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Office of Scientific and Technical Information
Effect of Return Air Leakage on Air Conditioner Performance in Hot/Humid Climates
E-Print Network (OSTI)
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.
Alternate Air Delivery Systems for Hot and Humid Climates
Carter & Burgess first began using triple deck multi-zone units, in place of traditional VAV systems, on the Texas State Capitol restoration. Since the completion of that project design in early 1991, our firm has now used triple deck multi-zone units in the Harris County Criminal Courts Building in Houston, one of the most hot and humid climates in the United States, as well as in several other facilities. This paper will discuss the adoption of ASHRAE 62, its effects on VAV systems, and how triple deck multi-zone units offer an alternative system to cooling in hot and humid climates. We recommend all design firms add triple deck multizone units to their repertoire of design solutions.
Wallace, M.
Indoor air movement acceptability and thermal comfort in hot-humid climates
in Brazil's hot humid climate zone. Building and Environmentin moderate thermal climate zones. Building and EnvironmentBrazil's hot humid climate zone. Building and Environment,
Candido, Christhina Maria
Simulation of Dehumidification Characteristics of High Efficiency Residential Central Air-Conditioners in Hot and Humid Climates
This study assesses the dehumidifying performance of the high efficiency residential central air conditioners (CAC) in hot/humid climates typified by that of Houston and Galveston. The performance study is based on such factors as: (i) weather (ii) thermostat set point and dead band, and (ill) sizing of unit relative to the design load of the residence. The units are evaluated on their ability to maintain conditions in the ASHRAE comfort zone in a typical residence in Houston area. The units, the thermostat, and the residence are simulated on a minute-by-minute basis using a commercial software (TRNSYS) after making certain modifications to it.
Katipamula, S.; O'Neal, D.; Somasundram, S.
Windsor Conference - Air Conditioning and the Low CarbonA. , Thomas, PC (2010). Air conditioning, comfort and energyAmerica's Romance with Air- Conditioning. Washington, D.C.
Analysis and design of a solar-powered liquid-desiccant air conditioner for use in hot and humid climates
SciTech Connect
An experimental and theoretical investigation of the feasibility of a solar-powered liquid-desiccant air conditioner, for use in hot and humid climates, was carried out at the Mechanical Engineering Department, University of Florida. The proposed liquid desiccant system used nonadiabatic contactors, packed with finned-tube coils, for both moist air dehumidification and liquid-desiccant regeneration. A theoretical model was developed to analyze the complex phenomena of simultaneous heat and mass transfer in nonadiabatic contactors, as well as the continuous interaction between the dehumidification and regeneration processes. A computer code was written to assist in the analysis of the dehumidification and regeneration processes separately and coupled, for continuous operation. It was used to investigate the interaction between the different controlling parameters and their effects on the overall performance of the desiccant system. A fully solar-powered liquid-desiccant air-conditioner, with three tons of capacity was designed and optimized including economical criteria. The overall coefficient of performance (COP) of the optimized system was determined to be 0.312.
Chebbah, A.
country�s building sector is responsible for 46.7% of China�s total energy consumption and heating and air-conditioning
comfort in warm conditions. ASHRAE Trans 84 (2): 263 � 277.Moving air for comfort. ASHRAE Journal: 18-29. [9] Zhang,control, and occupant comfort. ASHRAE Trans 110:17�35. [11
Atmospheric Condensation Potential of Windows in Hot, Humid Climates
In hot, humid climates, the internal surfaces of windows in air-conditioned buildings are in contact with relatively colder air. Meanwhile, the external surfaces are exposed to hot humid atmospheric air. This hygro-thermal condition may cause frequent atmospheric condensation on external surfaces of windows when their surface temperature drops below the dew point temperature of the hot humid air. To date, external surface condensation on windows has been given relatively much less importance than their internal surface condensation. In addition, the thermal analysis of windows in hot humid climates has always been performed in the absence of condensation. Under moderate air temperature and humidity conditions, such practice is acceplable. However, when windows experience atmospheric condensation on their external surfaces, the effect of condensation on window energy loss needs to be examined. In this paper, the external condensation process is analyzed and the atmospheric water vapor mass condensation rate has been obtained by utilizing a simplified transient uni-dimensional finite difference model. The results show that this model has enhanced the assessment of the potential for atmospheric condensation on windows in hot, humid climates and in predicting the amount of condensation expected, as well as the associated energy loss for given thermal and moisture conditions. The numerical computation of the model is able to account for condensation and its impact on the temperature gradient across the window. Thermal analysis of both single and insulated double-glazed windows under condensation conditions is presented. The work also includes the computational procedure used and the results or a case study demonstrating the model's capabilities.
El Diasty, R.; Budaiwi, I.
Evaluation of Energy Efficiency Measures in Hot and Humid Climates
Hot and humid climates present some of the most complex challenges for sustainable building designs. High temperatures coupled with high humidity create extreme comfort problems and exacerbate the potential for condensation, mold and mildew. These are usually remedied with conventional mechanical air conditioning systems, but the move toward sustainability urges designers to find less energy intensive solutions. An integrated design process coupled with energy modeling and lifecycle analysis can unite design teams around desired outcomes to provide an optimized design solution for projects in these climates. Such an approach involves first minimizing building loads and then reducing residual energy consumed by the HVAC systems.
This paper presents an integrated design approach to evaluating the most efficient energy measures in hot and humid climates and summarizes the findings of a series of cases using this approach, including international examples of office, education, and small retail buildings in ASHRAE Climate Zones 1A and 2A.
Zhao, Y.; Erwine, B.; Leonard, P.; Pease, B.; Dole, A.; Lee, A.
Energy and economic assessment of desiccant cooling systems coupled with single glazed air and hybrid PV/thermal solar collectors for applications in hot and humid climate
This paper presents a detailed analysis of the energy and economic performance of desiccant cooling systems (DEC) equipped with both single glazed standard air and hybrid photovoltaic/thermal (PV/t) collectors for applications in hot and humid climates. The use of 'solar cogeneration' by means of PV/t hybrid collectors enables the simultaneous production of electricity and heat, which can be directly used by desiccant air handling units, thereby making it possible to achieve very energy savings. The present work shows the results of detailed simulations conducted for a set of desiccant cooling systems operating without any heat storage. System performance was investigated through hourly simulations for different systems and load combinations. Three configurations of DEC systems were considered: standard DEC, DEC with an integrated heat pump and DEC with an enthalpy wheel. Two kinds of building occupations were considered: office and lecture room. Moreover, three configurations of solar-assisted air handling units (AHU) equipped with desiccant wheels were considered and compared with standard AHUs, focusing on achievable primary energy savings. The relationship between the solar collector's area and the specific primary energy consumption for different system configurations and building occupation patterns is described. For both occupation patterns, sensitivity analysis on system performance was performed for different solar collector areas. Also, this work presents an economic assessment of the systems. The cost of conserved energy and the payback time were calculated, with and without public incentives for solar cooling systems. It is worth noting that the use of photovoltaics, and thus the exploitation of related available incentives in many European countries, could positively influence the spread of solar air cooling technologies (SAC). An outcome of this work is that SAC systems equipped with PV/t collectors are shown to have better performance in terms of primary energy saving than conventional systems fed by vapour compression chillers and coupled with PV cells. All SAC systems present good figures for primary energy consumption. The best performances are seen in systems with integrated heat pumps and small solar collector areas. The economics of these SAC systems at current equipment costs and energy prices are acceptable. They become more interesting in the case of public incentives of up to 30% of the investment cost (Simple Payback Time from 5 to 10 years) and doubled energy prices. (author)
Beccali, Marco; Finocchiaro, Pietro; Nocke, Bettina [Universita degli Studi di Palermo, Palermo (Italy)
Air humidity requirements for human comfort
Upper humidity limits for the comfort zone determined from two recently presented models for predicting discomfort due to skin humidity and insufficient respiratory cooling are proposed. The proposed limits are compared with the maximum permissible humidity level prescribed in existing standards for the thermal indoor environment. The skin humidity model predicts discomfort as a function of the relative humidity of the skin, which is determined by existing models for human heat and moisture transfer based on environmental parameters, clothing characteristics, and activity level. The respiratory model predicts discomfort as a function of the driving forces for heat loss from the respiratory tract, namely, the temperature and humidity of the surrounding air. An upper humidity limit based on a relative skin humidity of 0.54, corresponding to 20% dissatisfied, results in a maximum permissible humidity level near 100% RH. The requirements for respiratory comfort are much more stringent and result in lower permissible indoor air humidities. Compared with the upper humidity limit specified in existing thermal comfort standards, e.g., ASHRAE Addendum 55a, the humidity limit based on skin humidity was less restrictive and the humidity limit based on respiratory comfort was far more restrictive.
Toftum, J.; Fanger, P.O.
A passive cooling design for multifamily residences [sic] in hot, humid climates
People living in hot, humid climates suffer either from extremely uncomfortable weather conditions or from the great cost of air-conditioning systems for maintaining comfort. Most of the available passive cooling techniques ...
Tang, Joseph C
Residential Humidity Control: Exciting New Opportunities with Air Flow Modulation
This paper reviews psychrometric principles and shows how to formulate a psychrometric chart from a single equation. The chart is used to demonstrate the manner in which a conventional single-speed air conditioner adjusts its operating point in an attempt to control humidity over a range of conditions. The system performance with an electronically commutated motor (ECM) driving the blower is then presented. With ECM blower speed control, it is possible to raise the sensible capacity, reduce the sensible capacity, and boost the efficiency of an otherwise conventional air conditioner. This makes such systems ideal to respond to the changing loads in a hot and humid climate.
Crawford, J. G.
A tropical grammar : an architectural grammar for hot humid climates
This thesis considers the viability of an architectural grammar based on traditional Caribbean architecture as an aid to designing climatically responsive architecture in hot humid climates. It argues that since traditional ...
Beamish, Anne, 1954-
Abstract Radiative Cooling in Hot Humid Climates
Passive radiative cooling of buildings has been an underachieving concept for decades. The few deployments have generally been in dry climates with low solar angles. The greatest need for cooling is in the tropics. The high humidity endemic to many of these regions severely limits the passive cooling available per radiative area. To wrest temperature relief from humid climates, not just nocturnal cooling but solar irradiance, both direct and indirect, must be addressed. This investigation explores the extent to which thermal radiation can be used to cool buildings in the tropics. It concludes that inexpensive materials could be fabricated into roof panels providing passive cooling day and night in tropical locations with an unobstructed view of sky.
Aubrey Jaffer
Hot air drum evaporator
DOE Patents (OSTI)
An evaporation system for aqueous radioactive waste uses standard 30 and 55 gallon drums. Waste solutions form cascading water sprays as they pass over a number of trays arranged in a vertical stack within a drum. Hot dry air is circulated radially of the drum through the water sprays thereby removing water vapor. The system is encased in concrete to prevent exposure to radioactivity. The use of standard 30 and 55 gallon drums permits an inexpensive compact modular design that is readily disposable, thus eliminating maintenance and radiation build-up problems encountered with conventional evaporation systems.
Black, Roger L. (Idaho Falls, ID)
Residential Dehumidification Systems Research for Hot-Humid Climates: September 1, 2001 -- December 30, 2003
Twenty homes were tested and monitored in the hot-humid climate of Houston, Texas, U.S.A., to evaluate the humidity control performance and operating cost of six different integrated dehumidification and ventilation systems that could be applied by production homebuilders. Temperature and relative humidity were monitored at four living-space locations and in the conditioned attic where the space-conditioning equipment and air-distribution ducts were located. Equipment operational time was monitored for heating, cooling, dehumidification, and ventilation. Results showed that energy efficiency measures, combined with controlled mechanical ventilation, change the sensible and latent cooling load fractions such that dehumidification separate from the cooling system is required to maintain indoor relative humidity below 60% throughout the year. The system providing the best overall value, including humidity control, first cost, and operating cost, involved a standard dehumidifier located in a hall closet with a louvered door and central-fan-integrated supply ventilation with fan cycling.
Rudd, A. F.; Lstiburek, J. W.; Eng, P.; Ueno, K.
Evaluation of Humidity Control Options in Hot-Humid Climate Homes (Fact Sheet)
DOE Green Energy (OSTI)
This technical highlight describes NREL research to analyze the indoor relative humidity in three home types in the hot-humid climate zone, and examine the impacts of various dehumidification equipment and controls. As the Building America program researches construction of homes that achieve greater source energy savings over typical mid-1990s construction, proper modeling of whole-house latent loads and operation of humidity control equipment has become a high priority. Long-term high relative humidity can cause health and durability problems in homes, particularly in a hot-humid climate. In this study, researchers at the National Renewable Energy Laboratory (NREL) used the latest EnergyPlus tool equipped with the moisture capacitance model to analyze the indoor relative humidity in three home types: a Building America high-performance home; a mid-1990s reference home; and a 2006 International Energy Conservation Code (IECC)-compliant home in hot-humid climate zones. They examined the impacts of various dehumidification equipment and controls on the high-performance home where the dehumidification equipment energy use can become a much larger portion of whole-house energy consumption. The research included a number of simulated cases: thermostat reset, A/C with energy recovery ventilator, heat exchanger assisted A/C, A/C with condenser reheat, A/C with desiccant wheel dehumidifier, A/C with DX dehumidifier, A/C with energy recovery ventilator, and DX dehumidifier. Space relative humidity, thermal comfort, and whole-house source energy consumption were compared for indoor relative humidity set points of 50%, 55%, and 60%. The study revealed why similar trends of high humidity were observed in all three homes regardless of energy efficiency, and why humidity problems are not necessarily unique in the high-performance home. Thermal comfort analysis indicated that occupants are unlikely to notice indoor humidity problems. The study confirmed that supplemental dehumidification is needed to maintain space relative humidity (RH) below 60% in a hot-humid climate home. Researchers also concluded that while all the active dehumidification options included in the study successfully controlled space relative humidity excursions, the increase in whole-house energy consumption was much more sensitive to the humidity set point than the chosen technology option. In the high-performance home, supplemental dehumidification equipment results in a significant source energy consumption penalty at 50% RH set point (12.6%-22.4%) compared to the consumption at 60% RH set point (1.5%-2.7%). At 50% and 55% RH set points, A/C with desiccant wheel dehumidifier and A/C with ERV and high-efficiency DX dehumidifier stand out as the two cases resulting in the smallest increase of source energy consumption. At an RH set point of 60%, all explicit dehumidification technologies result in similar insignificant increases in source energy consumption and thus are equally competitive.
Not Available
Humidity Control Systems for Civil Buildings in Hot Summer and Cold Winter Zone in China
In the hot summer and cold winter zone, moisture-laden outside air poses real problems for proper ventilation, air-conditioner sizing, and strategies to overcome the reduced dehumidification capacity of more energy-efficient air-conditioning (AC) systems. Based on our research, this paper further provides the rate and characteristics of moisture resources in civil buildings. Although the ventilation rate is limited with the minimum ventilation rate in the sanitation ventilation mode of the air conditioning period, dehumidifying period and heating period, the ventilation rate is unrestricted in thermal comfort ventilation mode. It is suggested that the operating conditions of the forced ventilation system should be determined on both outdoor air temperature and outdoor air relative humidity (RH). Therefore, the ventilation system should satisfy these requirements during prolonged periods of high ambient humidity. After a detailed presentation of the technical issues, this paper gives specific recommendations for providing adequate ventilation, moisture control and dehumidifying for buildings in hot-humid climates, and takes both the indoor environmental quality (IEQ) and the building energy efficiency into account. Supplying conditioned ventilation air to the buildings appears to be a promising approach to solve the heath problems associated with excessive indoor RH by installation of a separately controlled unit to dry and cool outdoor air.
Yu, X.
Internal Microclimate Resulting From Ventilated Attics in Hot and Humid Regions
Ventilated spaces in the built environment create unique and beneficial microclimates. While the current trends in building physics suggest sealing attics and crawlspaces, comprehensive research still supports the benefits of the ventilated microclimate. Data collected at the University of Florida Energy Park show the attic environment of asphalt shingled roofs to be typically hotter than the outdoor conditions, but when properly ventilated sustains a much lower relative humidity. The hot, humid regions of the United States can utilize this internally convective, exchanging air mass to provide stable moisture levels within attic spaces. Positioning the buildings primary boundary at the ceiling deck allows for utilization of this buffer climate to minimize moisture trapping in insulation and maximize the insulation�s thermal benefits. This investigation concludes the conditions in a ventilated attic are stable through seasonal changes and promotes cost effective, energy efficient climate control of unconditioned spaces in hot, humid regions.
Mooney, B. L.; Porter, W. A.
Energy from humid air. Final report
Results to date are presented for a research project which is in progress at the South Dakota School of Mines and Technology. The goal of the research is to find a cost-effective process to convert the energy in humid air into mechanical work, which will be used to drive an electrical generator. The research is being carried out by computer modeling. Results for a natural draft tower show that it is not a cost-effective way to get energy from humid air. Parametric studies are presented for expansion-compression cycles. With suitable conditions, including large amounts of cooling during compression, this cycle has an attractive net work output. To avoid using all the output power to overcome machine losses, it appears necessary to use a one-machine mechanization. The most promising uses vortex flow to achieve the necessary expansion and subsequent compression with cooling. Power output and costs have been estimated for a vortex plant located in Puerto Rico.
Oliver, T.K.; Groves, W.N.; Gruber, C.L.; Cheung, A.
BC TIPS - Hot-Humid Climate: New Orleans
Energy.gov (U.S. Department of Energy (DOE)) Indexed Site
Hot-Humid Climate: New Orleans Hot-Humid Climate: New Orleans Building Technologies Program The U.S. Department of Energy's Builders Challenge recognizes quality homes that also save you money. U.S. homebuilders from all areas of the country report growing buyer interest in energy-efficient houses, yet buyers often lack basic information that can help them make informed decisions. How can homebuyers tell exceptional energy performance from average energy performance? And how do they figure out just what that difference will mean in their energy bills? Spearheaded by the U.S. Department of Energy (DOE), the Builders Challenge is a voluntary effort to address these consumer questions. The Builders
Technical and Economic Analysis of Solar Cooling Systems in a Hot and Humid Climate
The aim of this paper is to promote efficient and cost effective implementation of advanced solar cooling systems and techniques for the hot and humid climates cities in the United States. After an introduction of basic principles, the development history and recent progress in solar cooling technologies are reported. Nevertheless, the economics of solar energy systems are particularly complex with much inevitable uncertainty due to several factors. In this paper, a simplified comprehensive economic optimization model is developed to determine whether a particular solar system is economically advantageous for a particular project. This model explains and illustrates with simple, but realistic examples the use of life-cycle cost analysis and benefit-cost analysis to evaluate and compare the economic efficiency of the solar cooling system. Consequently, under appropriate conditions, solar or solar-assisted air conditioning systems may be reasonable alternatives to conventional air-conditioning systems in a hot and humid climate.
Moaveni, H.
Building Technologies Office: Guides and Case Studies for Hot-Humid
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A conventional alpha proportional counter which uses air as the counter gas is sensitive to high relative humidity and generates spurious pulses that cannot be distinguished from actual alpha pulses. It was found possible to operate such a counter satisfactorily at high relative humidity by passing a small current ( approximates 15 ma) through the center wire. In this manner the center wire is heated and the relative humidity of the surrounding sheath of air is reduced sufficiently so that operation of the counter at high relative humidity is comparable to operation with dry air, Two different mechanisms are proposed for the formation of spurious pulses in such a counter at high relative humidity. (auth)
Ferrari, A.M.R.; Borkowski, C.J.
The Humid Air Turbine (HAT) Cycle Technology Development Program focused on obtaining HAT cycle combustor technology that will be the foundation of future products. The work carried out under the auspices of the HAT Program built on the extensive low emissions stationary gas turbine work performed in the past by Pratt & Whitney (P&W). This Program is an integral part of technology base development within the Advanced Turbine Systems Program at the Department of Energy (DOE) and its experiments stretched over 5 years. The goal of the project was to fill in technological data gaps in the development of the HAT cycle and identify a combustor configuration that would efficiently burn high moisture, high-pressure gaseous fuels with low emissions. The major emphasis will be on the development of kinetic data, computer modeling, and evaluations of combustor configurations. The Program commenced during the 4th Quarter of 1996 and closed in the 4th Quarter of 2001. It teamed the National Energy Technology Laboratory (NETL) with P&W, the United Technologies Research Center (UTRC), and a subcontractor on-site at UTRC, kraftWork Systems Inc. The execution of the program started with bench-top experiments that were conducted at UTRC for extending kinetic mechanisms to HAT cycle temperature, pressure, and moisture conditions. The fundamental data generated in the bench-top experiments was incorporated into the analytical tools available at P&W to design the fuel injectors and combustors. The NETL then used the hardware to conduct combustion rig experiments to evaluate the performance of the combustion systems at elevated pressure and temperature conditions representative of the HAT cycle. The results were integrated into systems analysis done by kraftWork to verify that sufficient understanding of the technology had been achieved and that large-scale technological application and demonstration could be undertaken as follow-on activity. An optional program extended the experimental combustion evaluations to several specific technologies that can be used with HAT technology. After 5 years of extensive research and development, P&W is pleased to report that the HAT Technology Development Program goals have been achieved. With 0 to 10 percent steam addition, emissions achieved during this program featured less than 8 ppm NO{sub x}, less than 16 ppm CO, and unburned hydrocarbons corrected to 15 percent O{sub 2} for an FT8 engine operating between 0 and 120 F with 65 to 100 percent power at any day.
Richard Tuthill
Guides and Case Studies for Hot-Humid Climates | Department of Energy
Humid Climates Humid Climates Guides and Case Studies for Hot-Humid Climates Map of the Hot and Humid Climate Zone of the United States. This zone covers eastern Texas through Florida and reaches up to mid-Georgia it also includes Puerto Rico and Hawaii. The U.S. Department of Energy (DOE) Building America program has developed a series of best practices and case studies to help builders improve whole-house energy performance in buildings found in hot-humid climates. Best Practice Guides New Construction Case Studies Improvements to Existing Homes Case Studies Best Practice Guides 40% Whole-House Energy Savings in the Hot-Humid Climates - Volume 15 New Construction Case Studies Florida Project: Ravenwood Homes and Energy Smart Home Plans, Inc. - Cape Coral Builder: Ravenwood Homes
Small Residence Multizone Modeling with Partial Conditioning for Energy Effieiency in Hot and Humid Climates
The purpose of this study is to reduce the energy cost of the low-income households in the hot and humid climates of the U.S. and thereby to help them afford comfortable homes. In this perspective, a new HVAC energy saving strategy, i.e. �partial conditioning� was modeled and its potential to reduce the HVAC energy consumption of the low income homes in Texas was quantified. The �partial conditioning� strategy combined three primary ideas: 1) using historic courtyard building schemes to provide a buffer zone between conditioned spaces, 2) zoning and applying occupancy based heating/cooling in each zone, and 3) reusing the conditioned air returning from the occupied zones in the unoccupied zones before it is returned to the system. The study was conducted in four steps: 1) data collection, 2) baseline design and modeling, 3) partial conditioning design and modeling, and 4) analyses and recommendations. First, a site visit was held to the Habitat for Humanity office in Bryan, Texas to collect data on the characteristics of the Habitat for Humanity houses built in Bryan. Second, a base-line Habitat for Humanity house was designed and modeled based on this information along with multiple other resources including International Energy Conservation Code 2012 and Building America benchmark definitions. A detailed comparison was made between the commonly used energy modeling tools (DOE-2.1e, EnergyPlus and TRNSYS) and a modeling method was developed for the estimation of the baseline energy consumption. Third, the �partial conditioning� strategy was introduced into the baseline energy model to simulate a partially conditioned atrium house. As the occupied zone and the direction of the airflow changed throughout the year in the partially conditioned house, this step required an innovative air loop model with interzonal air ducts that allowed for sched- uled bi-directional airflow. This air loop was modeled with the AirflowNetwork model of EnergyPlus. Fourth, the modeling results were analyzed and discussed to determine the performance of the partial conditioning strategy in a hot and humid climate. It was found that partial conditioning strategy can provide substantial (37%-46%) reduction in the overall HVAC energy consumption of small residences (?1,000 ft2) in hot and humid climates while performing better in meeting the temperature set points in each room. It was also found that the quantity of the energy savings that can be obtained with the partial conditioning strategy depends significantly on the ground coupling condition of the house for low rise residential buildings.
