water absorption chiller. Firstly, the system performance and its total cost are optimized separately using single objective optimization algorithms. The design variables considered are: the collector slope, the collector mass flow rate, the collector area and the storage tank volume. The single objective optimization results show that MATLAB global optimization methods agree with the TRNSYS optimizer. Secondly, MATLAB is used to solve a multi-objective optimization problem to improve the system's performance and cost, simultaneously. The optimum designs are presented using Pareto curve and show the potential improvements of the baseline system. (author)
Al-Alili, A.; Hwang, Y.; Radermacher, R. [Department of Mechanical Engineering, University of Maryland, College Park, MD (United States); Kubo, I. [Department of Mechanical Engineering, The Petroleum Institute, Abu Dhabi (United Arab Emirates)
Experimental Investigation on the Operation Performance of a Liquid Desiccant Air-conditioning System
A large share of energy consumption is taken by an air-conditioning system. It worsens the electricity load of the power network. Therefore, more and more scholars are paying attention to research on new types of air-conditioning systems that are energy- saving and environment-friendly. A liquid desiccant air conditioning system is among them, as it has a tremendous ability for power storage and low requirements for heat resources. Heat with low temperatures, such as excess heat, waste heat, and solar power, is suitable for the liquid desiccant air-conditioning system. The feasibility and economical efficiency of the system are studied in this experimental research. The result shows that when the temperature of the regeneration is about 80?, the thermodynamic coefficient of the system is about 0.6, and the supply air temperature of the air-conditioning system remains stable at 21?, the air-conditioning system can meet human comfort levels.
Liu, J.; Wang, J.; Wu, Z.; Gu, W.; Zhang, G.
"10 of Io absorbed by Ocean Fig. 1. Contrast of clear air tropical condition with normal solar absorption the surrounding air primarily ('" 94%) by direct solar energy absorption and rapid molecular conduction~ensive ground generators into the boundary layer. By warming the boundary layer air under proper conditions
Gray, William
Energy.gov (U.S. Department of Energy (DOE))
OE Framework Document and Stakeholder Meeting regarding the Enforcement of the updated Energy Conservation Standards for Air Conditioners, Furnaces and Heat Pumps.
Analysis of a Dedicated Outdoor Air System and Low Temperature Supply Air Conditioning System
This paper presents the principles and the characteristics of a dedicated outdoor air system (DOAS) and low temperature supply air system. DOAS is offered based on the demands of indoor air quality and the low temperature supply air system is offered based on the demands of saving energy. The two systems are very similar, which is analyzed in this paper. Using actual engineering, we compute the air flow rate, cold load and energy consumption in detail, and provide some good conclusions.
Guang, L.; Li, R.
Intelligent Residential Air-Conditioning System with Smart-Grid Functionality
1 Intelligent Residential Air-Conditioning System with Smart-Grid Functionality Auswin George residential air-conditioning (A/C) system controller that has smart grid functionality. The qualifier, conditional on anticipated retail energy prices. The term "smart- grid functionality" means that retail energy
Tesfatsion, Leigh
Active improvement of air-conditioning system energy consumption with adaptive thermal comfort approach.
??The MSc research project aims to suggest improvements to building air-conditioning control systems, to reduce energy consumption while maintaining the comfort level of the occupants.� (more)
Muhammad Saleh, Muhammad Fadzli
Theoretical analysis of the steam pressure exchange ejector for an automotive air conditioning application.
?? The project conducted at The George Washington University is a computer simulation and theoretical analysis of the steam pressure exchange ejector air conditioning system� (more)
Gould, David
Effects of ambient humidity on the energy use of air conditioning equipment.
??This paper addresses the real-time use of ambient wet bulb temperature measurements in the optimization of building air conditioning system control as a means to� (more)
White, Justin George
The Stakeholders Using Strategy of Diversification for Taiwan's Business Transformation: Case on Air Conditioning Industry.
??As environmental protection issue become the most hot global issues recently, Air Conditioning Industry has to face not only its own management and marketing problems,� (more)
Hung, Li-Yun
Study of a solar-assisted air conditioning system for South Africa.
??In South Africa, a significant amount of electrical energy is used for air conditioning in commercial buildings, on account of the high humidity experienced. Due� (more)
Joseph, Jerusha Sarah.
Superheat control for air conditioning and refrigeration systems: Simulation and experiments.
??Ever since the invention of air conditioning and refrigeration in the late nineteenth century, there has been tremendous interest in increasing system efficiency to reduce� (more)
Otten, Richard J.
Demonstration and Testing of ClimaStat for Improved Rooftop Air-Conditioning Efficeincy
Presentation covers the demonstration and testing of ClimaStat for improved rooftop air-conditioning efficiency at the March 15, 2012, Federal Technology Deployment Working Group meeting.
Table CE3-3e. Electric Air-Conditioning Energy Expenditures in U.S ...
Electric Air-Conditioning Energy Expenditures in U.S. Households by Household Income, 2001 RSE Column Factor: Total 2001 Household Income Below Poverty Line Eli-
Energy studies on central and variable refrigerant flow air-conditioning systems
Air-conditioning is a major contributor to energy end-use in commercial buildings. Different types of airconditioning systems are installed in commercial buildings including packaged systems
Table HC6.7 Air-Conditioning Usage Indicators by Number of Household...
Gasoline and Diesel Fuel Update (EIA)
7 Air-Conditioning Usage Indicators by Number of Household Members, 2005 Total... 111.1 30.0 34.8 18.4 15.9...
Table CE3-1e. Electric Air-Conditioning Energy Expenditures in U.S ...
Dollars per Household4,a Electric Air-Conditioning Expenditures per Household ... per Household4 2001 Cooling Degree-Days per Household Total U.S. Households ...
Table CE3-6.1u. Electric Air-Conditioning Energy Consumption and ...
Table CE3-6.1u. Electric Air-Conditioning Energy Consumption and Expenditures by Household Member and Usage Indicators, 2001 Usage Indicators RSE Column Factor:
Impact of Vehicle Air-Conditioning on Fuel Economy, Tailpipe Emissions, and Electric Vehicle Range: Preprint
Vehicle air-conditioning can significantly impact fuel economy and tailpipe emissions of conventional and hybrid electric vehicles and reduce electric vehicle range. In addition, a new US emissions procedure, called the Supplemental Federal Test Procedure, has provided the motivation for reducing the size of vehicle air-conditioning systems in the US. The SFTP will measure tailpipe emissions with the air-conditioning system operating. Current air-conditioning systems can reduce the fuel economy of high fuel-economy vehicles by about 50% and reduce the fuel economy of today's mid-sized vehicles by more than 20% while increasing NOx by nearly 80% and CO by 70%.
Farrington, R.; Rugh, J.
Table AC6. Average Consumption for Air-Conditioning by Equipment ...
Central System 5 Table AC6. Average Consumption for Air-Conditioning by Equipment Type, 2005 Million British Thermal Units (Btu) per Household
Table CE3-6.2u. Electric Air-Conditioning Energy Consumption and ...
Table CE3-6.2u. Electric Air-Conditioning Energy Consumption and Expenditures by Square Feet and Usage Indicators, 2001 Usage Indicators RSE Column Factor:
Analysis of Air Conditioning Effectiveness vs. Outdoor Conditions: Traditional Bins or Joint Frequency Bins?
There are a number of methods used to estimate the effectiveness of air conditioning equipment in handling loads. Full hourly computer simulations are probably the most accurate, but lack flexibility and are more cumbersome to use than more compact approaches. Alternately, some form of binned weather data has been used with load and performance estimation carried out for each of the bin weather conditions. The most common binning method puts weather into bins of dry bulb temperature with mean coincident wet bulb temperatures. Mean coincident humidity terms lose the extreme humidity levels that commonly exist. This can lead one to assume that conditions will be held at all times, while in fact the humidity loads will not be met and discomfort, among other consequences, will result. Three-dimensional plots of the joint frequency results clearly illustrate problem areas. A better procedure, it will be shown, is to use a joint frequency bin data set, which puts hours of occurrence into a matrix with dry bulb ranges on one axis and humidity ratio ranges on the second axis. This form of binning is easily accomplished if a utility like BinMaker is used to generate the binned data set.
Cohen, B. M.
Influence of air conditioning management on heat island in Paris air street temperatures
spatial cartography of air- cooled chillers and cooling towers in the city of Paris and surroundings have); secondly the actual situation including individual air dry coolers, wet cooling towers and an urban cooling the air cooling demand. Results of a meso-scale meteorological model (MESO-NH), coupled to an urban energy
We employ detailed photoionization models to infer the physical conditions of intrinsic narrow absorption line systems found in high-resolution spectra of three quasars at z = 2.6-3.0. We focus on a family of intrinsic absorbers characterized by N V lines that are strong relative to the Ly{alpha} lines. The inferred physical conditions are similar for the three intrinsic N V absorbers, with metallicities greater than 10 times the solar value (assuming a solar abundance pattern), and with high ionization parameters (log U {approx} 0). Thus, we conclude that the unusual strength of the N V lines results from a combination of partial coverage, a high ionization state, and high metallicity. We consider whether dilution of the absorption lines by flux from the broad emission line region can lead us to overestimate the metallicities and we find that this is an unlikely possibility. The high abundances that we infer are not surprising in the context of scenarios in which metal enrichment takes place very early on in massive galaxies. We estimate that the mass outflow rate in the absorbing gas (which is likely to have a filamentary structure) is less than a few M{sub sun} yr{sup -1} under the most optimistic assumptions, although it may be embedded in a much hotter, more massive outflow.
Wu Jian; Charlton, Jane C.; Misawa, Toru; Eracleous, Michael [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Ganguly, Rajib, E-mail: email@example.com, E-mail: firstname.lastname@example.com [Department of Computer Science, Engineering, and Physics, University of Michigan-Flint, 213 Murchie Science Building, 303 Kearsley Street, Flint, MI 48502 (United States)
Performance Evaluation of a 4.5 kW (1.3 Refrigeration Tons) Air-Cooled Lithium Bromide/Water Solar Powered (Hot-Water-Fired) Absorption Unit
During the summer months, air-conditioning (cooling) is the single largest use of electricity in both residential and commercial buildings with the major impact on peak electric demand. Improved air-conditioning technology has by far the greatest potential impact on the electric industry compared to any other technology that uses electricity. Thermally activated absorption air-conditioning (absorption chillers) can provide overall peak load reduction and electric grid relief for summer peak demand. This innovative absorption technology is based on integrated rotating heat exchangers to enhance heat and mass transfer resulting in a potential reduction of size, cost, and weight of the "next generation" absorption units. Rotartica Absorption Chiller (RAC) is a 4.5 kW (1.3 refrigeration tons or RT) air-cooled lithium bromide (LiBr)/water unit powered by hot water generated using the solar energy and/or waste heat. Typically LiBr/water absorption chillers are water-cooled units which use a cooling tower to reject heat. Cooling towers require a large amount of space, increase start-up and maintenance costs. However, RAC is an air-cooled absorption chiller (no cooling tower). The purpose of this evaluation is to verify RAC performance by comparing the Coefficient of Performance (COP or ratio of cooling capacity to energy input) and the cooling capacity results with those of the manufacturer. The performance of the RAC was tested at Oak Ridge National Laboratory (ORNL) in a controlled environment at various hot and chilled water flow rates, air handler flow rates, and ambient temperatures. Temperature probes, mass flow meters, rotational speed measuring device, pressure transducers, and a web camera mounted inside the unit were used to monitor the RAC via a web control-based data acquisition system using Automated Logic Controller (ALC). Results showed a COP and cooling capacity of approximately 0.58 and 3.7 kW respectively at 35 C (95 F) design condition for ambient temperature with 40 C (104 F) cooling water temperature. This is in close agreement with the manufacturer data of 0.60 for COP and 3.9 kW for cooling capacity. This study resulted in a complete performance map of RAC which will be used to evaluate the potential benefits of rotating heat exchangers in making the "next-generation" absorption chillers more compact and cost effective without any significant degradation in the performance. In addition, the feasibility of using rotating heat exchangers in other applications will be evaluated.
Zaltash, Abdolreza [ORNL; Petrov, Andrei Y [ORNL; Linkous, Randall Lee [ORNL; Vineyard, Edward Allan [ORNL
Ice storage rooftop retrofit for rooftop air conditioning
A significant fraction of the floor space in commercial and federal buildings is cooled by single-package rooftop air conditioning units. These units are located on flat roofs and usually operate during the day under hot conditions. They are usually less energy efficient than a chiller system for building cooling. Several U.S. companies are developing systems that employ ice storage in conjunction with chillers to replace older, inefficient rooftop units for improved performance and minimal use of on-peak electricity. Although the low evaporator temperatures needed for ice making tend to reduce the efficiency of the chiller, the overall operating costs of the ice storage system may be lower than that of a packaged, conventional rooftop installation. One version of this concept, the Roofberg{reg_sign} System developed by the Calmac Corporation, was evaluated on a small building at Oak Ridge National Laboratory in Oak Ridge, Tennessee. The Roofberg system consists of a chiller, an ice storage tank, and one or more rooftop units whose evaporator coils have been adapted to use a glycol solution for cooling. The ice storage component decouples the cooling demand of the building from the operation of the chiller. Therefore, the chiller can operate at night (cooler, more efficient condensing temperatures) to meet a daytime cooling demand. This flexibility permits a smaller chiller to satisfy a larger peak cooling load. Further, the system can be operated to shift the cooling demand to off-peak hours when electricity from the utility is generated more efficiently and at lower cost. This Roofberg system was successfully installed last year on a small one-story office building in Oak Ridge and is currently being operated to cool the building. The building and system were sufficiently instrumented to allow a determination of the performance and efficiency of the Roofberg system. Although the energy efficiency of a simulated Roofberg storage/chiller concept operating in the full storage mode was about equal to what could be expected through a simple rooftop efficiency upgrade, the operating costs for the Roofberg system could be much more favorable depending on the utility rate structure. The ability of Roofberg to move much of the cooling load to off-peak periods enables it to take advantage of on-peak demand charges and time-of-use electricity rates. The Roofberg system, as installed, was able to reduce the on-peak energy use of the cooling system to 35% of the on-peak energy consumption of the baseline system. A comparative analysis of a rooftop replacement and Roofberg indicated that the Roofberg system on Building 2518 would be the better economic choice over a range of demand charges and on-off peak energy prices which are typical of utility rate tariffs for commercial buildings.
Tomlinson, J.J. [Oak Ridge National Lab., TN (United States); Jennings, L.W. [Univ. of Tennessee, Knoxville (United States)
Fault Diagnosis of an Air-Conditioning System Using LS-SVM
This paper describes fault diagnosis of an air-conditioning system for improving reliability and guaranteeing the thermal comfort and energy saving. To achieve this goal, we proposed a technique which is model based fault diagnosis technique. Here, a ... Keywords: Air-Conditioning System, FDD, LS-SVM, Residuals generator
Mahendra Kumar; I. N. Kar
Impact of the Variable Refrigerant Volume Air Conditioning System on Building Energy Efficiency
The application of the variable refrigerant volume multi-zone air conditioning systems has met with mixed results since the publication of the Design Standard for Energy Efficiency of Public Buildings. This paper analyzes the characteristics of the variable refrigerant volume multi-zone air conditioning system, and discusses the advantages of its application.
Zhu, H.
Performance simulation of R410A air conditioning system with variable speeds
With the implementation of "Montreal protocol on substances that deplete the ozone layer", HCFCs especially R22 will be phased out. R410A (R32/R125,50/50wt%), as one alternative of R22, is a promising refrigerant for air conditioning ... Keywords: R410A, air conditioning, electronic expansion valve, performance, refrigerants, system simulation, variable speeds
Zaoxiao Zhang; Yongzhang Yu; Leping Zhang
Opportunities to Reduce Air-Conditioning Loads Through Lower Cabin Soak Temperatures
Air-conditioning loads can significantly reduce electric vehicle (EV) range and hybrid electric vehicle (HEV) fuel economy. In addition, a new U. S. emissions procedure, called the Supplemental Federal Test Procedure (SFTP), has provided the motivation for reducing the size of vehicle air-conditioning systems in the United States. The SFTP will measure tailpipe emissions with the air-conditioning system operating. If the size of the air-conditioning system is reduced, the cabin soak temperature must also be reduced, with no penalty in terms of passenger thermal comfort. This paper presents the impact of air-conditioning on EV range and HEV fuel economy, and compares the effectiveness of advanced glazing and cabin ventilation. Experimental and modeled results are presented.
Farrington, R.; Cuddy, M.; Keyser, M.; Rugh, J.
Retrofitting Air Conditioning and Duct Systems in Hot, Dry Climates
This technical report describes CARB's work with Clark County Community Resources Division in Las Vegas, Nevada, to optimize procedures for upgrading cooling systems on existing homes in the area to implement health, safety, and energy improvements. Detailed monitoring of five AC systems showed that three of the five systems met or exceeded air flow rate goals.
Shapiro, C.; Aldrich, R.; Arena, L.
Module Development and Simulation of the Variable Refrigerant Flow Air Conditioning System under Cooling Conditions in Energyplus
As a high-efficiency air conditioning scheme, the variable refrigerant flow (VRF) air-conditioning system is finding its way into medium-sized office buildings. Based on a generic dynamic building energy simulation environment, EnergyPlus, a new module is developed and the energy usage of the VRF system is investigated. This paper compares the energy consumption of the VRF system with that of two conventional air-conditioning systems, namely, the variable air volume (VAV) system and the fan-coil plus fresh air (FPFA) system. A generic office building is used to accommodate the different types of heating, ventilating, and air conditioning (HVAC) systems. Our objective is to examine the energy consumption of the VRF system applied to office buildings and make suggestions for evaluating and making decisions on HVAC systems in the early stages of building design. Simulation results show that the energy-saving potential of the VRF system is expected to achieve 22.2 percent and 11.7 percent, compared to the VAV system and the FPFA system, respectively. An energy-usage breakdown of electricity end-users in various systems is also presented.
Zhou, Y.; Wu, J.; Wang, R.; Shiochi, S.
Air entrainment by a plunging jet under intermittent vortex conditions
This fluid dynamic video entry to the 2011 APS-DFD Gallery of Fluid Motion details the transient evolution of the free surface surrounding the impact region of a low-viscosity laminar liquid jet as it enters a quiescent pool. The close-up images depict the destabilization and breakup of the annular air gap and the subsequent entrainment of bubbles into the bulk liquid.
Kim, Kevin Jin; Li, Kevin; Kiger, Ken T
Improving the Performance of Air-Conditioning Systems in an ASEAN Climate
This paper describes an analysis of air conditioning performance under hot and humid tropical climate conditions appropriate to the Association of South East Asian Nations (ASEAN) countries. This region, with over 280 million people, has one of the fastest economic and energy consumption growth rates in the world. The work reported here is aimed at estimating the conservation potential derived from good design and control of air conditioning systems in commercial buildings.
Busch, J. F.; Warren, M. L.
Evaluation of an Absorption Heat Pump to Mitigate Plant Capacity Reduction Due to Ambient Temperature Rise for an Air-Cooled Ammonia and Water Cycle: Preprint
Air-cooled geothermal plants suffer substantial decreases in generating capacity at increased ambient temperatures. As the ambient temperature rises by 50 F above a design value of 50 F, at low brine-resource temperatures, the decrease in generating capacity can be more than 50%. This decrease is caused primarily by increased condenser pressure. Using mixed-working fluids has recently drawn considerable attention for use in power cycles. Such cycles are more readily amenable to use of absorption ''heat pumps.'' For a system that uses ammonia and water as the mixed-working fluid, this paper evaluates using an absorption heat pump to reduce condenser backpressure. At high ambient temperatures, part of the turbine exhaust vapor is absorbed into a circulating mixed stream in an absorber in series with the main condenser. This steam is pumped up to a higher pressure and heated to strip the excess vapor, which is recondensed using an additional air-cooled condenser. The operating conditions are chosen to reconstitute this condensate back to the same concentration as drawn from the original system. We analyzed two power plants of nominal 1-megawatt capacity. The design resource temperatures were 250 F and 300 F. Ambient temperature was allowed to rise from a design value of 50 F to 100 F. The analyses indicate that using an absorption heat pump is feasible. For the 300 F resource, an increased brine flow of 30% resulted in a net power increase of 21%. For the 250 F resource, the increase was smaller. However, these results are highly plant- and equipment-specific because evaluations must be carried out at off-design conditions for the condenser. Such studies should be carried out for specific power plants that suffer most from increased ambient temperatures.
Bharathan, D.; Nix, G.
Effect of a Radiant Panel Cooling System on Indoor Air Quality of a Conditioned Space
This paper discusses the effect of a radiant cooling panel system on an indoor air quality (IAQ) of a conditioned space. In this study, ceiling radiant cooling panel, mechanical ventilation with fan coil unit (FCU) and 100% fresh air are used. Temperature sensors are located at different locations inside the conditioned space in order to sense dry bulb temperatures, relative humidity to compare it with standard ASHRAE comfort values. The present investigation indicates that the radiant cooling system not only improves the indoor air quality but also reduces the building energy consumption in the conditioned space.
Mohamed, E.; Abdalla, K. N.
September 10, 2013 What is Seawater Air Conditioning (SWAC)?
and sewage savings through the elimination of cooling towers SWAC Solutions Waikiki SWAC (25,000 tons) Fossil conditioning systems · Cold seawater is pumped to cooling plant · The cold temperature of the seawater
Laboratory Testing of the Heating Capacity of Air-Source Heat Pumps at Low Outdoor Temperature Conditions
Air-source heat pump systems offer an alternative to the common heating, ventilating, and air conditioning (HVAC) configuration of single split unitary air conditioners with gas heating. In simple terms, heat pumps are traditional air conditioning units with the added capability of running in reverse as required by the building load. Thus, where the traditional air conditioning unit has an indoor evaporator to remove heat from the space and an outdoor condenser to reject heat to the ambient environment, ...
Air Conditioning Stall Phenomenon Testing, Model Development, and Simulation
Electric distribution systems are experiencing power quality issues of extended reduced voltage due to fault-induced delayed voltage recovery (FIDVR). FIDVR occurs in part because modern air conditioner (A/C) and heat pump compressor motors are much more susceptible to stalling during a voltage sag or dip such as a sub-transmission fault. They are more susceptible than older A/C compressor motors due to the low inertia of these newer and more energy efficient motors. There is a concern that these local reduced voltage events on the distribution system will become more frequent and prevalent and will combine over larger areas and challenge transmission system voltage and ultimately power grid reliability. The Distributed Energy Communications and Controls (DECC) Laboratory at Oak Ridge National Laboratory (ORNL) has been employed to (1) test, (2) characterize and (3) model the A/C stall phenomenon.
Irminger, Philip [ORNL; Rizy, D Tom [ORNL; Li, Huijuan [ORNL; Smith, Travis [ORNL; Rice, C Keith [ORNL; Li, Fangxing [ORNL; Adhikari, Sarina [ORNL
"Table HC13.6 Air Conditioning Characteristics by South Census Region, 2005"
U.S. Energy Information Administration (EIA) Indexed Site
6 Air Conditioning Characteristics by South Census Region, 2005" 6 Air Conditioning Characteristics by South Census Region, 2005" " Million U.S. Housing Units" ,,"South Census Region" ,"U.S. Housing Units (millions)" ,,,"Census Division" ,,"Total South" "Air Conditioning Characteristics",,,"South Atlantic","East South Central","West South Central" "Total",111.1,40.7,21.7,6.9,12.1 "Do Not Have Cooling Equipment",17.8,1.4,0.8,0.2,0.3 "Have Cooling Equipment",93.3,39.3,20.9,6.7,11.8 "Use Cooling Equipment",91.4,38.9,20.7,6.6,11.7 "Have Equipment But Do Not Use it",1.9,0.5,"Q","Q","Q" "Air-Conditioning Equipment1, 2 "
Air-Conditioning, Heating, and Refrigeration Institute (AHRI) Regulatory Burden RFI
These comments are submitted by the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) in response to the U.S. Department of Energy�s (DOE) notice in the August 8, 2012 Federal Register...
Proposal for a Vehicle Level Test Procedure to Measure Air Conditioning Fuel Use: Preprint
A procedure is described to measure approximate real-world air conditioning fuel use and assess the impact of thermal load reduction strategies in plug-in hybrid electric vehicles.
Rugh, J.
Table CE3-10e. Electric Air-Conditioning Energy Expenditures in U ...
Table CE3-10e. Electric Air-Conditioning Energy Expenditures in U.S. Households by Midwest Census Region, 2001 RSE Column Factor: Total U.S. Midwest Census Region
Analysis of a Retrofitted Thermal Energy Storage Air-conditioning System of a Marine Museum.
??Thermal energy storage(TES) air-conditioning system is a electrical load management technology with great potential to shift load from peak to off-peak utility periods. TES is� (more)
Yu, Po-wen
An Analysis of Price Determination and Markups in the Air-Conditioning...
An Analysis of Price Determination and Markups in the Air-Conditioning and Heating Equipment Industry NOTICE Due to the current lapse of federal funding, Berkeley Lab websites are...
Table CE3-4c. Electric Air-Conditioning Energy Consumption in U.S ...
Table CE3-4c. Electric Air-Conditioning Energy Consumption in U.S. Households by Type of Housing Unit, 2001 RSE Column Factor: Total Type of Housing Unit
A Historical Look at the Invention of Air-conditioned Comfort...
- 12:00pm Location: Bldg. 90 Seminar HostPoint of Contact: Satkartar K. Kinney Comfort air conditioning is largely an American development which grew out of the need for the...
Heavy Precipitation Events in New Jersey: Attendant Upper-Air Conditions
The first of an anticipated multipart study of atmospheric conditions occurring before and during heavy precipitation events in New Jersey, representative of the mid-Atlantic region, is presented. Upper-air data parameters were analyzed for 81 ...
Robert P. Harnack; Kirk Apffel; Joseph R. Cermak III
Table CE3-1c. Electric Air-Conditioning Energy Consumption in U.S ...
Table CE3-1c. Electric Air-Conditioning Energy Consumption in U.S. Households by Climate Zone, 2001 RSE Column Factor: Total Climate Zone1 RSE Row
"Table HC11.6 Air Conditioning Characteristics by Northeast Census Region, 2005"
6 Air Conditioning Characteristics by Northeast Census Region, 2005" 6 Air Conditioning Characteristics by Northeast Census Region, 2005" " Million U.S. Housing Units" ,,"Northeast Census Region" ,"U.S. Housing Units (millions)" ,,,"Census Division" ,,"Total Northeast" "Air Conditioning Characteristics",,,"Middle Atlantic","New England" "Total",111.1,20.6,15.1,5.5 "Do Not Have Cooling Equipment",17.8,4,2.4,1.7 "Have Coolling Equipment",93.3,16.5,12.8,3.8 "Use Cooling Equipment",91.4,16.3,12.6,3.7 "Have Equipment But Do Not Use it",1.9,0.3,"Q","Q" "Air-Conditioning Equipment1, 2 " "Central System",65.9,6,5.2,0.8 "Without a Heat Pump",53.5,5.5,4.8,0.7
Desiccant Enhanced Evaporative Air-Conditioning (DEVap): Evaluation of a New Concept in Ultra Efficient Air Conditioning
NREL has developed the novel concept of a desiccant enhanced evaporative air conditioner (DEVap) with the objective of combining the benefits of liquid desiccant and evaporative cooling technologies into an innovative 'cooling core.' Liquid desiccant technologies have extraordinary dehumidification potential, but require an efficient cooling sink. DEVap's thermodynamic potential overcomes many shortcomings of standard refrigeration-based direct expansion cooling. DEVap decouples cooling and dehumidification performance, which results in independent temperature and humidity control. The energy input is largely switched away from electricity to low-grade thermal energy that can be sourced from fuels such as natural gas, waste heat, solar, or biofuels.
Kozubal, E.; Woods, J.; Burch, J.; Boranian, A.; Merrigan, T.
Economic Analysis of a Waste Water Resource Heat Pump Air-Conditioning System in North China
This paper describes the situation of waste water resource in north China and the characteristics and styles of a waste water resource heat pump system, and analyzes the economic feasibility of a waste water resource heat pump air-conditioning system including investment, operating fee and pay-back time. The results show that waste water resource heat pump air-conditioning system has a low investment, low operating fee and short payback time.
Chen, H.; Li, D.; Dai, X.
The Effect of Pressure Difference Control on Hydraulic Stability in a Variable Flow Air Conditioning System
This paper analyzes the effects of different pressure difference control methods on hydraulic stability in a variable flow air conditioning system when it is applied to different air conditioning water systems. According to control method and water system, it can be divided into direct return system pass-by control, direct return system terminal control, reversed return system pass-by control and reversed return system terminal control. The results indicate that reversed return system terminal control has the best hydraulic stability.
Zhang, Z.; Fu, Y.; Chen, Y.
HVAC Technology Report: A Review of Heating, Ventilation and Air Conditioning Technology and Markets
For many of us, roughly 95 percent of our time is spent indoors. To enable humans to spend this much time inside, mechanical equipment is necessary to provide space conditioning to control the temperature (heating and cooling), ventilation, humidity, and indoor air quality. This report introduces the heating, ventilation, and air-conditioning (HVAC) industry to EPRI member utility employees. The document describes the most common technologies and applications and provides an overview of industry statisti...
Analysis of Energy Saving in a Clean Room Air-conditioning System
To address the issue of the substantial energy cost and operating cost of an all-return air system for a clean room, we changed the former system to a 2nd return air system. With the newest building energy simulation program, Energy Plus, we simulated and compared the summer energy consuming conditions of the two systems. Results prove the superiority of the 2nd return air system, and the validity of the simulation. Also, the air system energy performance in summer was illustrated with typical meteorological hour-to-hour data.
Liu, S.; Liu, J.; Pei, J.; Wang, M.
Test and Reconstruction of Air Conditioning System in a Hotel Lobby
Two air conditioning systems are equipped in a hotel lobby. It is found from the field test that the actual air rate is 40% and 16% of the nominal value, respectively, of the two systems, which is far lower than the design requirement. The air rate of the outlets varies greatly, and the coefficient of uniformity is 129.1% and 111.6% respectively of the two systems. Air distribution in the lobby is bad and thermal comfort is poor. Moreover, sharp reduction of return air makes portions of fresh air increase, which will lead to high energy consumption. Reconstruction is carried out to improve the thermal environment with the assistance of the CFD method. First, the original system is simulated by CFD method to verify the CFD method and propose modification suggestions. Then air conditioning load and air rate of the lobby is recalculated and duct redesigned. Simulation results show that the air distribution and thermal comfort of the improved scheme can meet the design requirement. The reconstructed system has been running for about two years and has shown good performance.
Wang, G.; Hu, Y.; Hu, S.; Chen, Q.
Fluorescence emission induced by extensive air showers in dependence on atmospheric conditions
Charged particles of extensive air showers (EAS), mainly electrons and positrons, initiate the emission of fluorescence light in the Earth's atmosphere. This light provides a calorimetric measurement of the energy of cosmic rays. For reconstructing the primary energy from an observed light track of an EAS, the fluorescence yield in air has to be known in dependence on atmospheric conditions, like air temperature, pressure, and humidity. Several experiments on fluorescence emission have published various sets of data covering different parts of the dependence of the fluorescence yield on atmospheric conditions. Using a compilation of published measurements, a calculation of the fluorescence yield in dependence on altitude is presented. The fluorescence calculation is applied to simulated air showers and different atmospheric profiles to estimate the influence of the atmospheric conditions on the reconstructed shower parameters.
Keilhauer, Bianca
Operation of Energy-Efficient Air-Conditioned Buildings: An Overview
To design an optimum HVAC airside system that provides comfort and air quality in the air-conditioned spaces with efficient energy consumption is a great challenge. This paper evaluates recent progresses of HVAC airside design for the air-conditioned spaces. The present evaluation study defines the current status, future requirements, and expectations. It has been found that, the experimental investigations should be considered in the new trend of studies, not to validate the numerical tools only, but also to provide a complete database of the airflow characteristics in the air-conditioned spaces. Based on this analysis and the vast progress of computers and associated software, the artificial intelligent technique will be a competitor candidate to the experimental and numerical techniques. Finally, the researches that relate between the different designs of the HVAC systems and energy consumption should concern with the optimization of airside design as the expected target to enhance the indoor environment.
Khalil, E. E.
Candidate chemical systems for air cooled, solar powered, absorption air conditioner design. Part II. Solid absorbents, high latent heat refrigerants
Work done in attempting to qualify absorption refrigeration systems based on refrigerants with intermediate latent heats of vaporization is summarized. In practice, these comprise methanol, ammonia, and methylamine. A wide variety of organic substances, salts, and mixtures were evaluated in as systematic a manner as possible. Several systems of interest are described. The system, LiClO/sub 3/--LiBr--H/sub 2/O, is a good back up system to our first choice of an antifreeze additive system, and thermodynamically promising but subject to some inconvenient materials limitations. The system, LiBr/ZnBr/sub 2/--methanol, is thermodynamically promising but requires additional kinetic qualification. Chemical stability of the system, LiCNS--ammonia/methylamine with various other third components, does not appear to be adequate for a long-lived system.
Biermann, W. J.
Gas conditioning and processing. Volume II. Absorption and fractionation; pumping, compression and expansion; refrigeration; hydrate inhibition, dehydration and process control
Volume II of a two volume publication is presented in which aspects of conditioning and/or processing of natural gas for sale are examined. Chapters are included on absorption and fractionation, compression and expansion of fluids, refrigeration systems, liquefaction processes, water-hydrocarbon system behavior, dehydration and sweetening, adsorption processing, sulfur recovery, process control, and cost estimation. (JRD)
Campbell, J.M.
Model Based Sensor System for Temperature Measurement in R744 Air Conditioning Systems
The goal is the development of a novel principle for the temperature acquisition of refrigerants in CO2 air conditioning systems. The new approach is based on measuring the temperature inside a pressure sensor, which is also needed in the system. On the basis of simulative investigations of different mounting conditions functional relations between measured and medium temperature will be derived.
Reitz, Sven; Schneider, Peter
Optimization of the Fin Heat Pipe for Ventilating and Air Conditioning with a Genetic Algorithm
This paper illustrates that use of a heat pipe as a heat-reclaiming device can significantly influence the air-conditioning system. It analyzes the heat transfer model of the uniform annular fin heat pipe under the condition of air conditioning. It establishes functions of the fin structure parameters such as height,spacing and thickness of the fin when the volume of fin is the smallest under unit temperature difference and unit quantity of heat. It uses a genetic algorithm to optimize the model of the uniform annular fin heat pipe. The calculation result shows that the method of genetic algorithm is effective.
Qian, J.; Sun, D.; Li, G.
Proposal for an Adsorption Solar-Driven Air-Conditioning Unit for Public Offices
A simple prototype air conditioning unit driven entirely by solar energy is proposed aiming at replacing the conventional vapor compression air conditioning systems which are reasonable for the global warming. The proposed model is supposed to be used in conditioning the governmental offices during the working hours in the weekdays when both the sunshine and the need for air-conditioning reach their maximum levels at the same instance. Solar adsorption refrigeration devices have no moving parts consequently they are noiseless, non-corrosive, cheap to maintain, long lasting in addition to being environmentally friendly with zero ozone depletion as well as zero global warming potentials. For these reasons, the research activities are of increasing interest in this aspect in order to provide optimum solutions for the crucial points that impede making these systems capable to meet the criteria for commercialization.
Elsamni, O. A.; Sahmarani, K.J.; Obied, F. K.
Issues and Factors of Train Air-conditioning System Design and Operation
Like a moving building, a train's outer meteorologic parameter will change a lot with the local meteorologic parameter on the way. In this paper, we put forward the design method of the typical design period and some dynamic energy-saving ways to solve the problem. These methods consider the dynamic changes of the outer environment when the train is moving, which will supply the theoretical basis for the calculation of the dynamic load and real-time running and regulation of the train's air-conditioning. Modifications to the air-conditioning system and some advanced air conditioning systems are introduced, which are helpful for system optimization. In this paper, based on analysis of the characteristics of the air - conditioning system in foreign high speed passenger cars and demands for its acceleration, developing trends for air - conditioning systems for high speed passenger cars are pointed out and some advice is put forward. Above all, we should not only satisfy the comfort need of the passengers, but also succeed in saving energy.
Air Conditioning with Magnetic Refrigeration : An Efficient, Green Compact Cooling System Using Magnetic Refrigeration
BEETIT Project: Astronautics is developing an air conditioning system that relies on magnetic fields. Typical air conditioners use vapor compression to cool air. Vapor compression uses a liquid refrigerant to circulate within the air conditioner, absorb the heat, and pump the heat out into the external environment. Astronautics� design uses a novel property of certain materials, called �magnetocaloric materials�, to achieve the same result as liquid refrigerants. These magnetocaloric materials essentially heat up when placed within a magnetic field and cool down when removed, effectively pumping heat out from a cooler to warmer environment. In addition, magnetic refrigeration uses no ozone-depleting gases and is safer to use than conventional air conditioners which are prone to leaks.
Analysis of historical residential air-conditioning equipment sizing using monitored data
Monitored data were analyzed to determine whether residential air conditioners in the Pacific Northwest historically have been sized properly to meet or slightly exceed actual cooling requirements. Oversizing air-conditioning equipment results in a loss of efficiency because of increased cycling and also lowers humidity control. On the other hand, the penalty of undersizing air-conditioning equipment may be some loss of comfort during extremely hot weather. The monitored data consist of hourly space-conditioning electrical energy use and internal air temperature data collected during the past 7 years from 75 residences in the Pacific Northwest. These residences are equipped with central air conditioners or heat pumps. The periods with the highest cooling energy use were analyzed for each site. A standard industry sizing methodology was used for each site to determine a sizing estimate. Both the sizing recommendation based on Manual J and peak monitored loads are compared to the capacity of the installed equipment for each site to study how the actual capacity differed from both the estimate of proper sizing and from actual demands. Characteristics of the maximum cooling loads are analyzed here to determine which conditions put the highest demand on the air conditioner. Specifically, internal air temperature data are used to determine when the highest cooling loads occur, at constant thermostat settings or when the thermostat was set down. This analysis of monitored data also provides insight into the extent that occupant comfort may be affected by undersizing air conditioners. The findings of this research indicate that cooling equipment historically has often but not always been oversized beyond industry-recommended levels. However, some occupants in homes with undersized, properly sized, and, in rare occasions, even oversized cooling equipment appear to suffer because the cooling equipment cannot always provide adequate cooling. Key findings are summarized.
Lucas, R.G.
Future Air Conditioning Energy Consumption in Developing Countries and what can be done about it: The Potential of Efficiency in the Residential Sector
Henderson (2005) Home air conditioning in Europe � how muchA.A. Pavlova ( 2003). Air conditioning market saturation and+ paper 6,306 Future Air Conditioning Energy Consumption in
McNeil, Michael A.; Letschert, Virginie E.
Demonstration and Testing of ClimaStat® for Improved Rooftop Air-Conditioning Efficiency Presented at IA Technology Deployment Working Group Meeting March 15, 2012 By Dan Howett, PE Oak Ridge National Laboratory Demonstration/Testing of ClimaStat ® for Improved Efficiency of RTU Air Conditioners * Technology from Advantek Consulting - Patented by Dr. Michael West in 2003. (US Patent #6427454) - Originally demonstrated under DOE's Inventions & Innovations program. * Current demonstration sponsored by DOD's ESTCP program * Uses off-the-shelf components to either... - Modify existing packaged air conditioners, or - Incorporate changes into new RTU equipment before installation * Initial tests show 15% improvement in HVAC efficiency.
Flywheel Cooling: A Cooling Solution for Non Air-Conditioned Buildings
"Flywheel Cooling" utillzes the natural cooling processes of evaporation, ventilation and air circulation. These systems are providing low-cost cooling for distribution centers, warehouses, and other non air-conditioned industrial assembly plants with little or no internal loads. The evaporative roof cooling system keeps the building from heating up during the day by misting the roof surface with a fine spray of water -just enough to evaporate. This process keeps the roof surface at 90� levels instead of 150� and knocks out the radiant heat transfer from the roof into the building. The system is controlled by a thermostat and automatically shuts off at night or when the roof surface cools below the set point. The same control system turns on exhaust fans to load the building with cool night air. Air circulators are installed to provide air movement on workers during the day. Best results are achieved by closing dock doors and minimizing hot air infiltration during the day. The typical application will maintain inside temperatures that will average 84� -86� when outside ambient temperatures range from 98 �-100�. Many satisfied users will attest to marked improvements in employee moral and productivity, along with providing safe storage temperatures for many products. Installed "Flywheel" systems' costs are usually less than 20% of comparable air-conditioning equipment. By keeping a built up roof cooler, the system will eliminate thermal shock and extend roof life while reducing maintenance.
Abernethy, D.
Numerical Analysis of the Channel Wheel Fresh Air Ventilator Under Frosting Conditions
As new equipment, the channel wheel fresh air ventilator has become increasingly popular in recent years. However, when such equipment is operated under low ambient temperature in the freezing area in winter, the formation of frost on the outdoor waste air surface becomes problematic, leading to the degradation of the channel wheel fresh air ventilator's performance or even the shutdown of equipment. Therefore, it is necessary to have a detailed investigation on the operational characteristics of the channel wheel fresh air ventilator under frosting in order to guide its application. This paper first reports on the development of a detailed model for the channel wheel heat exchanger, which is the core part of the channel wheel fresh air ventilator under frosting conditions. The model developed, first seen in open literature, consists of a frosting sub-model and a channel wheel heat exchanger sub-model. This is followed by reporting an evaluation of the operational characteristics of a frosted channel wheel heat exchanger under different ambient conditions using the model developed. These include frost formation on the surface of the channel wheel heat exchanger, and impacts on the operational performance of the channel wheel fresh air ventilator. Furthermore, the interval of defrosting is obtained, which provides the basis for the adoption of effective defrosting measures, and thus increasing the channel wheel fresh air ventilator's energy efficiency and operating reliability.
Gao, B.; Dong, Z.; Cheng, Z.; Luo, E.
CFD Simulation and Analysis of the Combined Evaporative Cooling and Radiant Ceiling Air-conditioning System
Due to such disadvantages as large air duct and high energy consumption of the current all- outdoor air evaporative cooling systems used in the dry region of Northwest China, as well as the superiority of the ceiling cooling system in improving thermal comfort and saving energy, a combined system is presented in this paper. It combines an evaporative cooling system with ceiling cooling, in which the evaporative cooling system handles the entire latent load and one part of the sensible loads, and the ceiling cooling system deals with the other part of sensible loads in the air-conditioned zone, so that the condensation on radiant panels and the insufficiency of cooling capacity can be avoided. The cooling water at 18? used in the cooling coils of ceiling cooling system can be ground water, tap water or the cooled water from cooling towers in the summer. This new air-conditioning system and existing all- outdoor air evaporative cooling system are applied to a project in the city of Lanzhou. Energy consumption analysis of the building is carried out using the energy consumption code. Velocity and temperature distribution in the air-conditioned zone is computed using CFD. According to the results, the energy consumption and indoor human thermal comfort of both systems are then compared. It is concluded that the new system occupies less building space, reduces energy consumption, improves indoor human thermal comfort and saves initial investment.
Xiang, H.; Yinming, L.; Junmei, W.
Carbon Dioxide and Ionic Liquid Refrigerants: Compact, Efficient Air Conditioning with Ionic Liquid-Based Refrigerants
BEETIT Project: Notre Dame is developing an air-conditioning system with a new ionic liquid and CO2 as the working fluid. Synthetic refrigerants used in air conditioning and refrigeration systems are potent GHGs and can trap 1,000 times more heat in the atmosphere than CO2 alone�making CO2 an attractive alternative for synthetic refrigerants in cooling systems. However, operating cooling systems with pure CO2 requires prohibitively high pressures and expensive hardware. Notre Dame is creating a new fluid made of CO2 and ionic liquid that enables the use of CO2 at low pressures and requires minimal changes to existing hardware and production lines. This new fluid also produces no harmful emissions and can improve the efficiency of air conditioning systems� enabling new use of CO2 as a refrigerant in cooling systems.
Use of seawater for air conditioning at Waikiki Convention Center. Master's thesis
A large part of operating costs of a hotel in Hawaii is the cost of energy for air conditioning. Buildings can be constructed to use energy more efficiently by using many methods, however, some of these methods conflict with other concerns, aesthetics for example. Thus the process of designing and building an energy efficient hotel often involves trade-offs between energy efficiency and other objectives. The method proposed herein to reduce energy costs is to introduce seawater, pumped from the deep ocean at a temperature of approximately six degrees celsius, directly to heat exchangers which cool the chilled water circulating in the building air conditioning system. The energy required to run the system would be reduced to only the cost of the seawater pumps, the fans and controls. The savings would be in the operating costs of the seawater pumps versus the cost to the compressors of a conventional air conditioning system.
Williams, M.
Table HC15.7 Air-Conditioning Usage Indicators by Four Most Populated States, 2005
7 Air-Conditioning Usage Indicators by Four Most Populated States, 2005 7 Air-Conditioning Usage Indicators by Four Most Populated States, 2005 Total.................................................................................. 111.1 7.1 7.0 8.0 12.1 Do Not Have Cooling Equipment.................................... 17.8 1.8 Q Q 4.9 Have Cooling Equipment................................................. 93.3 5.3 7.0 7.8 7.2 Use Cooling Equipment.................................................. 91.4 5.3 7.0 7.7 6.6 Have Equipment But Do Not Use it................................ 1.9 Q N Q 0.6 Type of Air-Conditioning Equipment 1, 2 Central System............................................................. 65.9 1.1 6.4 6.4 5.4 Without a Heat Pump................................................. 53.5 1.1 3.5 5.7 4.9 With a Heat Pump......................................................
Derivation of a merging condition for two interacting streamers in air
The simulation of the interaction of two simultaneously propagating air streamers of the same polarity is presented. A parametric study has been carried out using an accurate numerical method which ensures a time-space error control of the solution. For initial separation of both streamers smaller or comparable to the longest characteristic absorption length of photoionization in air, we have found that the streamers tend to merge at the moment when the ratio between their characteristic width and their mutual distance reaches a value of about 0.35 for positive streamers, and 0.4 for negative ones. Moreover it is demonstrated that these ratios are practically independent of the applied electric field, the initial seed configuration, and the pressure.
Bonaventura, Zdenek; Bourdon, Anne; Massot, Marc
A Field Study on Residential Air Conditioning Peak Loads During Summer in College Station, Texas
Severe capacity problems are experienced by electric utilities during hot summer afternoons. Several studies have found that, in large part, electric peak loads can be attributed to residential airconditioning use. This air-conditioning peak depends primarily on two factors: (i) the manner in which the homeowner operates his air-conditioner during the hot summer afternoons, and (ii) the amount by which the air-conditioner has been over-designed. Whole-house and air-conditioner electricity use data at 15 minute time intervals have been gathered and analyzed for 8 residences during the summer of 1991, six of which had passed the College Station Good Cents tests. Indoor air temperatures were measured by a mechanical chart recorder, while a weather station located on the main campus of Texas A&M university provided the necessary climatic data, especially ambient temperature, relative humidity and solar radiation. The data were analysed to determine the extent to which air-conditioning over-sizing and homeowner intervention contributes to peak electricity use for newer houses in College Station, Texas.
Reddy, T. A.; Vaidya, S.; Griffith, L.; Bhattacharyya, S.; Claridge, D. E.
Theoretical Study of a Novel Control Method of VAV Air-conditioning System Based on MATLAB
The main purpose of this study is to put forward a novel nonlinear feedback control strategy on controlling indoor air temperature by variable air volume. A dynamic model of a typical room for a VAV air-conditioning system is established. The performance of the novel control strategy is investigated. Simulation of the controlling air temperature, on which the novel strategy is adopted, was carried out based on MATLAB in the VAV system. In order to show that the novel control strategy outperforms conventional PID control, a comparison is made between the performance of conventional PID and the novel nonlinear feedback control strategy. The results show that nonlinear feedback control strategy outperforms a conventional PID control system in terms of celerity, stability and other aspects.
Shi, Z.; Hu, S.; Wang, G.; Li, A.
Monitoring the Performance of a Residential Central Air Conditioner under Degraded Conditions on a Test Bench
This report presents the measured degradation in performance of a residential air conditioning system operating under degraded conditions. Experiments were conducted using a R-22 threeton split-type cooling system with a short-tube orifice expansion device. Results are presented here for a series of tests in which the various commonly occurring degraded conditions were simulated on a test bench. At present, very little information is available which quantifies the performance of a residential cooling system operating under degraded conditions. Degraded performance measurements can provide information which could help electric utilities evaluate the potential impact of systemwide maintenance programs. This report also discuss the development of a diagnostic procedure based on measurement of refrigerant and air side temperatures.
Palani, M.; O'Neal, D. L.; Haberl, J. S.
Corrosion Behavior of Interconnect Candidate Alloys under Air//Simulated Reformate Dual Exposure Conditions
Metallic interconnects in solid oxide fuel cell (SOFC) stacks, perform in a very challenging dual environment, as they are simultaneously exposed to a reducing fuel (either hydrogen or a hydrocarbon fuel) on one side and air on the other side at elevated temperatures. Thus candidate metals or alloys for the interconnect applications must demonstrate excellent surface stability under the SOFC operating conditions. Following previous studies which led to an improved understanding of the oxidation/corrosion behavior of metals and alloys under air/hydrogen dual exposure conditions, PNNL recently investigated the behavior of Fe-Cr and Ni-Cr base interconnect candidate alloys in an air/simulated reformate dual environment. This paper reports and discusses the findings of this work.
Yang, Z Gary; Xia, Gordon; Stevenson, Jeffry W.; Singh, Prabhakar
Innovative Evaporative and Thermally Activated Technologies Improve Air Conditioning, The Spectrum of Clean Energy Innovation (Fact Sheet)
Innovative Evaporative and Innovative Evaporative and Thermally Activated Technologies Improve Air Conditioning Researchers at the National Renewable Energy Laboratory (NREL) invented a breakthrough technology that improves air conditioning in a novel way-with heat. NREL combined desiccant materials, which remove moisture from the air using heat, and advanced evaporative technologies to develop a cooling unit that uses 90% less electricity and up to 80% less total energy than traditional air conditioning (AC). This solution, called the desiccant enhanced evaporative air conditioner (DEVap), also controls humidity more effectively to improve the comfort of people in buildings. Desiccants are an example of a thermally activated technology (TAT) that relies on heat instead
Investigation of air supply conditions in the room of a B11type gas appliance
In Hungary, the prevalently used "B11" type gas appliances equipped with atmospheric burner and they have a draught hood beyond the outlet of the appliance. For the appropriate adjustment of the gas boiler to the conditions of the building, ... Keywords: CFD method, air supply, chimney, design requirements, gas appliances, numerical modelling
Lajos Barna; R�bert Goda
Air-Conditioning Effect Estimation for Mid-Term Forecasts of Tunisian Electricity Consumption
: Engineering-industry, secondary: Econometrics. 1 Introduction The electric power mid-term loads forecasting: Estimated annual temperature sensitive electricity load components 3 Mid-term load forecasting StatisticalAir-Conditioning Effect Estimation for Mid-Term Forecasts of Tunisian Electricity Consumption
Paris-Sud XI, Université de
Long-Range Transport of Air Pollution under Light Gradient Wind Conditions
The long-range transport of air pollution on clew days under light gradient wind conditions is investigated from an analysis of all days with high oxidant concentrations in 1979 at locations in central Japan that are far from pollutant sources. ...
Hidemi Kurita; Kazutoshi Sasaki; Hisao Muroga; Hiromasa Ueda; Shinji Wakamatsu
Air Distribution and Microenvironment Evaluation of a Desktop Task Conditioning System
Task conditioning aims to provide each occupant with personalized clean air direct to the breathing zone. The microenvironment of a typical office workplace, consisting of two desktop task conditioning systems (a Horizontal Desk Grill (HDG) and Vertical Desk Grill (VDG)) were studied by numerical simulation. Numerical simulation by k- 3-D turbulent flow was separately conducted to study the influence of supply velocity on the microenvironment of these two desktop task conditioning systems. Three task conditioning velocities were studied. Temperature and velocity distribution, Draught Rating (DR) and Predicted Percentage of Dissatisfied (PPD) of the room and workstation were applied to study the performance of task air conditioning. Results show that the performances of HDG and VDG are almost the same. Results also show that task conditioning can provide excellent working environment when supply velocity is well designed. The supply velocity of task conditioning can be set between 0.8-1.0 m/s. However, task conditioning may cause draught, and engineers should seriously consider this problem. The results can provide important references for design and optimization of the task conditioning system.
Zheng, G.
Discussion of Air-Conditioning Energy-Savings in Hot-Summer and Cold-Winter Regions
Introducing several kinds of air-conditioning systems energy conservation measures, and according to the climate of the hot-summer and cold-winter region in China, this paper puts forward an overall conception for air-conditioning energy-savings at this area. Namely, we may use the combination of evaporative cooling, dehumidifier and mechanical cooling to save energy for air-conditioning.
Zheng, W.; Gong, F.; Lou, X.; Cheng, J.
Total environmental warming impact (TEWI) calculations for alternative automative air-conditioning systems
The Montreal Protocol phase-out of chlorofluorocarbons (CFCs) has required manufacturers to develop refrigeration and air-conditioning systems that use refrigerants that can not damage stratospheric ozone. Most refrigeration industries have adapted their designs to use hydrochlorofluorocarbon (HCFC) or hydrofluorocarbon (HFC) refrigerants; new automobile air- conditioning systems use HFC-134a. These industries are now being affected by scientific investigations of greenhouse warming and questions about the effects of refrigerants on global warming. Automobile air-conditioning has three separate impacts on global warming; (1) the effects of refrigerant inadvertently released to the atmosphere from accidents, servicing, and leakage; (2) the efficiency of the cooling equipment (due to the emission of C0{sub 2} from burning fuel to power the system); and (3) the emission of C0{sub 2} from burning fuel to transport the system. The Total Equivalent Warming Impact (TEWI) is an index that should be used to compare the global warming effects of alternative air-conditioning systems because it includes these contributions from the refrigerant, cooling efficiency, and weight. This paper compares the TEWI of current air-conditioning systems using HFC-134a with that of transcritical vapor compression system using carbon dioxide and systems using flammable refrigerants with secondary heat transfer loops. Results are found to depend on both climate and projected efficiency of C0{sub 2}systems. Performance data on manufacturing prototype systems are needed to verify the potential reductions in TEWI. Extensive field testing is also required to determine the performance, reliability, and ``serviceability`` of each alternative to HFC-134a to establish whether the potential reduction of TEWI can be achieved in a viable consumer product.
Sand, J.R.; Fischer, S.K.
Air Conditioning, & Electric Power Machinery 29(1): 1-4 Solutions for Summer Electric Power Shortages: DemandUSA Solutions for summer electric power shortages: Demand
Application of the VRV Air-Conditioning System Heat Recovery Series in Interior Zone and Analysis of its Energy Saving
To reduce the energy consumption of air conditioning systems, we can use the VRV air conditioning system to supply cold loads in the winter for rooms in the construction inner zone where cold loads need to be supplied. The VRV air-conditioning system of variable frequency technology can achieve the effect of energy conservation. In this article, we analyze the application of the VRV air conditioning system heat recovery series in the construction inner zone and its energy saving characteristics via a project example.
Zhang, Q.; Li, D.; Zhang, J.
Effect of Intake Air Filter Condition on Light-Duty Gasoline Vehicles
Proper maintenance can help vehicles perform as designed, positively affecting fuel economy, emissions, and the overall drivability. This effort investigates the effect of one maintenance factor, intake air filter replacement, with primary focus on vehicle fuel economy, but also examining emissions and performance. Older studies, dealing with carbureted gasoline vehicles, have indicated that replacing a clogged or dirty air filter can improve vehicle fuel economy and conversely that a dirty air filter can be significantly detrimental to fuel economy. The effect of clogged air filters on the fuel economy, acceleration and emissions of five gasoline fueled vehicles is examined. Four of these were modern vehicles, featuring closed-loop control and ranging in model year from 2003 to 2007. Three vehicles were powered by naturally aspirated, port fuel injection (PFI) engines of differing size and cylinder configuration: an inline 4, a V6 and a V8. A turbocharged inline 4-cylinder gasoline direct injection (GDI) engine powered vehicle was the fourth modern gasoline vehicle tested. A vintage 1972 vehicle equipped with a carburetor (open-loop control) was also examined. Results reveal insignificant fuel economy and emissions sensitivity of modern vehicles to air filter condition, but measureable effects on the 1972 vehicle. All vehicles experienced a measured acceleration performance penalty with clogged intake air filters.
Thomas, John F [ORNL; Huff, Shean P [ORNL; West, Brian H [ORNL; Norman, Kevin M [ORNL
Start-Up of Air Conditioning Systems After Periods of Shutdown (Humidity Considerations)
In many cases the single most important energy conservation measure that can be taken is to turn equipment off when it is not needed. In the case of air conditioning, this generally means turning it off when occupants leave and turning it back on in time to have the space comfortable when they return. In humid climates special problems are often encountered when a system is restarted after a period of shutdown. The temperature and humidity in the space rises during the period of shutdown. Unfortunately the latent load required to bring the space back to comfort conditions is usually much higher than the sensible load. Most methods of control are ill suited for this duty. This paper examines the response of various types of air conditioning systems during this recovery period and makes recommendations for system designers.
Todd, T. R.
Research on Thermal Properties in a Phase Change Wallboard Room Based on Air Conditioning Cold Storage
After comparing the thermal performance parameters of an ordinary wall room to a phase change wall (PCW) room, we learn that phase change wallboard affects the fluctuation of temperature in air-conditioning room in the summer. We built a PCW room and an ordinary wall room, which are cooled by an air-conditioner. We used differential scanning calorimetry (DSC) to test the temperature field and heat flow fluctuation in these rooms. Through analyzing the data tested, we found that the mean temperature of PCW is lower than that of ordinary wall room by 1 to 2?, and PCW can lower the heat flow by 4.6W/m2. Combining phase change material with the building envelope can lower the indoor temperature, make the room thermally comfortable, and cut down the turn-on-and-off frequency of the air-conditioner and the primary investment and operating costs. It alleviates the urgent need for electricity.
Feng, G.; Li, W.; Chen, X.
Solar absorption aqua-ammonia absorption system simulation base on climate of Malaysia
Solar energy is one of the most well known green sources of energy. This research presents a feasibility study of evacuated solar thermal collector by aqua-ammonia ejector absorption systems as a small scale air conditioning unit. The modeling has been ... Keywords: ejector, evacuated tubes, solar assisted absorption system
Poorya Ooshaksaraei; Sohif Mat; M. Yahya; Ahmad Mahir Razali; Azami Zaharim; K. Sopian
Comparative Study Between Air-Cooled and Water-Cooled Condensers of the Air-Conditioning Systems
The weather in Kuwait is very dry where the dry-bulb temperature exceeds the wet-bulb temperature more than 20oC in most of the summer months. Thus, the air-conditioning (A/C) system with the water-cooled (WC) condensers is expected to perform more efficiently than with the air-cooled (AC) condensers. This fact was behind the idea of a field study conducted in one of the major hospital in Kuwait during a summer season to investigate the performance of WC and AC systems in terms of peak power and energy consumptions. The cooling capacities for WC and AC systems were 373 and 278 tons-of- refrigeration, respectively. It was found that for the same cooling production, the peak power demand and the daily energy consumption of the WC system were 45 and 32% less than that of the AC system, respectively. The maximum reduction in the power demand coincided with the peak power demand period of the utilities i.e. between 14:00 and 17:00 hr, thereby offering a maximum advantage of peak power saving.
Maheshwari, G. P.; Mulla Ali, A. A.
Energy Performance Comparison of Heating and Air Conditioning Systems for Multi-Family Residential Buildings
The type of heating, ventilation and air conditioning (HVAC) system has a large impact on the heating and cooling energy consumption in multifamily residential buildings. This paper compares the energy performance of three HVAC systems: a direct expansion (DX) split system, a split air source heat pump (ASHP) system, and a closed-loop water source heat pump (WSHP) system with a boiler and an evaporative fluid cooler as the central heating and cooling source. All three systems use gas furnace for heating or heating backup. The comparison is made in a number of scenarios including different climate conditions, system operation schemes and applicable building codes. It is found that with the minimum code-compliant equipment efficiency, ASHP performs the best among all scenarios except in extremely code climates. WSHP tends to perform better than the split DX system in cold climates but worse in hot climates.
Wang, Weimin; Zhang, Jian; Jiang, Wei; Liu, Bing
Influencing Factors on Energy Consumption of Air Conditioning System in Railway Passenger Station Based on Orthogonal Experiment
Orthogonal experiment was used to analyze the energy consumption of air conditioning system, which belongs to four typical passenger stations in four regions, including severe cold region, cold region, hot summer and cold winter region, hot summer and ... Keywords: Railway Passenger Station, Orthogonal Experiment, Air Conditioning Energy Consumption, Energy Conservation
Weiwu Ma; Liqing Li; Suoying He; Jia Cheng; Guijie Huang; Chenn Q. Zhou
Impact of cool storage air-conditioning in commercial sector on power system operation in Thailand
The results are presented from an investigation into the potential application for cool storage air-conditioning, and the resultant beneficial impact on power system operation in Thailand is discussed. Field assessment through interviews with decision makers in the identified customer groups produces results that show good potential for cool storage application. Results from a computer program used to calculate power production cost and other characteristics show that substantial benefits would also accrue to the generating utility.