Andolsun, Simge
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.
Air Conditioner Efficiency Under Hot Dry and Hot Humid Conditions
Science Conference Proceedings (OSTI)
The seasonal energy efficiency ratio (or SEER) has been the subject of extensive research, development, use, and revision for over 30 years. This report gives a review of the past, present, and future of SEER. This review is needed to provide a common background and perspective in response to a move away from one national standard to three standards. Recommendations are made for what electric utilities can do in response to the challenges and opportunities presented by regional climate-sensitive SEERs.
Related Links on New Orleans and Hot-Humid Climates | Department of Energy
New Orleans and Hot-Humid Climates New Orleans and Hot-Humid Climates Related Links on New Orleans and Hot-Humid Climates Below are related links to resources specifically for New Orleans, Louisiana, and other hot-humid climates on building with energy efficiency and renewable energy technologies. Learn more about deployment efforts in New Orleans. Building a Durable and Energy Efficient Home in Post-Katrina New Orleans This report from Building Science examines designing homes with key sustainability concepts, durability, and energy efficiency that can provide insurance to people in the event of a hurricane. Designing and Building Hurricane-Resistant Homes This article from the Consortium for Advanced Residential Buildings details a production builder's efforts to identify better wall systems to use in
Simulation Study of Hybrid Ground Source Heat Pump System in the Hot-Humid Climate.
??The beachfront hotel with hybrid geothermal heat pump system (HyGSHP), located in the hot-humid climate, is simulated by TRNSYS in the thesis, and the simulation� (more)
Zhu, Jiang
Wet-Bulb Temperature from Relative Humidity and Air Temperature
An equation is presented for wet-bulb temperature as a function of air temperature and relative humidity at standard sea level pressure. It was found as an empirical fit using gene-expression programming. This equation is valid for relative ...
Roland Stull
Building for the Pacific Rim Countries. Energy-efficient building strategies for hot, humid climates
This book has been published by the Solar Energy Industries Association (SEIA), the US trade association of the solar thermal, photovoltaic, and passive solar manufacturers, distributors, and component suppliers. Its purpose is to help architects, builders, and developers construct energy-efficient homes in hot humid climates like the Pacific Rim Countries, and to allow occupants of these homes to enjoy enhanced comfort without reliance on mechanical air-conditioning systems. Two important factors are addressed in this book. First, the past few years have seen a tremendous increase in practical applications of new research. The current popularity of ceiling paddle fans, attic radiant barriers and natural daylighting attest to the importance of keeping up with the latest concepts in energy-reduction and comfort-awareness. Professionals who have been in the field for the past few years may be unaware of the latest research findings--some of which dramatically alter prior thinking on such subjects as natural ventilation or mechanical air conditioning. The second factor is the importance of site-specific characteristics, which greatly affect building strategies and designs. A thorough understanding of the climate is a prerequisite to good building design. Such factors as temperature, humidity, wind speed and direction, and solar radiation must be understood and properly integrated into the design for the home to be truly energy-efficient.
Sheinkopf, K. [ed.
Can ASHRAE Standard 62-1989 Requirements be Satisfied while Maintaining Moisture Control using Stock HVAC Equipment in Hot, Humid Climates?
Outdoor air intake rates are studied to determine their impacts on moisture control in buildings, especially in hot, humid climates. Key impacts of outdoor air intake rates can be readily modeled and studied using computer simulations of building energy costs. Increased ventilation rates create real capital and operating costs for building owners and operators, with implications beyond energy costs relating to increased ventilation requirements. In hot, humid climates, increased ventilation rates increase latent loads more than sensible loads, requiring lower sensible heat ratios. Stock HVAC package units and split systems are not available with the requisite sensible heat ratios, and cannot maintain moisture control in small commercial buildings without costly modifications.
Turner, S. C.
Appropriate Conservation Measures for Single-Family Buildings in Hot, Humid Climates
The effectiveness of a number of energy conservation measures for homes located in hot, humid climates was analyzed using the DOE-2.1B building simulation model. Measures having the greatest benefits to the homeowner are predicted to be the addition of ceiling insulation only if the house is not already insulated, weatherization, and reduction of the wall outer surface solar absorptance. The weatherization and solar absorptance reduction measures should be do-it-yourself installations to be cost-effective Replacement of an air-conditioning unit with a new high-efficiency unit was very effective in reducing peak demand and annual cooling energy. Unless the energy efficiency ratio of the existing unit is low (< 6), replacement is generally not cost-effective. The measures were predicted to result in slightly increased indoor humidities, but their effect on human comfort was predicted to be small. However, this conclusion should be considered preliminary since the simulation models used for these predictions have limitations. The amount of energy that can be saved by these measures is very dependent on the occupant's lifestyle, such as the degree to which the occupants will alter clothing to achieve comfort.
McLain, H. A.; MacDonald, J. M.; Goldenberg, D.
Performance Evaluation of a Hot-Humid Climate Community
Project Home Again is a development in New Orleans, LA created to provide new homes to victims of Hurricane Katrina. Building Science Corporation acted as a consultant for the project, advocating design strategies for durability, flood resistance, occupant comfort, and low energy use while maintaining cost effectiveness. These techniques include the use of high density spray foam insulation, LoE3 glazing, and supplemental dehumidification to maintain comfortable humidity levels without unnecessary cooling.
Osser, R.; Kerrigan, P.
BAIHP (www.baihp.org ) conducts systems
research and technical assistance activities for new
housing. Hot-humid climate efforts described here
Systems research : NightCool � A hybrid cooling
and dehumidification strategy employing radiative
cooling and desiccant materials. Interior Duct
Systems in Manufactured Houses � Tests are ongoing
in an occupied prototype home in Alabama and the
FSEC manufactured housing lab. Ventilation and
Dehumidification � A new strategy has been
developed to hook up a whole-house dehumidifier so
that it only runs when the air conditioning
compressor is off. Plug Load Reduction � Whole
house feedback devices and security system based
plug load reductions are being evaluated in prototype
homes. Solar and Conventional Domestic Hot Water
(DHW) Testing � A test facility is being constructed
to conduct side by side testing of three active and
passive solar, two gas and two electric DHW
Technical assistance was provided on the design,
construction and evaluation of four near zero energy
homes and over 300 highly energy efficient
production homes in subdivisions during 2007 and
Chandra, S.; Parker, D.; Sherwin, J.; Colon, C.; Fonorow, K.; Stroer, D.; Martin, E.; McIlvaine, J.; Chasar, D.; Moyer, N.; Thomas-Rees, S.; Hoak, D.; Beal, D.; Gil, C.
Improving Comfort in Hot-Humid Climates with a Whole-House Dehumidifier, Windermere, Florida (Fact Sheet)
Maintaining comfort in a home can be challenging in hot-humid climates. At the common summer temperature set point of 75 degrees F, the perceived air temperature can vary by 11 degrees F because higher indoor humidity reduces comfort. Often the air conditioner (AC) thermostat set point is lower than the desirable cooling level to try to increase moisture removal so that the interior air is not humid or "muggy." However, this method is not always effective in maintaining indoor relative humidity (RH) or comfort. In order to quantify the performance of a combined whole-house dehumidifier (WHD) AC system, researchers from the U.S. Department of Energy's Building America team Consortium of Advanced Residential Buildings (CARB) monitored the operation of two Lennox AC systems coupled with a Honeywell DH150 TrueDRY whole-house dehumidifier for a six-month period. By using a WHD to control moisture levels (latent cooling) and optimizing a central AC to control temperature (sensible cooling), improvements in comfort can be achieved while reducing utility costs. Indoor comfort for this study was defined as maintaining indoor conditions at below 60% RH and a humidity ratio of 0.012 lbm/lbm while at common dry bulb set point temperatures of 74 degrees -80 degrees F. In addition to enhanced comfort, controlling moisture to these levels can reduce the risk of other potential issues such as mold growth, pests, and building component degradation. Because a standard AC must also reduce dry bulb air temperature in order to remove moisture, a WHD is typically needed to support these latent loads when sensible heat removal is not desired.
Short-Term Test Results: Transitional Housing Energy Efficiency Retrofit in the Hot-Humid Climate
This project evaluates the renovation of a 5,800 ft2, multi-use facility located in St. Petersburg, on the west coast of central Florida, in the hot humid climate. An optimal package of retrofit measures was designed to deliver 30-40% annual energy cost savings for this building with annual utility bills exceeding $16,000 and high base load consumption. Researchers projected energy cost savings for potential retrofit measures based on pre-retrofit findings and disaggregated, weather normalized utility bills as a basis for simulation true-up. A cost-benefit analysis was conducted for the seven retrofit measures implemented; adding attic insulation and sealing soffits, tinting windows, improving whole building air-tightness, upgrading heating and cooling systems and retrofitting the air distribution system, replacing water heating systems, retrofitting lighting, and replacing laundry equipment. The projected energy cost savings for the full retrofit package based on a post-retrofit audit is 35%. The building's architectural characteristics, vintage, and residential and commercial uses presented challenges for both economic projections and retrofit measure construction.
Sutherland, K.; Martin, E.
Evaluation of Humidity Control Options in Hot-Humid Climate Homes (Fact Sheet), Building America: Technical Highlight, Building Technologies Program (BTP)
Humidity Control Options in Hot-Humid Climate Homes As the Building America program researches construction of homes that achieve greater source energy savings over typical mid-1990s construction, proper modeling of whole-house latent loads and operation of humidity control equipment has become a high priority. Long-term high relative humidity can cause health and durability problems in homes, particularly in a hot-humid climate. In this study, researchers at the National Renewable Energy Laboratory (NREL) used the latest EnergyPlus tool equipped with the moisture capacitance model to analyze the indoor relative humidity in three home types: a Building America high-performance home; a mid- 1990s reference home; and a 2006 International Energy Conservation
Univariate and Multivariate Assimilation of AIRS Humidity Retrievals with the Local Ensemble Transform Kalman Filter
This study uses the local ensemble transform Kalman filter to assimilate Atmospheric Infrared Sounder (AIRS) specific humidity retrievals with pseudo relative humidity (pseudo-RH) as the observation variable. Three approaches are tested: (i) ...
Junjie Liu; Hong Li; Eugenia Kalnay; Eric J. Kostelich; Istvan Szunyogh
D-Zero Instrument Air System Humidity Transmitter Evaluation
This report shows the findings that resulted in the purchase of the optimum dew point hygrometer for use in the D-Zero instrument air system (see diagram 2 on page 9). The hygrometer will monitor the air syste m to insure that the dew point level does not go above the normal operating output of the driers (this precise value will be determined during initial system start-up). The following criteria was used in the evaluation: (1) Long term durability; (2) Minimum calibration; (3) Indicate a dew point level down to -40 C accurately; (4) Designed to work in a low humidity region; (5) Minimum maintenance; (6) Fast response time; and (7) Lowest cost provided all other criteria is met.
Serges, T.J.; /Fermilab
Enthalpy Wheels Come of Age: Applying Energy Recovery Ventilation to Hospitality Venues in Hot, Humid Climate
Energy recovery ventilation systems, including rotary heat exchangers or enthalpy wheels, utilize mature technologies that are routinely applied in commercial buildings. Energy recovery is particularly important in buildings with significant outdoor air intake requirements and has recently become widely accepted in applications such as schools and theatres. Hospitality applications including restaurants, bars, casinos and similar settings also stand to benefit from application of the technology, however, there is a lack of experience and therefore of accepted guidance in these applications. Furthermore, the unique challenges inherent in the variety of hospitality venues may limit appropriate use of the technology. Applying energy recovery ventilation to hospitality venues in hot, humid climates need not be complex. This paper proposes guidelines that can facilitate application of the technology by specifiers or other construction professionals. These guidelines address evaluation of typical projects for the suitability of energy recovery, selection of appropriate energy recovery ventilation technology, and criteria for successful application of enthalpy wheels. Examples of applications developed for different mechanical systems and building types are provided. The literature describing the opportunities and limitations associated with enthalpy wheels is summarized and referenced. Installation, operation, and maintenance insights are presented, derived from the body of industry experience with enthalpy wheels.
Wellford, B. W.
Critical Plane Analysis of Wall Assembly in a Hot, Humid Climate
Condensation plane analysis for determining critical planes at which condensation may occur can be performed for building assemblies in any climate. Procedures for doing so in heating climates where buildings dry to the outside of envelope assemblies are given in 1997 ASHRAE Fundamentals Handbook, Chapter 22 "Thermal and Moisture Control in Insulated Assemblies - Fundamentals." Little original work is available elsewhere in the literature to guide analysis for buildings in hot and humid climates. Example 1 in Chapter 22 of the Fundamentals Handbook gives step-by-step calculations, for a heating climate. To analyze envelope assemblies in hot and humid climates where drying predominately occurs to the indoors, no direct discussion or examples are available. This paper presents this detail for a typical light commercial wall assembly, and provides the basis for analysis of any envelope assembly in hot and humid climates. Analysis of an envelope assembly in hot and humid climates seeks to determine if there is a critical plane in the wall towards which water vapor flows more rapidly from the outdoors than it flows to the indoors. (In heating climates, the analysis is reversed). In order to do this, weather data must be examined to yield outdoor conditions, and indoor conditions must be identified. Water vapor and thermal resistance of the materials in the wall assembly must also be established. These data are then used to perform calculations using the basic diffusion equation and methods described in the Fundamentals Handbook.' Each potentially critical plane is analyzed to determine if water vapor can accumulate more rapidly than it dissipates. This potential accumulation would signify a heightened risk of equilibrium relative humidity sufficient to amplify microbial growth, or to promote the deterioration of building materials.
Analysis of Innovative HVAC System Technologies and Their Application for Office Buildings in Hot and Humid Climates
Analysis of Innovative HVAC System Technologies and Their Application for Office Buildings in Hot and Humid Climates. (December 2010)
Oleksandr Tanskyi, B.S., National Technical University of Ukraine;
M.S., National Technical University of Ukraine
Co-Chairs of Advisory Committee: Dr. David E. Claridge
Dr. Michael B. Pate
The commercial buildings sector in the United States used 18% (17.93 Quads) of the U.S. primary energy in 2006. Office buildings are the largest single energy consumption category in the commercial buildings sector of the United States with annual energy consumption around 1.1 Quads. Traditional approaches used in commercial building designs are not adequate to save energy in both depth and scale. One of the most effective ways to reduce energy consumption is to improve energy performance of HVAC systems.
High-performance HVAC systems and components, as well as application of renewable energy sources, were surveyed for buildings in hot and humid climates. An analysis of performance and energy saving potential estimation for selected HVAC systems in hot and humid climates was developed based on energy consumption simulation models in DOE-2.1E.
A calibrated energy consumption model of an existing office building located in the hot and humid climate conditions of Texas was developed. Based on this model, the energy saving potential of the building was estimated.
In addition, energy consumption simulation models were developed for a new office building, including simulation of energy saving measures that could be achieved with further improvements of HVAC system above the energy conservation codes requirements. The theoretical minimum energy consumption level for the same office building was estimated for the purpose of evaluating the whole building energy efficiency level. The theoretical minimum energy consumption model of the office building was designed to provide the same level of comfort and services to the building occupants as provided in the actual building simulation model.
Finally, the energy efficiency of the building that satisfies valid energy conservation codes and the building with an improved HVAC system was estimated based on theoretically minimum energy consumption level.
The analysis provided herein can be used for new building practitioners and existing building owners to evaluate energy reduction potential and the performance of innovative technologies such as dedicated outdoor air system, displacement ventilation, improved cooling system efficiency, air source heat pumps and natural gas heat pumps.
Tanskyi, Oleksandr
This paper investigates the feasibility of off-grid, off-pipe housing in hot-humid and hot-arid climates in the U.S. The study aims to eliminate the need for non-renewable sources of energy and municipal water in residences by using off-grid, off-pipe design approach. To accomplish this, a 2001 International Energy Conservation Code compliant house in Houston, TX and Phoenix, AZ was simulated to determine the base-case energy and water use. Based on the availability of on-site renewable energy and water sources (i.e., solar, wind and biomass and rainfall) in these locations, energy and water efficiency measures were selected in order to reduce the energy and water use to a level that could be met solely by on-site renewable resources. Finally, the sizing of the renewable energy and rainwater harvesting systems was performed to provide for daily needs as well as cumulative needs during the critical periods, in order to achieve complete self sufficiency in terms of energy and water use. The analysis was performed by integrating the results of DOE-2.1e, F-Chart and PV F-Chart programs, and cumulative rainwater supply and water demand analysis. The simulation results demonstrate the differences between the priorities for energy efficiency, water-efficiency and renewable energy measures in hot-humid and hot-arid climates.
Malhotra, M.; Haberl, J.
Modeling Building Energy Use and HVAC Efficiency Improvements in Extreme Hot and Humid Regions
An energy analysis was performed on the Texas A & M University at Qatar building in Doha, Qatar. The building and its HVAC systems were modeled using EnergyPlus. Building chilled water and electrical data were collected to validate the computer simulation. The simulated monthly electricity consumption was within plus/minus 5 percent of the metered building data. Ninety-five percent of simulated hourly electricity data in a day were within plus/minus 10 percent of metered data. Monthly chilled water demand was within plus/minus 18 percent of measurements, and simulated monthly demand was correlated to metered monthly values with an R-squared correlation coefficient of 0.95. Once the simulation was verified with the metered data, an optimization of the building's HVAC systems was performed. Better utilizing the building's variable speed fans at part loads showed potential annual electricity savings of 16 percent over the base case, with another 22 percent savings in chilled water energy. After converting chilled water savings to equivalent chiller electricity savings, the potential utility cost savings over the base case were found to be $90,000/yr at local utility rates. Reducing outdoor air intake to ASHRAE indoor air quality minimums yielded an additional 17 percent in potential chilled water savings and brought total monetary savings over the base case to $110,000/yr. Using a dedicated outside air system to precisely control individual zone ventilation showed potential for an additional 12 percent chilled water savings and $14,000 in yearly utility savings, while also eliminating cases of under-ventilation. A hypothetical retrofit of fan powered terminal units (FPTU's) resulted in energy savings only at very low minimum flow rates, below ventilation standards. Savings were never more than 20 percent over the no-fan case. Series FPTU's showed no savings at any flow setting and negligible difference was found between ECM and SCR motor control. Finally, the dependence on climate of each improvement was studied. Simulations were run in the relatively milder climates of Houston and Phoenix and compared to those found for Doha. It was found that variable speed fan operation is a more cost effective option for milder climates, while outside air control is more cost effective in extreme hot and humid climates such as Doha. Future study is needed to make the FPTU model valid for different climates and flow ranges.
Bible, Mitchell
Measured Energy Savings from Retrofits Installed in Low-Income Housing in a Hot and Humid Climate
The Florida Solar Energy Center (FSEC) is metering energy use in a Habitat for Humanity housing development. The objective is to understand the way in which energy is used in low income housing and how it can be effectively reduced. The ten homes come from a conventional housing project built by in 1993 Habitat for Humanity in Homestead, Florida. The instrumentation was installed in the homes in July of 1994 with over three years of 15-minute data collected on all sites. Data were obtained on seven electrical end-uses (air conditioning, heating, hot water, dryer, range, refrigerator, washer/freezer) as well as total. Weather conditions were also monitored as well as interior comfort conditions (temperature and humidity) and hot water consumption and window ventilation status. Baseline field data from a year of monitoring from the ten homes allowed unique insight into how energy is used in low income housing and suggested where consumption might be reduced. In April of 1997, a series of detailed retrofits were applied to eight of the ten Habitat homes. These included solar water heaters installed in seven homes. In eight homes we retrofit light features to compact fluorescent types, repaired and sealed duct air distribution systems, cleaned refrigerator coils and installed low-flow showerheads. Since each of he associated energy end-uses (including hot water consumption) is metered, we are able to assess the relative performance of each of the retrofits. We also measured of air conditioner performance and house tightness. These audits revealed numerous problems, but low-evaporator coil air flow was discovered in all homes. The paper describes the retrofit installation, audit data collected and the impact on measured energy consumption. Preliminary economics are explored.
Parker, D. S.; Sherwin, J. R.; Floyd, D. B.
Experimental results for diffusion and infiltration of moisture in concrete masonry walls exposed to hot and humid climates
This paper presents experimental test results for heat and moisture migration in walls exposed to hot and humid climates. The research was conducted to study the problem of mold and mildew caused by moisture transfer into walls of concrete masonry unit (CMU) type construction by diffusion and convective transport by air infiltration. This type of construction is common in commercial buildings in the southern US. The tests were conducted in two phases. Phase 1 evaluated heat and moisture transfer by diffusion. Phase 2 testing involved air infiltration through the test walls. Data were also collected to determine the rate at which the test walls would dry out without infiltration present. Test results indicate that an exterior vapor retarder will reduce the moisture migration into the wall and thereby lower the moisture accumulation due to infiltration when a vapor retarder (such as vinyl wallpaper) is used for the interior surface treatment. Testing also showed that while the exterior wall treatment does have an effect on reducing the total moisture accumulation in the test walls, the interior wall treatment has a much larger impact when infiltration is present. The data support a proposed criterion for the onset of mold and mildew, which requires a monthly average surface relative humidity of 80% with temperatures between 32 F and 105 F.
Hosni, M.H.; Sipes, J.M.; Wallis, M.H.
An analysis of maximum residential energy-efficiency in hot and humid climates
Energy-efficient building design involves minimizing the energy use and optimizing the performance of individual systems and components of the building. The benefits of energyefficient design, in the residential sector, are direct and tangible, provided that design strategies with a substantial combined energy and cost-saving potential are adopted. Many studies have been performed to evaluate the energy-saving potential and the costeffectiveness of various design options, and to identify conditions for optimizing the performance of building systems and components. The results of these studies, published in various resources, were analyzed discretely using different techniques, and were reported using different bases for comparison. Considering the complex interaction of, and energy flows through various building components, it is difficult to directly compare/combine the results from various studies to determine the energy-saving potential of combination of strategies, and to select an appropriate set of strategies for making design decisions. Therefore, this thesis develops a comprehensive survey and analysis of energy-efficient design strategies and their energy-saving potential, in isolation as well as in combination, using a DOE-2 simulation model of a prototype house in the hot and humid climate of Houston, Texas. Optimized strategies that included building configuration, materials/ assembly for building envelop components, and efficient mechanical and electrical systems, equipment and appliances, were applied in combination that could minimize the annual energy use. Application of these strategies is expected to allow downsizing systems and equipment and to confirm their operation at their rated performance, resulting in additional installation and operation cost savings. The study is concluded by outlining the procedures for selecting optimized set of strategies, and by developing guidelines for achieving maximum energy-efficiency in singlefamily detached houses in hot and humid climates. Thus, this study will facilitate the selection of energy-saving measures for their individual or combined application for developing energyefficient residences in hot and humid climates.