Surapong, C.; Bundit, L. [Asian Inst. of Tech., Bangkok (Thailand)
Nuclear Maintenance Applications Center: Heating, Ventilating, and Air Conditioning Specialist Guide
The people responsible for heating, ventilating, and air conditioning (HVAC) in the nuclear power industry are known by various titles--HVAC specialist, HVAC component engineer, HVAC system manager, and HVAC system engineer, to name a few. Although HVAC duties and responsibilities are often spread across several departments, such as maintenance, operations, engineering, and procurement, it is up to the HVAC specialist to ensure that HVAC system and component health and reliability are maintained. This re...
Exploratory Research on MEMS Technology for Air-Conditioning and Heat-Pumps
Multiple refrigerant channels are essential for improving system efficiency in refrigeration and air-conditioning systems. A study was conducted to study the use of micro-electrical-mechanical- systems (MEMS) and micro device technologies to improve current vapor compression refrigeration cycles. The first step toward realizing this goal, and the focus of this report, is to determine how to better control multi-channel evaporators by reducing refrigerant maldistribution among channels.
Performance Assessment of a Variable Refrigerant Flow Heat Pump Air Conditioning System
Variable refrigerant flow (VRF) technology uses smart integrated controls, variable speed drives, and refrigerant piping to provide energy efficiency, flexible operation, ease of installation, low noise, zone control, and comfort through all-electric technology. This report describes and documents the construction, performance, and application of a heat pump air conditioning system that uses VRF technology8212the Daikin VRV system. This variable refrigerant volume (VRV) system is manufactured by Daikin I...
The Earth-Coupled or Geothermal Heat Pump Air Conditioning System
As utility costs have risen despite political campaign promises and energy conserving measures implemented by the utility companies such as alternative fuel use (coal and nuclear), co-generation, etc., homeowners have begun to search for effective methods of reducing their electricity bills. In some cases homeowners are faced with utility bills That are approaching the cost of their mortgage payments. For those with fixed incomes, such as the elderly or those looking forward to retirement in the near future, this has become an alarming reality. Virtually every homeowner would like to reduce his utility bill but the question is, what items should he address in order to have a significant impact on his electricity costs? According to Houston Lighting h Power Company, 50% of an electricity bill can be attributed to the air conditioning system, and another 15-20% to the hot water heating system. Therefore, to dramatically reduce utility costs one should look first at these two "energy gulpers" and next at proper home insulation, window coverings, etc. The other electrical appliances in the home use relatively minor amounts of electricity compared to the air conditioning and hot water heating system. This paper will describe the geothermal heat pump and the desuperheater as the latest developments in energy efficient air conditioning and water heating.
Wagers, H. L.; Wagers, M. C.
Comparison of global warming impacts of automobile air-conditioning concepts
The global warming impacts of conventional vapor compression automobile air conditioning using HFC-134a are compared with the potential impacts of four alternative concepts. Comparisons are made on the basis of total equivalent warming impact (TEWI) which accounts for the effects of refrigerant emissions, energy use to provide comfort cooling, and fuel consumed to transport the weight of the air conditioning system. Under the most favorable assumptions on efficiency and weight, transcritical compression using CO{sub 2} as the refrigerant and adsorption cooling with water and zeolite beds could reduce TEWI by up to 18%rlative to HFC-134a compression air conditioning. Other assumptions on weight and efficiency lead to significant increases in TEWI relative to HFC-134a, and it is impossible to determine which set of assumptios is valid from existing data, Neither Stirling cycle or thermoelectric cooling will reduce TEWI relative to EFC-134a. Brief comments are also made concerning technical barriers that must be overcome for succesful development of the new technologies.
Table HC6.7 Air-Conditioning Usage Indicators by Number of Household Members, 2005
7 Air-Conditioning Usage Indicators by Number of Household Members, 2005 7 Air-Conditioning Usage Indicators by Number of Household Members, 2005 Total........................................................................ 111.1 30.0 34.8 18.4 15.9 12.0 Do Not Have Cooling Equipment.......................... 17.8 5.4 5.3 2.7 2.5 2.0 Have Cooling Equipment...................................... 93.3 24.6 29.6 15.7 13.4 10.0 Use Cooling Equipment....................................... 91.4 24.0 29.1 15.5 13.2 9.7 Have Equipment But Do Not Use it...................... 1.9 0.6 0.5 Q 0.2 0.4 Type of Air-Conditioning Equipment 1, 2 Central System................................................... 65.9 15.3 22.6 10.7 9.9 7.3 Without a Heat Pump....................................... 53.5 12.5 17.9 8.7 8.2 6.3 With a Heat Pump............................................ 12.3
Table HC9.6 Air Conditioning Characteristics by Climate Zone, 2005
6 Air Conditioning Characteristics by Climate Zone, 2005 6 Air Conditioning Characteristics by Climate Zone, 2005 Million U.S. Housing Units Total......................................................................... 111.1 10.9 26.1 27.3 24.0 22.8 Do Not Have Cooling Equipment........................... 17.8 3.2 4.7 3.6 5.5 0.9 Have Cooling Equipment........................................ 93.3 7.7 21.4 23.7 18.5 21.9 Use Cooling Equipment......................................... 91.4 7.6 21.0 23.4 17.9 21.7 Have Equipment But Do Not Use it........................ 1.9 Q 0.4 0.4 0.6 0.3 Air-Conditioning Equipment 2, 3 Central System...................................................... 65.9 4.8 12.3 15.1 14.9 18.7 Without a Heat Pump......................................... 53.5 4.7 11.5 11.6 12.3 13.6 With a Heat Pump..............................................
Refinery Waste Heat Ammonia Absorption Refrigeration Plant (WHAARP) Recovers LPG's and Gasoline, Saves Energy, and Reduces Air Pollution
A first-of-its-kind Waste Heat Ammonia Absorption Refrigeration Plant (WHAARP�) was installed by Planetec Utility Services Co., Inc. in partnership with Energy Concepts Co. at Ultramar Diamond Shamrock's 30,000 barrel per day refinery in Denver, Colorado. The refrigeration unit is designed to provide refrigeration for two process units at the refinery while utilizing waste heat as the energy source. The added refrigeration capacity benefits the refinery by recovering salable products, debottlenecking process units, avoiding additional electrical demand, and reducing the refinery Energy Intensity Index. In addition, the WHAARP unit lowers air pollutant emissions by reducing excess fuel gas that is combusted in the refinery flare. A comprehensive utility and process efficiency Master Plan developed for the Denver refinery by Planetec provided the necessary platform for implementing this distinctive project. The $2.3 million WHAARP system was paid for in part by a $760,000 grant from the U.S. Department of Energy, as part of their "Industry of the Future Program". Total combined benefits are projected to be approximately $1 million/year with a 1.6 year simple payback including the grant funding.
Brant, B.; Brueske, S.; Erickson, D.; Papar, R.
The Histoty of Ventilation and Air Conditioning is CERN Up to Date with the latest Technological Developments?
The invention of ventilation cannot be ascribed to a certain date. It started with simple aeration when man brought fire into his abode and continued through different stages including air cooling using ice to finally arrive at the time when ventilation and air conditioning has become an essential part of our life and plays an important role in human evolution. This paper presents the history of ventilation and air conditioning, explains the key constraints over the centuries, and shows its influence on everyday life. Some examples of previous air-conditioning plants are described and different approaches to the way of calculation of ventilation systems discussed. It gives an overview of the Heating, Ventilation and Air Conditioning (HVAC) installations at CERN and points out their particularities. It also compares them with the latest technological developments in the field as well as showing the new trends that are being applied at CERN.
K�hnl-Kinel, J
The Oklahoma Field Test: Air-conditioning electricity savings from standard energy conservation measures, radiant barriers, and high-efficiency window air conditioners
A field test Involving 104 houses was performed in Tulsa, Oklahoma, to measure the air-conditioning electricity consumption of low-income houses equipped with window air conditioners, the reduction in this electricity consumption attributed to the installation of energy conservation measures (ECMS) as typically installed under the Oklahoma Weatherization Assistance Program (WAP), and the reduction achieved by the replacement of low-efficiency window air conditioners with high-efficiency units and the installation of attic radiant barriers. Air-conditioning electricity consumption and indoor temperature were monitored weekly during the pre-weatherization period (June to September 1988) and post-weatherization period (May to September 1989). House energy consumption models and regression analyses were used to normalize the air-conditioning electricity savings to average outdoor temperature conditions and the pre-weatherization indoor temperature of each house. The following conclusions were drawn from the study: (1) programs directed at reducing air-conditioning electricity consumption should be targeted at clients with high consumption to improve cost effectiveness; (2) replacing low-efficiency air conditioners with high-efficiency units should be considered an option in a weatherization program directed at reducing air-conditioning electricity consumption; (3) ECMs currently being installed under the Oklahoma WAP (chosen based on effectiveness at reducing space-heating energy consumption) should continue to be justified based on their space-heating energy savings potential only; and (4) attic radiant barriers should not be included in the Oklahoma WAP if alternatives with verified savings are available or until further testing demonstrates energy savings or other benefits in this typo of housing.
Ternes, M.P.; Levins, W.P.
Vehicle Air- Vehicle Air- Conditioning on Fuel Economy, Tailpipe Emissions, and Electric Vehicle Range Preprint September 2000 * NREL/CP-540-28960 R. Farrington and J. Rugh To Be Presented at the Earth Technologies Forum Washington, D.C. October 31, 2000 National Renewable Energy Laboratory 1617 Cole Boulevard Golden, Colorado 80401-3393 NREL is a U.S. Department of Energy Laboratory Operated by Midwest Research Institute * * * * Battelle * * * * Bechtel Contract No. DE-AC36-99-GO10337 NOTICE The submitted manuscript has been offered by an employee of the Midwest Research Institute (MRI), a contractor of the US Government under Contract No. DE-AC36-99GO10337. Accordingly, the US Government and MRI retain a nonexclusive royalty-free license to publish or reproduce the published
Proposal for a Vehicle Level Test Procedure to Measure Air Conditioning Fuel Use
The air-conditioning (A/C) compressor load significantly impacts the fuel economy of conventional vehicles and the fuel use/range of plug-in hybrid electric vehicles (PHEV). A National Renewable Energy Laboratory (NREL) vehicle performance analysis shows the operation of the air conditioner reduces the charge depletion range of a 40-mile range PHEV from 18% to 30% in a worst case hot environment. Designing for air conditioning electrical loads impacts PHEV and electric vehicle (EV) energy storage system size and cost. While automobile manufacturers have climate control procedures to assess A/C performance, and the U.S. EPA has the SCO3 drive cycle to measure indirect A/C emissions, there is no automotive industry consensus on a vehicle level A/C fuel use test procedure. With increasing attention on A/C fuel use due to increased regulatory activities and the development of PHEVs and EVs, a test procedure is needed to accurately assess the impact of climate control loads. A vehicle thermal soak period is recommended, with solar lamps that meet the SCO3 requirements or an alternative heating method such as portable electric heaters. After soaking, the vehicle is operated over repeated drive cycles or at a constant speed until steady-state cabin air temperature is attained. With this method, the cooldown and steady-state A/C fuel use are measured. This method can be run at either different ambient temperatures to provide data for the GREEN-MAC-LCCP model temperature bins or at a single representative ambient temperature. Vehicles with automatic climate systems are allowed to control as designed, while vehicles with manual climate systems are adjusted to approximate expected climate control settings. An A/C off test is also run for all drive profiles. This procedure measures approximate real-world A/C fuel use and assess the impact of thermal load reduction strategies.
Rugh, J. P.
The Experimentation System Design and Experimental Study of the Air-Conditioning by Desiccant Type Using Solar Energy
Using a special solar air heater to gain heat power for regenerating an adsorption desiccant wheel made by composite silica gel, a desiccant air-conditioning experimentation system was designed and manufactured. Combining the advantage of measure and control by �PLC� and the software of �Kingview�, the whole year's operating results of this system was tested and analysed. The results indicate this system can keep the indoor air temperature range at 26�2�C and the relative humidity range being 50-70% under the low electricity cost on the whole year in the south of China region when the special solar air heater can offer flux air heating up to 60�C. In this paper some ideas are offered in order to facilitate the availability for air-conditioning using low grade energy, for example, solar energy and surplus or waste heat energy in the industrial process.
Zhuo, X.; Ding, J.; Yang, X.; Chen, S.; Yang, J.
Fuel-Free Compressed-Air Energy Storage: Fuel-Free, Ubiquitous Compressed-Air Energy Storage and Power Conditioning
GRIDS Project: General Compression has developed a transformative, near-isothermal compressed air energy storage system (GCAES) that prevents air from heating up during compression and cooling down during expansion. When integrated with renewable generation, such as a wind farm, intermittent energy can be stored in compressed air in salt caverns or pressurized tanks. When electricity is needed, the process is reversed and the compressed air is expanded to produce electricity. Unlike conventional compressed air energy storage (CAES) projects, no gas is burned to convert the stored high-pressure air back into electricity. The result of this breakthrough is an ultra-efficient, fully shapeable, 100% renewable and carbon-free power product. The GCAES� system can provide high quality electricity and ancillary services by effectively integrating renewables onto the grid at a cost that is competitive with gas, coal and nuclear generation.
Solutions for Summer Electric Power Shortages: Demand Response andits Applications in Air Conditioning and Refrigerating Systems
Demand response (DR) is an effective tool which resolves inconsistencies between electric power supply and demand. It further provides a reliable and credible resource that ensures stable and economical operation of the power grid. This paper introduces systematic definitions for DR and demand side management, along with operational differences between these two methods. A classification is provided for DR programs, and various DR strategies are provided for application in air conditioning and refrigerating systems. The reliability of DR is demonstrated through discussion of successful overseas examples. Finally, suggestions as to the implementation of demand response in China are provided.
How refrigeration, heating, ventilation, and air conditioning service technicians learn from troubleshooting (Dissertation ABstract)
The purpose of this study was to understand how refrigeration, heating, ventilation, and air conditioning (RHVAC) service technicians (techs) learned from troubleshooting. This understanding resulted in instructional and curricular strategies designed to help community colleges prepare vocational students to learn more effectively from informal workplace learning. RHVAC techs were studied because they increasingly learn their trade skills through a combination of formal schooling and informal workplace learning, though many still learn their trade almost exclusively in the workplace. Even those with formal training require considerable workplace experience to become fully competent. Troubleshooting is a major job function for RHVAC service techs, and troubleshooting
Denis F. H. Green
Desiccant solar air conditioning in tropical climates: II-field testing in Guadeloupe
This paper presents the results of the experimental investigation of a solar desiccant air conditioning device exposed to the sun in Guadeloupe to test that adaptability of a silicagel compact bed, the most simple technology, in a tropical climate. It has been shown that it is possible to make use of solar flat plate collectors with a balancing water tank, to produce heat for the regeneration of a solid desiccant as silicagel, with solar energy. Second, the compact bed system proposed gives the foreseen cooling power, but considerable losses appear, particularly in the sorption process, which is not close enough to the reversible adiabatic one.
Dupont, M.; Celestine, B.; Beghin, B. (Solar Energy Lab., Pointe-a-Pitre (Guadeloupe))
cooled, ammonia-water absorption chiller as a starting pointabsorption cycle under such conJitions. A nominal three-ton,continuous operation, heat-actuated water chiller
Dao, K.
Numerical Simulations of Air�Sea Interaction under High Wind Conditions Using a Coupled Model: A Study of Hurricane Development
In this study, a coupled atmosphere�ocean wave modeling system is used to simulate air�sea interaction under high wind conditions. This coupled modeling system is made of three well-tested model components: The Pennsylvania State University�...
J-W. Bao; J. M. Wilczak; J-K. Choi; L. H. Kantha
The Impact of Climate Change on Air Quality�Related Meteorological Conditions in California. Part I: Present Time Simulation Analysis
This study investigates the impacts of climate change on meteorology and air quality conditions in California by dynamically downscaling Parallel Climate Model (PCM) data to high resolution (4 km) using the Weather Research and Forecast (WRF) ...
Zhan Zhao; Shu-Hua Chen; Michael J. Kleeman; Mary Tyree; Dan Cayan
"Table HC15.6 Air Conditioning Characteristics by Four Most Populated States, 2005"
6 Air Conditioning Characteristics by Four Most Populated States, 2005" 6 Air Conditioning Characteristics by Four Most Populated States, 2005" " Million U.S. Housing Units" ,"U.S. Housing Units (millions)","Four Most Populated States" "Air Conditioning Characteristics",,"New York","Florida","Texas","California" "Total",111.1,7.1,7,8,12.1 "Do Not Have Cooling Equipment",17.8,1.8,"Q","Q",4.9 "Have Cooling Equipment",93.3,5.3,7,7.8,7.2 "Use Cooling Equipment",91.4,5.3,7,7.7,6.6 "Have Equipment But Do Not Use it",1.9,"Q","N","Q",0.6 "Air-Conditioning Equipment1, 2 " "Central System",65.9,1.1,6.4,6.4,5.4
"Table HC11.7 Air-Conditioning Usage Indicators by Northeast Census Region, 2005"
7 Air-Conditioning Usage Indicators by Northeast Census Region, 2005" 7 Air-Conditioning Usage Indicators by Northeast Census Region, 2005" " Million U.S. Housing Units" ,,"Northeast Census Region" ,"U.S. Housing Units (millions)" ,,,"Census Division" ,,"Total Northeast" "Air Conditioning Usage Indicators",,,"Middle Atlantic","New England" "Total",111.1,20.6,15.1,5.5 "Do Not Have Cooling Equipment",17.8,4,2.4,1.7 "Have Cooling Equipment",93.3,16.5,12.8,3.8 "Use Cooling Equipment",91.4,16.3,12.6,3.7 "Have Equipment But Do Not Use it",1.9,0.3,"Q","Q" "Type of Air-Conditioning Equipment1, 2" "Central System",65.9,6,5.2,0.8 "Without a Heat Pump",53.5,5.5,4.8,0.7
"Table HC15.7 Air-Conditioning Usage Indicators by Four Most Populated States, 2005"
7 Air-Conditioning Usage Indicators by Four Most Populated States, 2005" 7 Air-Conditioning Usage Indicators by Four Most Populated States, 2005" " Million U.S. Housing Units" ,"Housing Units (millions)","Four Most Populated States" "Air Conditioning Usage Indicators",,"New York","Florida","Texas","California" "Total",111.1,7.1,7,8,12.1 "Do Not Have Cooling Equipment",17.8,1.8,"Q","Q",4.9 "Have Cooling Equipment",93.3,5.3,7,7.8,7.2 "Use Cooling Equipment",91.4,5.3,7,7.7,6.6 "Have Equipment But Do Not Use it",1.9,"Q","N","Q",0.6 "Type of Air-Conditioning Equipment1, 2" "Central System",65.9,1.1,6.4,6.4,5.4
"Table HC10.7 Air-Conditioning Usage Indicators by U.S. Census Region, 2005"
7 Air-Conditioning Usage Indicators by U.S. Census Region, 2005" 7 Air-Conditioning Usage Indicators by U.S. Census Region, 2005" " Million U.S. Housing Units" ,"Housing Units (millions)","U.S. Census Region" "Air Conditioning Usage Indicators",,"Northeast","Midwest","South","West" "Total",111.1,20.6,25.6,40.7,24.2 "Do Not Have Cooling Equipment",17.8,4,2.1,1.4,10.3 "Have Cooling Equipment",93.3,16.5,23.5,39.3,13.9 "Use Cooling Equipment",91.4,16.3,23.4,38.9,12.9 "Have Equipment But Do Not Use it",1.9,0.3,"Q",0.5,1 "Type of Air-Conditioning Equipment1, 2" "Central System",65.9,6,17.3,32.1,10.5 "Without a Heat Pump",53.5,5.5,16.2,23.2,8.7
"Table HC13.7 Air-Conditioning Usage Indicators by South Census Region, 2005"
7 Air-Conditioning Usage Indicators by South Census Region, 2005" 7 Air-Conditioning Usage Indicators by South Census Region, 2005" " Million U.S. Housing Units" ,,"South Census Region" ,"U.S. Housing Units (millions)" ,,,"Census Division" ,,"Total South" "Air Conditioning Usage Indicators",,,"South Atlantic","East South Central","West South Central" "Total",111.1,40.7,21.7,6.9,12.1 "Do Not Have Cooling Equipment",17.8,1.4,0.8,0.2,0.3 "Have Cooling Equipment",93.3,39.3,20.9,6.7,11.8 "Use Cooling Equipment",91.4,38.9,20.7,6.6,11.7 "Have Equipment But Do Not Use it",1.9,0.5,"Q","Q","Q" "Type of Air-Conditioning Equipment1, 2"
Transformation of Sulfur Species during Steam/Air Regeneration on a Ni Biomass Conditioning Catalyst
Sulfur K-edge XANES identified transformation of sulfides to sulfates during combined steam and air regeneration on a Ni/Mg/K/Al2O3 catalyst used to condition biomass-derived syngas. This catalyst was tested over multiple reaction/regeneration/reduction cycles. Postreaction catalysts showed the presence of sulfides on H2S-poisoned sites. Although H2S was observed to leave the catalyst bed during regeneration, sulfur remained on the catalyst, and a transformation from sulfides to sulfates was observed. Following the oxidative regeneration, the subsequent H2 reduction led to a partial reduction of sulfates back to sulfides, indicating the difficulty and sensitivity in achieving complete sulfur removal during regeneration for biomass-conditioning catalysts.
Yung, M. M.; Cheah, S.; Magrini-Bair, K.; Kuhn, J. N.
Energy and global warming impacts of next generation refrigeration and air conditioning technologies
Significant developments have occurred in hydrofluorocarbon (HFC) and the application of ammonia and hydrocarbons as refrigerant working fluids since the original TEWI (Total Equivalent Warming Impact) report in 1991. System operating and performance data on alternative refrigerants and refrigeration technologies justify and updated evaluation of these new alternative refrigerants and competing technologies in well-characterized applications. Analytical and experimental results are used to show quantitative comparisons between HFCS, HFC blends, hydrocarbons, and ammonia, used as refrigerants. An objective evaluation is presented for commercial and near commercial non-CFC refrigerants/blowing agents and alternative refrigeration technologies. This information is needed for objective and quantitative decisions on policies addressing greenhouse gas emissions from refrigeration and air conditioning equipment. The evaluation assesses the energy use and global warming impacts of refrigeration and air conditioning technologies that could be commercialized during the phase out of HCFCS. Quantitative comparison TEWI for two application areas are presented. Opportunities for significant reductions in TEWI are seen with currently known refrigerants through improved maintenance and servicing practices and improved product designs.
Sand, J.R.; Fischer, S.K.; Baxter, V.D.
The Influence of Air-Conditioning Efficiency in the Peak Load Demand for Kuwait
A model co-relating the peak load demand of a utility with the allowable power rating (PR) of air-conditioning (AC) systems has been developed in this paper through a well defined methodology. The model is capable to predict the extent of allowable increase in the capital cost of the AC system for an improvement in PR from its base case as well. Furthermore, effectiveness of better PR of AC system for peak load management has been analyzed for Kuwait as a case study. It is found that up to 5,752 MW in reduction in peak load demand and savings of KD 2,301 million in capital expenditures are possible for the years between 2001 and 2025 if the PR of AC systems are improved to 1.2 kW/RT from its present level of 2.0 kW/RT. Also, it is estimated that extent of increase in capital cost of AC system by 106 % is justified for reducing the expenditure for new power plants. The paper will be useful for the energy planner and policy makers in the countries of Arabian Peninsula with huge demand for air-conditioning.
Ali, A. A.; Maheshwari, G. P.
A genetic rule weighting and selection process for fuzzy control of heating, ventilating and air conditioning systems
In this paper, we propose the use of weighted linguistic fuzzy rules in combination with a rule selection process to develop accurate fuzzy logic controllers dedicated to the intelligent control of heating, ventilating and air conditioning systems concerning ... Keywords: BEMS, building energy management system, FLC, fuzzy logic controller, Fuzzy logic controllers, GA, genetic algorithm, Genetic algorithms, HVAC systems, HVAC, heating, ventilating, and air conditioning, KB, knowledge base, PMV, predicted mean vote index for thermal comfort, Rule selection, Weighted fuzzy rules
Rafael Alcal�; Jorge Casillas; Oscar Cord�n; Antonio Gonz�lez; Francisco Herrera
Experimental investigation on the photovoltaic-thermal solar heat pump air-conditioning system on water-heating mode
An experimental study on operation performance of photovoltaic-thermal solar heat pump air-conditioning system was conducted in this paper. The experimental system of photovoltaic-thermal solar heat pump air-conditioning system was set up. The performance parameters such as the evaporation pressure, the condensation pressure and the coefficient of performance (COP) of heat pump air-conditioning system, the water temperature and receiving heat capacity in water heater, the photovoltaic (PV) module temperature and the photovoltaic efficiency were investigated. The experimental results show that the mean photovoltaic efficiency of photovoltaic-thermal (PV/T) solar heat pump air-conditioning system reaches 10.4%, and can improve 23.8% in comparison with that of the conventional photovoltaic module, the mean COP of heat pump air-conditioning system may attain 2.88 and the water temperature in water heater can increase to 42 C. These results indicate that the photovoltaic-thermal solar heat pump air-conditioning system has better performances and can stably work. (author)
Fang, Guiyin; Hu, Hainan; Liu, Xu [Department of Physics, Nanjing University, Nanjing 210093 (China)
Energy Consumption Measuring and Diagnostic Analysis of Air-conditioning Water System in a Hotel Building in Harbin
This paper introduces an air-conditioning water system in a hotel building in Harbin, finishes its air-conditioning energy consumption measurement in summer conditions, and presents an estimation index of performance of chiller, pump and motor. By means of testing data analysis, it is indicated that several problems such as unsuitable operation schedule of the chiller, low COP, irrational matching of pump and motor, unbalanced conditions of chilled water flow, and low working stability and efficiency ratio of the pump are existent. The paper presents suggestions for improvement with relevance based on the induction and analysis of system fault found in measurements.
Zhao, T.; Zhang, J.; Li, Y.
Structural analysis of porous rock reservoirs subjected to conditions of compressed air energy storage
Investigations are described which were performed to assess the structural behavior of porous rock compressed air energy storage (CAES) reservoirs subjected to loading conditions of temperature and pressure felt to be typical of such an operation. Analyses performed addressed not only the nominal or mean reservoir response but also the cyclic response due to charge/discharge operation. The analyses were carried out by assuming various geometrical and material related parameters of a generic site. The objective of this study was to determine the gross response of a generic porous reservoir. The site geometry for this study assumed a cylindrical model 122 m in dia and 57 m high including thicknesses for the cap, porous, and base rock formations. The central portion of the porous zone was assumed to be at a depth of 518 m and at an initial temperature of 20/sup 0/C. Cyclic loading conditions of compressed air consisted of pressure values in the range of 4.5 to 5.2 MPa and temperature values between 143 and 204/sup 0/C.Various modes of structural behavior were studied. These response modes were analyzed using loading conditions of temperature and pressure (in the porous zone) corresponding to various operational states during the first year of simulated site operation. The results of the structural analyses performed indicate that the most severely stressed region will likely be in the wellbore vicinity and hence highly dependent on the length of and placement technique utilized in the well production length. Analyses to address this specific areas are currently being pursued.
Friley, J.R.
High Efficiency Liquid-Desiccant Regenerator for Air Conditioning and Industrial Drying
Over 2 quads of fossil fuels are used each year for moisture removal. This includes industrial and agricultural processes where feedstocks and final products must be dried, as well as comfort conditioning of indoor spaces where the control of humidity is essential to maintaining healthy, productive and comfortable working conditions. Desiccants, materials that have a high affinity for water vapor, can greatly reduce energy use for both drying and dehumidification. An opportunity exists to greatly improve the competitiveness of advanced liquid-desiccant systems by increasing the efficiency of their regenerators. It is common practice within the chemical process industry to use multiple stage boilers to improve the efficiency of thermal separation processes. The energy needed to regenerate a liquid desiccant, which is a thermal separation process, can also be reduced by using a multiple stage boiler. In this project, a two-stage regenerator was developed in which the first stage is a boiler and the second stage is a scavenging-air regenerator. The only energy input to this regenerator is the natural gas that fires the boiler. The steam produced in the boiler provides the thermal energy to run the second-stage scavenging-air regenerator. This two-stage regenerator is referred to as a 1?-effect regenerator. A model of the high-temperature stage of a 1?-effect regenerator for liquid desiccants was designed, built and successfully tested. At nominal operating conditions (i.e., 2.35 gpm of 36% lithium chloride solution, 307,000 Btu/h firing rate), the boiler removed 153 lb/h of water from the desiccant at a gas-based efficiency of 52.9 % (which corresponds to a COP of 0.95 when a scavenging-air regenerator is added). The steam leaving the boiler, when condensed, had a solids concentration of less than 10 ppm. This low level of solids in the condensate places an upper bound of about 6 lb per year for desiccant loss from the regenerator. This low loss will not create maintenance problems nor will it significantly increase operating expenses. An energy balance on the boiler showed that heat loss through the insulated jacket was 10%. This value is much higher than the 2% to 5% that is typical of most boilers and indicates a need to better insulate the unit. With insulation that brings jacket losses down to 5%, a 1?-effect regenerator that uses this boiler as its high-temperature stage will have a gas-based COP of 1.05. The estimated cost to manufacture a 300-lb/h, 1?-effect regenerator at 500 units per year is $17,140. Unfortunately, the very high cost for natural gas that now prevails in the U.S. makes it very difficult for a gas-fired LDAC to compete against an electric vapor-compression air conditioner in HVAC applications. However, there are important industrial markets that need very dry air where the high price of natural gas will encourage the sale of a LDAC with the 1?-effect regenerator since in these markets it competes against less efficient gas-fired desiccant technologies. A manufacturer of industrial dehumidification equipment is now negotiating a sales agreement with us that would include the 1?-effect regenerator.
Andrew Lowenstein
Smart Operations of Air-Conditioning and Lighting Systems in Government Buildings for Peak Power Reduction
During the summer 2007 smart operation strategies for air-conditioning (A/C) and lighting systems were developed and tested in a number of governmental buildings in Kuwait as one of the solutions to reduce the national peak demand for electrical power that commonly occur around 15:00 h. The working hours for these building are generally between 07:00 and 14:00 h and their peak demand exceeds 600 MW. The smart operation strategies implemented in these buildings included pre-closing treatment (PCT) between 13:00 and 14:00 h and time-of-day control (TDC) after 14:00 h. Also de-lamping was carried out in some of the buildings to readjust the higher than recommended illumination levels. This paper presents the achievements of implementing these smart operations strategies in Justice Palace Complex (JPC) as a case study. The peak load of this building was 3700 kW. The achievements are summarized as an all time saving of 22 kW by de-lamping, an additional saving of 27 kW through TDC of lighting, direct savings between 13:00 and 22:00 h by closing supply and return air fans of 52 air-handling units with a connected load 400 kW, and an additional saving of 550 kW during the same period by optimizing the cooling production and distribution. In conclusion project achieved an overall reduction in power demand of around 20% between 13:00 to 17:00 h and reduction ranging from 7% to 15% between 17:00 to 20:00 h.
Al-Hadban, Y.; Maheshwari, G. P.; Al-Nakib, D.; Al-Mulla, A.; Alasseri, R.