Malhotra, Mini
Energy Retrofit Field Study and Best Practices in a Hot-Humid Climate
Energy efficiency improvement as a component of comprehensive renovation was investigated under U.S. Department of Energy (DOE) funding of the Building America Partnership for Improved Residential Construction (BA-PIRC). Researchers at the Florida Solar Energy Center (FSEC) worked with affordable housing partners renovating foreclosed homes built from the 1950's through the 2000's in the hot-humid climate (within the Southern census region), primarily in Florida. Researchers targeted a 30% improvement in whole-house energy efficiency along with the health and safety, durability, and comfort guidelines outlined in DOE's Builders Challenge Program (Version 1) Quality Criteria.
McIvaine, J.; Sutherland, K.; Martin, E.
Daylight Analysis with Microcomputers for School Buildings in a Hot, Humid Climate
Daylighting and other passive energy technologies are critical issues that should be considered in the early stages of building planning and architectural design. Both new design and retrofit of existing buildings benefit greatly by use of microcomputer-generated models, especially as they relate to building studies in zones of extreme climate. The hot, humid environment of Louisiana poses unique problems and calls for creative solutions. The use of microcomputers as analytical tools to develop suggestions for optimizing the amount of energy consumed for lighting and climatic comfort is illustrated. The effective use of daylighting can, as might be expected, produce net energy savings in most school buildings.
Leaver, J.; McQueen, T.
Development and Construction of Bioclimatic Double Skin Active Facade for Hot and Humid Climate of UAE
Transparency in architecture is desirable for many reasons. In order to build transparent buildings with high levels of occupant comfort without compromising energy performance, facade technology and integration of facade and environmental systems become still more advanced. The present paper deals with the development and construction of mechanically ventilated double skin facade with HVAC integration for hot and humid climate like UAE. A case study is presented, illustrating potential benefits of careful application of the available technologies adopting an integrated approach from the early design phases. Moreover, the paper gives an introduction to test and demonstrate the performance of the facade and HVAC integration.
Karbor, R. G.; Mohamed, I.
Thermal Comfort Study in a Naturally Ventilated Residential Building in a Tropical Hot-Humid Climate Region
This paper presents a thermal comfort study in a naturally ventilated residential building located in a tropical hot-humid climate region. The specific objective of this study is to investigate whether thermal comfort in this house can be achieved through a passive system only. The methods used in this study included conducting hourly monitoring of the temperature and relative humidity; measuring the air velocities; and assessing occupants' thermal sensations through questionnaires and interview. The data from the questionnaires were matched to the monitored data to assess the acceptable range of comfortable condition. Then using an hourly simulation program, some components of the building were also "modified" to investigate whether the building can be made "more comfortable". This study shows that it is possible to provide a thermally comfortable space in this region without using mechanical air-conditioning systems. The occupants' acceptable range of comfortable condition is different than that of people in the northern latitudes. The occupants sensed "neutrality" when the operative temperature in the house was about 27 degree Celsius (80�F). The occupants could also tolerate slightly warm conditions, that is up to 29 degree Celsius (84OF), and still never wanted to install any air-conditioning systems. The simulation showed that using light wall materials would result in cooler indoor temperature at night but warmer during the day. If all windows were opened (25% the total floor area) the house could be more comfortable at night but less comfortable during the day. Findings of this study are important for architects and engineers in designing comfortable living spaces in these regions.
Soebarto, V. I.; Handjarinto, S.
Approaches to 30% Energy Savings at the Community Scale in the Hot-Humid Climate
BA-PIRC has worked with several community-scale builders within the hot humid climate zone to improve performance of production, or community scale, housing. Tommy Williams Homes (Gainesville, FL), Lifestyle Homes (Melbourne, FL), and Habitat for Humanity (various locations, FL) have all been continuous partners of the BA Program and are the subjects of this report to document achievement of the Building America goal of 30% whole house energy savings packages adopted at the community scale. The scope of this report is to demonstrate achievement of these goals though the documentation of production-scale homes built cost-effectively at the community scale, and modeled to reduce whole-house energy use by 30% in the Hot Humid climate region. Key aspects of this research include determining how to evolve existing energy efficiency packages to produce replicable target savings, identifying what builders' technical assistance needs are for implementation and working with them to create sustainable quality assurance mechanisms, and documenting the commercial viability through neutral cost analysis and market acceptance. This report documents certain barriers builders overcame and the approaches they implemented in order to accomplish Building America (BA) Program goals that have not already been documented in previous reports.
Thomas-Rees, S.; Beal, D.; Martin, E.; Fonorow, K.
Relations between Optically Derived Aerosol Parameters, Humidity, and Air-Quality Data in an Urban Atmosphere
This paper deals with diurnal and mensual correlations between ground-based atmospheric observations of columnar and surface optical parameters, standard surface humidity parameters, and surface air-quality data. The implications of a significant ...
N. T. O'Neill; A. Royer; P. Cot�; L. J. B. McArthur
Surface Air Temperature and Humidity from Intersatellite-Calibrated HIRS Measurements in High Latitudes
High-latitude ocean surface air temperature and humidity derived from intersatellite-calibrated High-Resolution Infrared Radiation Sounder (HIRS) measurements are examined. A neural network approach is used to develop retrieval algorithms. HIRS ...
Lei Shi; Ge Peng; John J. Bates
Hot air drum evaporator. [Patent application
Black, R.L.
Integrated Hygrothermal Performance of Building Envelopes and Systems in Hot and Humid Climates
In hot and humid climates the interior and exterior environmental loads that building envelopes must respond to are larger than many other climatic conditions. Moisture-originated failures in low-rise residential buildings have put a significant pressure to change construction codes in North America. Solutions to moisture induced problems may be difficult when several interacting mechanisms of moisture transport are present. A new approach to building envelope durability assessment has been introduced in North America; a moisture engineering approach. This requires system information about the wall systems as constructed along with aging characteristics coupled with advanced modeling that 0 term allow the designer to predict the Iong-term performances of building envelope systems. This permits the comparison and ranking of individual building envelope systems with respect to total hygrothermal performance. Critical information can be obtained by investigating the one to one relationships of a building envelope to interior and exterior environments, however, the total behavior of the actual whole building is not accounted for. This paper goes one step further, by incorporating the individual hygrothermal performances of all walls, roof, floor and mechanical systems. The direct and indirect coupling of the building envelope and indoor environment with HVAC system are included in the analysis. The full house hygrothermal performance of an aerated concrete wall system are examined for a hot and humid climate. The hour by hour drying potential of each system was then numerically analyzed using weather conditions of Miami (hot and humid climate). The results clearly demonstrate the limited drying potential for the wall system in that climate. Furthermore, the selected exterior thermal insulation strategies and interior vapor control strategies in this study clearly show the critical behavior of the full house with respect to drying initial construction moisture. The results show the importance of the total hygrothermal behavior of the whole house to the coupling between the various envelope parts, interior and exterior environments and HVAC system. From these results moisture control strategies are identified for the whole house hygrothermal performance.
Karagiozis, A. N.; Desjarlais, A.; Salonvaara, M.
The U-tube sizes and varied thermal conductivity with different grout materials are studied based on the benchmark residential building in Hot-humid Pensacola, Florida. In this study, the benchmark building is metered and the data is used to validate the simulation model. And a list of comparative simulation cases with varied parameter value are simulated to study the importance of pipe size and grout to the ground source heat pump energy consumption. The simulation software TRNSYS [1] is employed to fulfill this task. The results show the preliminary energy saving based on varied parameters. Future work needs to be conducted for the cost analysis, include the installation cost from contractor and materials cost.
Jiang Zhu; Yong X. Tao
Exploring Cost-Effective, High Performance Residential Retrofits for Affordable Housing in the Hot Humid Climate
In 2009, a Department of Energy Building America team led by the Florida Solar Energy Center began working with partners to find cost-effective paths for improving the energy performance of existing homes in the hot humid climate. A test-in energy audit and energy use modeling of the partner�s proposed renovation package was performed for 41 affordable and middle income foreclosed homes in Florida and Alabama. HERS1 Indices ranged from 92 to 184 with modeled energy savings ranging from 3% to 50% (average of 26%). Analyses and recommendations were discussed with partners to encourage more efficient retrofits, highlight health and safety issues, and gather feedback on incremental cost of high performance measures. Ten completed renovations have modeled energy savings ranging from 9% to 48% (average 31%.) This paper presents the project�s process including our findings thus far and highlights of the first home to meet the target HERS Index of 70.
McIlvaine, J.; Sutherland, K.; Chandra, S.; Schleith, K.
In 2009, a Department of Energy Building America team led by the Florida Solar Energy Center began working with partners to find cost-effective paths for improving the energy performance of existing homes in the hot humid climate. A test-in energy audit and energy use modeling of the partner's proposed renovation package was performed for 41 affordable and middle income foreclosed homes in Florida and Alabama. HERS1 Indices ranged from 92 to 184 with modeled energy savings ranging from 3% to 50% (average of 26%). Analyses and recommendations were discussed with partners to encourage more efficient retrofits, highlight health and safety issues, and gather feedback on incremental cost of high performance measures. Ten completed renovations have modeled energy savings ranging from 9% to 48% (average 31%.) This paper presents the project's process including our findings thus far and highlights of the first home to meet the target HERS Index of 70.
McIlvaine, Janet; Sutherland, Karen; Schleith, Kevin; Chandra, Subrato
Efficient Multifamily Homes in a Hot-Humid Climate by Atlantic Housing Partners
With assistance from the Florida Solar Energy Center (FSEC) and its Building America Partnership for Improved Residential Construction (BA-PIRC), Atlantic Housing Partners (AHP) has implemented a high performance, systems engineered package of measures. This report demonstrates how the initiative achieves Building America (BA) goals of 30%-50% energy savings. Specifically, the goals are documented as being achieved in the new construction multifamily housing sector in the hot humid climate. Results from energy modeling of the high performance package are presented. The role of utility allowance calculations, used as part of the low-income housing tax credit process, to value those energy savings is discussed, as is customer satisfaction with heat pump water heaters.
Chasar, D.; Martin, E.
Thermal and lighting performance of toplighting systems in the hot and humid climate of Thailand
This study evaluated the potential of toplighting systems in the hot and humid tropics by using Bangkok, Thailand (latitude 13.7�?°N) as a test location. The analysis tested both the thermal and lighting performance of three toplighting systems. Toplighting, designed for use in one-story buildings or on the top floor of taller buildings, yields a uniformly distributed light throughout a space. However, in lower latitude locations, where there is no heating period, heat gain is a critical design issue since it significantly affects the annual energy consumption of the building. Accordingly, the decision to use toplighting in these locations needs to be carefully examined before any design considerations occur. In this study, the thermal and lighting performance of three toplighting systems were compared. For the thermal performance, total cooling loads, heat gains and losses, and interior temperature were evaluated. The lighting performance parameters examined were daylight factor, illuminance level, light distribution, and uniformity. EnergyPlus was used as the thermal analysis tool, and RADIANCE, along with a physical scale model, was used as the lighting performance analysis tool. The sky conditions tested were overcast, clear sky, and intermediate sky. Results have shown that, for locations with hot and humid climates with variable sky conditions such as Bangkok, Thailand, the roof monitors perform better than the other two systems in terms of the thermal and lighting performance. With similar cooling loads, the roof monitor provides better illuminance uniformity than the skylights and lightscoops, with adequate illuminance level (at mostly higher than 500 lux).
Harntaweewongsa, Siritip
Control Humidity With Single-Duct, Single-Zone, Constant Air Volume System
The lecture hall of the Richardson Petroleum Building at Texas A&M University is a large lecture hall, with a total floor area of approximately 2500 ft^2. The lecture hall was served by a constant air volume (CAV) air handling unit (AHU) which had no reheat coil. This resulted in high room humidity levels although the room temperature was satisfied for part load conditions, especially when there was very little sensible load from the room. This paper presents Continuous Commissioning efforts (CC), which turned this inefficient, humid lecture hall into a comfortable learning environment. This case study also explores other possibilities to solve the humidity control problem with single-duct, single-zone constant air volume systems.
Chen, H.; Deng, S.; Bruner, H. L.; Claridge, D. E.
Methodology for the Preliminary Design of High Performance Schools in Hot and Humid Climates
A methodology to develop an easy-to-use toolkit for the preliminary design of high performance schools in hot and humid climates was presented. The toolkit proposed in this research will allow decision makers without simulation knowledge easily to
evaluate accurately energy efficient measures for K-5 schools, which would contribute to the accelerated dissemination of energy efficient design.
For the development of the toolkit, first, a survey was performed to identify high performance measures available today being implemented in new K-5 school buildings.
Then an existing case-study school building in a hot and humid climate was selected and analyzed to understand the energy use pattern in a school building and to be used in developing a calibrated simulation. Based on the information from the previous step, an
as-built and calibrated simulation was then developed. To accomplish this, five
calibration steps were performed to match the simulation results with the measured
energy use. The five steps include: 1) Using an actual 2006 weather file with measured solar radiation, 2) Modifying lighting & equipment schedule using ASHRAE�s RP-1093iv
methods, 3) Using actual equipment performance curves (i.e., scroll chiller), 4) Using the Winkelmann�s method for the underground floor heat transfer, and 5) Modifying the
HVAC and room setpoint temperature based on the measured field data. Next, the calibrated simulation of the case-study K-5 school was compared to an ASHRAE Standard 90.1-1999 code-compliant school.
In the next step, the energy savings potentials from the application of several
high performance measures to an equivalent ASHRAE Standard 90.1-1999 codecompliant
school. The high performance measures applied included the
recommendations from the ASHRAE Advanced Energy Design Guides (AEDG) for K-12 and other high performance measures from the literature review as well as a daylighting strategy and solar PV and thermal systems. The results show that the net energy consumption of the final high performance school with the solar thermal and a
solar PV system would be 1,162.1 MMBtu, which corresponds to the 14.9 kBtu/sqft-yr
of EUI. The calculated final energy and cost savings over the code compliant school are
68.2% and 69.9%, respectively. As a final step of the research, specifications for a simplified easy-to-use toolkit were then developed, and a prototype screenshot of the toolkit was developed. The
toolkit is expected to be used by non-technical decision-maker to select and evaluate
high performance measures for a new school building in terms of energy and cost savings in a quick and easy way.
Im, Piljae
A methodology to develop an easy-to-use toolkit for the preliminary design of high performance schools in hot and humid climates was presented. The toolkit proposed in this research will allow decision makers without simulation knowledge easily to evaluate accurately energy efficient measures for K-5 schools, which would contribute to the accelerated dissemination of energy efficient design. For the development of the toolkit, first, a survey was performed to identify high performance measures available today being implemented in new K-5 school buildings. Then an existing case-study school building in a hot and humid climate was selected and analyzed to understand the energy use pattern in a school building and to be used in developing a calibrated simulation. Based on the information from the previous step, an as-built and calibrated simulation was then developed. To accomplish this, five calibration steps were performed to match the simulation results with the measured energy use. The five steps include: 1) Using an actual 2006 weather file with measured solar radiation, 2) Modifying lighting & equipment schedule using ASHRAE's RP-1093 methods, 3) Using actual equipment performance curves (i.e., scroll chiller), 4) Using the Winkelmann's method for the underground floor heat transfer, and 5) Modifying the HVAC and room setpoint temperature based on the measured field data. Next, the calibrated simulation of the case-study K-5 school was compared to an ASHRAE Standard 90.1-1999 code-compliant school. In the next step, the energy savings potentials from the application of several high performance measures to an equivalent ASHRAE Standard 90.1-1999 codecompliant school. The high performance measures applied included the recommendations from the ASHRAE Advanced Energy Design Guides (AEDG) for K- 12 and other high performance measures from the literature review as well as a daylighting strategy and solar PV and thermal systems. The results show that the net energy consumption of the final high performance school with the solar thermal and a solar PV system would be 1,162.1 MMBtu, which corresponds to the 14.9 kBtu/sqft-yr of EUI. The calculated final energy and cost savings over the code compliant school are 68.2% and 69.9%, respectively. As a final step of the research, specifications for a simplified easy-to-use toolkit were then developed, and a prototype screenshot of the toolkit was developed. The toolkit is expected to be used by non-technical decision-maker to select and evaluate high performance measures for a new school building in terms of energy and cost savings in a quick and easy way.
Better Unitary Equipment Air-Handlers for Efficiency and Humidity Control
Regulatory requirements drive unitary equipment design. For residential equipment, SEER reflects performance at moderate temperatures, and is largely independent of high temperature efficiency and high latent heat removal capability. The test procedure gives too little credit for advanced air handlers that reduce air conditioning load and facilitate adaptive humidity control through automatic fan speed adjustment. DC permanent magnet variable speed motors have much lower market share than less efficient permanent split capacitor designs: changing saves 15% - 25% at high fan speed, and at least 50% at lower speeds (high latent cooling). Humidistats allow dynamic humidity control by reducing air flow, cooling the evaporator. Following market transformation to increase market share, federal equipment stanards should be augmented to include specific air handler air flow efficiency levels, such as 0.2 watts/cfm at size-dependent static pressures. We estimate that customer payback will be less than three years in a mature market.
Sachs, H. M.
Best Practice Upgrades for New Energy Efficient Homes in Hot and Humid Climates
The EPA's ENERGY STAR Homes program is a national voluntary program that promotes the construction of new homes that are 30% more efficient than the Model Energy Code. Accordingly, with the Home Energy Rating System (HERS) scoring system, ENERGY STAR Homes must achieve a score of at least an 86. This performance-based compliance requirement enables builders to be creative in the specific energy efficiency features that they build in their new homes. However, builders often want to know what the minimum energy efficiency features of an ENERGY STAR Home would likely be - before they joined the program. To solve this problem, EPA developed the Builder Option Packages (BOPs). BOPS are currently used as marketing tools to communicate the typical energy efficiency features of ENERGY STAR Homes. This paper will focus on the hot and humid portion of the US. and explain the technical methodology used to develop the BOPS as well as the energy use and HERS scores obtained for the various configurations analyzed.
Meisegeier, D.; Hall, J.
Development and analysis of a sustainable, low energy house in a hot and humid climate
This study examines the lifetime building energy consumption of a typical house in Bangkok, Thailand. The lifetime building energy consumption is composed of three major components: 1) the energy used during building construction (embodied energy), 2) the energy used in building operation (annual energy), and 3) the energy used during building demolition (demolition energy). For the embodied energy and the energy used during building demolition analyses, the reference data from reliable sources both in the U.S. and the UK were compared. For the annual energy analysis, the DOE-2 computer energy simulation program was the major analysis tool. The annual energy use of different materials and design strategies were compared based on the DOE-2 simulations. The best energy performances from each comparison were selected to design a new energy efficient house. The results from all three components were combined and compared to a typical American house. Finally, design guidelines for sustainable low energy houses in hot and humid climates were developed.
Chulsukon, Pattarayut
Influence of glazing selection on commercial building energy performance in hot and humid climates
This paper presents a comparative study in which commercial building perimeter zone electric energy (cooling, lighting, fan) and peak electric demand are analyzed as a function of window glazing type, with a particular emphasis on the use of glazings with wavelength-selective solar-optical properties. The DOE-2 energy analysis simulation program was used to generate a data base of the electric energy requirements of a prototypical office building module located in Singapore. Algebraic expressions derived by multiple regression techniques permitted a direct comparison of those parameters that characterize window performance in hot and humid climates: orientation, size, and solar-optical properties. Also investigated were the effects of exterior and interior shading devices, as well as interior illuminance level, power density, and lighting controls to permit the use of daylighting. These regression equations were used to compare the energy implications of conventional window designs and newer designs in which the type of coating and substrate were varied. The analysis shows the potential for substantial savings through combined solar load control and lighting energy use reduction with daylighting.
Sullivan, R.; Arasteh, D.; Sweitzer, G.; Johnson, R.; Selkowitz, S.
Evaluation of Vegetative Roofs' Performance on Energy Consumption in Hot and Humid Climates
Green roofs have been widely used in Europe proved to be beneficial. However, in the US they are not
widespread. Previous studies have concluded that the main obstacle that makes architects, developers, etc. reluctant
to introduce vegetative roofs is their preference for the traditional roofing since it is a tried-and-true technology. A
positive feedback on the performance of vegetative roofs will encourage developers and possibly government
authorities to invest more in them. Therefore, a survey was conducted to determine the performance of green roofs
in existing buildings in hot and humid climates. This paper presents the results of this survey of around 40 buildings.
The methodology and pertinent questions are also presented.
Due to the many parameters involved in determining the rate of energy consumption in a building, a definite
conclusion regarding how much exactly they can effect on saving can not be drawn, however, the results showed
that green roofs can result in saving in the annual energy consumption and using shrubs as well as increasing soil
thickness were found to be most effective in reducing building energy consumption.
Anderson, J.; Azarbayjani, M.
Applications of Commercial Heat Pump Water Heaters in Hot, Humid Climates
Heat pump water heaters can provide high-efficiency water heating and supplemental space cooling and dehumidification in commercial buildings throughout the United States. They are particularly attractive in hot, humid areas where cooling loads are high and the cooling season is long. Because commercial kitchens and laundry facilities have simultaneous water heating and cooling needs, they are excellent applications for heat pump water heaters.
Typical heat pump water heaters (HPWHs) operate at an annual coefficient of performance (COP) of approximately 3.0 for water heating alone. Space conditioning benefits of about 0.67 Btu are delivered at no additional cost for each Btu of water heating output. In situations in which this cooling output is valued, the dual thermal outputs for heating and cooling make heat pump water heaters particularly attractive. The comfort value of added cooling in overheated facilities and the resulting increase in employee and customer satisfaction are frequently cited as additional benefits.
This paper describes currently available heat pump water heating equipment and offers guidelines for successful applications in commercial facilities. The results of field test programs involving more than 100 units in Alabama, Georgia, Mississippi, Tennessee, South Carolina, and other areas are incorporated. Initial conclusions are drawn from a reliability database, and interviews with utility applications specialists and manufacturers are discussed. Design tools are reviewed, including a new comprehensive computer simulation model. Emphasis is placed on identifying sound candidates for installations and on application and design considerations. A brief survey is provided of environmental implications of heat pump water heaters and new developments in heat pump water heater equipment.
Johnson, K. F.; Shedd, A. C.
Analysis of improved fenestration for code-compliant residential buildings in hot and humid climates
This thesis presents an analysis of energy efficient residential windows in hot and humid climates.
To accomplish this analysis, the use of accurate simulation tools such as DOE-2.1e is required, which
incorporates the results from the WINDOW-5.2 simulation program to assess accurate fenestration
performance. The thesis also investigates the use of optimal glazing types, which, for future
applications, could be specified in the code to reduce annual net energy consumption to zero.