Evaluation Framework and Analyses for Thermal Energy Storage Integrated with Packaged Air Conditioning
Few third-party guidance documents or tools are available for evaluating thermal energy storage (TES) integrated with packaged air conditioning (AC), as this type of TES is relatively new compared to TES integrated with chillers or hot water systems. To address this gap, researchers at the National Renewable Energy Laboratory conducted a project to improve the ability of potential technology adopters to evaluate TES technologies. Major project outcomes included: development of an evaluation framework to describe key metrics, methodologies, and issues to consider when assessing the performance of TES systems integrated with packaged AC; application of multiple concepts from the evaluation framework to analyze performance data from four demonstration sites; and production of a new simulation capability that enables modeling of TES integrated with packaged AC in EnergyPlus. This report includes the evaluation framework and analysis results from the project.
Kung, F.; Deru, M.; Bonnema, E.
New Automotive Air Conditioning System Simulation Tool Developed in MATLAB/Simulink
Further improvements in vehicle fuel efficiency require accurate evaluation of the vehicle's transient total power requirement. When operated, the air conditioning (A/C) system is the largest auxiliary load on a vehicle; therefore, accurate evaluation of the load it places on the vehicle's engine and/or energy storage system is especially important. Vehicle simulation software, such as 'Autonomie,' has been used by OEMs to evaluate vehicles' energy performance. A transient A/C simulation tool incorporated into vehicle simulation models would also provide a tool for developing more efficient A/C systems through a thorough consideration of the transient A/C system performance. The dynamic system simulation software Matlab/Simulink was used to develop new and more efficient vehicle energy system controls. The various modeling methods used for the new simulation tool are described in detail. Comparison with measured data is provided to demonstrate the validity of the model.
Kiss, T.; Chaney, L.; Meyer, J.
Japanese power electronics inverter technology and its impact on the American air conditioning industry
Since 1983, technological advances and market growth of inverter- driven variable-speed heat pumps in Japan have been dramatic. The high level of market penetration was promoted by a combination of political, economic, and trade policies in Japan. A unique environment was created in which the leading domestic industries-- microprocessor manufacturing, compressors for air conditioning and refrigerators, and power electronic devices--were able to direct the development and market success of inverter-driven heat pumps. As a result, leading US variable-speed heat pump manufacturers should expect a challenge from the Japanese producers of power devices and microprocessors. Because of the vertically-integrated production structure in Japan, in contrast to the out-sourcing culture of the United States, price competition at the component level (such as inverters, sensors, and controls) may impact the structure of the industry more severely than final product sales. 54 refs., 47 figs., 1 tab.
Ushimaru, Kenji.
Effect of Intake Air Filter Condition on Vehicle Fuel Economy--ORNL/TM-2009/021
021 021 Effect of Intake Air Filter Condition on Vehicle Fuel Economy February 2009 Prepared by Kevin Norman Shean Huff Brian West DOCUMENT AVAILABILITY Reports produced after January 1, 1996, are generally available free via the U.S. Department of Energy (DOE) Information Bridge. Web site http://www.osti.gov/bridge Reports produced before January 1, 1996, may be purchased by members of the public from the following source. National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Telephone 703-605-6000 (1-800-553-6847) TDD 703-487-4639 Fax 703-605-6900 E-mail firstname.lastname@example.com Web site http://www.ntis.gov/support/ordernowabout.htm Reports are available to DOE employees, DOE contractors, Energy Technology Data Exchange
�F for removing heat from the condenser and absorber coils.temperature. Air-cooled condensers and absorbers are limitedfor water- cooling the condenser was an overriding concern
NREL's Energy-Saving Technology for Air Conditioning Cuts Peak Power Loads Without Using Harmful Refrigerants (Fact Sheet)
This fact sheet describes how the DEVAP air conditioner was invented, explains how the technology works, and why it won an R&D 100 Award. Desiccant-enhanced evaporative (DEVAP) air-conditioning will provide superior comfort for commercial buildings in any climate at a small fraction of the electricity costs of conventional air-conditioning equipment, releasing far less carbon dioxide and cutting costly peak electrical demand by an estimated 80%. Air conditioning currently consumes about 15% of the electricity generated in the United States and is a major contributor to peak electrical demand on hot summer days, which can lead to escalating power costs, brownouts, and rolling blackouts. DEVAP employs an innovative combination of air-cooling technologies to reduce energy use by up to 81%. DEVAP also shifts most of the energy needs to thermal energy sources, reducing annual electricity use by up to 90%. In doing so, DEVAP is estimated to cut peak electrical demand by nearly 80% in all climates. Widespread use of this cooling cycle would dramatically cut peak electrical loads throughout the country, saving billions of dollars in investments and operating costs for our nation's electrical utilities. Water is already used as a refrigerant in evaporative coolers, a common and widely used energy-saving technology for arid regions. The technology cools incoming hot, dry air by evaporating water into it. The energy absorbed by the water as it evaporates, known as the latent heat of vaporization, cools the air while humidifying it. However, evaporative coolers only function when the air is dry, and they deliver humid air that can lower the comfort level for building occupants. And even many dry climates like Phoenix, Arizona, have a humid season when evaporative cooling won't work well. DEVAP extends the applicability of evaporative cooling by first using a liquid desiccant-a water-absorbing material-to dry the air. The dry air is then passed to an indirect evaporative cooling stage, in which the incoming air is in thermal contact with a moistened surface that evaporates the water into a separate air stream. As the evaporation cools the moistened surface, it draws heat from the incoming air without adding humidity to it. A number of cooling cycles have been developed that employ indirect evaporative cooling, but DEVAP achieves a superior efficiency relative to its technological siblings.
3172, Page 1 International Refrigeration and Air Conditioning Conference at Purdue, July 16-19, 2012
insulation, thermal conductivity, heat transfer, moisture accumulation, chiller pipelines ABSTRACT Mechanical of pipe insulation systems had quite different water absorption rates due to different characteristics
Ghajar, Afshin J.
SOLERAS - Solar Cooling Engineering Field Tests Project: Arizona State University. Prototype carrier 10 ton air-cooled solar absorption chiller. Final evaluation report
A prototype air-cooled 10 ton solar absorption chiller was disassembled and inspected after having been field-tested for three consecutive cooling seasons. Included in the inspection were some flow visualization experiments which revealed some problems in the absorber header design. The objectives of this evaluation project were to determine possible causes for the frequent crystallization and generally below-design performance of the chiller during the testing period. The major conclusions reached were that a combination of leaks and of poor (50%) flow distribution in the absorber could account for most of the chiller's poor performance.
Energy Comparison Between Conventional and Chilled Water Thermal Storage Air Conditioning Systems
During the summer of previous years, Kuwait faced a series of power shortages emphasizing the need for urgent commissioning of power generation projects. It is estimated that the demand for electricity is growing at an average of 6.2% per year, encouraged by government subsidies and driven by the rapid and continual expansion in building construction, urban development, and the heavy reliance on Air Conditioning (AC) systems for the cooling of buildings. The Chilled Water Thermal Storage (CWTS) system is one of the available techniques that can be utilized to reduce peak electricity demand of buildings when national electricity consumption is at its highest level. This paper demonstrates that the use of CWTS system reduces the peak power demand and energy consumption of AC systems for design day conditions by 36.7% - 87.5% and 5.4% - 7.2%, respectively. This reduction depends on selected operating strategies as compared with conventional AC system. Furthermore, results show that the annual energy consumption of CWTS systems decreases by between 4.5% and 6.9% compared with conventional systems, where chillers and pumps significantly contribute to this reduction.
Sebzali, M.; Hussain, H. J.; Ameer, B.
Regression analysis of residential air-conditioning energy consumption at Dhahran, Saudi Arabia
The energy consumption of a house air conditioner located at Dhahran, Saudi Arabia, is modeled as a function of weather parameters and total (global) solar radiation on a horizontal surface. The selection of effective parameters that significantly influence energy consumption is carried out using general stepping regression methods. The problem of collinearity between the regressors is also investigated. The final model involves parameters of total solar radiation on a horizontal surface, wind speed, and temperature difference between the indoor and outdoor condition. However, the model coefficients are functions of relative humidity and/or temperature difference between the indoor and outdoor condition. Model adequacy is examined by the residual analysis technique. Model validation is carried out by the data-splitting technique. The sensitivity of the model indicates that relative humidity and temperature difference strongly influence the cooling energy consumption. It was found that an increase in relative humidity from 20% to 100% can cause a 100% increase in cooling energy consumption during the high cooling season.
Abdel-Nabi, D.Y.; Zubair, S.M.; Abdelrahman, M.A.; Bahel, V. (Energy Systems Group, Div. of Energy Resources, Research Inst., King Fahd Univ. of Petroleum and Minerals, Dhahran (SA))
Modelica Library for Building Heating, Ventilation and Air-Conditioning Systems
This paper presents a freely available Modelica library for building heating, ventilation and air conditioning systems. The library is based on the Modelica.Fluid library. It has been developed to support research and development of integrated building energy and control systems. The primary applications are controls design, energy analysis and model-based operation. The library contains dynamic and steady-state component models that are applicable for analyzing fast transients when designing control algorithms and for conducting annual simulations when assessing energy performance. For most models, dimensional analysis is used to compute the performance for operating points that differ from nominal conditions. This allows parameterizing models in the absence of detailed geometrical information which is often impractical to obtain during the conceptual design phase of building systems. In the first part of this paper, the library architecture and the main classes are described. In the second part, an example is presented in which we implemented a model of a hydronic heating system with thermostatic radiator valves and thermal energy storage.
Wetter, Michael
Numerical Simulations of the Meteorological and Dispersion Conditions during an Air Pollution Episode over Athens, Greece
In this study a summer air pollution episode from 6 to 8 August 1994 over Athens, Greece, is investigated through advanced atmospheric modeling. This episode was reported from the air quality monitoring network, as well as from research aircraft ...
V. Kotroni; G. Kallos; K. Lagouvardos; M. Varinou; R. Walko
Investigating the Performance of Solar Air Conditioning Motivation/Background Findings
Absorption 29% Desiccant 38% Adsorption 43% Absorption 63% House Rochester Glasgow Miami Phoenix Cooling Load of thermal and electrical energy systems ii. Medium Office Building Solar Thermal Assisted Cooling Technology is less energy efficient than the other two Office 0 10 20 30 40 50 60 70 80 Rochester Glasgow Miami
Fuel Savings and Emission Reductions from Next-Generation Mobile Air Conditioning Technology in India
Up to 19.4% of vehicle fuel consumption in India is devoted to air conditioning (A/C). Indian A/C fuel consumption is almost four times the fuel penalty in the United States and close to six times that in the European Union because India's temperature and humidity are higher and because road congestion forces vehicles to operate inefficiently. Car A/C efficiency in India is an issue worthy of national attention considering the rate of increase of A/C penetration into the new car market, India's hot climatic conditions and high fuel costs. Car A/C systems originally posed an ozone layer depletion concern. Now that industrialized and many developing countries have moved away from ozone-depleting substances per Montreal Protocol obligations, car A/C impact on climate has captured the attention of policy makers and corporate leaders. Car A/C systems have a climate impact from potent global warming potential gas emissions and from fuel used to power the car A/Cs. This paper focuses on car A/C fuel consumption in the context of the rapidly expanding Indian car market and how new technological improvements can result in significant fuel savings and consequently, emission reductions. A 19.4% fuel penalty is associated with A/C use in the typical Indian passenger car. Car A/C fuel use and associated tailpipe emissions are strong functions of vehicle design, vehicle use, and climate conditions. Several techniques: reducing thermal load, improving vehicle design, improving occupants thermal comfort design, improving equipment, educating consumers on impacts of driver behaviour on MAC fuel use, and others - can lead to reduced A/C fuel consumption.
Chaney, L.; Thundiyil, K.; Andersen, S.; Chidambaram, S.; Abbi, Y. P.
Global warming impacts of ozone-safe refrigerants and refrigeration, heating, and air-conditioning technologies
International agreements mandate the phase-out of many chlorine containing compounds that are used as the working fluid in refrigeration, air-conditioning, and heating equipment. Many of the chemical compounds that have been proposed, and are being used in place of the class of refrigerants eliminated by the Montreal Protocol are now being questioned because of their possible contributions to global warming. Natural refrigerants are put forth as inherently superior to manufactured refrigerants because they have very low or zero global warming potentials (GWPs). Questions are being raised about whether or not these manufactured refrigerants, primarily hydrofluorocarbons (HFCs), should be regulated and perhaps phased out in much the same manner as CFCs and HCFCs. Several of the major applications of refrigerants are examined in this paper and the results of an analysis of their contributions to greenhouse warming are presented. Supermarket refrigeration is shown to be an application where alternative technologies have the potential to reduce emissions of greenhouse gases (GHG) significantly with no clear advantage to either natural or HFC refrigerants. Mixed results are presented for automobile air conditioners with opportunities to reduce GHG emissions dependent on climate and comfort criteria. GHG emissions for hermetic and factory built systems (i.e. household refrigerators/freezers, unitary equipment, chillers) are shown to be dominated by energy use with much greater potential for reduction through efficiency improvements than by selection of refrigerant. The results for refrigerators also illustrate that hydrocarbon and carbon dioxide blown foam insulation have lower overall effects on GHG emissions than HFC blown foams at the cost of increased energy use.
Fischer, S.; Sand, J.; Baxter, V.
"Table HC3.6 Air Conditioning Characteristics by Owner-Occupied Housing Units, 2005"
6 Air Conditioning Characteristics by Owner-Occupied Housing Units, 2005" 6 Air Conditioning Characteristics by Owner-Occupied Housing Units, 2005" " Million U.S. Housing Units" ,," Owner-Occupied Housing Units (millions)","Type of Owner-Occupied Housing Unit" ,"U.S. Housing Units (millions" ,,,"Single-Family Units",,"Apartments in Buildings With--" "Air Conditioning Characteristics",,,"Detached","Attached","2 to 4 Units","5 or More Units","Mobile Homes" "Total",111.1,78.1,64.1,4.2,1.8,2.3,5.7 "Do Not Have Cooling Equipment",17.8,11.3,9.3,0.6,"Q",0.4,0.9 "Have Cooling Equipment",93.3,66.8,54.7,3.6,1.7,1.9,4.8 "Use Cooling Equipment",91.4,65.8,54,3.6,1.7,1.9,4.7
Upgrading of the Air-conditioning of the Computer Room in the Computer Centre for the LHC era
Built in the beginning of 1970's, the Computer Centre air-conditioning and cooling systems were designed to be modular and easily adaptable to the unpredictable future needs of computing. The infrastructure of LHC-computing that will be housed in the existing Computer Room with its five Computing farms and over 11000 PC's increases the requirements of cooling and air-conditioning power to a new level. The nominal thermal loads from the equipment rise from the current design maximum of 1MW to estimated maximum of 2MW in the future. This paper presents calculations and proposes solutions to meet the new nominal requirements. The air-conditioning system must also be able to cope with a situation of power cut in the main supply. A calculation of the temperature evolution during the power cut and a justified operation strategy for this scenario is also presented.
"Table HC3.7 Air-Conditioning Usage Indicators by Owner-Occupied Housing Unit, 2005"
7 Air-Conditioning Usage Indicators by Owner-Occupied Housing Unit, 2005" 7 Air-Conditioning Usage Indicators by Owner-Occupied Housing Unit, 2005" " Million U.S. Housing Units" ,," Owner-Occupied Housing Units (millions)","Type of Owner-Occupied Housing Unit" ,"U.S. Housing Units (millions)" ,,,"Single-Family Units",,"Apartments in Buildings With--" "Air Conditioning Usage Indicators",,,"Detached","Attached","2 to 4 Units","5 or More Units","Mobile Homes" "Total",111.1,78.1,64.1,4.2,1.8,2.3,5.7 "Do Not Have Cooling Equipment",17.8,11.3,9.3,0.6,"Q",0.4,0.9 "Have Cooling Equipment",93.3,66.8,54.7,3.6,1.7,1.9,4.8 "Use Cooling Equipment",91.4,65.8,54,3.6,1.7,1.9,4.7
Size and Type of the Heat Exchangers Air Cooled Condensora packed-tower counterflow heat exchanger for the generator.to strong solution heat exchanger) was added. iv. The
Energy Savings and Economics of Advanced Control Strategies for Packaged Air-Conditioning Units with Gas Heat
Pacific Northwest National Laboratory (PNNL) with funding from the U.S. Department of Energy's Building Technologies Program (BTP) evaluated a number of control strategies that can be implemented in a controller, to improve the operational efficiency of the packaged air conditioning units. The two primary objectives of this research project are: (1) determine the magnitude of energy savings achievable by retrofitting existing packaged air conditioning units with advanced control strategies not ordinarily used for packaged units and (2) estimating what the installed cost of a replacement control with the desired features should be in various regions of the U.S. This document reports results of the study.
Wang, Weimin; Katipamula, Srinivas; Huang, Yunzhi; Brambley, Michael R.
The Coordinated Control of a Central Air Conditioning System Based on Variable Chilled Water Temperature and Variable Chilled Water Flow
At present, regulation of water flow by means of pump frequency conversion is one of the major methods for power-saving in central air conditioning systems. In this article, optimization regulation for central air conditioning system on the basis of coordinative optimization control for variable chilled water temperature and variable chilled water flow to obtain better power savings is put forward. According to typical meteorological year data, hourly air conditioning load of whole year for every typical room has been calculated with the transmission function method. In order to guarantee each typical room, the highest cooling load rate is used as an input parameter for optimization calculation. Based on the surface cooler check model, the smallest energy consumption of chiller and chiller water pump was taken as the objective function of the optimization model. The performance characteristics of a chiller, water pump, regulation valve and pipeline are taken into account, and the optimization chilled water temperature and chilled water flow were carried out. The case study for a commercial building in Guangzhou showed that the annual power consumption of the chillers and pumps of the air conditioning system is lower by 17% only with employment of variable water flow regulation by pump frequency conversion. In the case of optimization control with coordinative control of variable chilled water temperature and variable chilled water flow, the annual power consumption of the chillers and pumps of the air conditioning system is reduced by 22% in presence of remarkable power saving effects. Increasing the chilled water temperature will reduce the dehumidified capability of the air cooler, and the indoor relative humidity will increase. The simulation showed that the adjustment optimized process meets the comfort of each typical room. The lower the cooling load rate is, the more obvious the effect of power-saving is. The highest power-saving rate appears in December, which is 36.7%. Meanwhile, the least rate appears in July, which is only 14.5%.
Liu, J.; Mai, Y.; Liu, X.
Air-Source Heat Pumps for Residential and Light Commercial Space Conditioning Applications
This technology brief provides the latest information on current and emerging air-source heat pump technologies for space heating and space cooling of residential and light commercial buildings. Air-source heat pumps provide important options that can reduce ownership costs while reducing noise and enhancing reliability and customer comfort. The tech brief also describes new air-source heat pumps with an important load shaping and demand response option.
The determinants of the governance of air conditioning maintenance in Australian retail centres.
??Retail centres are a visible sign of developed capitalist societies and make an appreciable contribution to these economies. For the firms involved in supplying air� (more)
Bridge, Adrian J.
Performance assessment and improvement of an existing air conditioning system of a supermarket: a case study on bi-lo supermarket
Bi-Lo Supermarket in this study is located in sub-tropical coastal area in Queensland, Australia. The main objective of air conditioning in any building or supermarket is to provide comfort to the occupants and patrons of the conditioned space, an objective ... Keywords: air conditioning systems, design principles, performance improvement, supermarket
M. Hansen; M. G. Rasul
Survey on Electricity Consumption Characteristics of Homethe stakes for energy consumption are high, as we hope atAir Conditioning Energy Consumption in Developing Countries
Using Hydrated Salt Phase Change Materials for Residential Air Conditioning Peak Demand Reduction and Energy Conservation in Coastal and Transitional Climates in the State of California.
??The recent rapid economic and population growth in the State of California have led to a significant increase in air conditioning use, especially in areas� (more)
Lee, Kyoung Ok
Proposal for the award of a contract for the design, supply, installation and commissioning of Heating, Ventilation and Air-Conditioning (HVAC) systems for the PS accelerator infrastructure
Proposal for the award of a contract for dismantling, removal and packaging of the existing Heating, Ventilation and Air-Conditioning (HVAC) systems in the PS tunnel
??Mechanical Engineering M.S.E. Experiments were carried out to investigate the effect of ambient air temperatures on the heat pump performance using a variable speed compressor.� (more)
Zhang, Hao
Candidate chemical systems for air cooled, solar powered, absorption air conditioner design. Part III. Lithium salts with anti-freeze additives
The two most promising anti-solidification additives which have been identified are ethanolamine and ethylene glycol. Considerations of viscosity, corrosion, crystallization temperature and vapor pressure have led to a selection of lithium bromide - ethylene glycol - water as the basis of a prototype air-cooled machine, with the lithium bromide; ethylene glycol ratio being 4.5. Using what appear to be reasonable heat exchanger approach temperatures, cycle thermal COP's of 0.7/sup +/ appear possible at the specified design point, based on solution properties which were determined with qualification accuracy. The prototype, delivering 10,000 watts of cooling, has a calculated parasitical electrical load of about 175 watts (theoretical) to drive the internal fans and pumps, equivalent to about a 0.5 horsepower motor.
Biermann, W.J.
Study of Air Ingress Across the Duct During the Accident Conditions
The goal of this project is to study the fundamental physical phenoena associated with air ingress in very high temperature reactors (VHTRs). Air ingress may occur due to a nupture of primary piping and a subsequent breach in the primary pressure boundary in helium-cooled and graphite-moderated VHTRs. Significant air ingress is a concern because it introduces potential to expose the fuel, graphite support rods, and core to a risk of severe graphite oxidation. Two of the most probable air ingress scenarios involve rupture of a control rod or fuel access standpipe, and rupture in the main coolant pipe on the lower part of the reactor pressure vessel. Therefor, establishing a fundamental understanding of air ingress phenomena is critical in order to rationally evaluate safety of existing VHTRs and develop new designs that mimimize these risks. But despite this importance, progress toward development these predictive capabilities has been slowed by the complex nature of the underlaying phenomena. The combination of interdiffusion among multiple species, molecular diffusion, natural convection, and complex geometries, as well as the multiple chemical reactions involved, impose significant roadblocks to both modeling and experiment design. The project team will employ a coordinated experimental and computational effort that will help gain a deeper understanding of multiphased air ingress phenomena. THis project will enhance advanced modeling and simulation methods, enabling calculation of nuclear power plant transients and accident scenarios with a high degree of confidence. The following are the project tasks: Perform particle image velocimetry measurement of multiphase air ingresses Perform computational fluid dynamics analysis of air ingress phenomena
Hassan, Yassin
Experimental Research and Performance Analysis of a Solar-Powered Air-conditioning System in a Green Building
Based on the green building of the Shanghai Institute of Architectural Science, a solar-powered adsorption air-conditioning system was designed. The operational performance under a typical operating mode in summer was studied, which includes temperature variations of solar collector arrays, heat storage tank and adsorption chillers as well as refrigerating output variations of the system. Experimental results show that adsorption chillers have the advantages of low driving temperature, stability and long working time with high efficiency. Under representative working conditions in summer, the average refrigerating output of solar powered air-conditioning system is 15.31kW during operation of 8 hours; moreover, the maximum attains 20kW. Correspondingly, the average system COP is 0.35, and the average solar COP is 0.15. The solar fraction in summer is concluded to be 71.73%. In addition, the variations of solar-powered air-conditioning system performance with ambient parameters (solar radiant intensity and ambient temperature) and operating parameters (temperatures and flow rates) are analyzed.
Zhai, X.; Wang, R.; Dai, Y.; Wu, J.
Experimental study of the performance of a laminar flow silica gel desiccant packing suitable for solar air conditioning application
An experimental study of the performance of a low pressure drop silica gel desiccant packing has been carried out. The packing is in the form of narrow passages lined with a single layer of small silica gel particles. A near optimum particle size of 0.25 mm, and a range of passage widths of 1.46 to 3.75 mm were chosen based on the predictions of a computer simulation model. A test chamber was constructed with sufficient thermal insulation to allow close to adiabatic conditions for the 12 cm x 12 cm cross section of packing. Step change adsorption and desorption tests were performed for various plate spacings, air flow rates, air inlet conditions, and gel initial water contents. Air outlet moisture content and temperature, as well as pressure drop were measured. The experimental results were compared with predictions of the computer simulation model: This model is based on gas side controlled heat and mass transfer, with the small solid side mass transfer resistance incorporated in a crude manner, and heat transfer into the packing handled as a lumped thermal capacitance. Reasonable agreement was obtained between theoretical prediction and experiment. The match was found to improve with increased passage width. The discrepancies are chiefly attributed to an excessive air bypass, and to inaccurate accounting for heat transfer from the sides of the unit. Use of the computer code for prototype scale design purposes is recommended.
Biswas, P.
A multi-objective evolutionary algorithm for an effective tuning of fuzzy logic controllers in heating, ventilating and air conditioning systems
This paper focuses on the use of multi-objective evolutionary algorithms to develop smartly tuned fuzzy logic controllers dedicated to the control of heating, ventilating and air conditioning systems, energy performance, stability and indoor comfort ... Keywords: Fuzzy logic controllers, Genetic tuning, HVAC systems, Heating, ventilating, and air conditioning systems, Linguistic 2-tuples representation, Multi-objective evolutionary algorithms, Rule selection
Mar�a Jos� Gacto; Rafael Alcal�; Francisco Herrera
Energy Basics: Absorption Heat Pumps
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Systems Air-Source Heat Pumps Ductless Mini-Split Heat Pumps Absorption Heat Pumps Geothermal Heat Pumps Supporting Equipment for Heating & Cooling Systems Water Heating...
Large HVAC Codes and Standards Update 2000: American Society of Heating, Refrigerating and Air-Conditioning Engineers
This report documents EPRI activities in the year 2000 related to building codes and standards. The following activities are covered: attendance at the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) meetings and participation in technical committee and subcommittee meetings related to ASHRAE Standard 90.l; review of relevant U.S Department of Energy (DOE) appliance standards; review of developments of other building energy code organizations; and participation in the E...
Energy audits reveal significant energy savings potential in India`s commercial air-conditioned building sector
The United States Agency for International Development (USAID) began its Energy Management Consultation and Training (EMCAT) project in India. The EMCAT project began in 1991 as a six-year (1991--1997) project to improve India`s technological and management capabilities for both the supply of energy and its efficient end use. The end-use component of EMCAT aims for efficient energy utilization by industries and other sectors such as the commercial sector. A specific task under the end-use component was to conduct energy surveys/audits in high energy-use sectors, such as air-conditioned (AC) buildings in the commercial sector, and to identify investment opportunities that could improve energy utilization. This article presents results of pre-investment surveys that were conducted at four commercial air-conditioned facilities in 1995. The four facilities included two luxury hotels in New Delhi, and one luxury hotel and a private hospital in Bombay. Energy conservation opportunities (ECOs) were explored in three major energy-using systems in these buildings: air-conditioning, lighting, and steam and domestic hot water systems.
Singh, G.; Presny, D.; Fafard, C. [Resource Management Associates of Madison, Inc., WI (United States)
Dehumidification Performance of Unitary Rooftop Air Conditioning Systems: K-Mart Demonstration
Applying various HVAC options--including heat pipe heat exchangers, reduced airflow, low temperature air, and modified fan operation--reduced the average relative humidity of a K-Mart store on the Mississippi coast during the hot humid summer season to below 50 percent. This demonstration will help utilities recommend the best practices for their retail customers.
A smart GUI based air-conditioning and lighting controller for energy saving in building
This paper will concentrate on the algorithm and control strategies where the air-conditioners and lighting system can be controlled using microcontroller; a microcontroller is chosen due to its low cost and high flexibility. Conceptually, the controller ... Keywords: energy saving control system, graphic LCD, graphical user interface (GUI), microcontroller
M. F. Abas; N. MD. Saad; N. L. Ramli
A thermal comfort levels investigation of a naturally ventilated and air-conditioned office
The purpose of this study is to investigate thermal comfort levels of a naturally ventilated and air-conditioner office. Field experiments conducted in an office room in Universiti Putra Malaysia (UPM) used survey questionnaires and physical measurements. ... Keywords: PMV, mechanically ventilation, naturally ventilated, neutral temperature, objective study, subjective approach, thermal comfort
R. Daghigh; N. M. Adam; K. Sopian; A. Zaharim; B. B. Sahari
A Bulk Turbulent Air�Sea Flux Algorithm for High-Wind, Spray Conditions
Sensible and latent heat can cross the air�sea interface by two routes: as interfacial fluxes controlled by molecular processes right at the interface, and as spray fluxes from the surface of sea spray droplets. Once the 10-m wind speed over the ...
Edgar L. Andreas; P. Ola G. Persson; Jeffrey E. Hare
Investigation and Analysis of Energy Consumption and Cost of Electric Air Conditioning Systems in Civil Buildings in Changsha
We investigated 40 typical air conditioned buildings in Changsha in 2005, including 15 hotel buildings, 6 commercial buildings, 5 office buildings, 6 hospital buildings and 8 synthesis buildings. On this basis we analyze the relation between types of cold and heat sources and the HVAC area of the buildings. Meanwhile the economical and feasible types of cold and heat sources are pointed out, i.e., oil boilers and gas boilers for heat source, and centrifugal and screw water chillers for cold source based on the electric refrigeration. Among the heat sources, the prospect of gas boilers is better. In addition, the air source heat pump depends heavily on whether some crucial issues such as frost can be solved during its application. The water-source heat pump will likely be applied. Based on the analysis of energy consumption and energy bills, we determine the feasible measures for energy conservation including the aspects of design, operation and management. Among them, special attention should be paid to energy metering and running time of air conditioning systems in civil buildings in Changsha.
Xie, D.; Chen, J.; Zhang, G.; Zhang, Q.
Risk Factors in Heating, Ventilating, and Air-Conditioning Systems for Occupant Symptoms in
six buildings had cooling towers, of which 46 were cleanedor poor condition of cooling tower was associated with aunscheduled cleaning of cooling towers was associated with
Mendell, M.J.; Lei-Gomez, Q.; Mirer, A.; Seppanen, O.; Brunner, G.
Memorandum To: GENERAL COUNSEL, DEPARTMENT OF ENERGY (DOE) From: JONATHAN MELCHI, HEATING, AIR-CONDITIONING AND REFRIGERATION
To: GENERAL COUNSEL, DEPARTMENT OF ENERGY (DOE) To: GENERAL COUNSEL, DEPARTMENT OF ENERGY (DOE) From: JONATHAN MELCHI, HEATING, AIR-CONDITIONING AND REFRIGERATION DISTRIBUTORS INTERNATIONAL (HARDI) Date: 1/12/2012 Subject: EX PARTE COMMUNICATION MEMO DOE ATTENDEES: Ashley Armstrong, John Cymbalsky, David Case, Laura Barhydt HARDI ATTENDEES: Talbot Gee, Jonathan Melchi AREAS OF DISCUSSION: DOE Framework Document and Stakeholder Meeting regarding the Enforcement of the updated Energy Conservation Standards for Air Conditioners, Furnaces and Heat Pumps. The meeting took place on Thursday January 5 th , 2012 from 2pm to 3-pm. The following topics were discussed. 1.) Sell-Through. HARDI asked for clarification on the DOE's notation on the Framework Document
Predictions of thermal comfort and pollutant distributions for a thermostatically-controlled, air-conditioned, partitioned room: Numerical results and enhanced graphical presentation
An index of local thermal comfort and pollutant distributions have been computed with the TEMPEST computer code, in a transient simulation of an air-conditioned enclosure with an incomplete partition. This complex three-dimensional air conditioning problem included forced ventilation through inlet veins, flow through a partition, remote return air vents, and infiltration source, a pollutant source, and a thermostatically controlled air conditioning system. Five forced ventilation schemes that varied in vent areas and face velocities were simulated. Thermal comfort was modeled as a three-dimensional scalar field dependent on the fluid velocity and temperature fields; where humidity activity levels, and clothing were considered constants. Pollutants transport was incorporated through an additional constituent diffusion equation. Six distinct graphic techniques for the visualization of the three-dimensional data fields of air velocity, temperature, and comfort index were tested. 4 refs., 7 figs., 1 tab.
White, M.D.; Eyler, L.L.
Problem of Vain Energy Consumption in a VAV Air Conditioning System Shared By an Inner Zone and Exterior Zone
In northern China, there are a large number of space buildings divided in inner zone and exterior zone based on usage requirements. The exterior zone needs to be heated in winter and cooled in summer, while the inner zone needs to be cooled both in winter and summer. Taking a practical project as example, this paper analyzes the energy consumption of a VAV air conditioning system that is shared by inner zone and exterior zone. The paper also points out the serious problem of useless energy consumption for this kind of system.
Wenji, G.; Ling, C.; Dongdong, L.; Mei, S.; Li, Z.
Field Demonstration of a High-Efficiency Packaged Rooftop Air Conditioning Unit at Fort Gordon, Augusta, GA
As part of a larger program targeting the market transformation of packaged rooftop air conditioning, five high-efficiency rooftop air conditioning products were selected in 2002 by the U.S. Department of Energy (DOE) under the Unitary Air Conditioner (UAC) Technology Procurement (http://www.pnl.gov/uac). In February 2003, Fort Gordon in Augusta, Georgia was chosen as the demonstration site. With the goal of validating the field performance and operation of one of the awarded products, a 10-ton high-efficiency packaged rooftop unit (RTU) manufactured by Global Energy Group (GEG) was installed at Fort Gordon in October 2003. Following equipment installation, power metering, air- and refrigerant-side instrumentation was installed on the GEG RTU and a 4-year old typical-efficiency 20-ton RTU manufactured by AAON . The GEG and AAON units were instrumented identically and operated May through July, 2005, to observe performance under a range of conditions. Based on the data collected as part of this demonstration, the GEG equipment performed at least 8% better in stage-1 (single compressor running) cooling and at least 16% better in stage-2 (both compressors running) than the baseline AAON equipment. Performance comparisons are based on what we call application EER normalized to equivalent specific fan power. The full-load, specific-fan-power-normalized application EERs at ARI design conditions were 10.48 Btu/Wh for the GEG and 9.00 Btu/Wh for the baseline machine. With a cost premium of nearly 50%, and slightly higher maintenance costs, the life-cycle cost analysis shows that the GEG technology pays for itself--a positive net-present value (NPV)--only in climates and buildings with long cooling seasons. Manufacture of this equipment on a larger scale can be expected to reduce costs to the point where it is more broadly cost-effective. The assumed 10-ton baseline and new-technology unit costs are $3824.00 and $5525.00 respectively. If the new technology cost is assumed to drop as sales increase to $4674.50 for a 10-ton unit (i.e. the original cost difference is halved), the life-cycle costs improve. A grid of first cost, annual maintenance cost and electricity price is enumerated and the results presented in the report show the sensitivity of life cycle cost to these three financial parameters in each of eight different climates.
Armstrong, Peter R.; Sullivan, Gregory P.; Parker, Graham B.
Smart Operations of Air-Conditioning and Lighting Systems in a Government Buildings for Peak Power Reduction
This paper presents the achievements of implementing smart operations strategies for air-conditioning (A/C) and lighting systems in Justice Palace Complex (JPC), Kuwait during the summer 2007. The peak load of this building was 3700 kW. The achievements are summarized as direct savings between 13:00 and 22:00 h by closing supply and return air fans of 52 air-handling units with a connected load 400 kW, and an additional saving of 550 kW during the same period by optimizing the cooling production and distribution. Also an all time saving of 22 kW by de-lamping, and additional saving of 27 kW through TDC of lighting were achieved. In conclusion project achieved an overall reduction in power demand of around 20% between 13:00 to 17:00 h and reduction ranging from 7% to 15% between 17:00 to 20:00 h.
Energy and economic performance analysis of an open cycle solar desiccant dehumidification air-conditioning system for application in Hong Kong
In this article, a transient simulation model and the EnergyPlus were used to study the energy performance and economical feasibility for integrating a solar liquid desiccant dehumidification system with a conventional vapor compression air-conditioning system for the weather condition of Hong Kong. The vapor compression system capacity in the solar assisted air-conditioning system can be reduced to 19 kW from original 28 kW of a conventional air-conditioning system as a case study due to the solar desiccant cooling. The economical performance of the solar desiccant dehumidification system is compared with that of the conventional air-conditioning system. The results show that the energy saving potentials due to incorporation of the solar desiccant dehumidification system in a traditional air-conditioning system is significant for the hot wet weather in Hong Kong due to higher COP resulted from higher supply chilled water temperature from chiller plants. The annual operation energy savings for the hybrid system is 6760 kWh and the payback period of the hybrid system is around 7 years. The study shows that the solar assisted air-conditioning is a viable technology for utilizations in subtropical areas. (author)
Li, Yutong; Lu, Lin; Yang, Hongxing [Renewable Energy Research Group (RERG), Department of Building Services Engineering, Hong Kong Polytechnic University, Hung Hom (China)
Distortions of Experimental Muon Arrival Time Distributions of Extensive Air Showers by the Observation Conditions
Event-by-event measured arrival time distributions of Extensive Air Shower (EAS) muons are affected and distorted by various interrelated effects which originate from the time resolution of the timing detectors, from fluctuations of the reference time and the number (multiplicity) of detected muons spanning the arrival time distribution of the individual EAS events. The origin of these effects is discussed, and different correction procedures, which involve detailed simulations, are proposed and illustrated. The discussed distortions are relevant for relatively small observation distances (R < 200 m) from the EAS core. Their significance decreases with increasing observation distance and increasing primary energies. Local arrival time distributions which refer to the observed arrival time of the first local muon prove to be less sensitive to the mass of the primary. This feature points to the necessity of arrival time measurements with additional information on the curvature of the EAS disk.
R. Haeusler; A. F. Badea; H. Rebel; I. M. Brancus; J. Oehlschlaeger
Simulations of Mesoscale Circulations in the Center of the Iberian Peninsula for Thermal Low Pressure Conditions. Part II: Air-Parcel Transport Patterns
This paper discusses the variability of air-parcel transport under similar summer thermal low pressure conditions over the Iberian Peninsula. Three-dimensional trajectories were estimated by means of the Topography Vorticity-Mode Mesoscale model. ...
Fernando Mart�n; Magdalena Palacios; Sylvia N. Cresp�
Fuzzy expert system design for operating room air-condition control systems
In this study, a controlled fuzzy expert system (FES) was designed to provide the conditions necessary for operating rooms. For this purpose, existing operating rooms have been studied to see if there are more useful, reliable and comfortable ones. How ... Keywords: Adaptive fuzzy control, Expert systems, Fuzzy control systems, Operating room control
Nazmi Etik; Novruz Allahverdi; Ibrahim Unal Sert; Ismail Saritas
Absorption chillers: Technology for the future
In an era of heightened awareness of energy efficiency and the associated environmental impacts, many industries worldwide are exploring ``environmentally friendly`` technologies that provide equivalent or improved performance while reducing or eliminating harmful side-effects. The refrigeration and air-conditioning industry, due to its reliance on CFCs and HCFCs, has invested in research in alternatives to the industry standard vapor compression machines. One alternative technology with great promise is chemical absorption. Absorption chillers offer comparable refrigeration output with reduced SO{sub 2}, CO{sub 2}, and NO{sub x} emissions. Absorption chillers do not use CFCs or HCFCs, refrigerants that contribute to ozone depletion and global warming. Additionally, gas-fired absorption chillers can save significant amounts in energy costs when used in combination with a vapor compression chiller in a hybrid system. The hybrid system can take advantage of the comparatively low price of natural gas (per unit ton) and rely on the high performance of vapor compression when electricity prices are lower. The purpose of this article is to provide an introduction for those new to absorption technology as well as a discussion of selected high efficiency cycles, a discussion on the technology of coupling absorption with vapor compression systems to form a hybrid system, and the environmental impacts of absorption.
Garland, P.W. [Oak Ridge National Lab., TN (United States); Garland, R.W. [Dept. of Energy, Washington, DC (United States)
Japanese and American competition in the development of scroll compressors and its impact on the American air conditioning industry
This report examines the technological development of scroll compressors and its impact on the air conditioning equipment industry. Scroll compressors, although considered to be the compressors of the future for energy-efficient residential heat pumps and possibly for many other applications, are difficult to manufacture on a volume-production base. The manufacturing process requires computer-aided, numerically controlled tools for high-precision fabrication of major parts. Japan implemented a global strategy for dominating the technological world market in the 1970s, and scroll compressor technology benefited from the advent of new-generation machine tools. As a result, if American manufacturers of scroll compressors purchase or are essentially forced to purchase numerically controlled tools from Japan in the future, they will then become dependent on their own competitors because the same Japanese conglomerates that make numerically controlled tools also make scroll compressors. This study illustrates the importance of the basic machine tool industry to the health of the US economy. Without a strong machine tool industry, it is difficult for American manufacturers to put innovations, whether patented or not, into production. As we experience transformation in the air conditioning and refrigeration market, it will be critical to establish a consistent national policy to provide healthy competition among producers, to promote innovation within the industry, to enhance assimilation of new technology, and to eliminate practices that are incompatible with these goals. 72 refs., 8 figs., 1 tab.
Ushimaru, Kenji (Energy International, Inc., Bellevue, WA (USA))
Air-conditioning electricity savings and demand reductions from exterior masonry wall insulation applied to Arizona residences
A field test involving eight single-family houses was performed during the summer of 1991 in Scottsdale, Arizona to evaluate the potential of reducing air-conditioning electricity consumption and demand by insulating their exterior masonry walls. Total per house costs to perform the installations ranged from $3610 to $4550. The average annual savings was estimated to be 491 kWh, or 9% of pre-retrofit consumption. Peak demands without and with insulation on the hottest day of an average weather year for Phoenix were estimated to be 4.26 and 3.61 kill, for a demand reduction of 0.65 kill (15%). We conclude that exterior masonry wall insulation reduces air-conditioning electricity consumption and peak demand in hot, dry climates similar to that of Phoenix. Peak demand reductions are a primary benefit, making the retrofit worthy of consideration in electric utility conservation programs. Economics can be attractive from a consumer viewpoint if considered within a renovation or home improvement program.
Ternes, M.P.; Wilkes, K.E.
Deliberate ignition of hydrogen-air-steam mixtures under conditions of rapidly condensing steam
A series of experiments was conducted to determine hydrogen combustion behavior under conditions of rapidly condensing steam caused by water sprays. Experiments were conducted in the Surtsey facility under conditions that were nearly prototypical of those that would be expected in a severe accident in the CE System 80+ containment. Mixtures were initially nonflammable owing to dilution by steam. The mixtures were ignited by thermal glow plugs when they became flammable after sufficient steam was removed by condensation caused by water sprays. No detonations or accelerated flame propagation was observed in the Surtsey facility. The combustion mode observed for prototypical mixtures was characterized by multiple deflagrations with relatively small pressure rises. The thermal glow plugs were effective in burning hydrogen safely by igniting the gases as the mixtures became marginally flammable.
Blanchat, T.; Stamps, D.
Actinide leaching from waste glass: air-equilibrated versus deaerated conditions
Leach tests were conducted in aerated and deaerated solutions using glass containing /sup 239/Pu, /sup 237/Np and /sup 238/U, at temperatures of 25 and 75/sup 0/C and in deionized water, 0.03M NaHCO/sub 3/ and WIPP B salt brine for periods up to 341 days. Neptunium leaching was decreased by factors of 10 to 100 (depending on leach time) in the deaerated solutions at 75/sup 0/C. Plutonium leaching decreased by factors of 3 to 5 due to deaeration, but only in the deionized water leachate at 25/sup 0/C. Uranium leaching in salt brine and deionized water at 25/sup 0/C was decreased by factors of 2 to 5 in deaerated solutions. Time and temperature dependencies were also observed for the leaching of the actinides during the course of this work. After the first leach interval (2 days), the time dependent release curve for Pu was essentially flat or decreasing under all conditions, and maximum Pu solution concentration (at 25/sup 0/C), as implied by release in aerated leachate, agrees with independent solubility data. The low /sup 239/Pu releases observed in leach solutions are consistent with accumulation of /sup 239/Pu on the leached glass surface. The amounts of uranium and neptunium leached increased with time under most conditions. For Pu leaching, temperature has a small effect in deaerated leachates and negative effect in aerated leachates. Neptunium leaching generally increase with temperature under aerated conditions, but not in proportion to increases of matrix element leaching. In deaerated leachates, Np leaching decreases with temperature. Uranium leaching increases with temperature under aerated and deaerated conditions but not in proportion to matrix element increases. 4 figures, 6 tables.
Peters, R.D.; Diamond, H.
Study of the test method for prediction of air conditioning equipment seasonal performance
The test procedure, Method of Testing, Rating and Estimating the Seasonal Performance of Central Air-Conditioners and Heat Pumps Operating in the Cooling Mode, has been analyzed. The analysis of the test procedure incorporated two main functions: (1) to determine the validity of the test procedure; and (2) to determine if there are other alternate methods of obtaining the same results with less testing burden. Data were collected from industry and analyzed for any significant trends. Certain conclusions are drawn about the energy efficiency ratios, degradation coefficients and seasonal energy efficiency ratios. An error analysis was performed on the test procedure to determine the approximate amount of error when using this procedure. A semi-empirical model assuming a first order system response was developed to determine the factors that affect the part-load and cooling-load factors. The corresponding transient characteristics are then determined in terms of a single time constant. A thermostat demand cycle is used to determine the relationship between on-time and cycle-time. Recommendations are made regarding an alternate method being used to determine the seasonal energy efficiency ratio.
Thomas, S.B.
The effect of hardware configuration on the performance of residential air conditioning systems at high outdoor ambient temperatures
A study was performed which investigated the effect of hardware configuration on air conditioning cooling system performance at high outdoor temperatures. The initial phase of the investigation involved the testing of ten residential air conditioning units in psychrometric rooms at Texas A&M University. All units were tested using ARI Standard 210/240 (1989) test procedures. Tests were conducted at indoor conditions of 80'F (26.7'C) db and 67'F (19.4'C) wb, and outdoor db temperatures of 82'F (27.8'C), 95-F (35-C), 100-F (37.8-C), 105-F (40.6-C), 1 10-F (43.3-C), and 120-F (48.90C). The second phase of the research involved the analysis of manufacturers' published cooling performance data for various hardware configurations. For the experimental work, measurements were taken to determine total capacity, system power, EER, and power factor. These results were then compared to manufacturers' predicted values. For the capacity, the experimental results were an average of 2.6% below the manufacturers' published values for outdoor temperatures from 85'F (29.4'C) to 115'F (46.l'C). Experimental power measurements were on average 0.4% above manufacturers' listed results. For the EER, experimental results were an average of 2.9% less than the manufacturers' predicted values. The power factors of all units were above 0.95 for the tested outdoor temperatures. In the analysis of manufacturers' published data, relationships between steady-state performance, cyclic performance, and hardware configuration were investigated for a variety of air conditioning units. A statistical relationship was found between the SEER of a unit and its corresponding EER. The split-system units possessed greater increases in EER for a given increase in SEER than the package or two-speed units. Averages values of EER/SEER for EER's at 95F (350C) were highest for the split-system units, followed by the package and two-speed units, respectively. Normalized capacity, power, and EER curves were investigated at outdoor temperatures from 85F (29.40C) to 115OF (46.1"C). On average, the two-speed units showed the smallest decrease in capacity with an increase in outdoor temperature, followed by the split-system and package-system units. The smallest power increase and smallest EER decrease with an increase in outdoor temperature were exhibited by the split-system units, followed by the two-speed and package-system units.
Bain, Joel Alan
Influence of Attic Radiant Barrier Systems on Air Conditioning Demand in an Utility Pilot Project
A utility monitoring project has evaluated radiant barrier systems (RBS) as a new potential demand site management (DSM) program. The study examined how the retrofit of attic radiant barriers can be expected to alter utility residential space conditioning loads. An RBS consists of a layer of aluminum foil fastened to roof decking or roof trusses to block radiant heat transfer between the hot roof surface and the attic below. The radiant barrier can significantly lower summer heat transfer to the attic insulation and to the cooling duct system. Both of these mechanisms have strong potential impacts on cooling energy use as illustrated in Figures 1 and 2. The pilot project involved installation of RBS in nine homes that had been extensively monitored over the preceding year. The houses varied in conditioned floor area from 939 to 2,440 square feet; attic insulation varied from R-9 to R-30. The homes had shingle roofs with varying degrees of attic ventilation. The radiant barriers were installed during the summer of 2000. Data analysis on the pre and post cooling and heating consumption was used to determine impacts on energy use and peak demand for the utility. The average cooling energy savings from the RBS retrofit was 3.6 kWh/day, or about 9%. The average reduction in summer afternoon peak demand was 420 watts (or about 16%).
Parker, D. S.; Sherwin, J. R.
Influences of atmospheric conditions and air mass on the ratio of ultraviolet to total solar radiation
The technology to detoxify hazardous wastes using ultraviolet (UV) solar radiation is being investigated by the DOE/SERI Solar Thermal Technology Program. One of the elements of the technology evaluation is the assessment and characterization of UV solar radiation resources available for detoxification processes. This report describes the major atmospheric variables that determine the amount of UV solar radiation at the earth's surface, and how the ratio of UV-to-total solar radiation varies with atmospheric conditions. These ratios are calculated from broadband and spectral solar radiation measurements acquired at SERI, and obtained from the literature on modeled and measured UV solar radiation. The following sections discuss the atmospheric effects on UV solar radiation and provide UV-to-total solar radiation ratios from published studies, as well as measured values from SERI's data. A summary and conclusions are also given.
Riordan, C.J.; Hulstrom, R.L.; Myers, D.R.
Advanced control strategies for heating, ventilation, air-conditioning, and refrigeration systems�An overview: Part I: Hard control
A chronological overview of the advanced control strategies for heating, ventilation, air-conditioning, and refrigeration (HVAC&R) is presented in this article. The overview focuses on hard-computing or control techniques, such as proportional-integral-derivative, optimal, nonlinear, adaptive, and robust; soft-computing or control techniques, such as neural networks, fuzzy logic, genetic algorithms; and on the fusion or hybrid of hard- and soft-control techniques. Thus, it is to be noted that the terminology �hard� and �soft� computing/control has nothing to do with the �hardware� and �software� that is being generally used. Part I of a two-part series focuses on hard-control strategies, and Part II focuses on softand fusion-control in addition to some future directions in HVAC&R research. This overview is not intended to be an exhaustive survey on this topic, and any omission of other works is purely unintentional.
D. Subbaram Naidu; Craig G. Rieger
Comment submitted by the Air Conditioning, Heating and Refrigeration Institute (AHRI) regarding the Energy Star Verification Testing Program
AHRI Comments - DOE Verification Testing in Support of Energy Star AHRI Comments - DOE Verification Testing in Support of Energy Star May 9, 2011 P a g e | 1 May 9, 2010 Ms. Ashley Armstrong U.S. Department of Energy 1000 Independence Avenue, SW Washington, DC 20585 RE: DOE Verification Testing in Support of Energy Star Dear Ms. Armstrong: I am writing on behalf of the Air Conditioning, Heating and Refrigeration Institute (AHRI) to address the proposed DOE requirements for verification testing in support of the Energy Star program. AHRI is the trade association representing manufacturers of heating, cooling, and commercial refrigeration equipment. More than 300 members strong, AHRI is an internationally recognized advocate for the industry, and develops standards for and certifies the performance of many of the
Copper contamination effects on hydrogen-air combustion under SCRAMJET (supersonic combustion ramjet) testing conditions
Two forms of copper catalytic reactions (homogeneous and heterogeneous) in hydrogen flames were found in a literature survey. Hydrogen atoms in flames recombine into hydrogen molecules through catalytic reactions, and these reactions which affect the timing of the combustion process. Simulations of hydrogen flames with copper contamination were conducted by using a modified general chemical kinetics program (GCKP). Results show that reaction times of hydrogen flames are shortened by copper catalytic reactions, but ignition times are relatively insensitive to the reactions. The reduction of reaction time depends on the copper concentration, copper phase, particle size (if copper is in the condensed phase), and initial temperature and pressure. The higher the copper concentration of the smaller the particle, the larger the reduction in reaction time. For a supersonic hydrogen flame (Mach number = 4.4) contaminated with 200 ppm of gaseous copper species, the calculated reaction times are reduced by about 9%. Similar reductions in reaction time are also computed for heterogeneous copper contamination. Under scramjet testing conditions, the change of combustion timing appears to be tolerable (less than 5%) if the Mach number is lower than 3 or the copper contamination is less than 100 ppm. The higher rate the Mach number, the longer the reaction time and the larger the copper catalytic effects. 7 tabs., 8 figs., 34 refs.
Chang, S.L.; Lottes, S.A.; Berry, G.F.
High Efficiency Integrated Space Conditioning, Water Heating and Air Distribution System for HUD-Code Manufactured Housing
Recognizing the need for new space conditioning and water heating systems for manufactured housing, DeLima Associates assembled a team to develop a space conditioning system that would enhance comfort conditions while also reducing energy usage at the systems level. The product, Comboflair® was defined as a result of a needs analysis of project sponsors and industry stakeholders. An integrated system would be developed that would combine a packaged airconditioning system with a small-duct, high-velocity air distribution system. In its basic configuration, the source for space heating would be a gas water heater. The complete system would be installed at the manufactured home factory and would require no site installation work at the homesite as is now required with conventional split-system air conditioners. Several prototypes were fabricated and tested before a field test unit was completed in October 2005. The Comboflair® system, complete with ductwork, was installed in a 1,984 square feet, double-wide manufactured home built by Palm Harbor Homes in Austin, TX. After the home was transported and installed at a Palm Harbor dealer lot in Austin, TX, a data acquisition system was installed for remote data collection. Over 60 parameters were continuously monitored and measurements were transmitted to a remote site every 15 minutes for performance analysis. The Comboflair® system was field tested from February 2006 until April 2007. The cooling system performed in accordance with the design specifications. The heating system initially could not provide the needed capacity at peak heating conditions until the water heater was replaced with a higher capacity standard water heater. All system comfort goals were then met. As a result of field testing, we have identified improvements to be made to specific components for incorporation into production models. The Comboflair® system will be manufactured by Unico, Inc. at their new production facility in St. Louis, MO. The product will be initially launched in the hot-humid climates of the southern U.S.
Henry DeLima; Joe Akin; Joseph Pietsch
Using Acid Number as a Leading Indicator of Refrigeration and Air Conditioning System Performance
This report summarizes a literature review to assess the acidity characteristics of the older mineral oil and newer polyolester (POE) refrigeration systems as well as to evaluate acid measuring techniques used in other non-aqueous systems which may be applicable for refrigeration systems. Failure in the older chlorofluorocarbon/hydrochlorofluorocarbon (CFC/HCFC) / mineral oil systems was primarily due to thermal degradation of the refrigerant which resulted in the formation of hydrochloric and hydrofluoric acids. These are strong mineral acids, which can, over time, severely corrode the system metals and lead to the formation of copper plating on iron surfaces. The oil lubricants used in the older systems were relatively stable and were not prone to hydrolytic degradation due to the low solubility of water in oil. The refrigerants in the newer hydrofluorocarbon (HFC)/POE systems are much more thermally stable than the older CFC/HCFC refrigerants and mineral acid formation is negligible. However, acidity is produced in the new systems by hydrolytic decomposition of the POE lubricants with water to produce the parent organic acids and alcohols used to prepare the POE. The individual acids can therefore vary but they are generally C5 to C9 carboxylic acids. Organic acids are much weaker and far less corrosive to metals than the mineral acids from the older systems but they can, over long time periods, react with metals to form carboxylic metal salts. The salts tend to accumulate in narrow areas such as capillary tubes, particularly if residual hydrocarbon processing chemicals are present in the system, which can lead to plugging. The rate of acid production from POEs varies on a number of factors including chemical structure, moisture levels, temperature, acid concentration and metals. The hydrolysis rate of reaction can be reduced by using driers to reduce the free water concentration and by using scavenging chemicals which react with the system acids. Total acid number (TAN), which includes both mineral acids and organic acids, is therefore a useful indicator which can be used to monitor the condition of the system in order to perform remedial maintenance, when required, to prevent system failure. The critical TAN value is the acid level at which remedial action should be taken to prevent the onset of rapid acid formation which can result in system failure. The level of 0.05 mg KOH/g of oil was established for CFC/mineral oil systems based on analysis of 700 used lubricants from operating systems and failed units. There is no consensus within the refrigeration industry as to the critical TAN value for HFC/POE systems, however, the value will be higher than the CFC/mineral oil systems critical TAN value because of the much weaker organic acids produced from POE. A similar study of used POE lubricants should be performed to establish a critical TAN limit for POE systems. Titrimetric analysis per ASTM procedures is the most commonly used method to determine TAN values in lubricants in the refrigeration industry and other industries dealing with lubricating oils. For field measurements, acid test kits are often used since they provide rapid, semi-quantitative TAN results.
Dennis Cartlidge; Hans Schellhase
NRELs Energy-Saving Technology for Air Conditioning Cuts Peak Power Loads Without Using Harmful Refrigerants (Fact Sheet), NREL (National Renewable Energy Laboratory)
DEVAP Slashes Peak Power Loads DEVAP Slashes Peak Power Loads Desiccant-enhanced evaporative (DEVAP) air-condi- tioning will provide superior comfort for commercial buildings in any climate at a small fraction of the elec- tricity costs of conventional air-conditioning equip- ment, releasing far less carbon dioxide and cutting costly peak electrical demand by an estimated 80%. Air conditioning currently consumes about 15% of the electricity generated in the United States and is a major contributor to peak electrical demand on hot summer days, which can lead to escalating power costs, brownouts, and rolling blackouts. DEVAP employs an innovative combination of air-cooling technologies to reduce energy use by up to 81%. DEVAP also shifts most of the energy needs to thermal energy sources, reducing annual electricity use by up
Systematic method for the condition assessment of central heating plants in Air Force Logistics Command. Master's thesis
Air Force Logistics Command (AFLC), facing decreasing funds and aging utility systems, needed a method to objectively rate its central heating plants. Such a rating system would be used to compare heating plants throughout the command to identify potential problem areas and prioritize major repair projects. This thesis used a Delphi questionnaire to gather opinions from heating plant experts in order to identify and prioritize components considered most critical to overall plant operation. In addition, the experts suggested measurements which could be used to evaluate component conditions. By combining expert opinions and reading from technical literature, component model rating schemes were developed for AFLC's steam and high temperature hot water plants. Based on measurements and observations of critical components in the plant, a score between 0 and 100 is assigned to each component (for example, condensate piping, deaerator, etc.), each plant subsystem (distribution system, water treatment system, etc.), and to the plant as a whole. These component model rating schemes and the resultant overall condition index scores will enable AFLC to focus their management attention and allocate needed resources to the plants in greatest need of repair.
Starmack, G.J.
Impact of Solar Control PVB Glass on Vehicle Interior Temperatures, Air-Conditioning Capacity, Fuel Consumption, and Vehicle Range
The objective of the study was to assess the impact of Saflex1 S-series Solar Control PVB (polyvinyl butyral) configurations on conventional vehicle fuel economy and electric vehicle (EV) range. The approach included outdoor vehicle thermal soak testing, RadTherm cool-down analysis, and vehicle simulations. Thermal soak tests were conducted at the National Renewable Energy Laboratory's Vehicle Testing and Integration Facility in Golden, Colorado. The test results quantified interior temperature reductions and were used to generate initial conditions for the RadTherm cool-down analysis. The RadTherm model determined the potential reduction in air-conditioning (A/C) capacity, which was used to calculate the A/C load for the vehicle simulations. The vehicle simulation tool identified the potential reduction in fuel consumption or improvement in EV range between a baseline and modified configurations for the city and highway drive cycles. The thermal analysis determined a potential 4.0% reduction in A/C power for the Saflex Solar PVB solar control configuration. The reduction in A/C power improved the vehicle range of EVs and fuel economy of conventional vehicles and plug-in hybrid electric vehicles.
Rugh, J.; Chaney, L.; Venson, T.; Ramroth, L.; Rose, M.
Influence of Air-Conditioning Waste Heat on Air Temperature in Tokyo during Summer: Numerical Experiments Using an Urban Canopy Model Coupled with a Building Energy Model
A coupled model consisting of a multilayer urban canopy model and a building energy analysis model has been developed to investigate the diurnal variations of outdoor air temperature in the office areas of Tokyo, Japan. Observations and numerical ...
Yukitaka Ohashi; Yutaka Genchi; Hiroaki Kondo; Yukihiro Kikegawa; Hiroshi Yoshikado; Yujiro Hirano
Energy Basics: Air Conditioning
the same operating principles and basic components as refrigerators. Refrigerators use energy (usually electricity) to transfer heat from the cool interior of the refrigerator to...
Corrosion inhibitor for aqueous ammonia absorption system
A method of inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425.degree. F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25.degree. C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425.degree. F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer.
Phillips, Benjamin A. (Benton Harbor, MI); Whitlow, Eugene P. (St. Joseph, MI)
A method is described for inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425 F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25 C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425 F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer. 5 figs.
Phillips, B.A.; Whitlow, E.P.
Proprties of the Carrol system and a machine design for solar-powered, air-cooled, absorption space cooling. Phase I and Phase II. Final report, September 1977-March 1979
The name Carrol has been selected as a convenient short-hand designation for a prime candidate chemical system comprising ethylene glycol-lithium bromide as an absorbent mixture with water as a refrigerant. The instrumentation, methods of handling data and numerical results from a systematic determination of Carrol property data required to design an air cooled absorption machine based on this chemical system are described. These data include saturation temperature, relative enthalpy, density, specific heat capacity, thermal conductivity, viscosity and absorber film heat transfer coefficient as functions of solution temperature and Carrol concentration over applicable ranges. For each of the major components of the absorption chiller, i.e., generator, chiller, absorber, condenser, heat exchanger, purge and controls, the report contains an assembly drawing and the principal operating characteristics of that component.