Results show that combinations of low-E and double pane, clear-glazed windows, which are
optimally shaded according to orientation are the best solution for lowering both annual energy
consumption and peak electricity loads. The study also concludes that the method used to model
fenestration in the simulation program plays an important role in accurately determining the
effectiveness of the glazing option used. In this particular study, the use of the WINDOW-5.2 program
is highly recommended especially for high performance windows (i.e., low-E glazing). Finally, a
discussion on the incorporation of super high performance windows (i.e., super low-E, ultra low-E and
dynamic / switchable glazing) into the IECC code concludes that these types of glazing strategies can
reduce annual net energy use of the window to zero.
Future work identified by this thesis includes a more extensive examination of the passive solar
potential of high performance fenestration, and an examination of the appropriate methods for
specifying these properties in future versions of the IECC code. This implies that future specifications
for fenestration in the IECC code could aim for zero net annual energy consumption levels from
residential fenestration.
Mukhopadhyay, Jaya
An Analysis of Energy Consumption in Grocery Stores in a Hot and Humid Climate
The intent of this study was to investigate the efficient use of energy by developing an energy efficient grocery store combined with cogeneration. This study demonstrated the potential to reduce the energy use in buildings, by implementing a decentralized source of energy generation that allowed for the use of a portion of the energy generated to be shared across building boundaries. This study considered a high energy use building such as a grocery store to be a part of a residential community, which could potentially participate in the sharing of energy across building boundaries. To better utilize energy resources the study proposed the implementation of a cogeneration facility to supply energy primarily to the store. Surplus energy generated by this cogeneration system was then shared with the requirements of the surrounding residential community. Finally, in order to better account for energy consumption of these buildings both site and source energy was considered. The study focused on hot and humid climates. This study was presented in two parts: Analyzing conventional grocery store systems to determine the maximum savings possible; and examining the option of co-generation systems to provide power to grocery stores and a portion of the community in order to reduce source energy use for the grocery store and a portion of the surrounding community. Source energy savings were in the range of 47% to 54% depending on the energy efficiency measures selected and the cogeneration configuration determined in the grocery store. Economic payback periods in the range of 4 to 7 years (time until zero net present value) were observed. The selection of appropriate options was narrowed down to two options that utilized more thermal energy within the boundaries of the store and generated more amount of surplus energy to be absorbed by the neighboring residential buildings.
Building America Best Practices Series Volume 15: 40% Whole-House Energy Savings in the Hot-Humid Climate
This best practices guide is the 15th in a series of guides for builders produced by PNNL for the U.S. Department of Energy�s Building America program. This guide book is a resource to help builders design and construct homes that are among the most energy-efficient available, while addressing issues such as building durability, indoor air quality, and occupant health, safety, and comfort. With the measures described in this guide, builders in the hot-humid climate can build homes that have whole-house energy savings of 40% over the Building America benchmark with no added overall costs for consumers. The best practices described in this document are based on the results of research and demonstration projects conducted by Building America�s research teams. Building America brings together the nation�s leading building scientists with over 300 production builders to develop, test, and apply innovative, energy-efficient construction practices. Building America builders have found they can build homes that meet these aggressive energy-efficiency goals at no net increased costs to the homeowners. Currently, Building America homes achieve energy savings of 40% greater than the Building America benchmark home (a home built to mid-1990s building practices roughly equivalent to the 1993 Model Energy Code). The recommendations in this document meet or exceed the requirements of the 2009 IECC and 2009 IRC and those requirements are highlighted in the text. Requirements of the 2012 IECC and 2012 IRC are also noted in text and tables throughout the guide. This document will be distributed via the DOE Building America website: www.buildingamerica.gov.
Baechler, Michael C.; Gilbride, Theresa L.; Hefty, Marye G.; Cole, Pamala C.; Adams, Karen; Noonan, Christine F.
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.
El Roque de Los Muchachos Site Characteristics. II. Analysis of Wind, Relative Humidity and Air Pressure
In this paper we present an analysis of wind speed, wind direction, relative humidity and air pressure taken at TNG, CAMC and NOT at Observatorio del Roque de Los Muchachos, in the Canary Islands. Data are compared in order to check local variations and both long term and short term trends of the microclimate. Furthermore, influence of wind speed on the astronomical seeing is estimated to the aim to better understand the influence of wide scale parameters on local meteorological data. The three telescopes show different prevailing wind direction, wind speed, relative humidity and air pressure confirming differences in local microclimate. We found that seeing deteriorates when wind speed is lower than 3.3 m/s. Comparison in terms of wind speed and high relative humidity (> 90%) shows that TNG seems to have optimal observational conditions with respect to CAMC and NOT. Air pressure analysis shows that ORM is dominated by high pressure. Short time variations of pressure anticipate temperature variations tipically by 2-3 hours, this property vanishes in time scales higher than some hours and disappear in longer time scales.
G. Lombardi; V. Zitelli; S. Ortolani; M. Pedani
Building America Top Innovations Hall of Fame Profile
Moisture and Ventilation Solutions in Hot, Humid Climates: Florida Manufactured Housing
Duct leakage was a key factor in moisture Duct leakage was a key factor in moisture damage in manufactured homes in humid climates. BUILDING AMERICA TOP INNOVATIONS HALL OF FAME PROFILE INNOVATIONS CATEGORY: 2. House-as-a-System Solutions 2.1 New Homes with Whole-House Packages Moisture and Ventilation Solutions in Hot, Humid Climates: Florida Manufactured Housing Research by Building America diagnosed the causes and prescribed a cure that dramatically reduced moisture problems in manufactured housing in Florida. In the late 1990s, Building America researchers at the Florida Solar Energy Center (FSEC) worked with manufactured home builders to diagnose moisture problems in homes in Florida. Moisture issues were so severe that in some homes researchers could push their fingers through the saturated drywall. Using a
Exploring Maximum Humidity Control and Energy Conservation Opportunities with Single Duct Single Zone Air-Handling Units
Humidity control for single-duct single-zone (SDSZ) constant volume air handling units is known to be a challenge. The operation of these systems is governed by space temperature only. Under mild weather conditions, discharge air temperature can get much higher than the space dew point and the dehumidification capability of the system is diminished. Buildings served by this type of air handler often experience exceptionally high humidity levels under humid weather conditions. Many potential solutions and improvements exist. However, these solutions require system modifications or upgrades and therefore are less attractive to some facility owners. A Critical Humidity Control Program (CHCP) was developed to change the normal control sequence of the air-handling units during high humidity periods to help improve the moisture removal capability of the system. The program was not designed to solve the problem completely, but the overall humidity levels can be lowered and controlled within a reasonably low range (58% - 65%) for a significant part of the high humidity seasons. This approach is relatively easy to implement and does not require any hardware changes. This paper also summarizes various potential solutions to improve humidity control for SDSZ units. The advantages and disadvantages for each solution are compared.
Zhou, J.; Wei, G.; Turner, W. D.; Deng, S.; Claridge, D.
A New Method for Deriving Ocean Surface Specific Humidity and Air Temperature: An Artificial Neural Network Approach
A new methodology for deriving monthly averages of surface specific humidity (Qa) and air temperature (Ta) is described. Two main aspects characterize the new approach. First, remotely sensed parameters, total precipitable water (W), and sea ...
Charles Jones; Pete Peterson; Catherine Gautier
Building Design and Operation for Improving Thermal Comfort in Naturally Ventilated Buildings in a Hot-Humid Climate
The goal of this research was to develop new techniques for designing and operating unconditioned buildings in a hot-humid climate that could contribute to an improvement of thermal performance and comfort condition.
The recommendations proposed in this research will also be useful for facility managers on how to maintain unconditioned buildings in this climate. This study investigated two unconditioned Thai Buddhist temples located in the urban area of Bangkok, Thailand. One is a 100-year-old, high-mass temple. The other is a 5-year-old, lower-mass temple. The indoor measurements revealed that the thermal condition inside both temples exceed the ASHRAE-recommended comfort zone. Surprisingly, the older temple maintained a more comfortable indoor condition due to its thermal inertia, shading, and earth contacts.
A baseline thermal and airflow model of the old temple was established using a calibrated computer simulation method. To accomplish this, HEATX, a 3-D Computational Fluid Dynamics (CFD) code, was coupled with the DOE-2 thermal simulation program. HEATX was used to calculate the airflow rate and the surface convection coefficients for DOE-2, and DOE-2 was used to provide physical input variables to form the boundary conditions for HEATX. In this way calibrated DOE-2/CFD simulation model was accomplished, and the baseline model was obtained.
To investigate an improved design, four design options were studied: 1) a reflective or low-solar absorption roof, 2) R-30 ceiling insulation, 3) shading devices, and 4) attic ventilation. Each was operated using three modes of ventilation. The low-absorption roof and the R-30 ceiling insulation options were found to be the most effective options, whereas the shading devices and attic ventilation were less effective options, regardless of which ventilation mode was applied. All design options performed much better when nighttime-only ventilation was used.
Based on this analysis, two prototype temples was proposed (i.e., low-mass and high-mass temples). From the simulation results of the two prototypes, design and operation guidelines are proposed, which consist of: 1) increased wall and ceiling insulation, 2) white-colored, low-absorption roof, 3) slab-on-ground floor, 4) shading devices, 5) nighttime-only ventilation, 6) attic ventilation, and 7) wider openings to increase the natural ventilation air flow windows, wing walls, and vertical fins.
Sreshthaputra, Atch
Solar-Powered, Liquid-Desiccant Air Conditioner for Low-Electricity Humidity Control: Report and Summary Report
The primary objective of this project was to demonstrate the capabilities of a new high-performance, liquid-desiccant dedicated outdoor air system (DOAS) to enhance cooling efficiency and comfort in humid climates while substantially reducing electric peak demand at Tyndall Air Force Base (AFB), which is 12 miles east of Panama City, Florida.
Dean, J.; Kozubal, E.; Herrmann, L.; Miller, J.; Lowenstein, A.; Barker, G.; Slayzak, S.
Flow-temperature-humidity control system operating manual. [Controlled atmospheres for industrial hygiene and air pollution studies
A manual containing operating, maintenance, and troubleshooting procedures for the flow-temperature-humidity control system used at the Lawrence Livermore Laboratory to prepare test atmospheres for industrial hygiene and air pollution studies is presented. The system consists of two basic components: a commercially available temperature/humidity indicator unit and a specially built flow-temperature-humidity control module. Procedures are given for using the control system with a vapor generation system or with a trace-gas flowmeter to add vapor or a trace gas to the airstream after it leaves the control module.
Nelson, G.O.; Taylor, R.D.
Development of a Simplified Simulation Tool for High Performance K-5 Schools in Hot and Humid Climates
This paper presents the preliminary results of an effort
to develop a simplified simulation-based tool for
designing K-5 high performance schools in hot and
humid climates. As a first step of the research, a survey
to define the dominant school building shape was
conducted in an independent school district in Central
Texas. This survey used satellite views of the K-5
schools, where each school shape was classified based
on the classification defined by Perkins (2001). In
addition, more surveys and a literature review was
performed to verify input parameters to drive the
building size and other building characteristics. Once
the simulation tool and the default parameters are
developed, this tool is intended to be used to estimate
building energy consumption with limited information
about the school building. This paper reports on the
classification scheme and automatic building shape
generator, as well as preliminary results describing
calibration of the simulation to a case study K-5
Im, P.; Haberl, J. S.
Case Study of Stratified Chilled Water Storage Utilization for Comfort and Process Cooling in a Hot, Humid Climate
The advantages of thermal storage are enhanced in hot and humid climates. Year-round cooling loads increase thermal storage operating cost savings. The absence of a long winter during which major maintenance tasks can be accomplished without compromising system reliability increases the importance of thermal storage as back-up capacity. In an industrial setting, operating cost savings due to thermal storage go directly to the bottom line of a manufacturing process and the avoidance of lost production due to process cooling outages can save millions of dollars per year. This paper presents a case study of chilled water storage use at the campus of a major US electronics manufacturer located in Dallas, TX. An overview of the system and its operation is followed by presentation of operating data taken during 1997.
Bahnfleth, W. P.; Musser, A.
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.
Reducing Thermal Losses and Gains With Buried and Encapsulated Ducts in Hot-Humid Climates
The Consortium for Advanced Residential Buildings (CARB) monitored three houses in Jacksonville, FL, to investigate the effectiveness of encapsulated and encapsulated/buried ducts in reducing thermal losses and gains from ductwork in unconditioned attics. Burying ductwork beneath loose-fill insulation has been identified as an effective method of reducing thermal losses and gains from ductwork in dry climates, but it is not applicable in humid climates where condensation may occur on the outside of the duct jacket. By encapsulating the ductwork in closed cell polyurethane foam (ccSPF) before burial beneath loose-fill mineral fiber insulation, the condensation potential may be reduced while increasing the R-value of the ductwork.
Shapiro, C.; Magee, A.; Zoeller, W.
Hot Air Stratification of Ceiling Air Supply in a Large Space Building
The effects of different states of air supply and airflow patterns on temperature gradient distribution are calculated and analyzed with the help of FFSV3.0 software, using the LB models and LES and RANS methods. An experimental study with upper supply and upper return air flow was performed in normal airflow room. The results were compared with numerical simulation results and were found to agree well. Information on delaminating laws, and measurements of the relationship of delaminating heights and air supply temperature and velocity is also presented. According to the simulation results, a formula that avoids hot air delaminating in ceiling air supply is derived, which can guide engineering design.
Wang, H.; Wang, Z.; Liu, C.
Theoretical and experimental analysis of desiccant wheel performance for low humidity drying system
The drying process is influenced by three main factors temperature, flow rate and humidity, resulting in the drying process of hot air required in accordance with the character of materials with low humidity, so it can speed up the drying process. Malaysia ... Keywords: desiccant wheel, temperature and humidity, water evaporation
Tri Suyono; Sohif Mat; Muhammad Yahya; Muhd. Hafiz Ruslan; Azami Zaharim; Kamaruzzaman Sopian
Comparing Temperature and Humidity on a Mountain Slope and in the Free Air Nearby
Surface temperature and humidity data measured by eight remote weather stations on a south-facing slope in the San Bernardino Mountains of Southern California were compared with temperature and humidity data measured by a rawinsonde at the same ...
Morris H. McCutchan
Oxidation of delta-phase plutonium alloy: Corrosion kinetics in dry and humid air at 35 {degree}C
Kinetic data for oxidation of delta-phase plutonium alloy are evaluated to provide a technical basis for assessing the merit of an existing time limitation on air exposure of components during process operations. Data describing the effects of humidity and oxygen pressure on the oxidation rate of the Pu-1.0 wt% Ga alloy at elevated temperatures are obtained from literature sources and used to predict the oxidation behavior of the alloy in air at 35 C and 0 to 100% relative humidity. A mandated six-hour limit on air exposure is inconsistent with a predicted thirty-day period required for formation of a 1-{micro}m-thick oxide layer in moisture-saturated air at 35 C. Relationships are defined for predicting kinetic behavior of the alloy at other conditions, and recommendations for addressing oxidation-related concerns in production are presented.
Haschke, J.M.
The Relationship between Relative Humidity and the Dewpoint Temperature in Moist Air: A Simple Conversion and Applications
The relative humidity (RH) and the dewpoint temperature (td) are two widely used indicators of the amount of moisture in air. The exact conversion from RH to td, as well as highly accurate approximations, are too complex to be done easily without ...
Mark G. Lawrence
Development of a Simulation Toolkit for the Selection of High-Performance Systems for Office Buildings in Hot and Humid Climates (Phase I: Calibrated Simulation of the Case Study Building)
This paper reports on the development of an easy-to-use
tool for the selection of high-performance systems
in office buildings in hot and humid climates. In this
paper, the preliminary results of a calibrated simulation
of a typical large office building are presented for the
John Connally building (124,000 sq-ft) in College
Station, TX. To calibrate the DOE-2 simulation model,
measured data were retrieved from permanently
installed data loggers in the building, which measured
whole-building electricity use and sub-metered cooling
electricity use, lighting and miscellaneous equipment
use, as well as thermal energy measurements for
chilled water and hot water use. Also used in the
calibration process were portable data loggers for
comparing the performance of the building�s air-handling
units with the simulated performance. For the
calibration of the DOE-2 model, several calibration
methodologies were used, including manual & iterative
calibrations, graphical & statistical analysis, and
signature analysis. This calibrated simulation model
will be used as a base-case model for the development
of a easy-to-use simulation tool for the selection of
high-performance systems in office buildings in hot
and humid climates. This paper presents the calibrated
simulation results of the office building and outlines
the additional steps for the development of the high-performance
systems selection tool.
Cho, S.; Haberl, J. S.
Investigations were made on the effects of uv irradiation on E. coli and Pseudomonas aeroginosa and x irradiation on Serratia marcescens and on the influence of relative humidity and inositol on these effects. The effect of relative humidity was the same for all organisms tested. Under the experimental conditions used, little or no uv irradiation damage occurred above 70% relative humidity, nor were there many deaths occurring in unirradiated aerosols. At about 65% there was a rapid change in the sensitivity to both uv and drying alone, with the maximum rate of change taking place between 65 and 55% relative humidity for uv, and 65 and 45% relative humidity for non-irradiated cells. Some organisms showed an equally sharp increase in sensitivity to drying in the dark between 65 and 55% relative humidity. With uv irradiation relative humidity changes below 55% had little or no effect on the death rate and the same was true for non-irradiated cells below 45% relative humidity. Under all experimental conditions, with the possible exception of a relative humidity region around 40%, inositol completely prevented inactivation of the cells or viruses in the dark or under uv irradiation. Under x irradiation the cells were more stable at relative humidity values below 50% than at higher values, and once again the region in which a pronounced change occurred was between 50 and 70% relative humidity. (P.C.H.)
Webb, S.J.; Cormack, D.V.; Morrison, H.G.
Performance of a Heat Pump Water Heater in the Hot-Humid Climate, Windermere, Florida (Fact Sheet), Building America Case Study: Technology Solutions for New and Existing Homes, Building Technologies Office (BTO)
Performance of a Performance of a Heat Pump Water Heater in the Hot-Humid Climate Windermere, Florida Over recent years, heat pump water heaters (HPWHs) have become more read- ily available and more widely adopted in the marketplace. A key feature of an HPWH unit is that it is a hybrid system. When conditions are favorable, the unit will operate in heat pump mode (using a vapor compression system that extracts heat from the surrounding air) to efficiently provide domestic hot water (DHW). Homeowners need not adjust their behavior to conform to the heat pump's capabilities. If a heat pump cannot meet a higher water draw demand, the heater will switch to electric resistance to provide a higher heating rate. This flexibility
Small-scale AFBC hot air gas turbine power cycle
The Energy and Environmental Research Corporation (EER), the Ohio Agricultural Research and Development Center (OARDC), the Will-Burt Company (W-B) and the US Department of Energy (DOE) have successfully developed and completed pilot plant tests on a small scale atmospheric fluidized bed combustion (AFBC) system. This system can be used to generate electricity, and/or hot water, steam. Following successful pilot plant operation, commercial demonstration will take place at Cedar Lane Farms (CLF), near Wooster, Ohio. The system demonstration will be completed by the end of 1995. The project is being funded through a cooperative effort between the DOE, EER, W-B, OARDC, CLF and the Ohio Coal Development Office (OCDO). The small scale AFBC, has no internal heat transfer surfaces in the fluid bed proper. Combining the combustor with a hot air gas turbine (HAGT) for electrical power generation, can give a relatively high overall system thermal efficiency. Using a novel method of recovering waste heat from the gas turbine, a gross heat rate of 13,500 Btu/kWhr ({approximately}25% efficiency) can be achieved for a small 1.5 MW{sub e} plant. A low technology industrial recuperation type gas turbine is used that operates with an inlet blade temperature of 1,450 F and a compression ratio of 3.9:1. The AFBC-HAGT technology can be used to generate power for remote rural communities to replace diesel generators, or can be used for small industrial co-generation applications.
Ashworth, R.A. [Energy and Environmental Research Corp., Orrville, OH (United States); Keener, H.M. [Ohio State Univ., Wooster, OH (United States). Ohio Agricultural Research and Development Center; Hall, A.W. [USDOE Morgantown Energy Technology Center, WV (United States)
Humidity Sensors
Table 21 Applications for humidity sensors...parts 5 to 40 0 to 50 Magnetic heads, LSIs, ICs Agriculture, forestry stockbreeding Greenhouse air conditioning 5 to 40 0 to 100 Air conditioning Dew prevention in tealeaf growing -10 to 60 50 to 100 Dew prevention Broiler farming 20 to 25 40 to 70 Health control Measurement Thermostatic bath -5 to 100 0 to...
Analysis of Energy, Environmental and Life Cycle Cost Reduction Potential of Ground Source Heat Pump (GSHP) in Hot and Humid Climate
It has been widely recognized that the energy saving benefits of GSHP systems are best realized in the northern and central regions where heating needs are dominant or both heating and cooling loads are comparable. For hot and humid climate such as in the states of FL, LA, TX, southern AL, MS, GA, NC and SC, buildings have much larger cooling needs than heating needs. The Hybrid GSHP (HGSHP) systems therefore have been developed and installed in some locations of those states, which use additional heat sinks (such as cooling tower, domestic water heating systems) to reject excess heat. Despite the development of HGSHP the comprehensive analysis of their benefits and barriers for wide application has been limited and often yields non-conclusive results. In general, GSHP/HGSHP systems often have higher initial costs than conventional systems making short-term economics unattractive. Addressing these technical and financial barriers call for additional evaluation of innovative utility programs, incentives and delivery approaches. From scientific and technical point of view, the potential for wide applications of GSHP especially HGSHP in hot and humid climate is significant, especially towards building zero energy homes where the combined energy efficient GSHP and abundant solar energy production in hot climate can be an optimal solution. To address these challenges, this report presents gathering and analyzing data on the costs and benefits of GSHP/HGSHP systems utilized in southern states using a representative sample of building applications. The report outlines the detailed analysis to conclude that the application of GSHP in Florida (and hot and humid climate in general) shows a good potential.
Yong X. Tao; Yimin Zhu
Humidity Measurements
Thermodynamic Quantities. Humidity Measurements. Rate our Services. Technical ... Special Tests of Humidity (36070S). Tests ...
Building America Best Practices Series: Volume 1; Builders and Buyers Handbook for Improving New Home Efficiency, Comfort, and Durability in the Hot and Humid Climate
This Building America Best Practices guide book is a resource to help builders large and small build high-quality, energy-efficient homes that achieve 30% energy savings in space conditioning and water heating in the hot and humid climate. The savings are in comparison with the 1993 Model Energy Code. The guide contains chapters for every member of the builder's team. There is also a chapter for homeowners on how to use the book to provide help in selecting a new home or builder.
Baechler, M. C.; Love, P. M.
efficiency initiatives The energy matrix in Brazil is basedin a more sustainable energy matrix are essential for a
gender, acclimation state, the opportunity to adjust clothing and physical disability on requirements for thermal comfort. Energy
is heavily weighted towards hydroelectricity, accounting forof rain to drive hydroelectricity generation) and inadequatelack of rain for the hydroelectricity based system) and poor
votes, thermal preferences and cooling preferences. Thefor cooling and thermal preferences Cooling exposure Coolingterms of thermal sensation, heating preferences and cooling
climate zone showed almost 90% thermal acceptabil- ity within the operative temperature ranges prescribed in the ASHRAE
conservation initiatives including a recent Federal Regula- tion for Voluntary Labelling of Energy Ef?ciency Levels in Commercial, Public and Service Buildings [
after the exposure and water intake were recorded every 30rate were recorded. Water intake was also registered basedrate where recorded. Water intake was also registered based
Comfort and health considerations: air movement and humidity constraints, final report - phase 1
water systems such as cooling tower sump water and hot watersuch as humidifiers and cooling towers. The most importantwater such as i n cooling towers and in natural ponds as
Analysis on Wear Mechanism of Refractories Used in Hot Air ...
By analysis, the service life of hot wind stoves can be enhanced by the .... Production of Fe-Based Alloys by Metallothermic Reduction of Mill Scales from�...
Measurements of the Electrical Conductivities of Air over Hot Water
Measurements of the conduction current between two electrodes in air over recently boiled water have been interpreted by Carlon as indicating that the humidified air became highly conductive and that large numbers of ions were produced in the air ...
C. B. Moore; B. Vonnegut
Effectiveness of External Window Attachments Based on Daylight Utilization and Cooling Load Reduction for Small Office Buildings in Hot Humid Climates
This study explored the effectiveness of selected external shading devices and glazing treatments used to minimize the total annual energy consumption in small office buildings in hot humid climates. The external shading devices included a permanent horizontal overhang and a light shelf. The selected types of glazing included clear, reflective, tinted, low-emissivity coating, and heat-mirror glass. One concern about using external window attachments is that while reducing the solar heat gains, they also reduce the amount of the daylight needed to supplement interior lighting. Therefore the objective of this study was to explore which strategy would give a balance between solar heat gain reduction and daylight utilization and result in the most energy savings in the building. Computer simulations using an hourly energy calculation model were conducted to predict the building's total energy consumption using each strategy. The economics of each strategy were analyzed with lifecycle costing techniques using the present value technique. Results show that properly designed overhangs that shade clear glazing are slightly more cost-effective than specialized low-e glazing systems. These results are unique for hot humid climates where winter heating is not an issue. On the contrary, when used in cold climates, external shading devices tend to increase the building's energy consumption.
Soebarto, V. I.; Degelman, L. O.
Analysis of the Energy Savings Potential in K-5 Schools in Hot and Humid Climates: Application of High Performance Measures and Renewable Energy Systems
This paper presents the analysis of the energy savings
potential in an existing K-5 school in hot and humid
climates. Previous paper (Im and Haberl 2008b)
presented a calibrated simulation procedure for an
existing K-5 school in hot and humid area, and the first
step of the energy savings potential analysis by
applying the energy savings measures recommended as
in the ASHRAE Advanced Energy Design Guides for
K-12 Schools. As an effort to investigate more energy
savings potential for the school building, several other
energy savings measures and renewable energy
measures were applied to the target building. Those
measures include: increased glazing U-value, VFD
application for the HVAC system, cold deck reset,
variable speed for pumps, high-efficiency boiler,
skylights, and the application of solar thermal and PV
systems. The final simulation results show that the
estimated Energy Use Index (EUI) of the school by
applying all the measures but the solar thermal and PV
systems would be 29.9 kBtu/sqft (i.e., 38.6 % energy
savings against the baseline school). In addition, solar
thermal and PV systems were designed to provide half
of the electricity demand and all the SWH demand of
the school building, respectively. The final EUI for the
school with the solar thermal and PV systems was
estimated to be 15 kBtu/sqft.
Im, P.; Haberl, J.
NIST Humidity
Humidity. Summary: ... It also engages in research to improve humidity standards and study thermophysical properties of moist gases. Description: ...
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
Residential Humidity Control Strategies
Residential Humidity Control Strategies Residential Humidity Control Strategies Armin Rudd Residential Energy Efficiency Stakeholder Meeting 2/29 - 3/2/2012 Austin, Texas 2 Residential Energy Efficiency Stakeholder Meeting 2/29 - 3/2/2012 Austin, Texas Humidity control goals Comfort, and Indoor Air Quality Control indoor humidity year-around, just like we do temperature Durability and customer satisfaction Reduce builder risk and warranty/service costs 2 3 Residential Energy Efficiency Stakeholder Meeting 2/29 - 3/2/2012 Austin, Texas Humidity control challenges 1. In humid cooling climates, there will always be times of the year when there is little sensible cooling load to create thermostat demand but humidity remains high * Cooling systems that modify fan speed and temperature set point based on humidity can help but are still limited
Heat transfer and condensation of water vapour from humid air in compact heat exchangers.
??In this thesis, an experimental and simulation study of heat transfer in water-to-air compact-plate heat exchanger is presented. A compact-plate heat exchanger made of polypropylene,� (more)
Saraireh, Mohammad
Evaluating Energy Performance and Improvement Potential of China Office Buildings in the Hot Humid Climate Against U.S. Reference Buildings: Preprint
This study compares the building code standards for office buildings in hot humid climates of China and the USA. A benchmark office building model is developed for Guangzhou, China that meets China's minimum national and regional building codes with incorporation of common design and construction practices for the area. The Guangzhou office benchmark model is compared to the ASHRAE standard based US model for Houston, Texas which has similar climate conditions. The research further uses a building energy optimization tool to optimize the Chinese benchmark with existing US products to identify the primary areas for potential energy savings. The most significant energy-saving options are then presented as recommendations for potential improvements to current China building codes.
Herrman, L.; Deru, M.; Zhai, J.
Performance of a Heat Pump Water Heater in the Hot-Humid Climate, Windermere, Florida (Fact Sheet)
Over recent years, heat pump water heaters (HPWHs) have become more readily available and more widely adopted in the marketplace. For a 6-month period, the Building America team Consortium for Advanced Residential Buildings monitored the performance of a GE Geospring HPWH in Windermere, Florida. The study found that the HPWH performed 144% more efficiently than a traditional electric resistance water heater, saving approximately 64% on water heating annually. The monitoring showed that the domestic hot water draw was a primary factor affecting the system's operating efficiency.
Metzger, C.; Puttagunta, S.; Williamson, 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.
Methodology to Develop and Test an Easy-to-use Procedure for the Preliminary Selection of High-performance Systems for Office Buildings in Hot and Humid Climates
A procedure has been developed for the preliminary selection of high-performance systems for office buildings in hot and humid climates. High-performance building systems and components were surveyed for buildings in the U.S., which were applicable for office buildings in hot and humid climates. This research developed a calibrated DOE-2.1e simulation model of a prototypical large office building. In addition, a Simplified Geometry DOE-2.1e (SGDOE-2.1e) model, was also developed, which used a simplified geometry to demonstrate the use of a proposed easy-to-use tool. The calibrated DOE-2.1e simulation model and the SGDOE-2.1e were compared and showed a good match with each. The SGDOE-2.1e model was then further modified based on the ASHRAE Standard 90.1-1999 commercial building energy code. A code-compliant (ASHRAE Standard 90.1-1999) SGDOE-2.1e simulation model was then used as a baseline for the evaluation of the high-performance measures. A total of 14 high-performance measures were implemented including the energy savings, while the comfort level was maintained based on the ASHRAE comfort zone. In addition to the 14 high-performance measures, solar thermal and solar PV system analysis were integrated with the SGDOE-2.1e simulation model to further reduce the annual energy use. Finally, specifications of the proposed easy-to-use simulation tool were developed. This tool includes options to choose systems from the 14 high-performance measures and solar systems. The proposed easy-to-use systems selection tool can be used for new building practitioners and existing building owners as well to evaluate the performance of their new buildings compared to the ASHRAE Standard 90.1-1999 code-compliant building, and to assess the feasibility of implementing high-performance measures to their existing buildings in terms of energy and cost savings.
Cho, Sool Yeon
Methodology to Develop and Test an Easy-To-Use Procedure for the Preliminary Selection of High-Performance Systems for Office Buildings in Hot and Humid Climates
A procedure has been developed for the preliminary selection of high-performance
systems for office buildings in hot and humid climates. High-performance building
systems and components were surveyed for buildings in the U.S., which were applicable
for office buildings in hot and humid climates. This research developed a calibrated
DOE-2.1e simulation model of a prototypical large office building. In addition, a
Simplified Geometry DOE-2.1e (SGDOE-2.1e) model, was also developed, which used
a simplified geometry to demonstrate the use of a proposed easy-to-use tool. The
calibrated DOE-2.1e simulation model and the SGDOE-2.1e were compared and showed
a good match with each.
The SGDOE-2.1e model was then further modified based on the ASHRAE Standard
90.1-1999 commercial building energy code. A code-compliant (ASHRAE Standard
90.1-1999) SGDOE-2.1e simulation model was then used as a baseline for the
evaluation of the high-performance measures. A total of 14 high-performance measures
were implemented including the energy savings, while the comfort level was maintained
based on the ASHRAE comfort zone. In addition to the 14 high-performance measures,
solar thermal and solar PV system analysis were integrated with the SGDOE-2.1e
simulation model to further reduce the annual energy use. Finally, specifications of the
proposed easy-to-use simulation tool were developed. This tool includes options to
choose systems from the 14 high-performance measures and solar systems.
The proposed easy-to-use systems selection tool can be used for new building
practitioners and existing building owners as well to evaluate the performance of their
new buildings compared to the ASHRAE Standard 90.1-1999 code-compliant building,
and to assess the feasibility of implementing high-performance measures to their existing
buildings in terms of energy and cost savings.
Cho, S.
A triple hot-wire system for indoor air flow measurements
The application of a home made, triple hot-wire system in indoor air flow measurements is presented. Both the anemometer and sensor have been developed at Athens University with the aim to provide a reliable, research tool of reasonable cost, simple construction, and satisfactory performance. All three velocity components above a threshold of 10 cm s{sup {minus}1} can be measured. The system is also equipped with two thermometers for measuring the mean and fluctuating air temperature and for providing a means of temperature compensation of the hot wires` signal. After evaluation of the system in the laboratory, it was used in the measurement of the velocity profile of flows driven by the temperature difference between two internal zones. The implied accuracy of the method allows for its integration with measurements of air volume exchange rates between internal zones, as estimated by tracer gas techniques.
Papadopoulos, K.H.; Soilemes, A.T.; Helmis, C.G.; Santamouris, M.; Dascalaki, E. [Univ. of Athens (Greece); Asimakopoulos, D.N. [Univ. of Athens (Greece)]|[National Observatory of Athens (Greece). Inst. of Meteorology and Physics of the Atmospheric Environment; Argiriou, A. [National Observatory of Athens (Greece). Inst. of Meteorology and Physics of the Atmospheric Environment
VALIDATION OF THE eCALC COMMERCIAL CODE-COMPLIANT SIMULATION VERSUS
This paper compares the results of a calibrated simulation of a case-study building versus simulation using the web-based eCALC code-compliant commercial simulation program (Haberl et al., 2004). Previously, as-built calibrated simulation results for the case-study building were performed and reported in Cho and Haberl (2008). In this paper an extension of the previous work is presented using the eCALC commercial simulation model, which uses simplified geometry and ASHRAE Standard 90.1-compliant equipment selection and sizing values for energy calculation. This paper compares the results between the as-built geometry simulation and simplified geometry simulation with similar equipment configuration. The simplified geometry simulation model is a modified-eCALC DOE-2 model that includes simplifications of the case-study building�s characteristics. The modified-eCALC DOE-2 model was intended to be used for the development of an easy-to-use tool for the selection of high-performance systems for office buildings in hot and humid climates, which will be presented in another publication.
Cho, S.; Haberl, J.
Performance and Impact from Duct Repair and Ventilation Modifications of Two Newly Constructed Manufactured Houses Located in a Hot and Humid Climate
Two nearly identical houses situated next to each other in Bossier City, Louisiana were studied in an effort to better understand moisture and cooling energy related problems in manufactured houses with low thermostat set-points during the cooling season. By design, the major difference between houses was the type of air conditioning units. House A had a standard split air conditioner and House B had a twospeed split air conditioner. In an effort to make the buildings more similar, the building airtightness was adjusted until it was the same in each house, and duct leaks were sealed so that the ducts were tight and there was equal tightness in both houses. A ventilation system was also added at the same time of duct repair. Duct repair and the ventilation modifications resulted in significant impacts on the cooling energy, temperature, relative humidity, and building pressures. Cooling energy decreased 37% in House A and 18% in House B, while the floor space dewpoint increased significantly. It is estimated that 35 % savings was due solely to duct repair in House A and 17% in House B. The primary cause of House A savings being twice House B is attributed to House A operating at nearly twice the capacity most of the time and had more duct leakage repaired. This resulted in higher system pressures and therefore greater duct leakage than in House B. Before building modifications, House A used 15.4 kWh per day (32%) more than House B and 3.4 kWh per day (11%) more after modifications. A method of characterizing interstitial spaces using dewpoint measurement is presented and shows that the belly space became 2.6 times more like outdoor conditions after repairs in House A and 2.0 times more in House B.
Withers, C.; Moyer, N.; Chasar, D.; Chandra, S.
Humidity Control in Residences
Maintaining relative humidity below 60% for residential houses in humid climates promotes a healthy indoor environment. Yet, for such homes, these lower humidity levels are difficult to maintain with conventional recirculation air conditioning units. By introducing a separate vapor compression unit to pre-condition outside air, indoor relative humidity can be controlled. This new air conditioning system combines a ventilation unit with a conventional recirculation air conditioning unit. Although successful in maintaining indoor humidity levels below 60%, the new air conditioning system will require more electric energy to provide the additional dehumidification. However, this penalty is shown to be offset by reductions in sensible load during a summer week, which should result in lower energy consumption and peak electric demand during that period. The performance of this new air conditioning system is demonstrated using FSEC 3.0, a building energy simulation program developed by the Florida Solar Energy Center, to simulate the heat and moisture transport occurring within a prototypical residence located in Austin, Texas.
Trowbridge, J.; Peterson, J.
Energy Design Guidelines for High Performance Schools: Hot and...
Energy Design Guidelines for High Performance Schools: Hot and Humid Climates Energy Design Guidelines for High Performance Schools: Hot and Humid Climates School districts around...
Building Energy Software Tools Directory: Indoor Humidity Tools
Indoor Humidity Tools Indoor Humidity Tools Indoor Humidity Tools logo. Integrated computer program intended to assist in diagnosing and solving problems of indoor air humidity and dryness. Indoor Humidity Tools is comprised of two sections: - Calculations provide humidity calculations. - Reference provides background information on humidity in convenient lookup formats, such as recommended indoor humidity levels for different types of spaces, against which calculations may be compared. Keywords indoor air humidity, dryness, condensation Validation/Testing N/A Expertise Required No special expertise required. Users first released in July 1997. Audience engineers, industrial hygienists and safety professionals, architects, building scientists, contractors, government air quality specialists, and
Performance Testing Residential Heat Pump Water Heaters under South- and Central-Florida Climate Conditions: Hot, Humid Climate and Warm Ground Water Pose Unusual Operating Environment for Heat Pump Water Heaters
Heat pump water heaters (HPWHs) are known to provide considerable energy savings compared with electric resistance devices in many applications. However, as their performance is climate-dependent, it is important to understand their operation in extreme climates. Southern and Central Florida presents an extreme climate for HPWHs, as the air temperature, humidity, and entering water temperatures are all high nearly year-round. This report examines HPWH performance in the Florida Power & Light ...
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.
Active Humidity Control Through Gas-Fired Desiccant Humidity Pump
High equipment first cost and high operating costs, if electricity is used to drive such a system, have prohibited the application of active humidity control equipment in comfort conditioning in the past. Instead, passive techniques have been applied. A comparison of passive capacity control methods to control humidity shows that only the combined face and bypass and variable air volume system shows improved performance with respect to space humidity control, dew point depression, and response to perturbations. A gas-fired desiccant humidity pump will provide economical humidity control in existing and new construction using VAV or constant volume air distribution systems. The humidity pump is designed as a packaged make-up air module. It is coupled to new or existing conventional air-conditioning system via a duct. It consists of a triple integrated heat-exchanger combining (liquid) desiccant dehumidification with indirect evaporative cooling, a brine interchanger, and a gas-fired brine heater to regenerate the desiccant. Field experiments of two humidity pumps on existing commercial buildings have been initiated. Each system dehumidifies 5000 scfm of make-up air to meet all the latent loads, which is then fed to conventional, electric-driven HVAC equipment which meet all the sensible loads.
Novosel, D.; Griffiths, W. C.
Automated flow-temperature-humidity control system
An automated system that controls air flow, temperature, and humidity was developed from a commercially available temperature-humidity indicator and a specially built flow-temperature-humidity control module. Parameters are set using direct-reading dials on the control module. The air flow is maintained using a mass-flow controller while process controllers connected to the indicator regulate humidity and temperature. The system will run indefinitely without need for operator intervention. If the module and indicator are calibrated properly, accurate air flows (+-2% of full scale), temperatures (+-0.3/sup 0/C), and humidities (+-2% RH) can be achieved.
NIST Humidity in SSD
Humidity in the Sensor Science Division. Humidity. The Division develops, maintains, and disseminates national standards ...
Small-scale AFBC-hot air gas turbine power cycle
The Energy and Environmental Research Corporation (EER), the Ohio Agricultural Research and Development Center (OARDC), the Will-Burt Company (W-B) and the U.S. Department of Energy (DOE) have successfully developed and completed pilot plant tests on a small scale atmospheric fluidized bed combustion (AFBC) system. This system can be used to generate electricity, and/or hot water, steam. Following successful pilot plant operation, commercial demonstration will take place at Cedar Lane Farms (CLF), near Wooster, Ohio. The system demonstration will be completed by the end of 1995. The project is being funded through a cooperative effort between the DOE, EER, W-B, OARDC, CLF and the Ohio Coal Development Office (OCDO). The small scale AFBC, has no internal heat transfer surfaces in the fluid bed proper. Combining the combustor with a hot air gas turbine (HAGT) for electrical power generation, can give a relatively high overall system thermal efficiency. Using a novel method of recovering waste heat from the gas turbine, a gross heat rate of 13,500 Btu/kWhr ({approximately}25% efficiency) can be achieved for a small 1.5 MW, plant. A low technology industrial recuperation type gas turbine is used that operates with an inlet blade temperature of 1450{degrees}F and a compression ratio of 3.9:1. The AFBC-HAGT technology can be used to generate power for remote rural communities to replace diesel generators, or can be used for small industrial co-generation applications.
Ashworth, R.C. [Energy and Environmental Research Corp., Orrville, OH (United States); Keener, H.M. [Ohio State Univ., Wooster, OH (United States); Hall, A.W. [Morgantown Energy Technology Center, Morgantown, WV (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.
DISCOVER-AQ Outlook for Wednesday, July 20, 2011 The weather for Wednesday through the weekend is forecasted to be hazy, very hot, and very humid
be monitored closely. This heatwave builds as the massive upper-level ridge plaguing the Plains moves east and the Bermuda High pumps very moist air into the Mid-Atlantic. Air quality is expected to be poor through 21st, Thursday: Can Fly July 22nd, Friday: Can Fly July 23rd, Saturday: Can Fly Excessive Heat
A theoretical model for {sup 222}Rn adsorption on activated charcoal canisters in humid air based on Polanyi`s potential theory
Water vapor interferes with adsorption {sup 222}Rn gas by passive activated charcoal devices used to estimate indoor air concentrations. The {sup 222}Rn adsorption coefficient is the fundamental parameter characterizing charcoal`s ability to adsorb {sup 222}Rn. The Dubinin-Radushkevich equation, based on Polanyi`s potential theory, was modified to include two terms quantifying the effect of both water vapor and sampling time on the {sup 222}Rn adsorption coefficient of passive charcoal devices. A single equation was derived that quantities the {sup 222}Rn adsorption coefficients at any temperature, humidity and exposure time using six experimentally determined physical constants that are unique for a particular passive charcoal device. The theoretical model was verified with published experimental data, and it showed a good correlation between theory and experiment. The model proved to be consistent with experimental data, provided that the amount of water vapor adsorbed by the charcoal device during sampling remains below a critical level, termed the breakpoint. 44 refs., 5 figs., 2 tabs.
Scarpitta, S.C. [Dept. of Energy, New York, NY (United States)
Research Results from A Few Alternate Methods of Interior Duct
Systems in Factory Built Housing Located In the Hot Humid Climate
The U.S. Department of Energy�s (DOE) Building America1 Industrialized Housing Partnership (BAIHP) has collaborated with two of its industry partners to work on a portion of the project that relates to the construction and evaluation of prototype interior duct systems. In 2006, work began on a duct system design that would locate the entire length of duct work within the air and thermal barriers of the envelope. One of these designs incorporated a high-side supply register that connects to the conventional floor duct. The other design utilized a single soffit located within the conditioned space at the marriage line.
The Florida Solar Energy Center�s (FSEC) Manufactured Housing Lab (MHLab) was retrofitted with an interior soffit duct. The duct system was added on so that either the attic duct system or the new interior duct system would be able to supply air to the conditioned space using the same mechanical equipment.
The initial results of this work show approximately a 10% to 20% heating/cooling savings when compared to conventional attic duct work construction techniques and nearly 7% savings when compared to a conventional in-floor system.
Moyer, N.; Stroer, D.; Hoak, D.; McIlvaine, J.; Chandra, S.
Nanoscale adhesion in humid air
... a. National Institute of Standards and Technology, Gaithersburg, MD 20899 USA b. University of Lodz, 90-236, Lodz, Poland. Abstract. ...
Uncertainties of Derived Dewpoint Temperature and Relative Humidity
This paper presents an evaluation of derived dewpoint temperature and derived relative humidity, in which the dewpoint temperature is calculated using measured ambient air temperature and measured relative humidity variables and the derived ...
X. Lin; K. G. Hubbard
Modeling the Response of Canopy Stomatal Conductance to Humidity
Humidity of air is a key environmental variable in controlling the stomatal conductance (g) of plant leaves. The stomatal conductance�humidity relationships employed in the Ball�Woodrow�Berry (BWB) model and the Leuning model have been widely ...
Shusen Wang; Yan Yang; Alexander P. Trishchenko; Alan G. Barr; T. A. Black; Harry McCaughey
Dual flow--temperature--humidity control system operating manual
The manual contains operating, maintenance, and troubleshooting procedures for a dual flow--temperature--humidity control system used at the Lawrence Livermore Laboratory to prepare test atmospheres for industrial hygiene and air pollution studies. The system consists of two basic components: a commercially available temperature/humidity indicator unit and a specially built dual flow--temperature--humidity control module that provides two air sources controlled at the same conditions of flow, temperature, and relative humidity.
Measure Guideline: Combination Forced-Air Space and Tankless Domestic Hot Water Heating Systems
This document describes design and application guidance for combination space and tankless domestic hot water heating systems (combination systems) used in residential buildings, based on field evaluation, testing, and industry meetings conducted by Building Science Corporation. As residential building enclosure improvements continue to drive heating loads down, using the same water heating equipment for both space heating and domestic water heating becomes attractive from an initial cost and space-saving perspective. This topic is applicable to single- and multi-family residential buildings, both new and retrofitted.
Rudd, A.
Advanced Dehumidification and Humidity Control Solutions
This technical brief explains the foundation of conventional, advanced, and emerging technologies for humidity control in air-conditioned buildings in easy-to-understand language for utility executives as well as end-users. It also describes new packaged solutions that integrate vapor compression cooling and desiccant dehumidification technologies in creative ways to offer more energy efficient solutions for applications in existing or new construction, especially in humid climates.