Deemed Savings Estimates for Legacy Air Conditioning and WaterHeating Direct Load Control Programs in PJM Region
During 2005 and 2006, the PJM Interconnection (PJM) Load Analysis Subcommittee (LAS) examined ways to reduce the costs and improve the effectiveness of its existing measurement and verification (M&V) protocols for Direct Load Control (DLC) programs. The current M&V protocol requires that a PURPA-compliant Load Research study be conducted every five years for each Load-Serving Entity (LSE). The current M&V protocol is expensive to implement and administer particularly for mature load control programs, some of which are marginally cost-effective. There was growing evidence that some LSEs were mothballing or dropping their DLC programs in lieu of incurring the expense associated with the M&V. This project had several objectives: (1) examine the potential for developing deemed savings estimates acceptable to PJM for legacy air conditioning and water heating DLC programs, and (2) explore the development of a collaborative, regional, consensus-based approach for conducting monitoring and verification of load reductions for emerging load management technologies for customers that do not have interval metering capability.
Goldman, Charles
Computational Assessment of the GT-MHR Graphite Core Support Structural Integrity in Air-Ingress Accident Condition
The objective of this project was to perform stress analysis for graphite support structures of the General Atomics� 600 MWth GT-MHR prismatic core design using ABAQUS � (ver. 6.75) to assess their structural integrity in air-ingress accident conditions where the structure weakens over time due to oxidation damages. The graphite support structures of prismatic type GT-MHR was analyzed based on the change of temperature, burn-off and corrosion depth during the accident period predicted by GAMMA, a multi-dimensional gas multi-component mixture analysis code developed in the Republic of Korea (ROK)/United States (US) International �Nuclear Engineering Research Initiative (I-NERI) project. Both the loading and thermal stresses were analyzed, but the thermal stress was not significant, leaving the loading stress to be the major factor. The mechanical strengths are exceeded between 11 to 11.5 days after loss-of-coolant-accident (LOCA), corresponding to 5.5 to 6 days after the start of natural convection.
Jong B. Lim; Eung S. Kim; Chang H. Oh; Richard R. Schultz; David A. Petti
Distribution of small dispersive coal dust particles and absorbed radioactive chemical elements in conditions of forced acoustic resonance in iodine air filter at nuclear power plant
The physical features of distribution of the small dispersive coal dust particles and the adsorbed radioactive chemical elements and their isotopes in the absorber with the granular filtering medium with the cylindrical coal granules were researched in the case of the intensive air dust aerosol stream flow through the iodine air filter (IAF). It was shown that, at the certain aerodynamic conditions in the IAF, the generation of the acoustic oscillations is possible. It was found that the acoustic oscillations generation results in an appearance of the standing acoustic waves of the air pressure (density) in the IAF. In the case of the intensive blow of the air dust aerosol, it was demonstrated that the standing acoustic waves have some strong influences on both: 1) the dynamics of small dispersive coal dust particles movement and their accumulation in the IAF; 2) the oversaturation of the cylindrical coal granules by the adsorbed radioactive chemical elements and their isotopes in the regions, where the antin...
Ledenyov, Oleg P
Physical features of small disperse coal dust fraction transportation and structurization processes in iodine air filters of absorption type in ventilation systems at nuclear power plants
The research on the physical features of transportation and structurization processes by the air-dust aerosol in the granular filtering medium with the cylindrical coal adsorbent granules in an air filter of the adsorption type in the heating ventilation and cooling (HVAC) system at the nuclear power plant is completed. The physical origins of the coal dust masses distribution along the absorber with the granular filtering medium with the cylindrical coal granules during the air-dust aerosol intake process in the near the surface layer of absorber are researched. The quantitative technical characteristics of air filtering elements, which have to be considered during the optimization of air filters designs for the application in the ventilation systems at the nuclear power plants, are obtained.
Ledenyov, Oleg P; Poltinin, P Ya; Fedorova, L I
Research Director, PIER Demand Response Research CenterAssessment of Demand Response & Advanced Metering, staffPower Shortages: Demand Response and its Applications in Air
A Relationship between the Bowen Ratio and Sea�Air Temperature Difference under Unstable Conditions at Sea
At the air�sea interface, estimates of evaporation or latent heat flux and the Monin�Obukhov stability parameter require the measurements of dewpoint (Tdew) or wet-bulb temperature, which are not routinely available as compared to those of air (T...
S. A. Hsu
Partial CO2 Column-Averaged Dry-Air Mixing Ratio from Measurements by Coherent 2-?m Differential Absorption and Wind Lidar with Laser Frequency Offset Locking
A coherent 2-?m differential absorption and wind lidar (Co2DiaWiL) with a 2-?m single-frequency Q-switched laser with laser frequency offset locking was used for long-range CO2 measurement. The frequency stabilization of the single-frequency ? on ...
Shoken Ishii; Kohei Mizutani; Philippe Baron; Hironori Iwai; Ryoko Oda; Toshikazu Itabe; Hirotake Fukuoka; Takayoshi Ishikawa; Mizuki Koyama; Tomoaki Tanaka; Isamu Morino; Osamu Uchino; Atsushi Sato; Kazuhiro Asai
Future Air Conditioning Energy Consumption in Developing Countriesand what can be done about it: The Potential of Efficiency in theResidential Sector
The dynamics of air conditioning are of particular interestto energy analysts, both because of the high energy consumption of thisproduct, but also its disproportionate impact on peak load. This paperaddresses the special role of this end use as a driver of residentialelectricity consumption in rapidly developing economies. Recent historyhas shown that air conditioner ownership can grow grows more rapidly thaneconomic growth in warm-climate countries. In 1990, less than a percentof urban Chinese households owned an air conditioner; by 2003 this numberrose to 62 percent. The evidence suggests a similar explosion of airconditioner use in many other countries is not far behind. Room airconditioner purchases in India are currently growing at 20 percent peryear, with about half of these purchases attributed to the residentialsector. This paper draws on two distinct methodological elements toassess future residential air conditioner 'business as usual' electricityconsumption by country/region and to consider specific alternative 'highefficiency' scenarios. The first component is an econometric ownershipand use model based on household income, climate and demographicparameters. The second combines ownership forecasts and stock accountingwith geographically specific efficiency scenarios within a uniqueanalysis framework (BUENAS) developed by LBNL. The efficiency scenariomodule considers current efficiency baselines, available technologies,and achievable timelines for development of market transformationprograms, such as minimum efficiency performance standards (MEPS) andlabeling programs. The result is a detailed set of consumption andemissions scenarios for residential air conditioning.
Opportunities for Saving Energy and Improving Air Quality in Urban Heat Islands
Refrigeration, and Air conditioning Engineers, Atlanta,Refrigeration, and Air Conditioning Engineers, Atlanta,Refrigeration, and Air Conditioning Engineers, Atlanta,
Akbari, Hashem
4-80 Two rigid tanks connected by a valve to each other contain air at specified conditions. The volume of the second tank and the final equilibrium pressure when the valve is opened are to be determined.
. Treating air as an ideal gas, the volume of the second tank and the mass of air in the first tank temperatures and pressures in ideal gas calculations. Using gage pressures would result in pressure drop of 04-40 4-80 Two rigid tanks connected by a valve to each other contain air at specified conditions
Bahrami, Majid
Evaluation of the Relationship between Air and Land Surface Temperature under Clear- and Cloudy-Sky Conditions
Clear and cloudy daytime comparisons of land surface temperature (LST) and air temperature (Tair) were made for 14 stations included in the U.S. Climate Reference Network (USCRN) of stations from observations made from 2003 through 2008. ...
Kevin Gallo; Robert Hale; Dan Tarpley; Yunyue Yu
Analysis of the Window Side Thermal Environment Formed by Air Barrier Technique in Winter Conditions and Its Economy
The air barrier technique applies airflow through a window fan to decrease the heat load of a window surface and avoid dewfall in winter and decrease heat radiation from the window surface in summer. This paper uses numerical simulation to predict the energy-saving potential and thermal comfort of the air barrier technique used in office buildings. It also analyzes the surface temperature of the window by using the simulation software Airpak. According to the results, we can obtain the key control strategy of this technology. It can be found that the air barrier technique, instead of the heating-supply around outside-zone for office building, can avoid dewfall in winter and decrease the cold radiation, which has a great effect on thermal environment around the window. Characteristics such as outer air temperature, indoor load, thermal characteristics of structure, and air-supply parameters through window fans are analyzed in detail to measure their effects on energy consumption, window side environment and PMV values. The paper provides theoretical reference and technical guidance for applying air barrier technology correctly, improving the window side environment and reducing energy consumption.
Huang, C.; Jia, Y.; Liu, L.; Wang, X.
This paper describes the dynamic modeling of a solar absorption cooling plant that will be built for both research and demonstration purposes by the end of 2007. The synchronizing of cooling loads with solar radiation intensity is an important advantage when utilizing solar energy in air conditioning in buildings. The first part of this work deals with the dynamic modeling of an evacuated tube collector. A field of these collectors feed a single-effect absorption chiller of 35 kW nominal cooling capacity. The simulation model has been done in a modular way under TRNSYS16. In a second part, simulation and optimization of the system has been investigated in order to determine the effect of several parameters (collector area, tank volume...) on chiller performance.
J. P. Praene; D. Morau; F. Lucas; F. Garde; H. Boyer; J. P. Praene
DOE/EA-1673: Environmental Assessment for Energy Conservation Program for Certain Industrial Equipment: Energy Conservation Standards and Test Procedures for Commercial Heating, Air-Conditioning, and Water-Heating Equipment (July 2009)
3 3 Environmental Assessment for 10 CFR 431 Energy Conservation Program for Certain Industrial Equipment: Energy Conservation Standards and Test Procedures for Commercial Heating, Air- Conditioning, and Water-Heating Equipment July 2009 8-i CHAPTER 8. ENVIRONMENTAL ASSESSMENT TABLE OF CONTENTS 8.1 INTRODUCTION ............................................................................................................... 8-1 8.2 AIR QUALITY ANALYSIS ............................................................................................... 8-1 8.3 AIR POLLUTANT DESCRIPTIONS ................................................................................ 8-1 8.4 AIR QUALITY REGULATIONS ...................................................................................... 8-3
A Study of the Effect of Molecular and Aerosol Conditions in the Atmosphere on Air Fluorescence Measurements at the Pierre Auger Observatory
The air fluorescence detector of the Pierre Auger Observatory is designed to perform calorimetric measurements of extensive air showers created by cosmic rays of above 10^18 eV. To correct these measurements for the effects introduced by atmospheric fluctuations, the Observatory contains a group of monitoring instruments to record atmospheric conditions across the detector site, an area exceeding 3,000 km^2. The atmospheric data are used extensively in the reconstruction of air showers, and are particularly important for the correct determination of shower energies and the depths of shower maxima. This paper contains a summary of the molecular and aerosol conditions measured at the Pierre Auger Observatory since the start of regular operations in 2004, and includes a discussion of the impact of these measurements on air shower reconstructions. Between 10^18 and 10^20 eV, the systematic uncertainties due to all atmospheric effects increase from 4% to 8% in measurements of shower energy, and 4 g/cm^2 to 8 g/cm^...
Commissioning Tools for Heating/Cooling System in Residence - Verification of Floor Heating System and Room Air Conditioning System Performance
Tools of evaluating the performance of floor heating and room air conditioner are examined as a commissioning tool. Simple method is needed to check these performance while in use by residents, because evaluation currently requires significant time and effort. Therefore, this paper proposes a) two methods of evaluating the floor heating efficiency from the room / crawl space temperature and the energy consumption and b) method of evaluating COP of the room air conditioner from the data measured at the external unit. Case studies in which these tools were applied to actual residences are presented to demonstrate their effectiveness.
Miura, H.; Hokoi, S.; Iwamae, A.; Umeno, T.; Kondo, S.
The Technical and Economical Analysis of a Centralized Air-Conditioning System with Cold Storage Refrigeration in High-Rise Residential Buildings
In recent years, the application of a centralized air-conditioning system (CACS) with cold storage refrigeration in high-rise residential buildings has gradually increased. Due to the large difference between civil residential buildings and commercial buildings, characteristics such as the cooling load in summer and the storey height must be considered in the design of the air-conditioning system, and the cold storage equipment and the cold supplying means must be properly selected. The option of establishing centralized air-conditioning equipment with cold storage and supplying unified cold in high-rise residential buildings is analyzed objectively with technical and economical methods in this paper. It is not true that the option of supplying unified cold can save energy all the time. CACS with cold storage will not always be economical. Based on a 27-floor building, the running costs in summer and the first costs are both compared between CACS with and without cold storage refrigeration. The cold storage method selected will significantly impact the residents.
Xiang, C.; Xie, G.
Absorption Heat Pumps | Department of Energy
Absorption Heat Pumps Absorption Heat Pumps Absorption Heat Pumps June 24, 2012 - 2:11pm Addthis Absorption heat pumps are essentially air-source heat pumps driven not by electricity, but by a heat source such as natural gas, propane, solar-heated water, or geothermal-heated water. Because natural gas is the most common heat source for absorption heat pumps, they are also referred to as gas-fired heat pumps. There are also absorption (or gas-fired) coolers available that work on the same principle. Unlike some absorption heat pumps, however, these are not reversible and cannot serve as a heat source. Residential absorption heat pumps use an ammonia-water absorption cycle to provide heating and cooling. As in a standard heat pump, the refrigerant (in this case, ammonia) is condensed in one coil to release its heat; its
Absorption Heat Pump Basics | Department of Energy
Absorption Heat Pump Basics Absorption Heat Pump Basics Absorption Heat Pump Basics August 19, 2013 - 11:11am Addthis Absorption heat pumps are essentially air-source heat pumps driven not by electricity, but by a heat source such as natural gas, propane, solar-heated water, or geothermal-heated water. Because natural gas is the most common heat source for absorption heat pumps, they are also referred to as gas-fired heat pumps. There are also absorption coolers available that work on the same principal, but are not reversible and cannot serve as a heat source. These are also called gas-fired coolers. How Absorption Heat Pumps Work Residential absorption heat pumps use an ammonia-water absorption cycle to provide heating and cooling. As in a standard heat pump, the refrigerant (in this case, ammonia) is condensed in one coil to release its heat; its
Performance of underfloor air distribution: Results of a field study
Refrigerating, and Air Conditioning Engineers. AtlantaRefrigerating, and Air Conditioning Engineers. AtlantaRefrigerating, and Air-Conditioning Engineers, Inc. ,
Fisk, William; Faulkner, David; Sullivan, Douglas
Evaluation of beta partical densitometry for determination of self-absorption factors in gross alpha and gross beta radioactivity measurements on air particulate filter samples
Alpha and beta particles emitted from radioactive material collected on an air filter may be significantly attenuated by the mass (thickness) of collected dust. In this study, we determined the mass or thickness of the simulated dust deposit by measurement of the attenuation of beta particles from an external radioactive source as the particles pass through the filter-dust combination. This measured attenuation should be empirically related to demonstrated counting efficiency. A graph of mass density vs. fraction of beta source transmitted was developed. This graph provides factors which will correct for selfabsorption losses in the filter during the counting procedure. This experimental procedure could favorably affect the cost and effort required to accurately monitor airborne radioactivity releases from nuclear facilities.
Breida, Margaret A
Energy Consumption Simulation and Analysis of Heat Pump Air Conditioning System in Wuhan by the BIN Method
Based on the weather data of a standard year in Wuhan, derived from the data of the latest 15 years, the data for the BIN (temperature and humidity frequency) method of an annual and 8-hour system were calculated. Then the BIN method was adopted to simulate the annual energy consumption of groundwater heat pump systems (GWHPS) for an office building in Wuhan. Its annual energy consumption was obtained and compared with the partner of the air source heat pump systems (ASHPS). The results show that the energy consumption of the former was approximately less 23.3% than that of the latter in summer and 19.1% in winter.
Wen, Y.; Zhao, F.
Energy Performance Evaluation and Development of Control Strategies for the Air-conditioning System of a Building at Construction Stage
Energy consumption of HVAC systems in commercial buildings takes a great part of the total building energy consumption. Energy performance evaluation plays an important role in building energy efficiency improvement for existing buildings and new buildings. It is also the basis for the retrofitting measure evaluation for existing buildings and the control improvement evaluation of new buildings for building energy performance contracts. In this study, the energy performance evaluation of a super high-rising commercial office building in construction is presented. Alternative control strategies are proposed to improve the energy efficiency based on the current measurements of the original design as well as additional metering instruments as requested. These control strategies mainly involve optimal chiller sequencing control, cooling tower sequencing control, optimal water pressure differential set-point control, AHU supply air static pressure reset control and DCV-based fresh air control, etc. To assess the economic feasibility, the benchmark electricity consumption and the optimal electricity consumption using alternative controls strategies are estimated using dynamic simulations. The results show that the electricity savings using the alternative control strategies can cover the costs of an additional metering system and related software and hardware in about one year.
Wang, S.; Xu, X.; Ma, Z.
International Energy Agency Building Energy Simulation Test and Diagnostic Method for Heating, Ventilating, and Air-Conditioning Equipment Models (HVAC BESTEST); Volume 1: Cases E100-E200
This report describes the Building Energy Simulation Test for Heating, Ventilating, and Air-Conditioning Equipment Models (HVAC BESTEST) project conducted by the Tool Evaluation and Improvement International Energy Agency (IEA) Experts Group. The group was composed of experts from the Solar Heating and Cooling (SHC) Programme, Task 22, Subtask A. The current test cases, E100-E200, represent the beginning of work on mechanical equipment test cases; additional cases that would expand the current test suite have been proposed for future development.
Neymark, J.; Judkoff, R.
US Department of Energys Regulatory Negotiations Convening on Commercial Certification for Heating, Ventilating, Air-Conditioning, and Refrigeration Equipment
US Department of Energy's Regulatory Negotiations Convening on US Department of Energy's Regulatory Negotiations Convening on Commercial Certification for Heating, Ventilating, Air-Conditioning, and Refrigeration Equipment Public Information for Convening Interviews I. What are the substantive issues DOE seeks to address? Strategies for grouping various basic models for purposes of certification; Identification of non-efficiency attributes, which do not impact the measured consumption of the equipment as tested by DOE's test procedure; The information that is certified to the Department; The timing of when the certification should be made relative to distribution in commerce; and Alterations to a basic model that would impact the certification.
Proposal for the award of a contract for the design, supply, installation and commissioning of a Heating, Ventilation and Air-Conditioning (HVAC) system for the computer room of the CERN Control Centre
Proposal for the award of a contract for the design, supply, installation and commissioning of a Heating Ventilation and Air Conditioning (HVAC) system for the HIE-ISOLDE infrastructure
The physical features of distribution of the small dispersive coal dust particles and the adsorbed radioactive chemical elements and their isotopes in the absorber with the granular filtering medium with the cylindrical coal granules were researched in the case of the intensive air dust aerosol stream flow through the iodine air filter (IAF). It was shown that, at the certain aerodynamic conditions in the IAF, the generation of the acoustic oscillations is possible. It was found that the acoustic oscillations generation results in an appearance of the standing acoustic waves of the air pressure (density) in the IAF. In the case of the intensive blow of the air dust aerosol, it was demonstrated that the standing acoustic waves have some strong influences on both: 1) the dynamics of small dispersive coal dust particles movement and their accumulation in the IAF; 2) the oversaturation of the cylindrical coal granules by the adsorbed radioactive chemical elements and their isotopes in the regions, where the antinodes of the acoustic waves are positioned. Finally, we completed the comparative analysis of the theoretical calculations with the experimental results, obtained for the cases of: 1) the experimental aerodynamic modeling of physical processes of the absorbed radioactive chemical elements and their isotopes distribution in the IAF; and 2) the gamma-activation spectroscopy analysis of the absorbed radioactive chemical elements and their isotopes distribution in the IAF. We made the innovative propositions on the necessary technical modifications with the purpose to improve the IAF technical characteristics and increase its operational time at the nuclear power plant (NPP), going from the completed precise characterization of the IAF parameters at the long term operation.
Oleg P. Ledenyov; Ivan M. Neklyudov
Root Absorption
Root Absorption Root Absorption Name: Carolyn Location: N/A Country: N/A Date: N/A Question: MY Neice is doing a science fair project on plants. More specifically she needs to know if you water your flowering plants with colored water, does the flower change colors and if so, why? Replies: Dear Carolyn, Dyeing flowers works best on cut stems in water: http://youth.net/nsrc/sci/sci032.html#anchor598182 Title: The Effect Of Color On The Speed Of Dyeing Flowers Some rooted plants can change flower color by altering the soil pH: http://www.cahe.nmsu.edu/pubs/yard/1996/120996.html Sincerely, Anthony R. Brach This sounds like a good question for a science project. I think she should do the project first and get some data and then try to answer the question herself. If she can't figure it out, then she should look for some help.
Model test on underground coal gasification (UCG) with low-pressure fire seepage push-through. Part I: Test conditions and air fire seepage
The technology of a pushing-through gallery with oxygen-enriched fire-seepage combustion was studied during shaft-free UCG in this article, and the main experiment parameters were probed. The test results were analyzed in depth. The patterns of variation and development were pointed out for the fire source moving speed, temperature field, leakage rate, the expanding diameter for the gasification gallery, and blasting pressure. Test results showed that, with the increase in the wind-blasting volume, the moving velocity for the fire source speeded up, and the average temperature for the gallery continuously rose. Under the condition of oxygen-enriched air blasting, when O{sub 2} contents stood at 90%, the moving speed for the fire source was 4-5 times that of air blasting. In the push-through process, the average leakage rate for the blasting was 82.23%, with the average discharge volume of 3.43 m{sup 3}/h and average gallery diameter of 7.87 cm. With the proceeding of firepower seepage, the extent of dropping for the leakage rate increased rapidly, and the drop rate for the blasting pressure gradually heightened.
Yang, L.H. [China University of Mining & Technology, Xuzhou (China)
Ultra-sensitive surface absorption spectroscopy using sub-wavelength diameter optical fibers
The guided modes of sub-wavelength diameter air-clad optical fibers exhibit a pronounced evanescent field. The absorption of particles on the fiber surface is therefore readily detected via the fiber transmission. We show that the resulting absorption for a given surface coverage can be orders of magnitude higher than for conventional surface spectroscopy. As a demonstration, we present measurements on sub-monolayers of 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) molecules at ambient conditions, revealing the agglomeration dynamics on a second to minutes timescale.
F. Warken; E. Vetsch; D. Meschede; M. Sokolowski; A. Rauschenbeutel
Liquid phase thermal swing chemical air separation
A temperature swing absorption separation of oxygen from air is performed with an oxygen acceptor of alkali metal nitrate and nitrite. 2 figs.
Erickson, D.C.
Energy Basics: Air-Source Heat Pumps
An inlet air washer/chiller system for combined cycle planet repowering
A conditioning method to achieve increased output at any relative humidity condition is an air washer and absorption chiller arrangement. At elevated temperatures and low humidity, the air washer operates as an evaporative cooler without the chiller in operation. In this mode, the air washer will give similar results as a media type evaporative cooler at a fraction of the pressure loss. In the air washer plus chiller operating mode the chiller maintains cooling effectiveness of the air washer during periods of high relative humidity. This makes such a system very appropriate anywhere relative humidity is high. Many combined cycle plants utilize supplemental firing of the heat recovery steam generators to offset the loss of gas turbine power at high ambient temperatures. This paper shows that in contrast to supplementary firing, the combination air washer/chiller system can generate power more efficiently and at lower cost.
Sengupta, U.; Soroka, G. (Bechtel Power Corp., Gaithersburg, MD (USA))
Iron Absorption
Iron Absorption Iron Absorption Name: Mary Location: N/A Country: N/A Date: N/A Question: I wrote before to Steve and got a answer back. I would like more information. The cirmcustances were that I first had anaemia and then I went for a gastroscopy. The results of which were I had insufficient acid been produced in the stomach. I was told that acid was nessary for the absorbion of iron and it was because of this that I became anaemic. I was told to eat plently of red meat not too many vegetables. Is there any other information you can give me? Replies: It is very difficult to say for sure without seeing you chart and I am not your doctor. But it sounds to me like you are deficient in the vitamin B12. In your stomach you have 3 basic types of cells. One is called chief cells which secrete the precursor of the enzyme pepsin which begins the breakdown of protein. Another is called the parietal cells which secrete your stomach acid and a substance called intrinsic factor. Now-switch to your bone marrow which is where your red blood cells are made. In order for your red blood cells to mature in the bone marrow, vitamin B12 is necessary. B12 can only be obtained from animal food sources such as meat, milk and eggs. Unfortunately, B12 cannot be absorbed in the stomach without intrinsic factor. If there is sufficient B12 present in the diet, it can be stored in the liver. If you aren't eating enough animal sources your B12 will be taken from your liver until you run out. You could also be deficient in intrinsic factor. So while the outcome is anemia (not enough red blood cells) the problem could be from a few different things. Follow your doctor's recommendations and eat more sources of B12
and basic components as refrigerators. Refrigerators use energy (usually electricity) to transfer heat from the cool interior of the refrigerator to the relatively warm...
Experimental Investigation of the Padding Tower for Air Dehumidifier
Air conditioning with all fresh air is founded on the principle of dehumidifying by liquid desiccant. It has the characteristics of being clean, power-saving, easy to operate, and requiring low-grade heat. It is suitable for applying waste heat, and solar power as the heat source for regeneration. Hence, this system has a great latent potential for energy savings and environmental protection. The system chooses the padding tower as a dehumidifier and regenerator, which are often used in petrochemical industry. The system chooses a padding tower as a dehumidifier, and LiCl-Water as a liquid desiccant. The vapor in the air is absorbed by the spray of the LiCl solution, and then the absorbed vapor will be released by heating the absorbent. These processes form the circle of absorptive refrigeration operating in atmospheric pressure. This paper describes studies on the theory and experiment of the padding tower of the dehumidifying air conditioning, including selecting different padding and measuring the speed of the air flow and the solution flow and the pressure drop between the layers of the padding. The experimental and computational results indicate that the design parameters of the padding tower significantly influence the characteristics of the liquid desiccant air conditioning. Of these design parameters, the framework of the padding tower, ratio of the air and the concentration of the inlet solution is largest through the tower, the temperature and effects of the dehumidifying capability of the tower.
Wang, J.; Liu, J.; Li, C.; Zhang, G.; An, S.
China Energy Efficiency Round Robin Testing Results for Room Air Conditioners
Refrigeration and Air Conditioning Industry Association Junein the context of the air conditioning industry, the profileand improvement of the air conditioning industry and the
Zhou, Nan
Life-cycle cost and payback period analysis for commercial unitary air conditioners
Prices Computed from Air Conditioning Load Reductions UsingRefrigerating and Air-Conditioning Engineers, Inc. (ASHRAE)/Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE),
Rosenquist, Greg; Coughlin, Katie; Dale, Larry; McMahon, James; Meyers, Steve
Indoor air movement acceptability and thermal comfort in hot-humid climates
Windsor Conference - Air Conditioning and the Low CarbonA. , Thomas, PC (2010). Air conditioning, comfort and energyAmerica's Romance with Air- Conditioning. Washington, D.C.
Candido, Christhina Maria
State of Washington Department of Health radioactive air emission notice of construction phase 1 for spent nuclear fuel project - hot conditioning system annex, project W-484
This notice of construction (NOC) provides information regarding the source and the estimated annual possession quantity resulting from the operation of the Hot Conditioning System Annex (HCSA). This information will be discussed again in the Phase II NOC, providing additional details on emissions generated by the operation of the HCSA. This Phase I NOC is defined as construct in the substructure, including but limited to, pouring the concrete for the floor; construction of the process pits and exterior walls; making necessary interface connections to the Canister Storage Building (CSB) ventilation and utility systems for personnel comfort; and extending the multi-canister over-pack (MCO) handling machine rails into the HCSA. A Phase II NOC will be submitted for approval prior to installation and is defined as the completion of the HCSA, which will consist of installation of Hot Conditioning System Equipment (HCSA), air emissions control equipment, and emission monitoring equipment. About 80 percent of the U.S. Department of Energy`s spent nuclear fuel (SNF) inventory is stored under water in the Hanford Site K Basins. Spent nuclear fuel in the K West Basin is contained in closed canisters, while the SNF in the K East Basin is contained in open canisters, which allow free release of corrosion products to the K East Basin water. Storage in the K Basins was originally intended to be on an as-needed basis to sustain operation of the N Reactor while the Plutonium-Uranium Extraction (PUREX) Plant was refurbished and restarted. The decision in December 1992 to deactivate the PUREX Plant left approximately 2,300 MT (2,530 tons) of N Reactor SNF in the K Basins with no means for near-term removal and processing. The HCSA will be constructed as an addition to the CSB and will contain the HCSA. The hot conditioning system (HCS) will remove chemically-bound water and will passivate the exposed uranium surfaces associated,with the SNF. The HCSA will house seven hot conditioning process stations, six operational and one auxiliary pit, which could be used as a welding area for final sealing of the vessel containing the SNF, or for neutron interrogation of the vessel containing the SNF to determine residual water content. Figures 1 and 2 contain map locations of the Hanford Site and the HCSA. `Response to Requirement` subtitle under each of the following sections identifies the corresponding Appendix A NOC application requirement listed under WAC 246-247-1 10.
Turnbaugh, J.E.
Solar evacuated tube collector: absorption chiller systems simulation
A residential air conditioning system incorporating an Arkla Solaire absorption chiller and Corning Glass Works evacuated tube collectors is simulated and the design parameters studied. Mathematical models of the evacuated tube collector and Arkla absorption chiller based on experimental results of the components have been created and incorporated into a complete system simulation. The chiller model includes transient start-up effects and the evacuated tube collector model includes numerous optical effects. A standard Arkla chiller in a humid climate (Washington, D.C.) and an Arkla unit with a modified charge for dry climates (Fort Collins, Colorado) are studied. Design parameters considered include the use of chilled water storage to reduce transient start-up effects of the absorption unit, the effects of removing heat from the solar system for preheating service hot water, the use of a tempering valve to prevent over-firing of the absorption unit in dry climates, and solar storage sizing considerations. The study results and conclusions are used to specify a cooling system design.
Leflar, J.A.; Duff, W.S.
Performance comparison of absorption and desiccant solar cooling systems
Cooling systems are required to operate over a wide range of outdoor and load conditions; however, the performance of solar cooling components is often specified and compared at a typical design point such as ARI conditions. A method is presented to directly compare the performance of different desiccant and absorption cooling systems by using psychrometric analysis of air distribution cycles under a range of outdoor conditions that systems encounter over a year. Using analysis of cooling load distributions for a small commercial office building in Miami and Phoenix a seasonal COP is calculated for each system. The heat input can be provided by solar or by an auxiliary heat source, such as natural gas.