Development of a Humid Climate Definition
The role of humidity in indoor air quality has become of increasing concern in recent years. High indoor humidities can result in microbial growth on building surfaces, resulting in poor indoor air quality, as well as damage to the building and its contents. In addition to the IAQ impacts, high indoor humidity can cause occupant discomfort. The public review draft of ASHRAE Standard 62-1989R included requirements for installation of dehumidification controls in buildings with mechanical cooling located in humid climates. The draft standard included a definition of humid climate: where, during the warmest six consecutive months of a typical year, the wetbulb temperature is 19�C (67�F) or higher for 3500 hours or more, or 23�C (73�F) or higher for 1750 hours or more. This definition is that used in the 1993 ASHRAE Handbook of Fundamentals to define the humid climate region. The only areas in the continental United States which meet these criteria are close to the Gulf coast, all of Florida, and along the Atlantic coast as far north as southern North Carolina While it is clear that buildings in this humid climate region need to be carefully designed with regard to humidity control, it is also clear that buildings in other areas have an equal need for humidity control. The work described in this paper examines a number of potential indicators of "humid climate" and correlates them with the prevalence of indoor humidity problems in three building types. The FSEC 2.3 energy simulation computer program (Kerestecioglu et al. 1989) was used to simulate the three building types, using weather from 10 cities in the southeastern U.S. The FSEC software was selected because it is capable of accurately modeling moisture transfer within the building space and the dehumidification performance of cooling coils at part-load conditions, and predicting resulting humidity levels. The buildings modeled were a retail store (similar to a K-Mart or Wal-Mart), a large office building, and a fast food restaurant. Existing building models were employed for this study with ventilation rates in accordance with ASHRAE Standard 62-1989. The HVAC systems used were typical for these building types, without any special humidity control measures. The selected indicators of humidity problems are the number of hours per year with space humidity above 60% RH and the number of occupied hours with space humidity above 60% RH. TMY2 weather data (NREL 1995) for 10 cities was used for the annual building energy simulations. TMY2 data was also used to calculate a number of potential humid climate parameters for the same 10 cities. These included: the number of hours and the wetbulb-degree hours above 3 different wetbulb temperatures, the number of hours and grain-hours above 4 different humidity ratios, and the sensible, latent and total Ventilation Load Index (VLI). The VLI is the load (latent, sensible or total) generated by bringing one cfm of outdoor air to space neutral conditions over the course of one year (Hamman, et al. 1997). The ability of each climate parameter to predict indoor humidity problems was analyzed and compared. Implications of using the selected parameters to define a humid climate will be discussed
Hedrick, R. L.; Shirey, D. B.
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.
Moisture-sensitive systems to measure and indicate the maximum level of humidity exposure are discussed. A chemical indicator utilizing deliquescent salts and water-soluble dyes provides an irreversible color change at discrete levels of relative humidity. To provide indication of the time at which the exposure occurs, a circuit employing a resistive-type sensor was developed. A small, commercially available sensor is used in a portable probe to detect humidity leaks into controlled areas.
Abel, W B
Irreversible humidity indicator
This patent relates to a humidity indicator having particles of colored dye distributed over the surface of a dry, deliquescent salt of a neutral color. When exposed to a humidity level above that which causes deliquescence of the salt, the dye bleeds through and imparts its developed tincture to the resulting saturated salt solution. On dehydration, the dye remains infused throughout the dried salt to present an irreversible indication of the humidity exposure. (auth)
Reif, R.B.; Kurz, P.F.
Best Practice For the Location of Air and Thermal Boundaries in Small Commercial Buildings
Suspended t-bar ceilings are common in commercial buildings. Research has found that these ceilings are very leaky, and several problems arise from this. If the space above the ceiling is vented to outdoors, the entire building becomes leaky. Furthermore, if the insulation is located at the ceiling rather than the roof, then the ceiling space will be hot (summer), and if the ceiling space is also vented to outdoors, then the ceiling space will be hot and humid. The thermal and humidity conditions of the ceiling space have important implications for space conditioning loads, building ventilation rates, and indoor relative humidity. Conductive gains through ductwork add to loads, and various forms of uncontrolled air flow readily move air between the ceiling space and the occupied space. These factors should be considered during design and construction of commercial buildings. Best practice: locate the air and thermal boundaries of the building at the roof deck. This approach has many benefits.
Cummings, J. B.; Withers, C. R.
How factoring in humidity adds value
Humidity plays a major role in health, comfort, and production. This article is a brief overview of the technologies available and a detailed explanation of how to calculate humidification loads. The problems caused by dry air vary from one building to another and from one area to another. But basically, there are three major problem types: static electricity, poor moisture stability, health and comfort problems. In today's business offices, static electricity can disrupt operations and increase operating costs. In printing facilities, low humidity causes poor ink registration. Also, sheets of paper stick together and jam machines, wasting time and paper. In computer rooms and data processing areas, dry air leads to static electric discharges that cause circuit board failure, dust buildup on heads, and storage tape breakage. Moisture stability impacts industrial processes and the materials they use. In many cases, product and material deterioration is directly related to moisture fluctuations and lack of humidity control. Books, antiques, paper, wood and wood products, and fruits and vegetables are a few items that can be ruined by low or changing humidity. The health impact of low humidity shows up in dry nasal and thread membranes, dry and itchy skin, and irritated eyes. For employees, this means greater susceptibility to colds and other viral infections. The results is higher absenteeism when humidity is low, which translates into lost productivity and profits.
Berlin, G. (Nortec Industries, Inc., Ogdensburg, NY (United States))
HEXOS�Humidity Exchange Over the Sea A Program for Research on Water-Vapor and Droplet Fluxes from Sea of Air at Moderate to High Wind Speeds
HEXOS is an international program for the study of evaporation and spray-droplet flux from sea to air. The program includes measurements in the field at moderate-to-high wind speeds, wind-tunnel studies, instrument development, boundary-layer ...
Kristina B. Katsaros; Stuart D. Smith; Wiebe A. Oost
Air Pollution Control Regulations: No. 13- Particulate Emissions from Fossil Fuel Fired Steam or Hot Water Generating Units (Rhode Island)
Energy.gov (U.S. Department of Energy (DOE))
The purpose of this regulation is to limit emissions of particulate matter from fossil fuel fired and wood-fired steam or hot water generating units.
An Improved Humidity Sensor
A common feature of all capacitance humidity sensors is their undesirable hysteresis effect due to the unequal adsorption and desorption of water vapor on the surfaces of their dielectric porous materials. To eliminate this error, an improved ...
Shixuan Pang; Hartmut Gra�l; Horst J�ger
Influences of Isolated Cumulus Clouds on the Humidity of Their Surroundings
Measurements are described of the distributions of humidity in the clear air surrounding small to medium sized, isolated cumulus clouds. Wind shear is the most important factor in determining the radial distribution of enhanced humidity around ...
Kevin D. Perry; Peter V. Hobbs
PDFs of Tropical Tropospheric Humidity: Measurements and Theory
The spatial variations in the probability density functions (PDFs) of relative humidity (RH) in the tropical and subtropical troposphere are examined using observations from the Atmospheric Infrared Sounder (AIRS) and the Microwave Limb Sounder (...
Ju-Mee Ryoo; Takeru Igusa; Darryn W. Waugh
Chemical Engineering & Processing Humidity Information at ...
NIST Home > Chemical Engineering & Processing Humidity Information at NIST. Chemical Engineering & Processing Humidity Information at NIST. ...
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.
Optical humidity sensor
An optical dielectric humidity sensor is disclosed which includes a dielectric mirror having multiple alternating layers of two porous water-adsorbent dielectric materials with differing indices of refraction carried by a translucent substrate. A narrow-band polarized light source is positioned to direct light energy onto the mirror, and detectors are positioned to receive light energy transmitted through and reflected by the mirror. A ratiometer indicates humidity in the atmosphere which surrounds the dielectric mirror as a function of a ratio of light energies incident on the detectors. 2 figs.
Tarvin, J.A.
An optical dielectric humidity sensor which includes a dielectric mirror having multiple alternating layers of two porous water-adsorbent dielectric materials with differing indices of refraction carried by a translucent substrate. A narrow-band polarized light source is positioned to direct light energy onto the mirror, and detectors are positioned to receive light energy transmitted through and reflected by the mirror. A ratiometer indicates humidity in the atmosphere which surrounds the dielectric mirror as a function of a ratio of light energies incident on the detectors.
Tarvin, Jeffrey A. (Ann Arbor, MI)
Lanthanide-halide based humidity indicators
The present invention discloses a lanthanide-halide based humidity indicator and method of producing such indicator. The color of the present invention indicates the humidity of an atmosphere to which it is exposed. For example, impregnating an adsorbent support such as silica gel with an aqueous solution of the europium-containing reagent solution described herein, and dehydrating the support to dryness forms a substance with a yellow color. When this substance is exposed to a humid atmosphere the water vapor from the air is adsorbed into the coating on the pore surface of the silica gel. As the water content of the coating increases, the visual color of the coated silica gel changes from yellow to white. The color change is due to the water combining with the lanthanide-halide complex on the pores of the gel.
Beitz, James V. (Hinsdale, IL); Williams, Clayton W. (Chicago, IL)
Data Center Economizer Contamination and Humidity Study
Data centers require continuous air conditioning to address high internal heat loads (heat release from equipment) and maintain indoor temperatures within recommended operating levels for computers. Air economizer cycles, which bring in large amounts of outside air to cool internal loads when weather conditions are favorable, could save cooling energy. There is reluctance from many data center owners to use this common cooling technique, however, due to fear of introducing pollutants and potential loss of humidity control. Concerns about equipment failure from airborne pollutants lead to specifying as little outside air as permissible for human occupants. To investigate contamination levels, particle monitoring was conducted at 8 data centers in Northern California. Particle counters were placed at 3 to 4 different locations within and outside of each data center evaluated in this study. Humidity was also monitored at many of the sites to determine how economizers affect humidity control. Results from this study indicate that economizers do increase the outdoor concentration in data centers, but this concentration, when averaged annually, is still below current particle concentration limits. Study results are summarized below: (1) The average particle concentrations measured at each location, both outside and at the servers, are shown in Table 1. Measurements show low particle concentrations at all data centers without economizers, regardless of outdoor particle concentrations. Particle concentrations were typically an order of magnitude below both outside particle concentrations and recently published ASHRAE standards. (2) Economizer use caused sharp increases in particle concentrations when the economizer vents were open. The particle concentration in the data centers, however, quickly dropped back to pre-economizer levels when the vents closed. Since economizers only allow outside air part of the time, the annual average concentrations still met the ASHRAE standards. However, concentration were still above the levels measured in data centers that do not use economizers (3) Current filtration in data centers is minimal (ASHRAE 40%) since most air is typically recycled. When using economizers, modest improvements in filtration (ASHRAE 85%) can reduce particle concentrations to nearly match the level found in data centers that do not use economizers. The extra cost associated with improve filters was not determined in this study. (4) Humidity was consistent and within the ASHRAE recommended levels for all data centers without economizers. Results show that, while slightly less steady, humidity in data centers with economizers can also be controlled within the ASHRAE recommended levels. However, this control of humidity reduces energy savings by limiting the hours the economizer vents are open. (5) The potential energy savings from economizer use has been measured in one data center. When economizers were active, mechanical cooling power dropped by approximately 30%. Annual savings at this center is estimated within the range of 60-80 MWh/year, representing approximately a 5% savings off the mechanical energy load of the data center. Incoming temperatures and humidity at this data center were conservative relative to the ASHRAE acceptable temperature and humidity ranges. Greater savings may be available if higher temperature humidity levels in the data center area were permitted. The average particle concentrations measured at each of the eight data center locations are shown in Table 1. The data centers ranged in size from approximately 5,000 ft{sup 2} to 20,000 ft{sup 2}. The indoor concentrations and humidity in Table 1 represents measurements taken at the server rack. Temperature measurements at the server rack consistently fell between 65-70 F. The Findings section contains a discussion of the individual findings from each center. Data centers currently operate under very low contamination levels. Economizers can be expected to increase the particle concentration in data centers, but the increase appears to still be
Shehabi, Arman; Tschudi, William; Gadgil, Ashok
Indirect health effects of relative humidity in indoor environments
A review of the health effects of relative humidity in indoor environments suggests that relative humidity can affect the incidence of respiratory infections and allergies. Experimental studies on airborne-transmitted infectious bacteria and viruses have shown that the survival or infectivity of these organisms is minimized by exposure to relative humidities between 40 and 70%. Nine epidemiological studies examined the relationship between the number of respiratory infections or absenteeism and the relative humidity of the office, residence, or school. The incidence of absenteeism or respiratory infections was found to be lower among people working or living in environments with mid-range versus low or high relative humidities. The indoor size of allergenic mite and fungal populations is directly dependent upon the relative humidity. Mite populations are minimized when the relative humidity is below 50% and reach a maximum size at 80% relative humidity. Most species of fungi cannot grow unless the relative humidity exceeds 60%. Relative humidity also affects the rate of offgassing of formaldehyde from indoor building materials, the rate of formation of acids and salts from sulfur and nitrogen dioxide, and the rate of formation of ozone. The influence of relative humidity on the abundance of allergens, pathogens, and noxious chemicals suggests that indoor relative humidity levels should be considered as a factor of indoor air quality. The majority of adverse health effects caused by relative humidity would be minimized by maintaining indoor levels between 40 and 60%. This would require humidification during winter in areas with cold winter climates. Humidification should preferably use evaporative or steam humidifiers, as cool mist humidifiers can disseminate aerosols contaminated with allergens.
Arundel, A.V.; Sterling, E.M.; Biggin, J.H.; Sterling, T.D.
Forest Products: Acoustic Humidity Sensor
The new acoustic sensor, designed as a humidity-control system for the paper and textile industries, can both eliminate overdrying and improve product quality by measuring humidity precisely. This new fact sheet explains how the process works.
Poole, L.; Recca, L.
Moisture Advection Using Relative Humidity
This study introduces a moisture advection formulation that contains relative humidity. In the sigma coordinate system, rewriting the mixing ratio conservation equation in terms of relative humidity leads to an equation that explicitly contains ...
William H. Raymond
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.
humidity | OpenEI
Open Energy Info (EERE)
humidity humidity Dataset Summary Description This raw data reflects readings from instruments mounted on or near a 82 meter meteorological tower located at the National Wind Technology Center (NWTC), approximately 5 miles south of Boulder, CO (specifically: 39.9107 N, 105.2348 W, datum WGS84). The base elevation at the site is 1,855 meters AMSL. Source NREL Date Released Unknown Date Updated March 10th, 2011 (3 years ago) Keywords DOE humidity irrandiance NREL NWTC pressure temperature turbulence wind wind direction wind speed Data text/plain icon Raw data (8/24/2001 - 3/10/2011) (txt, 681 KiB) application/vnd.ms-excel icon Field IDs for above .txt file (xls, 69.6 KiB) Quality Metrics Level of Review Some Review Comment Scientists and Technicians are notified real-time via email of instruments outside the above min/max or delta comparisons (http://www.nrel.gov/midc/nwtc_m2/) Data have not been reviewed for accuracy or completeness; disclaimer available (http://www.nrel.gov/disclaimer.html).
Recent Climatology, Variability, and Trends in Global Surface Humidity
In situ observations of surface air and dewpoint temperatures and air pressure from over 15 000 weather stations and from ships are used to calculate surface specific (q) and relative (RH) humidity over the globe (60�S�75�N) from December 1975 to ...
Aiguo Dai
Humidity fluctuations in solar greenhouse-residences
The thermal performance of solar greenhouse-residences is well-documented. Data concerning temperature fluctuations and horticultural yield are obtainable and provide a clear picture of greenhouse-residence temperature extremes. However, both human comfort and plant growing environment are not dependent upon temperature alone. Air movement, radiation, and humidity are other criteria that can influence thermal comfort and growing conditions. The effect a vegetable peoducing greenhouse has on thermal comfort of an adjoining residence is illustrated in terms of temperature and humidity. An analysis of dewpoint conditions will further indicate the effect of moisture within the individual components. A solar greenhouse-residence with an integrated heating collection and distribution system exhibited higher internal humidities than conventional housing. The greenhouse exhibited greater diurnal swings than the adjoining residence. Transfer of moisture occurred from greenhouse to residence and caused infrequent dewpoint levels in the house. An analysis of two such buildings indicated a higher average relative humidity in the solar greenhouse-residence over conventional housing in the southeast.
Davis, M.A. (Clemson Univ., SC); Harrison, R.E.; Godbey, L.C.
Reevaluation of the Bulk Exchange Coefficient for Humidity at Sea during Unstable and Neutral Conditions
Processes influencing the air�sea exchange of humidity during unstable and neutral stratification were studied using tower measurements from the island of �stergarnsholm in the Baltic Sea. For small air�sea temperature differences, the neutral ...
Erik Sahl�e; Ann-Sofi Smedman; Ulf H�gstr�m; Anna Rutgersson
Humidity, Temperature, and Voltage (Presentation)
An update is given on the work of the PV Quality Assurance Task Force; Group 3: studying the effects of humidity, temperature, and voltage bias.
Wohlgemuth, J.
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.
Humidity requirements in WSCF Laboratories
The purpose of this paper is to develop and document a position on Relative Humidity (RH) requirements in the WSCF Laboratories. A current survey of equipment vendors for Organic, Inorganic and Radiochemical laboratories indicate that 25% - 80% relative humidity may meet the environmental requirements for safe operation and protection of all the laboratory equipment.
Evans, R.A.
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.
relative humidity | OpenEI
relative humidity relative humidity Dataset Summary Description (Abstract): Relative Humidity at 10 m Above The Surface Of The Earth (%)NASA Surface meteorology and Solar Energy (SSE) Release 6.0 Data Set (Nov 2007)22-year Monthly & Annual Average (July 1983 - June 2005)Parameter: Relative Humidity at 10 m Above The Surface Of The Earth (%)Internet: http://eosweb.larc.nasa.gov/sse/Note 1: SSE Methodology & Accuracy sections onlineNote 2: Lat/Lon values indicate the lower left corner of a 1x1 degree region. Negative values are south and west; Source U.S. National Aeronautics and Space Administration (NASA), Surface meteorology and Solar Energy (SSE) Date Released March 31st, 2009 (5 years ago) Date Updated Unknown Keywords climate GIS NASA relative humidity SWERA UNEP
A simple distribution method for two-dimensional temperature/humidity bin data
A distribution model is developed for relative humidity, and additional relationships are presented that allow the distribution model to be used on an hourly basis with either monthly-average daily relative humidity or monthly-average daily dry-bulb temperature and clearness index as the only meteorological data input. A procedure is described that allows the estimation of two-dimensional dry-bulb temperature/humidity ratio bin data from the distribution models for dry-bulb temperature and relative humidity. Comparisons of measured and estimated dry-bulb temperature/humidity ratio bin data are presented. A design method for the cooling load on a residential air conditioner is described, and air conditioning loads are calculated using both measured and estimated dry-bulb temperature/humidity ratio bin data.
Erbs, D.G.; Klein, S.A.; Beckman, W.A.
Dynamic Assimilation of MODIS-Retrieved Humidity Profiles within a Regional Model for High-Latitude Forecast Applications
A �hot start� technique is applied to the fifth-generation Pennsylvania State University�National Center for Atmospheric Research (PSU�NCAR) Mesoscale Model (MM5) to dynamically assimilate cloud properties and humidity profiles retrieved from the ...
Xingang Fan; Jeffrey S. Tilley
Humidity effects in ionization chambers
Capacitance variations due to humidity alterations have been suggested as the cause of ionization chamber current variations. The validity of the arguments is seriously questioned on several points. (auth)
Bengtsson, L.G.
Humidity Profiles over the Ocean
The distribution of water vapor in the atmosphere affects climate change through radiative balance and surface evaporation. The variabilities of atmospheric humidity profile over oceans from daily to interannual time scales were examined using ...
W. Timothy Liu; Wenqing Tang; Pearn P. Niiler
Variability and Trends of High Temperature, High Humidity, and Sultry Weather in the Warm Season in China during the Period 1961�2004
Using the daily maximum air temperature and mean humidity observations at 394 surface weather stations across China, the changes in the annual number of days of high temperature weather (HTW), high humidity weather (HHW), and sultry weather (STW) ...
Xiaohui Shi; Chungu Lu; Xiangde Xu
Laboratory Equipment - Dickson TH550 Humidity Meter
Dickson TH550 Humidity Meter. Description: ... Temperature: -30 �C to 50 �C; Humidity: 0% to 95% RH (no-condensing); Dew Point: -30 �C to 50 �C; ...
Calibration of Hygrometers with the Hybrid Humidity ...
... Hybrid Humidity Generator ... The HHG combines the two-pressure and divided-flow humidity generation techniques (hence the name �hybrid�). ...
Us Department Contacts Media Contacts Data Center Economizer Contamination and Humidity Study Title Data Center Economizer Contamination and Humidity Study Publication Type...
126.96.36.199. Humidity standards
... 18.104.22.168. Humidity standards. ... The designs shown in this catalog are drift-eliminating and may be suitable for artifacts other than humidity cylinders. ...
Commissioning High Performance Residences in Hot, Humid Climates
Since 2001, the authors have engaged several builders in the Gainesville, FL area to build over 500 high performance new energy efficient homes in multiple sub divisions. The builders keep building to increased levels of energy efficiency. Each home is individually designed, inspected, rated and commissioned for optimum performance. This paper summarizes the experiences to date with two production builders who have cost shared with the Building America program to deliver these outstanding results. Keys to success are commitment from the final decision maker; scopes of work for subcontractors with specific performance criteria; clear communication with the trades often accompanied by training and education activities; independent third party testing, commissioning and feedback to building; ongoing training of sales staff and model center displays and finally extensive marketing that educated the consumers about the benefits of high performance homes.
Fonorow, K.; Chandra, S.; McIlvaine, J.; Colon, C.
BC TIPS- Hot-Humid Climate: New Orleans
Homes that provide substantial reductions in energy use and home-owner utility bills and recognizes the best practices for quality, comfort, health, and safety in the market.
Nonlinear robust temperature-humidity control in livestock buildings
The physical environment of farm animals inside livestock buildings is primarily characterised by hygro-thermal parameters and air quality. These parameters are influenced by the interaction with the outdoor situation on one hand, and the livestock, ... Keywords: Humidity control, Livestock buildings, Robust control, Temperature control
A. G. Soldatos; K. G. Arvanitis; P. I. Daskalov; G. D. Pasgianos; N. A. Sigrimis
Diagnosis and Correction of Systematic Humidity Error in a Global Numerical Weather Prediction Model
Accuracy of humidity forecasts has been considered relatively unimportant to much of the operational numerical weather prediction (NWP) community. However, the U.S. Air Force is interested in accurate water vapor and cloud forecasts as end ...
Donald C. Norquist; Sam S. Chang
Two Major Experiments in the Humidity Exchange over the Sea (HEXOS) Program
Humidity Exchange over the Sea (HEXOS) is an international program for the study of evaporation and spray droplet flux from sea to air. The program includes measurements in the field, simulation studies in wind tunnels, interpretive studies such ...