Warren, M.L.; Wahlig, M.
ground water source), electrically operated, unitary central air conditioners and central air conditioning heat pumps
Formation of an optical pulsed discharge in a supersonic air flow by radiation of a repetitively pulsed CO{sub 2} laser
Results of optimisation of repetitively pulsed CO{sub 2}-laser generation are presented for finding physical conditions of forming stable burning of an optical pulsed discharge (OPD) in a supersonic air flow and for studying the influence of pulse parameters on the energy absorption efficiency of laser radiation in plasma. The optical discharge in a supersonic air flow was formed by radiation of a repetitively pulsed CO{sub 2} laser with mechanical Q-switching excited by a discharge with a convective cooling of the working gas. For the first time the influence of radiation pulse parameters on the ignition conditions and stable burning of the OPD in a supersonic air flow was investigated and the efficiency of laser radiation absorption in plasma was studied. The influence of the air flow velocity on stability of plasma production was investigated. It was shown that stable burning of the OPD in a supersonic flow is realised at a high pulse repetition rate where the interval between radiation pulses is shorter than the time of plasma blowing-off. Study of the instantaneous value of the absorption coefficient shows that after a breakdown in a time lapse of 100 - 150 ns, a quasi-stationary 'absorption phase' is formed with the duration of {approx}1.5 ms, which exists independently of air flow and radiation pulse repetition rate. This phase of strong absorption is, seemingly, related to evolution of the ionisation wave. (laser applications and other topics in quantum electronics)
Malov, Aleksei N; Orishich, Anatolii M [S.A. Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)
The Impact of GEM and MM5 Modeled Meteorological Conditions on CMAQ Air Quality Modeling Results in Eastern Canada and the Northeastern United States
The fifth-generation Pennsylvania State University�National Center for Atmospheric Research Mesoscale Model (MM5) is currently the meteorological model most widely used as input into the Community Multiscale Air Quality (CMAQ) modeling system. In ...
Steven C. Smyth; Dazhong Yin; Helmut Roth; Weimin Jiang; Michael D. Moran; Louis-Philippe Crevier
Combination of Local Wind Systems under Light Gradient Wind Conditions and Its Contribution to the Long-Range Transport of Air Pollutants
The meteorological structure and transport mechanism of long-range transport of air pollutants from the coastal region to the mountainous inland region were investigated using joint field observation data. The observations were conducted during ...
Hidemi Kurita; Hiromasa Ueda; Shigeki Mitsumoto
Investigation of Feasibility of All-Fresh Air Supply in an All-Air System
The feasibility of an all-fresh air supply in an all-air system is investigated in theory, and the problem of AHU-handling air in low efficiency in summer and winter conditions is analyzed. The air supply temperature is almost up to standards when a heat recovery unit is fixed in the air conditioning system.
Wang, J.; Yan, Z.
SolarAire LLC | Open Energy Information
SolarAire LLC Place Folsom, California Sector Solar Product Developing a solar thermal air conditioning unit. References SolarAire LLC1 LinkedIn Connections CrunchBase Profile...
Open-cycle absorption cooling using packed-bed absorbent reconcentration
The technical feasibility of a lithium chloride open-cycle absorption air conditioner using solar-heated air for reconcentration of the absorbent solution is examined. In contrast to a successfully operating Soviet design (in which absorbent reconcentration is accomplished by trickling the solution across a sloping black roof exposed to the sun), this study involves a packed-bed concentrator. Solar-heated air reconcentrates the solution by vaporizing water (the refrigerant) from the solution in the packed bed, enabling the system to be incorporated into a conventional solar air heating system and avoiding numerous problems associated with the roof concentrator. A thermodynamic analysis provides the criteria for the design of the packed bed. Heat and mass transfer processes occurring simultaneously in the bed are modeled using an iterative technique with the aid of a digital computer. The size of the packed-bed required to reconcentrate the absorbent solution at a rate corresponding to 10,550 W of cooling is determined, using flow rates, temperatures, and humidities typical of residential solar air-heating systems. Based on these results, the system air conditioning capability with solar energy input is predicted over the course of a clear summer day for Fort Collins, Colorado, and St. Louis, Missouri. Sufficient cooling capacity to meet a 10,550 W peak load using a 70 m/sup 2/ flatplate collector array is predicted by the model for both locations.
Leboeuf, C. M.; Loef, G. O.G.
Air Handling Unit Supply Air Temperature Optimization During Economizer Cycles
Most air handling units (AHUs) in commercial buildings have an air economizer cycle for free cooling under certain outside air conditions. During the economizer cycle, the outside air and return air dampers are modulated to seek mixing air temperature at supply air temperature setpoint. Mechanical cooling is always required when outside air temperature is higher than the supply air temperature setpoint. Generally the supply air temperature setpoint is set at 55�F for space humidity control. Actually the dehumidification is not necessary when outside air dew point is less than 55�F. Meanwhile the space may have less cooling load due to envelope heat loss and/or occupant schedule. These provide an opportunity to use higher supply air temperature to reduce or eliminate mechanical cooling and terminal box reheat. On the other hand the higher supply air temperature will require higher air flow as well as higher fan power. Therefore the supply air temperature has to be optimized to minimize the combined energy for fan, cooling and heating energy. In this paper a simple energy consumption model is established for AHU systems during the economizer and then a optimal supply air temperature control is developed to minimize the total cost of the mechanical cooling and the fan motor power. This paper presents AHU system energy modeling, supply air temperature optimization, and simulated energy savings.
Xu, K.; Liu, M.; Wang, G.; Wang, Z.
Optimum hot water temperature for absorption solar cooling
The hot water temperature that maximizes the overall instantaneous efficiency of a solar cooling facility is determined. A modified characteristic equation model is used and applied to single-effect lithium bromide-water absorption chillers. This model is based on the characteristic temperature difference and serves to empirically calculate the performance of real chillers. This paper provides an explicit equation for the optimum temperature of vapor generation, in terms of only the external temperatures of the chiller. The additional data required are the four performance parameters of the chiller and essentially a modified stagnation temperature from the detailed model of the thermal collector operation. This paper presents and discusses the results for small capacity machines for air conditioning of homes and small buildings. The discussion highlights the influence of the relevant parameters. (author)
Lecuona, A.; Ventas, R.; Venegas, M.; Salgado, R. [Dpto. Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganes, Madrid (Spain); Zacarias, A. [ESIME UPA, IPN, Av. de las Granjas 682, Col. Santa Catarina, 02550, D.F. Mexico (Mexico)
Common Air Conditioner Problems | Department of Energy
Common Air Conditioner Problems Common Air Conditioner Problems Common Air Conditioner Problems May 30, 2012 - 6:41pm Addthis A refrigerant leak is one common air conditioning problem. | Photo courtesy of ©iStockphoto/BanksPhotos. A refrigerant leak is one common air conditioning problem. | Photo courtesy of ©iStockphoto/BanksPhotos. What does this mean for me? You can eliminate the most common air conditioner problems before hiring an air conditioning technician. You can do some air conditioner maintenance and repair tasks yourself. One of the most common air conditioning problems is improper operation. If your air conditioner is on, be sure to close your home's windows and outside doors. For room air conditioners, isolate the room or a group of connected rooms as much as possible from the rest of your home.
Air-Con International: Noncompliance Determination and Proposed...
to Air-Con International finding that a variety of central air conditioners and air conditioning heat pumps distributed under the Air-Con private label do not comport...
The Impact of Climate Change on Air Quality�Related Meteorological Conditions in California. Part II: Present versus Future Time Simulation Analysis
In this study, the Weather Research and Forecasting (WRF) model was applied to dynamically downscale the Parallel Climate Model (PCM) projection for the climate change impact on regional meteorological conditions in California. Comparisons were ...
Zhan Zhao; Shu-Hua Chen; Michael J. Kleeman; Abdullah Mahmud
The Impact of Climate Change on Air Quality Related Meteorological Conditions in California � Part II: Present versus Future Time Simulation Analysis
In this study, the Weather Research and Forecasting (WRF) model was applied to dynamically downscale the Parallel Climate Model (PCM) projection for the climate change impact on regional meteorological conditions in California (CA). Comparisons ...
Energy Basics: Absorption Cooling
cooling. Other potential heat sources include propane, solar-heated water, or geothermal-heated water. Although mainly used in industrial or commercial settings, absorption...
Numerical Analysis of a Cold Air Distribution System
Cold air distribution systems may reduce the operating energy consumption of air-conditioned air supply system and improve the outside air volume percentages and indoor air quality. However, indoor temperature patterns and velocity field are easily non-uniform so that residents usually feel uncomfortable. The distribution of indoor airflow by cold air distribution is researched in this paper. We study indoor air distribution under different low temperature air supply conditions by numerical simulation. The simulated results agree well with the experiments.
Zhu, L.; Li, R.; Yuan, D.
Solar absorption surface panel
A composite metal of aluminum and nickel is used to form an economical solar absorption surface for a collector plate wherein an intermetallic compound of the aluminum and nickel provides a surface morphology with high absorptance and relatively low infrared emittance along with good durability.
Santala, Teuvo J. (Attleboro, MA)
U.S. Environmental Protection Agency Clean Air Act notice of construction for spent nuclear fuel project - hot conditioning system annex, project W-484
This notice of construction (NOC) provides information regarding the source and the estimated quantity of potential airborne radionuclide emissions resulting from the operation of the Hot Conditioning System (HCS) Annex. The construction of the HCS Annex is scheduled to conunence on or about December 1996, and will be completed when the process equipment begins operations. This document serves as a NOC pursuant to the requirements of 40 Code of Federal Regulations (CFR) 61 for the HCS Annex. About 80 percent of the U.S. Department of Energy`s spent nuclear fuel (SNF) inventory is stored under water in the Hanford Site K Basins. Spent nuclear fuel in the K West Basin is contained in closed canisters, while the SNF in the K East Basin is contained in open canisters, which allows release of corrosion products to the K East Basin water. Storage of the current inventory in the K Basins was originally intended to be on an as-needed basis to sustain operation of the N Reactor while the Plutonium-Uranium Extraction (PUREX) Plant was refurbished and restarted. The decision in December 1992 to deactivate the PUREX Plant left approximately 2, 1 00 MT (2,300 tons) of uranium, as part of 1133 N Reactor SNF in the K Basins with no means for near-term removal and processing. The HCS Annex will be constructed as an annex to the Canister Storage Building (CSB) and will contain the hot conditioning equipment. The hot conditioning system (HCS) will release chemically-bound water and will condition (process of using a controlled amount of oxygen to destroy uranium hydride) the exposed uranium surfaces associated with the SNF through oxidation. The HCS Annex will house seven hot conditioning process stations, six operational and one auxiliary, which could be used as a welding area for final closure of the vessel containing the SNF. The auxiliary pit is being evaluated at this time for its usefulness to support other operations that may be needed to ensure proper conditioning of the SNF and proper storage of the vessel containing the SNF. Figures I and 2 contain map locations of the Hanford Site and the HCS Annex.
Baker, S.K., Westinghouse Hanford
Room Air Conditioners | Department of Energy
Room Air Conditioners Room Air Conditioners Room Air Conditioners July 1, 2012 - 5:35pm Addthis A window air conditioner is one solution to cooling part of a house. | Photo courtesy of ©iStockphoto/kschulze. A window air conditioner is one solution to cooling part of a house. | Photo courtesy of ©iStockphoto/kschulze. What does this mean for me? Room air conditioners are less expensive and disruptive to install than central air conditioning systems. Room air conditioners can be a cost-effective alternative to central air conditioning systems. How does it work? Room air conditioners work by cooling one part of your home. Room or window air conditioners cool rooms rather than the entire home or business. If they provide cooling only where they're needed, room air conditioners are less expensive to operate than central units, even though
Air Quality
What We Monitor & Why » What We Monitor & Why » Air Quality Air Quality To preserve our existing wilderness-area air quality, LANL implements a conscientious program of air monitoring. April 12, 2012 Real-time data monitoring for particulate matter An air monitoring field team member tests one of LANL's tapered element oscillating microbalance samplers, which collects real-time particulate matter data. Contact Environmental Communication & Public Involvement P.O. Box 1663 MS M996 Los Alamos, NM 87545 (505) 667-0216 Email LANL monitors air quality 24 hours a day, 365 days a year. Why we monitor air LANL monitors many different pathways in order to assess their impact on workers, the public, animals, and plants. We monitor the air around the Laboratory to ensure our operations are not affecting the air of nearby
Absorption process for producing oxygen and nitrogen and solution therefor
Process for the separation and purification of oxygen and nitrogen is disclosed which utilizes solutions of oxygen carriers to selectively absorb oxygen from a gaseous stream, leaving nitrogen as a byproduct. In the process, an oxygen carrier capable of reversibly binding molecular oxygen is dissolved in a solvent solution, which absorbs oxygen from an oxygen-containing gaseous feed stream such as atmospheric air and desorbs oxygen to a gaseous product stream. The feed stream is maintained at a sufficiently high oxygen pressure to keep the oxygen carrier in its oxygenated form during absorption, while the product stream is maintained at a sufficiently low oxygen pressure to keep the carrier in its deoxygenated form during desorption. In an alternate mode of operation, the carrier solution is maintained at a sufficiently low temperature and high oxygen pressure to keep the oxygen carrier in its oxygenated form during absorption, and at a sufficiently high temperature to keep the carrier in its deoxygenated form during desorption. Under such conditions, exceptionally high oxygen concentrations on the order of 95% to 99% are obtained, as well as a long carrier lifetime in excess of 3 months, making the process commercially feasible. 1 figure
Roman, I.C.; Baker, R.W.
Solar Energy to Drive Absorption Cooling Systems Suitable for Small Building Applications
Air conditioning systems have a major impact on energy demand. With fossil fuels fast depleting, it is imperative to look for cooling systems that require less high-grade energy for their operation. In this context, absorption cooling systems have become increasingly popular in recent years from the viewpoints of energy and environment. Two types of the absorption chillers, the single effect and the half-effect systems, can operate using low temperature hot water. This paper presents the simulation results and an overview of the performance of low capacity single stage and half-effect absorption cooling systems, suitable for residential and small building applications. The primary heat source is solar energy supplied from flat plate collectors. The complete systems (solar collectors and absorption cooling system) were simulated using a developed software program. The energy and exergy analysis is carried out for each component of the two systems. When evaporator temperature is maintained constant at 5 C and the condenser temperature is fixed at 28 C, 32 C and 36 C respectively the percentage of the used energy covered by solar collectors and the percentage of auxiliary heating load were calculated versus time of day.
Gomri, R.
Ga Air Compressor, Ga Air Compressor Products, Ga Air ...
Ga Air Compressor, You Can Buy Various High Quality Ga Air Compressor Products from Global Ga Air Compressor Suppliers and Ga Air Compressor ...
Modeling of an adiabatic packed bed brine-air contactor for use in a solar energy driven food processing system
A mathematical model was developed for a packed bed brine-air contacting system which has applications in a solar energy driven food processing system. The model considers mass transfer resistances of both phases, but neglects the heat transfer resistance of the liquid phase. It takes into account the large heat effects associated with water absorption into and desorption from the brine. A computational method was also developed to calculate the minimum air flow rate which would prevent a pinch. A packed bed brine-air contactor was built, and experiments were conducted for a range of brine and air conditions. Good agreement between the computed and experimental results warrants use of the model to design and optimize the packed bed water stripping process. A periodic-flow packed bed heat regenerator was built to recover heat from the exit air of the contactor so as to improve the energy efficiency of the system. It was possible to preheat the inlet air to a temperature close to that of the exit air. The inlet air, however, during its passage through the regenerator picked up the condensate deposited from the exit air. This led to a decrease in the driving potential to mass transfer in the contactor. Optimization studies show that using a combined solar driven boiler and air assisted packed bed water stripper would be more economical than using a solar driven boiler alone or using flat plate solar collectors to drive the water stripper.
Biswal, R.N.
ARM - Measurement - Aerosol absorption
absorption absorption ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Aerosol absorption The process in which radiation energy is retained by aerosols. Categories Aerosols Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments AOS : Aerosol Observing System CSPHOT : Cimel Sunphotometer IAP : In-situ Aerosol Profiles (Cessna Aerosol Flights) PSAP : Particle Soot Absorption Photometer PASS : Photoacoustic Soot Spectrometer External Instruments OMI : Ozone Monitoring Instrument
Absorption heat pump system
The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.
Grossman, Gershon (Oak Ridge, TN)
Grossman, G.
Solar selective absorption coatings
A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron structure designed to efficiently absorb solar radiation, while retaining low thermal emissivity for infrared thermal radiation. A sol-gel layer protects the structured metallic overlayer from mechanical, thermal, and environmental degradation. Processes for producing such solar selective absorption coatings are also disclosed.
Mahoney, Alan R. (Albuquerque, NM); Reed, Scott T. (Albuquerque, NM); Ashley, Carol S. (Albuquerque, NM); Martinez, F. Edward (Horseheads, NY)
Optical absorption measurement system
The system of the present invention contemplates a non-intrusive method for measuring the temperature rise of optical elements under high laser power optical loading to determine the absorption coefficient. The method comprises irradiating the optical element with a high average power laser beam, viewing the optical element with an infrared camera to determine the temperature across the optical element and calculating the absorption of the optical element from the temperature.
Draggoo, V.G.; Morton, R.G.; Sawicki, R.H.; Bissinger, H.D.
Draggoo, Vaughn G. (Livermore, CA); Morton, Richard G. (San Diego, CA); Sawicki, Richard H. (Pleasanton, CA); Bissinger, Horst D. (Livermore, CA)
International Energy Agency Building Energy Simulation Test and Diagnostic Method for Heating, Ventilating, and Air-Conditioning Equipment Models (HVAC BESTEST): Volume 2: Cases E300-E545.
This report documents an additional set of mechanical system test cases that are planned for inclusion in ANSI/ASHRAE STANDARD 140. The cases test a program's modeling capabilities on the working-fluid side of the coil, but in an hourly dynamic context over an expanded range of performance conditions. These cases help to scale the significance of disagreements that are less obvious in the steady-state cases. The report is Vol. 2 of HVAC BESTEST Volume 1. Volume 1 was limited to steady-state test cases that could be solved with analytical solutions. Volume 2 includes hourly dynamic effects, and other cases that cannot be solved analytically. NREL conducted this work in collaboration with the Tool Evaluation and Improvement Experts Group under the International Energy Agency (IEA) Solar Heating and Cooling Programme Task 22.
Neymark J.; Judkoff, R.
Seven-effect absorption refrigeration
A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit.
DeVault, Robert C. (Knoxville, TN); Biermann, Wendell J. (Fayetteville, NY)
A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit. 1 fig.
DeVault, R.C.; Biermann, W.J.
Components for Advanced Power Conditioning Techniques
Symposium, Advanced Materials for Power Electronics, Power Conditioning, and Power Conversion ... Potential Ceramic Dielectrics for Air Force Applications.
Integrating ducts into the conditioned space: Successes and challenges
air into the conditioned space. Further conversations with construction crews indicated that sealing
Siegel, Jeffrey; Walker, Iain
Issue and Improvement Measure of Multi-split Air Conditioner
Existing problems of traditional air source variable refrigerant flow (VRF) air-conditioning system are analyzed. The disadvantages of traditional VRF air-conditioning system are described in detail: 1) its properties are seriously affected by outdoor ... Keywords: energy saving, simulation, variable refrigerant flow air conditioning, water loop
Sun Tingting; Ni Long; Yao Yang; Ma Zuiliang; Yi Lingli
Residential Forced Air System Cabinet Leakage and Blower Performance
CA. � CEC�(2008b). �Residential�Alternative�Calculation�Standard�for�Air�Handlers�in�Residential�Space�Conditioning�of�Standards�Options�for�Residential�Air�Handler�Fans. ��
Walker, Iain S.
World energy use is the main contributor to atmospheric CO2. In 2002, about 7.0 giga metric tons of carbon (GtC) were emitted internationally by combustion of gas, liquid, and solid fuels (CDIAC, 2006), 2 to 5 times the amount contributed by deforestation (Brown et al., 1988). The share of atmospheric carbon emissions for the United States from fossil fuel combustion was 1.6 GtC. Increasing use of fossil fuel and deforestation together have raised atmospheric CO{sub 2} concentration some 25% over the last 150 years. According to global climate models and preliminary measurements, these changes in the composition of the atmosphere have already begun raising the Earth's average temperature. If current energy trends continue, these changes could drastically alter the Earth's temperature, with unknown but potentially catastrophic physical and political consequences. During the last three decades, increased energy awareness has led to conservation efforts and leveling of energy consumption in the industrialized countries. An important byproduct of this reduced energy use is the lowering of CO{sub 2} emissions. Of all electricity generated in the United States, about one-sixth is used to air-condition buildings. The air-conditioning use is about 400 tera-watt-hours (TWh), equivalent to about 80 million metric tons of carbon (MtC) emissions, and translating to about $40 billion (B) per year. Of this $40 B/year, about half is used in cities that have pronounced 'heat islands'. The contribution of the urban heat island to the air-conditioning demand has increased over the last 40 years and it is currently at about 10%. Metropolitan areas in the United States (e.g., Los Angeles, Phoenix, Houston, Atlanta, and New York City) have typically pronounced heat islands that warrant special attention by anyone concerned with broad-scale energy efficiency (HIG, 2006). The ambient air is primarily heated through three processes: direct absorption of solar radiation, convection of heat from hot surfaces, and man-made heat (exhaust from cars, buildings, etc.). Air is fairly transparent to light--the direct absorption of solar radiation in atmospheric air only raises the air temperature by a small amount. Typically about 90% of solar radiation reaches the Earth's surface and then is either absorbed or reflected. The absorbed radiation on the surface increases the surface temperature. And in turn the hot surfaces heat the air. This convective heating is responsible for the majority of the diurnal temperature range. The contribution of man-made heat (e.g., air conditioning, cars) is very small, compared to the heating of air by hot surfaces, except for the downtown high-rise areas.
The Use of Positive Matrix Factorization with Conditional Probability Functions in Air Quality Studies: An Application to Hydrocarbon Emissions in Houston, Texas
As part of a study to identify groups of compounds (�source categories�) associated with different processing facilities, a multivariate receptor model called Positive Matrix Factorization (PMF) was applied to hourly average concentrations of volatile organic compounds (VOCs) measured at five Photochemical Assessment Monitoring Stations (PAMS) located near the Ship Channel in Houston, Texas. The observations were made between June and October, 2003, and limited to nighttime measurements (21:00 pm � 6:00 am) in order to remove the complexity of photochemical processing and associated changes in the concentrations of primary and secondary VOCs. Six to eight volatile organic compounds source categories were identified for the five Ship Channel sites. The dominant source categories were found to be those associated with petrochemical, chemical industries and fuel evaporation. In contrast, source categories associated with on-road vehicles were found to be relatively insignificant. Although evidence of biogenic emissions was found at almost all the sites, this broad category was significant only at the Wallisville site, which was also the site furthest away from the Ship Channels area and closest to the northeast forest of Texas. Natural gas, accumulation and fuel evaporation sources were found to contribute most to the ambient VOCs, followed by the petrochemical emission of highly reactive ethene and propylene. Solvent / paint industry and fuel evaporation and emission from refineries were next in importance while the on-road vehicle exhaust generally contributed less than 10% of the total ambient VOCs. Specific geographic areas associated with each source category were identified through the use of a Conditional Probability Function (CPF) analysis that related elevated concentrations of key VOCs in each category to a network of grids superimposed on the source inventories of the VOCs.
Xie, YuLong; Berkowitz, Carl M.
An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.
Grossman, Gershon (Oak Ridge, TN); Perez-Blanco, Horacio (Knoxville, TN)
Air-cleaning apparatus
An air-cleaning, heat-exchange apparatus includes a main housing portion connected by means of an air inlet fan to the kitchen exhaust stack of a restaurant. The apparatus includes a plurality of heat exchangers through which a heat-absorptive fluid is circulated, simultaneously, by means of a suitable fluid pump. These heat exchangers absorb heat from the hot exhaust gas, out of the exhaust stack of the restaurant, which flows over and through these heat exchangers and transfers this heat to the circulating fluid which communicates with remote heat exchangers. These remote heat exchangers further transfer this heat to a stream of air, such as that from a cold-air return duct for supplementing the conventional heating system of the restaurant. Due to the fact that such hot exhaust gas is heavily grease laden , grease will be deposited on virtually all internal surfaces of the apparatus which this exhaust gas contacts. Consequently, means are provided for spraying these contacted internal surfaces , as well as the hot exhaust gas itself, with a detergent solution in which the grease is soluble, thereby removing grease buildup from these internal surfaces.
Howard, A.G.
Gas Absorption into a Moving Spheroidal Water Drop
Theoretical and experimental studies have been carried out to describe the absorption of sulfur dioxide by moving spheroidal water drops under transient flow conditions. These investigations allow the determination of the rate at which SO2 is ...
H. Amokrane; B. Caussade
Presentation of the Air- Conditioning, Heating, and ...
... GCC Standardization Organization (GSO) on the ... Headquarters: Arlington, Virginia USA Page 4. AHRI � ... Directory ? www.ahridirectory.org Page 18. ...
The Quantum Absorption Refrigerator
A quantum absorption refrigerator driven by noise is studied with the purpose of determining the limitations of cooling to absolute zero. The model consists of a working medium coupled simultaneously to hot, cold and noise baths. Explicit expressions for the cooling power are obtained for Gaussian and Poisson white noise. The quantum model is consistent with the first and second laws of thermodynamics. The third law is quantified, the cooling power J_c vanishes as J_c proportional to T_c^{alpha}, when T_c approach 0, where alpha =d+1 for dissipation by emission and absorption of quanta described by a linear coupling to a thermal bosonic field, where d is the dimension of the bath.
Amikam Levy; Ronnie Kosloff
Optimal Outside Air Control for Air Handling Units with Humidity Control
Most air handling units (AHUs) in commercial buildings have the (air) economizer cycle to use outside air for free cooling under certain outside air conditions. Ideally the economizer cycle is enabled if outside air enthalpy is less than return air enthalpy. During the economizer cycle, outside air flow is modulated to seek mixed air temperature at a supply air temperature set point. Since the outside air may be dry during the economizer cycle, humidification is required for AHUs with humidity control. As a result, the economizer cycle saves cooling energy but requires excessive steam for humidification. Therefore the economizer cycle may not be economical. An optimal outside air control method is developed to minimize the total cost of mechanical cooling and steam humidification. The impacts of chilled water price, steam price, and space minimum humidity set point are analyzed. Finally the optimal outside air control zones are presented on a psychrometric chart under differential energy price ratios and minimum indoor humidity set points.
Wang, G.; Liu, M.
Oxygen production by molten alkali metal salts using multiple absorption-desorption cycles
A continuous chemical air separation is performed wherein oxygen is recovered with a molten alkali metal salt oxygen acceptor in a series of absorption zones which are connected to a plurality of desorption zones operated in separate parallel cycles with the absorption zones. A greater recovery of high pressure oxygen is achieved at reduced power requirements and capital costs.
Cassano, Anthony A. (Allentown, PA)
A continuous chemical air separation is performed wherein oxygen is recovered with a molten alkali metal salt oxygen acceptor in a series of absorption zones which are connected to a plurality of desorption zones operated in separate parallel cycles with the absorption zones. A greater recovery of high pressure oxygen is achieved at reduced power requirements and capital costs. 3 figs.
Cassano, A.A.
Ris-R-1053(EN) Particulate Air Pollution with
particulate matter in inner city air. The particle size distribution shows that 92 % of the mass of airborne91 F Main reaction pathways in non sulphur vulcanisation 94 G Flame atomic absorption spectrometer
DOE Takes Action to Stop the Sales of Air-Con Air Conditioner...
action against Air-Con, International, requiring the company to stop selling certain air conditioning systems in the U.S. that have been shown to violate minimum energy...
the Annual DOE Active Solar Heating and Cooling Contractors'and Annual DOE Active Solar Heating and Cooling Contractors'refrigeration systems for solar active heating and cooling
of the University of California, nor any of their employees,of the University of California. The views and opinions ofof the University of California. DEVELOPMENT OF SOLAR DRIVEN
Ultraviolet absorption hygrometer
An ultraviolet absorption hygrometer is provided including a source of pulsed ultraviolet radiation for providing radiation in a first wavelength region where water absorbs significantly and in a second proximate wavelength region where water absorbs weakly. Ultraviolet radiation in the first and second regions which has been transmitted through a sample path of atmosphere is detected. The intensity of the radiation transmitted in each of the first and second regions is compared and from this comparison the amount of water in the sample path is determined.
Gersh, Michael E. (Bedford, MA); Bien, Fritz (Concord, MA); Bernstein, Lawrence S. (Bedford, MA)
Air Resources: Prevention and Control of Air Contamination and Air
Air Resources: Prevention and Control of Air Contamination and Air Air Resources: Prevention and Control of Air Contamination and Air Pollution, Air Quality Classifications and Standards, and Air Quality Area Classifications (New York) Air Resources: Prevention and Control of Air Contamination and Air Pollution, Air Quality Classifications and Standards, and Air Quality Area Classifications (New York) < Back Eligibility Agricultural Fuel Distributor Industrial Institutional Investor-Owned Utility Local Government Multi-Family Residential Municipal/Public Utility Nonprofit Rural Electric Cooperative Schools State/Provincial Govt Transportation Tribal Government Utility Program Info State New York Program Type Environmental Regulations Provider NY Department of Environmental Conservation These regulations establish emissions limits and permitting and operational
Ductless Mini-Split Air Conditioners | Department of Energy
Ductless Mini-Split Air Conditioners Ductless Mini-Split Air Conditioners Ductless Mini-Split Air Conditioners August 9, 2012 - 4:05pm Addthis A ductless mini-split air conditioner is one solution to cooling part of a house. | Photo courtesy of ©iStockphoto/LUke1138. A ductless mini-split air conditioner is one solution to cooling part of a house. | Photo courtesy of ©iStockphoto/LUke1138. What does this mean for me? A ductless mini-split air conditioner is easier to install than a central air conditioning system. A ductless mini-split air conditioner provides zoned air conditioning without ducting. A ductless mini-split air conditioner is relatively easy to install and does not provide an entry point for intruders as some room air conditioners do. Ductless, mini split-system air-conditioners (mini splits) have numerous
Maintaining Your Air Conditioner | Department of Energy
Maintaining Your Air Conditioner Maintaining Your Air Conditioner Maintaining Your Air Conditioner June 18, 2013 - 6:20pm Addthis Replacing or cleaning air conditioner filters is a critical maintenance task. | Photo courtesy of ©iStockphoto/firemanYU. Replacing or cleaning air conditioner filters is a critical maintenance task. | Photo courtesy of ©iStockphoto/firemanYU. What does this mean for me? Regular maintenance keeps your air conditioner running as efficiently as possible. Maintaining your air conditioner will save you money by extending the unit's life. An air conditioner's filters, coils, and fins require regular maintenance for the unit to function effectively and efficiently throughout its years of service. Neglecting necessary maintenance ensures a steady decline in air conditioning performance while energy use steadily increases.