Stuart D. Smith; Kristina B. Katsaros; Wiebe A. Oost; Patrice G. Mestayer
Measurements of Humidity and Temperature in the Marine Environment during the HEXOS Main Experiment
Accurate measurement of fluctuations in temperature and humidity are needed for determination of the surface evaporation rate and the air-sea sensible heat flux using either the eddy correlation or inertial dissipation method for flux ...
K.B. Katsaros; J. DeCosmo; R.J. Lind; R.J. Anderson; S.D. Smith; R. Kraan; W. Oost; K. Uhlig; P.G. Mestayer; S.E. Larsen; M.H. Smith; G. De Leeuw
Tests to determine effect of humidity on high-efficiency filters when installed horizontally
The object of tests is to determine effect of high-humidity air on the physical characteristics of filter media and separators when the filter is mounted in the horizontal position. Usual installation is with the filter mounted vertically.
Palmer, J.H.
Climatology of Upper-Tropospheric Relative Humidity from the Atmospheric Infrared Sounder and Implications for Climate
Recently available satellite observations from the Atmospheric Infrared Sounder (AIRS) are used to calculate relative humidity in the troposphere. The observations illustrate many scales of variability in the atmosphere from the seasonal ...
Andrew Gettelman; William D. Collins; Eric J. Fetzer; Annmarie Eldering; Fredrick W. Irion; Phillip B. Duffy; Govindasamy Bala
A theoretical model for adsorption capacities of charcoal beds: I, Relative humidity effects
Water vapor is the major interferent in the adsorption of other vapors from air when that air is passed through an activated charcoal bed. A limited amount of data (published and unpublished) is available on the magnitudes of capacity (or service life) reduction as a function of relative humidity (water vapor concentration) and preadsorbed water. A simple equilibrium model has been developed which quantitatively explains observed humidity effects and allows extrapolation of data to untested conditions. 9 refs., 4 figs., 2 tabs.
Wood, G.O.
Case Study: Sick Building Syndrome in a Humid Climate
An indepth environmental investigation was conducted at a four-story building officing 1200 employees in Oklahoma. A preassessment and walkthrough of the facility revealed extensive ongoing renovations throughout the building. Renovations consisted of installations of new partitions, carpeting, ceiling tiles, and repainting. Management was receiving numerous complaints related to the indoor air quality from all parts of the building, particularly the unrenovated areas. The majority of employee complaints originated from the unrenovated second floor; in contrast, few complaints had been submitted from the finished fourth floor area. Due to the disparity in employee complaints from these two floors, the investigation focused on a comparison of the air quality on the second and fourth floors. The initial walkthrough revealed inordinate amounts of dust in the occupied space of the second floor. High humidity levels were measured throughout the building. Other potential problems -- i.e., poor lighting, job stress, poor air circulation, stuffy air, thermal discomfort. smokers in the area --were also noted at this point. Questionnaires were made available to occupants on both floors to attain a better understanding of employee problems and assist in formulating an investigation plan. Collectively the nonspecificity of the responses tended to indicate building-related problems often described by the term ''Sick Building Syndrome" (SBS). Based on the questionnaire responses, the walkthrough observations, and the lack of specific illnesses, the investigation focused on identification of and testing for sources of chemical and particulate emissions and possible inadequacies of the mechanical ventilation system in providing the necessary amount of outside air. Although the building investigation revealed few signs of biological contamination, problems of this nature are not uncommon in climates with high humidity. The potential for biological proliferation in buildings with excessive humidity are discussed in the paper. The SBS causation was multifactorial and thus could not be attributed to a single etiologic factor. Temperature and humidity problems were partially attributed to the inadequate provision of chilled water (at a low enough temperature) to ensure proper tempering and dehumidification of the supply air. These periodic excursions in temperature and relative humidity were compounded by an associated reduction in outside air which exacerbated the situation. Other recommendations had to do with improving the filtration system, balancing of the air handling system, improving the ventilation efficiency, separation of smokers and nonsmokers, and the infusion of a fastidious cleaning and maintenance program combined with an adequate supply of fresh air per ASHRAE 62-89 specifications.
Shaughnessy, R. J.; Levetin, E.
Humidity in Attics -- Sources and Control Methods
Guidelines for the control of moisture in attics are in a state of flux. The 1981 ASHRAE Handbook of Fundamentals gives only ''Past Practice'', and notes that such practice might not be currently valid. Furthermore, in the past it was assumed that the attic was an inert structure on which moisture would either condense or pass through unaffected. Results are presented which show that the attic is in a constant state of flux, absorbing and releasing moisture. A mathematical model for predicting the moisture content of attic wood members is presented. The model is used to predict hour-by-hour attic air humidity ratio, and seasonal wood moisture content. Results are compared with measured data. The application of the model to the re-calculation of attic ventilation standards is discussed, both with respect to condensation and wood rot.
Cleary, Peter
The Temperature and Relative Humidity Control in Cushing Library
Cushing Library located on TAMU campus is a special building, which needs precise temperature and relative humidity control, because it stores a number of rare collections and memorial books. There are five air-handling units (AHUs) serving the building. This paper will concentrate the unit, which serves the book stacks. This AHU is a multiple zone, constant air volume (MZCAV) system, with reheat and direct digital control (DDC). It has a standard cooling coil, glycol cooling coil, steam humidifier, and heat recovery. The chilled water to the standard cooling coil is served by the chilled water loop on the campus. There is a glycol chiller for the glycol cooling coil for added dehumidification ability. Because of programming problems and hardware problems, the relative humidity was not controlling properly. In this paper, the new control program for temperature and relative humidity control is implemented and the energy savings from the new control program is estimated. The temperature and relative humidity are now under control.
Liu, C.; Deng, S.; Claridge, D. E.; Turner, W. D.; Bruner, H., Jr.
Total Building Air Management: When Dehumidification Counts
Industry trends toward stringent indoor air quality codes, spearheaded by ASHRAE 62-89: Ventilation for Acceptable Indoor Air Quality, present four challenges to the building industry in hot and humid climates: 1. Infusion of large quantities of make-up air to code based on zone requirements 2. Maintenance of tight wet bulb and dry bulb temperature tolerances within zones based on use 3. Energy management and cost containment 4. Control of mold and mildew and the damage they cause Historically, total air management of sensible and latent heat, filtration and zone pressure was brought about through the implementation of non-integrated, composite systems. Composite systems typically are built up of multi-vendor equipment each of which perform specific, independent functions in the total control of the indoor air environment. Composite systems have a high up-front cost, are difficult to maintain and are costly to operate. Today, emerging technologies allow the implementation of fully integrated system for total building air management. These systems provide a single-vendor solution that is cost effective to purchase, maintain and operate. Operating saving of 23% and ROIs of 2.3 years have been shown. Equipment specification is no longer based primarily on total building load. Maximum benefits of these dynamic systems are realized when systems are designed with a total operating strategy in mind. This strategy takes into consideration every factor of building air management including: 1. Control of sensible heat 2. Balance management of heat rejection 3. Latent heat management 4. Control of process hot water 5. Indoor air quality management 6. Containment of energy consumption 7. Load shedding
Chilton, R. L.; White, C. L.
The General Circulation and Robust Relative Humidity
The sensitivity of free-tropospheric relative humidity to cloud microphysics and dynamics is explored using a simple 2D humidity model and various configurations of the National Center for Atmospheric Research (NCAR) Community Atmosphere Model ...
S. C. Sherwood; C. L. Meyer
Schools resolve IAQ/humidity problems with desiccant preconditioning
This article describes how desiccant-based total energy recovery systems were retrofitted to the mechanical systems at Willis Foreman Elementary and Spirit Creek Middle Schools to decouple the outdoor air latent load from the existing 3-ton packaged rooftop HVAC units. The resulting hybrid system maintains 50 to 52 percent relative humidity in the space while continuously providing 15 cfm per student of outdoor air to the facility (a three-fold increase of the original 5 cfm per student design) and does so in a very energy-efficient manner.
Smith, J.C. [James C. Smith and Associates, Augusta, GA (United States)
Air movement preferences observed in office buildings
in a Hot-humid Climate. ASHRAE Transactions 100: 457-475.in a Cold Climate. ASHRAE Transactions 103: 205-220. Fang L,Sensations of Sedentary Man. ASHRAE Transactions 80 (1):
Performance Evaluation for Modular, Scalable Cooling Systems with Hot Aisle Containment in Data Centers
Power Transformer Figure 3 Layout of Equipment � Front ViewPower Distribution Panel Cooling Module Air Temperature Water Temperature Relative Humidity Diff. Pressure Flow Rate Current Transformer
Adams, Barbara J
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
Impact of the humidity pump on indoor environments. Final report, August 1989-November 1990
The impact of the humidity pump, (a newly developed, gas-fired, liquid desiccant, make-up air conditioning unit) on the indoor air environment of two office buildings was investigated during a two month field program. The study generated a data base and gained insights on indoor air quality (IAQ), comfort, and ventilation parameters of each building operating under routine conditions. The objective of the study was to determine the impact of the humidity pump on (1) indoor pollution concentration levels; (2) comfort parameters as perceived by occupants of and visitors to each building; and (3) building ventilation (energy) parameters. Each objective was attained by testing the null hypothesis (Operation of the humidity pump has no impact.) The null hypothesis was tested on occupant exposure levels. Consequently, it was rejected only if the humidity pump affects potential factors that may alter significantly pollutant concentrations, comfort levels, and ventilation rates. Operation of the humidity pump affects levels of volatile organic compounds and microbiological conditions. The humidity pump did not affect comfort and ventilation parameters.
Moschandreas, D.J.; Relwani, S.M.
Observing Local-Scale Variability of Near-Surface Temperature and Humidity Using a Wireless Sensor Network
In this paper the influence of surface type, wind speed, and other environmental conditions on near-surface air temperature, specific humidity, and surface temperature is studied. A wireless sensor network consisting of 13 low-cost meteorological ...
Katharina Lengfeld; Felix Ament
Humidity, human factors, and the energy shortage
Little is known about humidity and its effects on human performance. An increased emphasis is being placed on the role of humidification and dehumidification of our working and living environments on performance. This paper was presented at a Symposium on Humidity Control and Energy Conservation, held during ASHRAE's 1975 Semiannual Meeting in Atlantic City, New Jersey. Other papers were: Residential Humidification vs. Energy Conservation, by J. A. Selvaag and Humidity Control and Energy Conservation, by Dr. G. Shavit.
Rohles, F.H. Jr.
Humidity response characteristics of barium titanate
Humidity response characteristics of BaTiO[sub 3] doped with lanthanum were examined using complex impedance measurements. A sample with relative density of 71% showed a nearly log-linear increase of conductivity with humidity at 118 Hz. The average capacitance of bulk changed little with humidity; however, the resistance showed a gradual decrease. The equivalent circuit explaining such an observation was presented.
Hwang, Tae Jin; Choi, Gyeong Man (Pohang Inst. of Science and Tech., Pohang (Korea, Republic of). Dept. of Materials Science and Engineering)
Group 3: Humidity, Temperature, and Voltage (Presentation)
Group 3 is chartered to develop accelerated stress tests that can be used as comparative predictors of module lifetime versus stresses associated with humidity, temperature and voltage.
Statistical Retrieval of Humidity Profiles from Precipitable Water Vapor and Surface Measurements of Humidity and Temperature
A new method is presented of statistical retrieval of humidity profiles based on measurements of surface temperature ?1, surface dewpoint ?2, and integrated water vapor ?3. In this method the retrieved values of humidity depend nonlinearly on ...
Viatcheslav V. Tatarskii; Maia S. Tatarskaia; Ed R. Westwater
Floating Loop System For Cooling Integrated Motors And Inverters Using Hot Liquid Refrigerant
A floating loop vehicle component cooling and air-conditioning system having at least one compressor for compressing cool vapor refrigerant into hot vapor refrigerant; at least one condenser for condensing the hot vapor refrigerant into hot liquid refrigerant by exchanging heat with outdoor air; at least one floating loop component cooling device for evaporating the hot liquid refrigerant into hot vapor refrigerant; at least one expansion device for expanding the hot liquid refrigerant into cool liquid refrigerant; at least one air conditioning evaporator for evaporating the cool liquid refrigerant into cool vapor refrigerant by exchanging heat with indoor air; and piping for interconnecting components of the cooling and air conditioning system.
Hsu, John S [Oak Ridge, TN; Ayers, Curtis W [Kingston, TN; Coomer, Chester [Knoxville, TN; Marlino, Laura D [Oak Ridge, TN
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
Effects of humidity and temperature on the conversion of SO/sub 2/ to particulate sulfate and sulfite. Final report
Effects of humidity and temperature on SO/sub 2/ conversion to particulate sulfate and sulfite in relation to heterogeneous conversion in droplets and on particle surfaces; homogeneous conversion in the gas phase; and gas-to-particle conversion are discussed. Theoretical quantitative expressions for some effects are derived and order-of-magnitude calculations are given. Detailed conclusions and comparisons regarding the effects of temperature and humidity on specific oxidation paths. Major conclusions documented are: rates of SO/sub 2/ to SO/sub 4//sup =/ converison in aqueous droplets are generally negatively correlated with temperature and positively correlated with relative humidity (particularly at high relative humidity); the rates of SO/sub 2/ to SO/sub 4//sup =/ conversion on reactive surfaces can be either positively correlated with relative humidity or unaffected by relative humidity, and can have a negative, a positive, or a zero correlation with temperture; the homogeneous photooxidation is considerably less sensitive to temperature than is the heterogeneous conversion. (The photooxidation of SO/sub 2/ is expected to be positively correlated with temperature, but the correlation will be weaker in clean air than in polluted air, the positive dependence of SO/sub 2/ photooxidation on humidity will be weaker in polluted air containing NMHC than in clean air); the specific conversion paths have rates with highly different sensitivities to relative humidity and temperature. Thus, a given conversion path can become more or less significant relative to other paths as relative humidity and temperature vary. This suggests that temperature and relative humidity variations can be major causes of the temporal and spatial variations in the rate and yield of conversion and in the type of sulfate produced, which in turn determine the extent of adverse environmental effects. 228 references, 1 figure, 28 tables.
Freiberg, J.E.
Air Conditioning | Department of Energy
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...
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.
The Effect of Humidity on the Reliability of a Surface Micromachined Microengine
Humidity is shown to be a strong factor in the wear of rubbing surfaces in polysilicon micromachines. We demonstrate that very low humidity can lead to very high wear without a significant change in reliability. We show that the volume of wear debris generated is a function of the humidity in an air environment. As the humidity decreases, the wear debris generated increases. For the higher humidity levels, the formation of surface hydroxides may act as a lubricant. The dominant failure mechanism has been identified as wear. The wear debris has been identified as amorphous oxidized silicon. Large slivers (approximately 1 micron in length) of debris observed at the low humidity level were also amorphous oxidized silicon. Using transmission electron microscopy, we observed that the wear debris forms spherical and rod-like shapes. We compared two surface treatment processes: a fluorinated si- lane chain, (FITl) and supercritical C02 dried (SCC02). The microengines using the SCC02 process were found to be less reliable than those released with the FIX process under two humidity levels.
Dugger, M.T.; Eaton, W.P.; Irwin, L.W.; Miller, S.L.; Miller, W.M.; Smith, N.F.; Tanner, D.M.; Walraven, J.A.
Calibrating Cylindrical Hot-Film Anemometer Sensors
We report the results of 82 separate calibrations of cylindrical, platinum hot-film anemometer sensors in air. The calibrations for each sensor involved a determination of its temperature-resistance characteristics, a study of its heat transfer ...
Edgar L. Andreas; Brett Murphy
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.
NEW ALUMINUM OXIDE HUMIDITY ELEMENT. Second Report
An aluminum oxide humidity sensing element is discussed. These elements, which were developed primarily for use in radiosonde weather measuring equipmeni, have a fast response over the entire humidity range and through a broad temperature range of -80 deg F to +l35 deg F. The elements are a marked improvement over previous humidity sensing devices, and their use in specially designed testers allows measurements to be made which were previously unobtainable. Among their other desirable features, these elements are small and lightweight, can be made inexpensively of readily available materials, and can be mass produced. (auth)
Stover, C.M.
Evolution and Accuracy of Surface Humidity Reports
Until recently surface humidity was predominantly measured using psychrometers (wet- and dry-bulb thermometers). In some countries, often in conjunction with increased automation, the measurement technique has changed�usually to capacitive ...
Bruce Ingleby; David Moore; Chris Sloan; Robert Dunn
Evolution and accuracy of surface humidity reports
Until recently surface humidity was predominantly measured using psychrometers (wet and dry bulb thermometers). In some countries, often in conjunction with increased automation, the measurement technique has changed � usually to capacitive ...
The Climatology of Relative Humidity in the Atmosphere
The present paper deals with the analysis of the time-average relative humidity fields in the atmosphere. Twice-daily estimates of relative humidity are used.
Jos�P. Peixoto; Abraham H. Oort
Tools Listed Alphabetically Tools by Platform Tools by Country Related Links Indoor Humidity Tools Indoor Humidity Tools logo. Integrated computer program intended to assist in...
Climate: monthly and annual average relative humidity GIS data...
Climate: monthly and annual average relative humidity GIS data at one-degree resolution of the World from NASASSE
(Abstract):��Relative Humidity at 10 m...
Africa Spain Sweden Switzerland United Kingdom United States Related Links Indoor Humidity Tools Indoor Humidity Tools logo. Integrated computer program intended to assist in...
Tools by Platform PC Mac UNIX Internet Tools by Country Related Links Indoor Humidity Tools Indoor Humidity Tools logo. Integrated computer program intended to assist in...
Surface Temperature Humidity Reference System Handbook - November 2005
The Surface Temperature and Humidity Reference (SURTHREF) system is intended to provide accurate reference values of ambient temperature and relative humidity for comparison with radiosonde prelaunch values.
MT Ritsche
Theory, electro-optical design, testing, and calibration of a prototype atmospheric supersaturation, humidity, and temperature sensor. Final report Mar 81-Jul 82
A new infrared differential absorption - passive thermal emission based instrument designed to make accurate in-cloud measurements of absolute humidity, air temperature, relative humidity, and ice and water supersaturations has been developed. Absolute humidity is measured by the differential infrared absorption of a broad-band light beam between 2.45 microns wavelength and the strongly absorbing water vapor band at 2.67 microns. Air temperature is sensed by a passive radiometric measurement of the Planck's law radiance emitted by carbon dioxide molecules in their very intense emission band at 4.25 microns. Significant operational advantages over previous 14-16 micron band radiometers are achieved. These non-contact optical measurements of absolute humidity and true air temperature can then be combined to yield relative humidity values with respect to both water and ice which remain valid in condensing supersaturated conditions and in spite of hydrometeors in the sample volume.
Nelson, L.D.
Secondary air interaction with main flow in axial turbines.
??Secondary air, known as purge air, is injected through seals in the hub and shroud of axial turbines to prevent hot gas ingestion into the� (more)
Zlatinov, Metodi B. (Metodi Blagoev)
Humidity effects on wire insulation breakdown strength.
Methods for the testing of the dielectric breakdown strength of insulation on metal wires under variable humidity conditions were developed. Two methods, an ASTM method and the twisted pair method, were compared to determine if the twisted pair method could be used for determination of breakdown strength under variable humidity conditions. It was concluded that, although there were small differences in outcomes between the two testing methods, the non-standard method (twisted pair) would be appropriate to use for further testing of the effects of humidity on breakdown performance. The dielectric breakdown strength of 34G copper wire insulated with double layer Poly-Thermaleze/Polyamide-imide insulation was measured using the twisted pair method under a variety of relative humidity (RH) conditions and exposure times. Humidity at 50% RH and below was not found to affect the dielectric breakdown strength. At 80% RH the dielectric breakdown strength was significantly diminished. No effect for exposure time up to 140 hours was observed at 50 or 80%RH.
Appelhans, Leah
Zero Carryover Liquid-Desiccant Air Conditioner for Solar Applications: Preprint
A novel liquid-desiccant air conditioner that dries and cools building supply air will transform the use of direct-contact liquid-desiccant systems in HVAC applications, improving comfort, air quality, and providing energy-efficient humidity control.
Lowenstein, A.; Slayzak, S.; Kozubal, E.
Texas Hot Water Report
coil hot water storage tank, a backup instantaneous electric water heater, a hydronic fan coil unit for space heating, and an efficient plumbing manifold for domestic hot water...
Studies by the Institute for Environmental Research, Kansas State University, show that in terms of comfort, health, and performance, humidity control is an important element of environmental control and should not be eliminated for the sake of energy conservation. A constant level of comfort can be maintained if the humidity is increased and the temperature is decreased and vice versa; school absenteeism due to upper respiratory infection is related to classroom humidifcation; and psychomotor performance is better under warm, dry conditions than under warm, moist conditions. Humidification may be valuable in thermostat-setback programs by making cooler conditions comfortable.
Room Temperature Control During Season Switchover with Single Duct Variable Air Volume System Without Reheat
The Langford �A� building houses the College of Architecture on TAMU campus. There are ten singleduct variable air volume (VAV) air-handling units (AHUs) without reheat serving the building. The local pneumatic thermostats modulate the dampers of VAV boxes to maintain room temperature at their setpoints. The thermostat action is switched from direct acting (DA) to reverse acting (RA) when the season changes from fall to winter and vice versa from winter to spring, based on the out side air temperature, when season changes. This results in various parts of the building ether too cold or too hot during the season change. This paper presents that the thermostat action will be switched according to cooling loads or discharge air temperature, instead of outside air temperature. For the interior zone, thermostat action does not need to be switched at all. The comfort is improved and savings is achieved by the new control scheme. Because some air-handling units (AHUs) serve both interior and exterior zones, this system never worked as intended. The system must be modified to have zone reheat and the AHUs discharge air temperature is set below dew point for humidity control.
Liu, C.; Deng, S.; Claridge, D. E.; Turner, W. D.; Bruner, H.
Group 3: Humidity, Temperature and Voltage (Presentation)
This is a summary of the work of Group 3 of the International PV QA Task Force. Group 3 is chartered to develop accelerated stress tests that can be used as comparative predictors of module lifetime versus stresses associated with humidity, temperature and voltage.
An Intelligent Chilled Mirror Humidity Instrument
An intelligent, chilled mirror humidity instrument has been designed for use on buoys and ships. Our design goal is for the instrument to make high-quality dewpoint temperature measurements for a period of up to one year from an unattended ...
David S. Hosom; Gennaro H. Crescenti; Clifford L. Winget; Sumner Weisman; Donald P. Doucet; James F. Price
Estimating the Soil Surface Specific Humidity
Based on the recent experiment results, a formula is proposed to be used in numerical weather-climate models to estimate the soil surface humidity. The formula has a very simple form and shows a smooth transition in the soil surface specific ...
Tsengdar J. Lee; Roger A. Pielke
Fluid Metrology Calibration Services - Air Speed
... National Institute of Standards and Technology provides calibration services for air speed instrumentation such as Pitot tubes, hot-wire or thermal ...
Considering Air Density in Wind Power Production
In the wind power production calculations the air density is usually considered as constant in time. Using the CIPM-2007 equation for the density of moist air as a function of air temperature, air pressure and relative humidity, we show that it is worth taking the variation of the air density into account, because higher accuracy can be obtained in the calculation of the power production for little effort.
Z�n� Farkas
A Note on Temperature and Relative Humidity Corrections for Humidity Sensors
A widely used relative humidity (RH) sensor in atmospheric science is based upon a capacitive device that outputs voltage as a linear function of RH and then is corrected by an empirically determined polynomial expression, which is only a ...