Strategy Guideline: Compact Air Distribution Systems
This Strategy Guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. Traditional systems sized by 'rule of thumb' (i.e., 1 ton of cooling per 400 ft2 of floor space) that 'wash' the exterior walls with conditioned air from floor registers cannot provide appropriate air mixing and moisture removal in low-load homes. A compact air distribution system locates the HVAC equipment centrally with shorter ducts run to interior walls, and ceiling supply outlets throw the air toward the exterior walls along the ceiling plane; alternatively, high sidewall supply outlets throw the air toward the exterior walls. Potential drawbacks include resistance from installing contractors or code officials who are unfamiliar with compact air distribution systems, as well as a lack of availability of low-cost high sidewall or ceiling supply outlets to meet the low air volumes with good throw characteristics. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.
Burdick, A.
Absorption Heat Pump Water Heater
Absorption Heat Pump Water Heater Absorption Heat Pump Water Heater Kyle Gluesenkamp Building Equipment Group, ETSD firstname.lastname@example.com 865-241-2952 April 3, 2013 CRADA - GE Development of High Performance Residential Gas Water Heater Image courtesy John Wilkes 2 | Building Technologies Office eere.energy.gov Purpose & Objectives Problem Statement: Absorption technology could greatly boost water heater efficiency, but faces barriers of high first cost and working fluid challenges. Impact of Project: Energy factor of gas storage water
X-ray Absorption Spectroscopy
This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.
Yano, Junko; Yachandra, Vittal K.
Effect of sample conditioning on the water absorption of ...
... the bottom surface of the sample to liquid water and ... of curvature, R is the universal gas constant, and T ... The sand used was natural river sand with a ...
Dehumidification of air by aqueous triethylene glycol solution in a spray tower
A spray tower in the absorber-stripper system has been designed to study the absorption of water vapor from moist air by contact with aqueous solutions that contained from 87.7 to 95.2% triethylene glycol (TEG). The design of a U-shape air tunnel with eliminators in the absorber and stripper is to prevent the carryover of the solution and to increase the absorption rate and the regeneration rate. This spray tower was capable of handling air flow rates from 1.94 to 3.77 kg/min and liquid flow rates from 2.17 to 3.,31 kg/min. Under the operating conditions of this study, the overall mass transfer coefficients calculated from the experimental data of 95.2% TEG solution varied from /1.78 to 1.95 mol/m{sup 3}s. These corresponded to the heights of a transfer unit of 0.63 to 0.38 m, respectively. The efficiencies of the spray tower typically varied from 64 to 86%.
Chung, T.W.; Wu, H. [Chung-Yuan Christian Univ., Chungli (Taiwan, Province of China). Chemical Engineering Dept.
Experimental study of the heat and mass transfer in a packed bed liquid desiccant air dehumidifier
Desiccant cooling systems have the ability to provide efficient humidity and temperature control while reducing the electrical energy requirement for air conditioning as compared to a conventional system. Naturally, the desiccant air dehumidification process greatly influences the overall performance of the desiccant system. Therefore, the effects of variables such as air and desiccant flow rates, air temperature and humidity, desiccant temperature and concentration, and the area available for heat and mass transfer are of great interest. Due to the complexity of the dehumidification process, theoretical modeling relies heavily upon experimental studies. However, a limited number of experimental studies are reported in the literature. This paper presents results from a detailed experimental investigation of the heat and mass transfer between a liquid desiccant (triethylene glycol) and air in a packed bed absorption tower using high liquid flow rates. A high performance packing that combines good heat and mass transfer characteristics with low pressure drop is used. The rate of dehumidification, as well as the effectiveness of the dehumidification process are assessed based on the variables listed above. Good agreement is shown to exist between the experimental findings and predictions from finite difference modeling. In addition, a comparison between the findings in the present study and findings previously reported in the literature is made. The results obtained from this study make it possible to characterize the important variables which impact the system design.
Oeberg, V.; Goswami, D.Y. [Univ. of Florida, Gainesville, FL (United States)
Air Corrosivity in U.S. Outdoor-Air-Cooled Data Centers is Similar to That
Air Corrosivity in U.S. Outdoor-Air-Cooled Data Centers is Similar to That Air Corrosivity in U.S. Outdoor-Air-Cooled Data Centers is Similar to That in Conventional Data Centers Title Air Corrosivity in U.S. Outdoor-Air-Cooled Data Centers is Similar to That in Conventional Data Centers Publication Type Report LBNL Report Number LBNL-4951E Year of Publication 2011 Authors Coles, Henry C., Tae Won Han, Phillip N. Price, Ashok J. Gadgil, and William F. Tschudi Date Published 03/2011 Abstract There is a concern that environmental-contamination caused corrosion may negatively affect Information Technology (IT) equipment reliability. Nineteen data centers in the United States and two in India were evaluated using Corrosion Classification Coupons (CCC) to assess environmental air quality as it may relate IT equipment reliability. The data centers were of two basic types: "closed" and outside-air cooled. A closed data center provides cool air to the IT equipment using air conditioning in which only a small percentage of the recirculation air is "make-up" air continuously supplied from outside to meet human health requirements. An outside-air cooled data center uses outside air directly as the primary source for IT equipment cooling. Corrosion measuring coupons containing copper and silver metal strips were placed in both "closed" and outside-air cooled data centers. The coupons were placed at each data center (closed and outside-air cooled types) with the location categorized into three groups:
Measuring of exhaust gas emissions using absorption spectroscopy
This paper describes an optical fibre sensor for the detection of NOx (NO2 and NO) and CO2 in the exhaust system of a road vehicle. The measurement is based on a free path interaction zone which is interrogated using ... Keywords: absorption spectroscopy, air pollution, carbon dioxide, emissions measurement, exhaust gas emissions, gas sensors, infrared, nitrogen dioxide, nitrogen oxide, optical fibre sensors, ultraviolet, vehicle emissions
Eamonn Hawe; Gerard Dooly; Colin Fitzpatrick; Paul Chambers; Elfed Lewis; W. Z. Zhao; T. Sun; K. T. V. Grattan; M. Degner; H. Ewald; S. Lochmann; G. Bramman; C. Wei; D. Hitchen; J. Lucas; A. Al-Shamma'a; E. Merlone-Borla; P. Faraldi; M. Pidria
??An air?cycle air conditioning system, using a typical automotive turbocharger as the core of the system, was designed and tested. Effects on engine performance were� (more)
Forster, Christopher James
Building Energy Software Tools Directory: DD4M Air Duct Design
friction, constant velocity and or static regain procedures to design air ducts for air conditioning, heating, ventilation and materials handling. Allows 1000 duct sections...
A comparison of eight solar-driven absorption cooling systems in the National Solar Data Network
Large solar driven cooling systems of the absorption chiller type offer opportunities to apply solar energy to the air conditioning of buildings with the attendant savings in conventional energy resources. Many complex design problems are encountered in the attempt to implement this technology. For instance, the range of readily available solar installation operating temperatures is at the low end of the required range for effective operation of the chillers. A study has been made of eight such systems which were operated in a variety of climates during the 1980 cooling season and instrumented within the National Solar Data Network (NSDN). Presented here are summary results of this study. Considerably more detail on the performance of these systems is contained in the reference along with a brief discussion of absorption chillers and their application in solar designs. The performance of the monitored installations was not very good. Only two systems showed energy savings and they were insignificant considering the size of the buildings. Nevertheless valuable lessons were learned from the study. Each system had some desirable design features. Taking these features together, a projected composite system was posited which would have performed fairly well. Suggestions are presented which should lead to more effective designs for this type of renewable energy application.
Kelly, C.J.; Logee, T.L.
Life Cycle cost Analysis of Waste Heat Operated Absorption Cooling Systems for Building HVAC Applications
In this paper, life cycle cost analysis (LCCA) of waste heat operated vapour absorption air conditioning system (VARS) incorporated in a building cogeneration system is presented and discussed. The life cycle cost analysis (LCCA) based on present worth cost (PWC) method, which covers the initial costs, operating costs, maintenance costs, replacement costs and salvage values is the useful tool to merit various cooling and power generation systems for building applications. A life cycle of 23 years was used to calculate the PWC of the system for annual operating hours of 8760 and the same is compared with the electric based vapour compression chiller (VCRS) of same capacity. The life cycle cost (LCC) of waste heat operated absorption chiller is estimated to be US $ 1.5 million which is about 71.5 % low compared to electric powered conventional vapour compression chiller. From the analysis it was found that the initial cost of VARS system was 125 % higher than that of VCRS, while the PWC of operating cost of VARS was 78.2 % lower compared to VCRS. The result shows that the waste heat operated VARS would be preferable from the view point of operating cost and green house gas emission reduction.
Saravanan, R.; Murugavel, V.
Air Pollution (Illinois)
This article states regulations for monitoring air pollution, methods for permit applications, emission limitations for pollutants and air quality standards.
Rooftop Unitary Air Conditioner with Integral Dedicated Outdoor Air System
Energy use of rooftop and other unitary air-conditioners in commercial applications accounts for about 1 quad (10{sup 15} Btu) of primary energy use annually in the U.S. [Reference 7]. The realization that this cooling equipment accounts for the majority of commercial building cooled floorspace and the majority also of commercial building energy use has spurred development of improved-efficiency equipment as well as development of stricter standards addressing efficiency levels. Another key market driver affecting design of rooftop air-conditioning equipment has been concern regarding comfort and the control of humidity. Trends for increases in outdoor air ventilation rates in certain applications, and the increasing concern about indoor air quality problems associated with humidity levels and moisture in buildings points to a need for improved dehumidification capability in air-conditioning equipment of all types. In many cases addressing this issue exacerbates energy efficiency, and vice versa. The integrated dedicated outdoor air system configuration developed in this project addresses both energy and comfort/humidity issues.
Tiax Llc
DOE Requires Air-Con International to Cease Sales of Inefficient Air
Requires Air-Con International to Cease Sales of Inefficient Requires Air-Con International to Cease Sales of Inefficient Air Conditioners and Proposes Penalties DOE Requires Air-Con International to Cease Sales of Inefficient Air Conditioners and Proposes Penalties September 21, 2010 - 6:43pm Addthis The Department has issued a Notice of Noncompliance Determination and Proposed Civil Penalty to Air-Con, International, requiring Air-Con to cease the sale of certain air-conditioning systems in the United States and proposing a civil penalty of $231,090 for sales of these products in violation of the applicable energy efficiency standards. This action reflects the Department's continued commitment to act aggressively to remove unlawful products from the market. In March, 2010, the Department issued a subpoena requiring Air-Con to
but by a heat source such as natural gas, propane, solar-heated water, or geothermal-heated water. Because natural gas is the most common heat source for absorption heat...
Compact Absorption Chiller - Energy Innovation Portal
The Compact Absorption Chiller uses microchannel technologies in an absorption heat pump which produces cooling using heat as the primary energy source.
Indoor Air Quality Observations in Public Schools
Investigations of indoor air qmlity or indoor environment problems were accomplished in seven different Texas schools. The schools were located in hot and humid climates. Comfort and mildew were the most frequent complaints. In all cases, the air-conditioning system maintenance and operation was a primary factor in the problem cause and solution. The significance of problems investigated cculd have been minimized had the symptoms been addressed when they were reported the first time. Preventive maintenance and better housekeeping of air-conditioning systems in Texas schools will improve the indoor environment. Schools are encouraged to be more aggressive in preventive maintenance and plan for indoor air quality and energy efficiency in school air-conditioning retrofits.
McClure, J. D.; Estes, J. M.
DOE Requires Air-Con International to Cease Sales of Inefficient...
Civil Penalty to Air-Con, International, requiring Air-Con to cease the sale of certain air-conditioning systems in the United States and proposing a civil penalty of 231,090...
Air Leakage of Furnaces and Air Handlers
Air Leakage of Furnaces and Air Handlers Air Leakage of Furnaces and Air Handlers Title Air Leakage of Furnaces and Air Handlers Publication Type Journal Article LBNL Report Number LBNL-5553E Year of Publication 2010 Authors Walker, Iain S., Mile Lubliner, Darryl J. Dickerhoff, and William W. Delp Journal 2010 ACEEE Summer Study on Energy Efficiency in Buildings The Climate for efficiency is now Date Published 08/2010 Abstract In recent years, great strides have been made in reducing air leakage in residential and to a lesser extent small commercial forced air duct systems. Several authorities have introduced low leakage limits for thermal distribution systems; for example, the State of California Energy Code for Buildings gives credit for systems that leak less than 6% of the total air flow at 25 Pa.
Metal-Air Batteries
Metal-air batteries have much higher specific energies than most currently available primary and rechargeable batteries. Recent advances in electrode materials and electrolytes, as well as new designs on metal-air batteries, have attracted intensive effort in recent years, especially in the development of lithium-air batteries. The general principle in metal-air batteries will be reviewed in this chapter. The materials, preparation methods, and performances of metal-air batteries will be discussed. Two main metal-air batteries, Zn-air and Li-air batteries will be discussed in detail. Other type of metal-air batteries will also be described.
Zhang, Jiguang; Bruce, Peter G.; Zhang, Gregory
Air Temperature in the Undulator Hall
Various analyses have been performed recently to estimate the performance of the air conditioning (HVAC) system planned for the Undulator Hall. This reports summarizes the results and provides an upgrade plan to be used if new requirements are needed in the future. The estimates predict that with the planned loads the tunnel air temperature will be well within the allowed tolerance during normal operation.
Improving air handler efficiency in houses
Although furnaces, air conditioners and heat pumps have become significantly more efficient over the last couple of decades, residential air handlers have typical efficiencies of only 10% to 15% due to poor electric motor performance and aerodynamically poor fans and fan housings. Substantial increases in performance could be obtained through improved air handler design and construction. A prototype residential air handler intended to address these issues has recently been developed. The prototype and a standard production fan were tested in a full-scale duct system and test chamber at LBNL specifically designed for testing heating, ventilation, and air conditioning systems. The laboratory tests compared efficiency, total airflow, sensitivity to duct system flow resistance, and the effects of installation in a smaller cabinet. The test results showed that the prototype air handler had about twice the efficiency of the standard air handler (averaged over a wide range of operating conditions) and was less sensitive to duct system flow resistance changes. The performance of both air handlers was significantly reduced by reducing the clearance between the air handler and cabinet it was placed in. These test results showed that in addition to the large scope for performance improvement, air handler fans need to be tested in the cabinets they operate in.
Ambient Operation of Li/Air Batteries
In this work, Li/air batteries based on nonaqueous electrolytes were investigated in ambient conditions (with an oxygen partial pressure of 0.21 atm and relative humidity of ~20%). A heat-sealable polymer membrane was used as both an oxygen-diffusion membrane and as a moisture barrier for Li/air batteries. The membrane also can minimize the evaporation of the electrolyte from the batteries. Li/air batteries with this membrane can operate in ambient conditions for more than one month with a specific energy of 362 Wh kg-1, based on the total weight of the battery including its packaging. Among various carbon sources used in this work, Li/air batteries using Ketjenblack (KB) carbon-based air electrodes exhibited the highest specific energy. However, KB-based air electrodes expanded significantly and absorbed much more electrolyte than electrodes made from other carbon sources. The weight distribution of a typical Li/air battery using the KB-based air electrode was dominated by the electrolyte (~70%). Lithium-metal anodes and KB-carbon anodes account for only 5.12% and 5.78% of the battery weight, respectively. We also found that only ~ 20% of the mesopore volume of the air electrode was occupied by reaction products after discharge. To further improve the specific energy of the Li/air batteries, the microstructure of the carbon electrode needs to be further improved to absorb much less electrolyte while still holding significant amounts of reaction products
Zhang, Jiguang; Wang, Deyu; Xu, Wu; Xiao, Jie; Williford, Ralph E.
An investigation of solar powered absorption cooling systems for South Africa.
??Increased standards of living and indoor comfort demands have led to an increase in the demand for air-conditioning in buildings in South Africa. Conventional vapor� (more)
Bvumbe, Tatenda Joseph.
Design and Analysis of a Solar Assisted Absorption Cooling System Integrated with Latent Heat Storage.
??Air conditioning is one of the major consumers of electrical energy in many parts of the world. The demand can be expected to increase because� (more)
Hosseini, L.
Thermodynamic Optimization of a Solar System for Cogeneration of Water Heating/Purification and Absorption Cooling.
?? This dissertation presents a contribution to understanding the behavior of solar powered air conditioning and refrigeration systems with a view to determining the manner� (more)
Hovsapian, Zohrob O.
DOE Takes Action to Stop the Sales of Air-Con Air Conditioner Models Shown
Takes Action to Stop the Sales of Air-Con Air Conditioner Takes Action to Stop the Sales of Air-Con Air Conditioner Models Shown to Violate Federal Energy Efficiency Appliance Standards DOE Takes Action to Stop the Sales of Air-Con Air Conditioner Models Shown to Violate Federal Energy Efficiency Appliance Standards September 23, 2010 - 12:00am Addthis Washington, DC - The Department of Energy announced today that it has taken action against Air-Con, International, requiring the company to stop selling certain air conditioning systems in the U.S. that have been shown to violate minimum energy efficiency appliance standards. DOE is proposing a civil penalty of more than $230,000 for importing and distributing these inefficient cooling products. This action and the proposed penalties are part of the Department's continued commitment to act aggressively to remove
Effect of Return Air Leakage on Air Conditioner Performance in Hot/Humid Climates
An experimental study was conducted to quantify the effect of return air leakage from hot/humid attic spaces on the performance of a residential air conditioner. Tests were conducted in psychrometric facilities where temperatures and humidities could be controlled closely. Return air leakage from hot attic spaces was simulated by assuming adiabatic mixing of the indoor air at normal conditions with the attic air at high temperatures. Effective capacity and Energy Efficiency Ratio both decreased with increased return air leakage. However, power consumption was relatively constant for all variables except outdoor temperature, which meant that for the same power consumption, the unit delivered much lower performance when there was return air leakage. The increase in sensible heat ratio (SHR) with increasing leakage showed one of the most detrimental effects of return air leakage on performance.
O'Neal, D. L.; Rodriguez, A.; Davis, M.; Kondepudi, S.
Supply Fan Control for Constant Air Volume Air Handling Units
Since terminal boxes do not have a modulation damper in constant volume (CV) air handling unit (AHU) systems, zone reheat coils have to be modulated to maintain the space temperature with constant supply airflow. This conventional control sequence causes a significant amount of reheat and constant fan power under partial load conditions. Variable Frequency Drives (VFDs) can be installed on these constant air volume systems. The fan speed can be modulated based on the maximum zone load. This paper present the procedure to control the supply fan speed and analyzes the thermal performance and major fan energy and thermal energy savings without expensive VAV retrofit through the actual system operation.
Cho, Y.; Wang, G.; Liu, M.
NETL: Pressure Swing Absorption Device
Pressure Swing Absorption Device and Process for Separating CO2 from Shifted Syngas and its Capture for Subsequent Storage Pressure Swing Absorption Device and Process for Separating CO2 from Shifted Syngas and its Capture for Subsequent Storage Project No.: DE-FE0001323 New Jersey Institute of Technology is developing an advanced pressure swing absorption-based (PSAB) device via laboratory-based experiments. The device will be used to accomplish a cyclic process to process low temperature post-shift-reactor synthesis gas resulting from the gasification process into purified hydrogen at high pressure for use by the combustion turbine of an integrated gasification combined cycle (IGCC) plant. The overall goal of the proposed work is to develop an advanced PSAB device and cyclic process for use in a coal-fired IGCC plant to produce purified hydrogen at high pressure and a highly purified CO2 stream suitable for use or sequestration.
Feasibility of air capture
Capturing CO2 from air, referred to as Air Capture, is being proposed as a viable climate change mitigation technology. The two major benefits of air capture, reported in literature, are that it allows us to reduce the ...
Ranjan, Manya
X-ray absorption fine structure spectroscopic determination of plutonium speciation at the Rocky Flats environmental technology
X-ray Absorption Fine Structure spectroscopy was used to probe the speciation of the ppm level Pu in thirteen soil and concrete samples from the Rocky Flats Environmental Technology Site in support of the site remediation effort that has been successfully completed since these measurements. In addition to X-ray Absorption Near Edge Spectra, two of the samples yielded Extended X-ray Absorption Fine Structure spectra that could be analyzed by curve-fits. Most of these spectra exhibited features consistent with PU(IV), and more specificaJly, PuO{sub 2+x}-type speciation. Two were ambiguous, possibly indicating that Pu that was originally present in a different form was transforming into PuO{sub 2+x}, and one was interpreted as demonstrating the presence of an unusual Pu(VI) compound, consistent with its source being spills from a PUREX purification line onto a concrete floor and the resultant extreme conditions. These experimental results therefore validated models that predicted that insoluble PuO{sub 2+x} would be the most stable form of Pu in equilibrium with air and water even when the source terms were most likely Pu metal with organic compounds or a Pu fire. A corollary of these models' predictions and other in situ observations is therefore that the minimal transport of Pu that occurred on the site was via the resuspension and mobilization of colloidal particles. Under these conditions, the small amounts of diffusely distributed Pu that were left on the site after its remediation pose only a negligible hazard.
Lezama-pacheco, Juan S [Los Alamos National Laboratory; Conradson, Steven D [Los Alamos National Laboratory; Clark, David L [Los Alamos National Laboratory
Absorption-heat-pump system
Grossman, G.; Perez-Blanco, H.
Sounding the Skin of Water: Sensing Air�Water Interface Temperature Gradients with Interferometry
Evidence for the radiometric determination of air�water interface temperature gradients is presented. Inherent radiometric characteristics in the water molecule cause variations in the absorption coefficient that allow radiation at near-infrared ...
W. McKeown; F. Bretherton; H. L. Huang; W. L. Smith; H. L. Revercomb
New Developments in High Velocity Air-fuel Spraying
This is possible because of the low temperature of air-fuel combustion. The heating of the spray ... Conditioning of Composite Lubricant Powder for Cold Spray.
Air Pollution Control (Indiana)
This legislation establishes the Department of Environmental Management and the Air Pollution Control Board, which are tasked with the prevention, abatement, and control of air pollution by all...
Primary zone air proportioner
An air proportioner is provided for a liquid hydrocarbon fueled gas turbine of the type which is convertible to oil gas fuel and to coal gas fuel. The turbine includes a shell for enclosing the turbine, an air duct for venting air in said shell to a gasifier, and a fuel injector for injecting gasified fuel into the turbine. The air proportioner comprises a second air duct for venting air from the air duct for mixing with fuel from the gasifier. The air can be directly injected into the gas combustion basket along with the fuel from the injector or premixed with fuel from the gasifier prior to injection by the fuel injector.
Cleary, Edward N. G. (San Diego, CA)
Air pollution
This book reports that homeowners do not have adequate assurance that companies have demonstrated a minimum level of competency in measuring radon and that the test results provided to them have some degree of accuracy. This is because the voluntary nature of the RMP program allows firms to market devices that have not been tested or that failed the test. In addition, the RMP program does not require measurement companies to implement quality assurance programs. GAO believes that two changes in the RMP program that would increase homeowners' assurance are requiring measurement firms to pass the RMP program before marketing their devices, and requiring radon measurement firms to demonstrate the existence of adequate quality assurance programs as a condition for participating in the RMP program.
Oxygen Absorption in Cooling Flows
The inhomogeneous cooling flow scenario predicts the existence of large quantities of gas in massive elliptical galaxies, groups, and clusters that have cooled and dropped out of the flow. Using spatially resolved, deprojected X-ray spectra from the ROSAT PSPC we have detected strong absorption over energies ~0.4-0.8 keV intrinsic to the central ~1 arcmin of the galaxy, NGC 1399, the group, NGC 5044, and the cluster, A1795. These systems have amongst the largest nearby cooling flows in their respective classes and low Galactic columns. Since no excess absorption is indicated for energies below ~0.4 keV the most reasonable model for the absorber is warm, collisionally ionized gas with T=10^{5-6} K where ionized states of oxygen provide most of the absorption. Attributing the absorption only to ionized gas reconciles the large columns of cold H and He inferred from Einstein and ASCA with the lack of such columns inferred from ROSAT, and also is consistent with the negligible atomic and molecular H inferred from HI, and CO observations of cooling flows. The prediction of warm ionized gas as the product of mass drop-out in these and other cooling flows can be verified by Chandra, XMM, and ASTRO-E.
David A. Buote
Stirling Air Conditioner for Compact Cooling
BEETIT Project: Infinia is developing a compact air conditioner that uses an unconventional high efficient Stirling cycle system (vs. conventional vapor compression systems) to produce cool air that is energy efficient and does not rely on polluting refrigerants. The Stirling cycle system is a type of air conditioning system that uses a motor with a piston to remove heat to the outside atmosphere using a gas refrigerant. To date, Stirling systems have been expensive and have not had the right kind of heat exchanger to help cool air efficiently. Infinia is using chip cooling technology from the computer industry to make improvements to the heat exchanger and improve system performance. Infinia�s air conditioner uses helium gas as refrigerant, an environmentally benign gas that does not react with other chemicals and does not burn. Infinia�s improvements to the Stirling cycle system will enable the cost-effective mass production of high-efficiency air conditioners that use no polluting refrigerants.
Laser supported solid state absorption fronts in silica
We develop a model based on simulation and experiment that explains the behavior of solid-state laser-supported absorption fronts generated in fused silica during high intensity (up to 5GW/cm{sup 2}) laser exposure. We find that the absorption front velocity is constant in time and is nearly linear in laser intensity. Further, this model can explain the dependence of laser damage site size on these parameters. This behavior is driven principally by the temperature-activated deep sub band-gap optical absorptivity, free electron transport and thermal diffusion in defect-free silica for temperatures up to 15,000K and pressures < 15GPa. The regime of parameter space critical to this problem spans and extends that measured by other means. It serves as a platform for understanding general laser-matter interactions in dielectrics under a variety of conditions.
Carr, C W; Bude, J D
Economical Analysis of the Cold Air Distribution System: A Case Study
In this paper, we briefly introduce the super cold air distribution technique. By comparing the schemes of two air conditioning systems, including a modified air conditioning system, this paper analyzes the technique parameters and the economics of the cold air distribution system in detail. The detailed analysis includes the air quality, comfort index, initial cost, life cost, static recycle period, and dynamic recycle period. The advantages and trends of super cold air distribution systems in the future are pointed out. The economical analysis and technical comparison is based on real data. The conclusion is useful for the design of super cold air conditioning systems of large shops and office buildings.
Zhou, Z.; Xu, W.; Li, J.; Zhao, J.; Niu, L.
Dynamic Absorption Model for Off-Gas Separation
Modeling and simulations will aid in the future design of U.S. advanced reprocessing plants for the recovery and recycle of actinides in used nuclear fuel. The specific fuel cycle separation process discussed in this report is the off-gas treatment system. The off-gas separation consists of a series of scrubbers and adsorption beds to capture constituents of interest. Dynamic models are being developed to simulate each unit operation involved so each unit operation can be used as a stand-alone model and in series with multiple others. Currently, a rate based, dynamic absorption model is being developed in gPROMS software. Inputs include liquid and gas stream constituents, column properties, liquid and gas phase reactions, number of stages, and inlet conditions. It simulates multiple component absorption with countercurrent flow and accounts for absorption by mass transfer and chemical reaction. The assumption of each stage being a discrete well-mixed entity was made. Therefore, the model is solved stagewise. The simulation outputs component concentrations in both phases as a function of time from which the rate of absorption is determined. Temperature of both phases is output as a function of time also. The model will be used able to be used as a standalone model in addition to in series with other off-gas separation unit operations. The current model is being generated based on NOx absorption; however, a future goal is to develop a CO2 specific model. The model will have the capability to be modified for additional absorption systems. The off-gas models, both adsorption and absorption, will be made available via the server or web for evaluation by customers.
Veronica J. Rutledge
Advanced Strategy Guideline: Air Distribution Basics and Duct Design
This report discusses considerations for designing an air distribution system for an energy efficient house that requires less air volume to condition the space. Considering the HVAC system early in the design process will allow adequate space for equipment and ductwork and can result in cost savings. Principles discussed that will maximize occupant comfort include delivery of the proper amount of conditioned air for appropriate temperature mixing and uniformity without drafts, minimization of system noise, the impacts of pressure loss, efficient return air duct design, and supply air outlet placement, as well as duct layout, materials, and sizing.
Reactive Air Aluminization
Ferritic stainless steels and other alloys are of great interest to SOFC developers for applications such as interconnects, cell frames, and balance of plant components. While these alloys offer significant advantages (e.g., low material and manufacturing cost, high thermal conductivity, and high temperature oxidation resistance), there are challenges which can hinder their utilization in SOFC systems; these challenges include Cr volatility and reactivity with glass seals. To overcome these challenges, protective coatings and surface treatments for the alloys are under development. In particular, aluminization of alloy surfaces offers the potential for mitigating both evaporation of Cr from the alloy surface and reaction of alloy constituents with glass seals. Commercial aluminization processes are available to SOFC developers, but they tend to be costly due to their use of exotic raw materials and/or processing conditions. As an alternative, PNNL has developed Reactive Air Aluminization (RAA), which offers a low-cost, simpler alternative to conventional aluminization methods.
Choi, Jung-Pyung; Chou, Y. S.; Stevenson, Jeffry W.
Permeation absorption sampler with multiple detection
A system for detecting analytes in air or aqueous systems includes a permeation absorption preconcentrator sampler for the analytes and analyte detectors. The preconcentrator has an inner fluid-permeable container into which a charge of analyte-sorbing liquid is intermittently injected, and a fluid-impermeable outer container. The sample is passed through the outer container and around the inner container for trapping and preconcentrating the analyte in the sorbing liquid. The analyte can be detected photometrically by injecting with the sorbing material a reagent which reacts with the analyte to produce a characteristic color or fluorescence which is detected by illuminating the contents of the inner container with a light source and measured the absorbed or emitted light, or by producing a characteristic chemiluminescence which can be detected by a suitable light sensor. The analyte can also be detected amperometrically. Multiple inner containers may be provided into which a plurality of sorbing liquids are respectively introduced for simultaneously detecting different analytes. baffling may be provided in the outer container. A calibration technique is disclosed. 9 figs.
Zaromb, S.
Krypton for Multi-Pane Windows: Selective Absorption of Krypton from Oxygen
Krypton for Multi-Pane Windows: Selective Absorption of Krypton from Oxygen Krypton for Multi-Pane Windows: Selective Absorption of Krypton from Oxygen in an Ionic Liquid Speaker(s): John Prausnitz Waheed Afzal Date: September 18, 2012 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Robert Hart Because of its low thermal conductivity, krypton is a useful gas for the vapor space of double- (or triple-) pane windows. However krypton is more expensive than argon, currently used for most of multi-pane windows. The high price of krypton is due to the energy-intensive cryogenic process for its recovery from oxygen that is obtained from air. Ionic liquids may provide a cost-effective absorption process for separation of krypton from the oxygen stream of a liquid-air plant. The polarizability of krypton is higher than that of oxygen; therefore, krypton solubility may be