Rex J. Fleming
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.
First-Principles Calculation of the Air�Water Second Virial ...
... indus- trial drying, and humid-air turbines for power ... 2. WATER WITH INDIVIDUAL GASES ... Calculating B(T ) for Individual Water�Gas Systems (the ...
Sustainable Energy - without the hot air
.� For example, Richard Branson says that if Virgin Trains� Voyager fleet switched to 20% biodiesel � incidentally, don�t you feel it�s outrageous to call a train a �green biodie- sel-powered train� when it runs on 80% fossil fuels and just 20% biodiesel? � sorry... .chemlink.com.au/conversions.htm This means that when the price of oil is $100 per barrel, oil energy costs 6c per kWh. If there were a carbon tax of $250 per ton of CO2 on fossil fuels, that tax would increase the price of a barrel of oil by $100. Gallons The gallon would be a fine human...
MacKay, David
Observed Interannual Variability of Tropical Troposphere Relative Humidity
Relative humidity fields from the High-Resolution Infrared Radiation Sounder (HIRS) flown on NOAA series satellites since 1979 have been used to study the seasonal aspects of the interannual variability of relative humidity in the tropical ...
Mark P. McCarthy; Ralf Toumi
Trends in U.S. Surface Humidity, 1930�2010
U.S. hourly surface observations are examined at 145 stations to identify annual and seasonal changes in temperature, dewpoint, relative humidity, and specific humidity since 1930. Because of numerous systematic instrument changes that have ...
Paula J. Brown; Arthur T. DeGaetano
Humidity and Particle Fields Around Some Small Cumulus Clouds
Aircraft-borne measurements showed that five small cumulus clouds were surrounded by regions of high humidity out to distances of several cloud radii from their centers. Total particle concentrations in the regions of high humidity were about ...
Lawrence F. Radke; Peter V. Hobbs
Antarctic Low-Tropospheric Humidity Inversions: 10-Yr Climatology
Humidity inversions are nearly permanently present in the coastal Antarctic atmosphere. This is shown based on an investigation of statistical characteristics of humidity inversions at 11 Antarctic coastal stations using radiosonde data from the ...
Tiina Nyg�rd; Teresa Valkonen; Timo Vihma
Inferring Relative Humidity Profiles from 3DNEPH Cloud Data
The inference of profiles of relative humidity from cloud data was investigated in a collocation study of 3DNEPH and radiosonde data over North America. Regression equations were developed for the first two EOFs of relative humidity, using ...
Thomas Nehrkorn; Ross N. Hoffman
Diurnally Asymmetric Trends of Temperature, Humidity, and Precipitation in Taiwan
In this work, 45 years (1961�2005) of hourly meteorological data in Taiwan, including temperature, humidity, and precipitation, have been analyzed with emphasis on their diurnal asymmetries. A long-term decreasing trend for relative humidity (RH) ...
Chein-Jung Shiu; Shaw Chen Liu; Jen-Ping Chen
Morning Temporal Variations of Shelter-Level Specific Humidity
The temporal variation of specific humidity during morning hours was evaluated by analytic and numerical model scaling as well as by observational means. The scaling quantified (i) the gradual increase in the shelter increase humidity as the ...
M. Segal; G. Kallos; J. Brown; M. Mandel
Energy Conservation Experiences with HVAC Systems in the High Humidity Climate, A Case History
The purpose of this paper is to discuss several commonly encountered problems associated with attempts to air condition buildings in the humid environment. It, first, reports observations made in the course of studying the air conditioning systems in approximately one hundred buildings at USMC Camp Smedley D. Butler in Okinawa, Japan. Three common problems are then discussed in some detail. It was found that in many cases humidity considerations lead to situations which were energy wasteful. In many instances this could be attributed to either design or operational errors. The most common error found was the selection of an improper method of capacity control. Methods of improved capacity control are suggested and the need for additional work is pointed out.
Solar drying studies in a low humidity environment
Comprehensive field performance data are reported for a solar cabinet dryer under low humidity conditions of local harmattan season. The field data collected provide a frame of reference for similar data on dryer performance gathered under the normal local conditions of high relative humidity. The relative humidity, it is found, plays a most decisive role in the entire drying process.
Mojola, O.O.
Using Absolute Humidity and Radiochemical Analyses of Water Vapor Samples to Correct Underestimated Atmospheric Tritium Concentrations
Los Alamos National Laboratory (LANL) emits a wide variety of radioactive air contaminants. An extensive ambient air monitoring network, known as AIRNET, is operated on-site and in surrounding communities to estimate radioactive doses to the public. As part of this monitoring network, water vapor is sampled continuously at more than 50 sites. These water vapor samples are collected every two weeks by absorbing the water vapor in the sampled air with silica gel and then radiochemically analyzing the water for tritium. The data have consistently indicated that LANL emissions cause a small, but measurable impact on local concentrations of tritium. In early 1998, while trying to independently verify the presumed 100% water vapor collection efficiency, the author found that this efficiency was normally lower and reached a minimum of 10 to 20% in the middle of summer. This inefficient collection was discovered by comparing absolute humidity (g/m{sup 3}) calculated from relative humidity and temperature to the amount of water vapor collected by the silica gel per cubic meter of air sampled. Subsequent experiments confirmed that the elevated temperature inside the louvered housing was high enough to reduce the capacity of the silica gel by more than half. In addition, their experiments also demonstrated that, even under optimal conditions, there is not enough silica gel present in the sampling canister to absorb all of the moisture during the higher humidity periods. However, there is a solution to this problem. Ambient tritium concentrations have been recalculated by using the absolute humidity values and the tritium analyses. These recalculated tritium concentrations were two to three times higher than previously reported. Future tritium concentrations will also be determined in the same manner. Finally, the water vapor collection process will be changed by relocating the sampling canister outside the housing to increase collection efficiency and, therefore, comparability to the true ambient concentrations of tritium.
Eberhart, C.F.
Indoor Air Quality Primer for HVAC System Design
Heating, ventilating, and air conditioning (HVAC) systems are major energy users in commercial and institutional buildings. Increased ventilation for acceptable indoor air quality (IAQ), besides increasing energy use, may result in unacceptably high indoor humidity, particularly in humid climates and/or applications requiring high ventilation rates. This report analyzes how increased ventilation affects the dehumidification capabilities of air conditioning systems in three applications -- offices, retail...
Madrid Hot Water Report
Comprehensive Assessment of Hot Water System Page 1 of 2 HOT WATER SYSTEM In general, the plumbing system in MAGIC BOX is designed to concentrate all devices, be they storage,...
NEWTON: Green Hot
to two different phenomena. The 'red-hot' or 'white-hot' designations are due to black body radiation, which you can read about on-line. The colors of flames are due to ionization...
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.
Improving DOE-2's RESYS routine: User defined functions to provide more accurate part load energy use and humidity predictions
In hourly energy simulations, it is important to properly predict the performance of air conditioning systems over a range of full and part load operating conditions. An important component of these calculations is to properly consider the performance of the cycling air conditioner and how it interacts with the building. This paper presents improved approaches to properly account for the part load performance of residential and light commercial air conditioning systems in DOE-2. First, more accurate correlations are given to predict the degradation of system efficiency at part load conditions. In addition, a user-defined function for RESYS is developed that provides improved predictions of air conditioner sensible and latent capacity at part load conditions. The user function also provides more accurate predictions of space humidity by adding ''lumped'' moisture capacitance into the calculations. The improved cooling coil model and the addition of moisture capacitance predicts humidity swings that are more representative of the performance observed in real buildings.
Henderson, Hugh I.; Parker, Danny; Huang, Yu J.
Oil and Gas Air Heaters
Most conventional air heaters adopt indirect heat transfer, which uses combustion gases to indirectly heat fresh air by heating surfaces to generate hot air used for material drying and dehumidification. We call them indirect air heaters. However, they have a higher manufacturing cost and lower thermal efficiency, especially when high temperature air is needed. For this reason, a direct air heater applicable for or feed and industrial raw products is put forward, which has advantages such as less production cost, smaller dimensions and higher thermal efficiency. Their design, working principles, characteristics, structure and applications are presented in this article, and brief comparisons are made between the indirect and direct air heater. Finally, the relation of hot-air temperature, oil or gas consumption and fresh airflow is determined based on energy equilibrium.
Kou, G.; Wang, H.; Zhou, J.
Roots of Mold Problems and Humidity Control Measures in Institutional Buildings with Pre-Existing Mold Condition
Humidity control and mold in buildings has become an increasingly important problem. Once a building has experience mold growth on walls, ceilings, and other surfaces, it does not take longterm exposure to moisture for mold to re-grow in the building. Some commercial buildings on the Texas A&M University (TAMU) campus have suffered with humidity problems for many years. The Continuous Commissioning (CCSM) group of the Energy Systems Lab in collaboration with the Utilities Office of Energy Management, and the TAMU Physical Plant, was dispatched to perform Continuous Commissioning on these commercial buildings in order to find viable solutions to the humidity problem. The CC group performed extensive field tests and analysis on building air handling unit (AHU), exhaust systems, building construction, and the Energy Management Control System (EMCS). Based on the field studies and analysis, a four-category (Design, construction, building retrofits and alterations, and poor maintenance) system was set up to classify sources for high humidity problems. This paper presents the investigation and follow-up efforts, which identified reasons and corrective measures for the high humidity levels in these buildings, turning these inefficient and humid commercial buildings into comfortable environments. Recommendations for dealing with such possible problems are provided.
Chen, H.; Deng, S.; Bruner, H.; Garcia, J.
Automatic monitoring of selected indoor air parameters at three apartment complexes
The impact of three different ventilation systems on the temperature and humidity of three similar apartment complexes is investigated in this study. Each complex has six apartments. The ventilation systems are: natural ventilation, mechanical exhaust ventilation, and mechanical supply and exhaust ventilation. The computer controlled data collection system measures the ventilation rate, relative humidity, indoor air temperature, wind speed, wind direction, outdoor temperature, and humidity. The air change rate depends mainly on the habits of the tenants. The mean air change rate of the houses was between 0.1 to 0.8 ac/h. Great daily variation of the air exchange was observed in the data. Negative correlation between relative humidity and ventilation was very significant in 27 out of 47 cases. Only two cases had very significant positive correlation between ventilation and humidity. Mechanical supply and exhaust ventilation have the greatest variation in ventilation/relative humidity relations.
Savolainen, T.; Raunemaa, T (Univ. of Kuopio (Finland)); Wellman, K. (Technical Research Centre of Finland, Helsinki (Finland))
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
Air Cooling | Open Energy Information
Cooling Cooling Jump to: navigation, search Dictionary.png Air Cooling: Air cooling is commonly defined as rejecting heat from an object by flowing air over the surface of the object, through means of convection. Air cooling requires that the air must be cooler than the object or surface from which it is expected to remove heat. This is due to the second law of thermodynamics, which states that heat will only move spontaneously from a hot reservoir (the heat sink) to a cold reservoir (the air). Other definitions:Wikipedia Reegle Air Cooling Air Cooling Diagram of Air Cooled Condenser designed by GEA Heat Exchangers Ltd. (http://www.gea-btt.com.cn/opencms/opencms/bttc/en/Products/Air_Cooled_Condenser.html) Air cooling is limited on ambient temperatures and typically require a
CVEN 6960 master's project, investigation of a cooling coil in high humidity conditions. Master's thesis
The primary purpose of this project is to validate the HVAC*2 Toolkit calculations for a cooling coil in high humidity conditions. A total of 19 experimental runs at different entering air temperature and humidity conditions were performed at the Joint Center for Energy Management HVAC Laboratory that exposed a cooling coil to temperature and humidity conditions that are typically found in the southern United States. The inlet conditions and manufacturer's coil rating data was used as input to the HVAC*2 Toolkit simple cooling coil subroutine (CCSIM). The predicted results from the toolkit were then compared to the experimental results.
Sloop, R.E.
Energy Design Guidelines for High Performance Schools: Hot and Humid Climates
Acknowledgements Acknowledgements The US Department of Energy would like to acknowledge the help and assistance of the EnergySmart Schools team and the many reviewers who provided input and feedback during the process of developing this report. Those include: National Laboratories Lawrence Berkeley National Laboratory: Dariush Arasteh, Doug Avery; National Renewable Energy Laboratory: Ren Anderson, Zahra Chaudhry, Kate Darby, Kyra Epstein, Patty Kappaz, Bryan King, Patricia Plympton, Amy Vaughn; Oak Ridge National Laboratory: Sherry Livengood, Ron Shelton; Pacific Northwest National Laboratory: Michael Baechler, Kim Fowler, Eric Richman, David Winiarski US Department of Energy David Hansen, George James, Arun Vohra; Chicago Regional Office: John Devine, Peter Dreyfuss; Seattle Regional Office:
Microcomputer Energy Analysis Studies of Selected Building Types in a Hot, Humid Climatic Zone
The DOE-2 building energy analysis computer program has been used in both the design and analysis of new or retrofitted buildings. The combination of ease of use, economy, and the capability of producing a comprehensive thermal analysis has made this tool valuable to the design professional. Recent developments in the microcomputer area make it possible to employ hourly building energy analysis computer models, such a s DOE-2, that were once available only through use of mainframe computers, A microcomputer version of the DOE-2 model is currently available for the study of design and analysis simulations of many building types. Several characteristic buildings emphasizing variations in housing, office/commercial, and school types are being studied. These building types form typical low-scale buildings that are found throughout the region. The discovery of the effects of shape, orientation , mass, and other architectonic elements on energy conservation form a major concern of the survey. A DOE-2 program version adapted for use on a microcomputer demonstrating similar modeling capabilities to the mainframe version is the primary analytical tool used in this study. DOE-2 simulates the heating and cooling loads and the energy consumed by both the primary plant and secondary HVAC energy sources.
McQueen, T. M.; Leaver, J. F.
Conservation of Mass: An Old Principle That Needs More Usage in Hot & Humid Climates
Conservation of mass is such a basic principal that most designers no longer consider it for most design calculations. Design phase commissioning checks on several recent projects indicate designers should include conservation of mass calculations in the design. Recent retro-commissioning project indicate the concept should be considered by building owners and operators as well.
Browning, B. K.; McKinney, G.
Ventilation Requirements in Hot Humid Iain S. Walker and Max H. Sherman
as it provides cooling (i.e. sensible load removal). Conventional systems have well known limits because it brings in moisture which can cause mold problems and/or increase loads on the cooling system for Energy Efficiency and Renewable Energy, Office of the Building Technologies Program, U.S. Department
Investigation of passive cooling for hot-humid climates. Progress report No. 3
Work on getting the Brookhaven National Laboratories computer program for modeling ground coil performance operational is described. Arrangements made to sink two 40 ft vertical wells for soil temperature measurements are described. Methods for evaluating the effect of pipe diameter, length, spacing, and material were investigated. Calculation results are shown. (MHR)
Akridge, J M
Field experiments on occupant comfort and office thermal environments in a hot-humid climate
analysis, and Cris Bentonof CEDR for advice in relation toMPRL and Nora Watanabe at CEDR thanked for their assistance
de Dear, Richard; Fountain, M.
Economic and design analysis of daylighting a commercial tower in a hot and humid climate
A forty story commercial office tower in Tampa, Florida was redesigned for daylighting. The methods are outlined and results illustrated, A cooling load comparison is done to determine the economic feasibility of such a ...
Roscow, Robert F
Prototype Passive Solar Buildings in Louisiana - A Hot-Humid Climate
This paper on prototype passive solar buildings in Louisiana presents state of the art passive solar design. According to U.S. Department of Energy report, the annual energy consumption for a single family detached dwelling in Louisiana is from 31,000 to 51,000 Btu's/sq.ft./yr. with a mean at 38,000 Btu's/sq.ft./yr. and for an office building is from 39,000 to 58,000 Btu's/sq.ft./yr. Incorporation of passive solar design may provide a major percentage of the energy consumption with only 2 to 8 percent of additional construction cost. The projected savings as presented in this report are an approximate estimation. However, the actual savings will vary depending upon the occupancy, operation, and maintenance of the building. At the same time, such design represents an increased involvement for the architect. The full potential of this passive solar design depends on a sensitive awareness of the relationship between climate, comfort and the thermal characteristics of buildings and building materials. The primary purpose of this work is to offer a working definition and fundamental understanding of a number of practical applications of passive solar designs in Louisiana. Four new buildings and six existing retrofitted buildings are presented.
Shih, J. C.
Case Study: Passive Solar Concepts Adapted to In-Fill Housing in a Hot, Humid Climate
In-fill housing for central city areas appears to be an answer to the continuing need for compact, affordable dwelling unite that will improve the neighborhood environment. There exist many central city areas in Louisiana where lots are unusually narrow but zoned for residential use. As a result of current building code improvement programs, there are numerous vacant lots in the prime downtown locations. Owners and builders seem to be poorly equipped to deal with the design constraints inherent in architectural proposals for contemporary housing design in these areas. Thin investigation considers the development of a case study that involves the planning and design of a compact, solar multi-family residential unit for a central city site condition. Emphasis will be placed on developing units that are highly energy conserving and have potential for one of three levels of passive solar technology--from a sun-tempered unit to a dominant passive solar system. The case study also focuses on the optional mix relationship between conservation options and passive system size. The site study area, a neighborhood in Baton Rouge, Louisiana, is distinctive in that narrow 40 x 100 feet lots predominate. Many are vacant.
McQueen, T. M.; White, J. T.
School districts around the country are finding that the smart energy choices can help them save money and provide healthier, more effective learning environments. By incorporating energy improvements into their construction or renovation plans, schools can significantly reduce energy consumption and costs. These savings can be redirected to educational needs such as additional teachers, instructional materials, or new computers. These design guidelines outline high performance principles for the new or retrofit design of your K-12 school. By incorporating these principles, you can create and exemplary building that is both energy and resource efficient.
Effects of Radiant Barrier Systems on Ventilated Attics in a Hot and Humid Climate
Results of side-by-side radiant barrier experiments using two identical 144 ft2 (nominal) test houses are presented. The test houses responded very similarly to weather variations prior to the retrofit. The temperatures of the test houses were controlled to within 0.3�F. Ceiling heat fluxes were within 2 percent for each house.
The results showed that a critical attic ventilation flow rate (0.25 CFM/ft2 ) existed after which the percentage reduction produced by the radiant barrier systems was not sensitive to increased airflows. The ceiling heat flux reductions produced by the radiant barrier systems were between 25 and 34 percent, with 28 percent being the reduction observed most often in the presence of attic ventilation. All results presented in this paper were for attics with R-19 unfaced fiberglass insulation and for a perforated radiant barrier with low emissivities on both sides.
Medina, M. A.; O'Neal, D. L.; Turner, W. D.
School districts around the country are finding that the smart energy choices can help them save money and provide healthier, more effective learning environments. By incorporating energy improvements into their construction or renovation plans,
Chemical maximum humidity indicator update report. Topical report
Raw materials and manufactured parts sometimes must be kept in a controlled-humidity environment. The use of moisture-sensitive systems to indicate the maximum level of humidity exposure is discussed. A chemical indicator made from deliquescent salts and water-soluble dyes provides an irreversible color change at discrete levels of relative humidity. The performance and long-term-stability characteristics of the indicator are described.
Abel, W.B.
Hexane Air Combustion
Hot surface ignition and subsequent flame propagation of premixed n-hexane air mixtures are shown in this fluid dynamics video. High speed schlieren photography revealed 3 distinct behaviors of ignition and propagation as a function of mixture composition and initial pressure.
Boettcher, Philipp A; Shepherd, Joseph E
A preliminary report which describes the development and present statas of a new Al humidity element is presented. Data are included. (auth)
Improved Humidity Profiling by Combining Passive and Active Remote...
Science Team Meeting Proceedings, Albuquerque, New Mexico, March 22-26, 2004 Improved Humidity Profiling by Combining Passive and Active Remote Sensors at the Southern Great Plains...
Impact of Vaisala Radiosonde Humidity Corrections on ARM IOP...
Proceedings, St. Petersburg, Florida, April 8-12, 2002 Impact of Vaisala Radiosonde Humidity Corrections on ARM IOP Data L. M. Miloshevich National Center for Atmospheric...
published ASHRAE standards. 2. Economizer use caused sharp increases in particle concentrations when, the annual average concentrations still met the ASHRAE standards. However, concentration were still above is minimal (ASHRAE 40%) since most air is typically r
Review of Radiosonde Humidity and Temperature Errors
An attempt is made to provide a brief but comprehensive summary of sources of error in National Weather Service upper air data, and a guide to the relevant literature. Error analysis must be tailored for particular applications. Temperature ...
Robert W. Pratt
Geothermal: Hot Documents Search
Office of Scientific and Technical Information (OSTI)
GEOTHERMAL TECHNOLOGIES LEGACY COLLECTION - Hot Documents Search Geothermal Technologies Legacy Collection HelpFAQ | Site Map | Contact Us | Admin Log On HomeBasic Search About...
Air Pollution Control Regulations: No. 13 - Particulate Emissions...
Pollution Control Regulations: No. 13 - Particulate Emissions from Fossil Fuel Fired Steam or Hot Water Generating Units (Rhode Island) Air Pollution Control Regulations: No. 13...
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.
Method and apparatus for controlling fuel/air mixture in a lean burn engine
The system for controlling the fuel/air mixture supplied to a lean burn engine when operating on natural gas, gasoline, hydrogen, alcohol, propane, butane, diesel or any other fuel as desired. As specific humidity of air supplied to the lean burn engine increases, the oxygen concentration of exhaust gas discharged by the engine for a given equivalence ratio will decrease. Closed loop fuel control systems typically attempt to maintain a constant exhaust gas oxygen concentration. Therefore, the decrease in the exhaust gas oxygen concentration resulting from increased specific humidity will often be improperly attributed to an excessive supply of fuel and the control system will incorrectly reduce the amount of fuel supplied to the engine. Also, the minimum fuel/air equivalence ratio for a lean burn engine to avoid misfiring will increase as specific humidity increases. A relative humidity sensor to allow the control system to provide a more enriched fuel/air mixture at high specific humidity levels. The level of specific humidity may be used to compensate an output signal from a universal exhaust gas oxygen sensor for changing oxygen concentrations at a desired equivalence ratio due to variation in specific humidity specific humidity. As a result, the control system will maintain the desired efficiency, low exhaust emissions and power level for the associated lean burn engine regardless of the specific humidity level of intake air supplied to the lean burn engine.
Kubesh, John Thomas (San Antonio, TX); Dodge, Lee Gene (San Antonio, TX); Podnar, Daniel James (San Antonio, TX)
Relative Humidity in Limited Streamer Tubes for Stanford Linear Accelerator Center's BaBar Detector
The BABAR Detector at the Stanford Linear Accelerator Center studies the decay of B mesons created in e{sup +}e{sup -} collisions. The outermost layer of the detector, used to detect muons and neutral hadrons created during this process, is being upgraded from Resistive Plate Chambers (RPCs) to Limited Streamer Tubes (LSTs). The standard-size LST tube consists of eight cells, where a silver-plated wire runs down the center of each. A large potential difference is placed between the wires and ground. Gas flows through a series of modules connected with tubing, typically four. LSTs must be carefully tested before installation, as it will be extremely difficult to repair any damage once installed in the detector. In the testing process, the count rate in most modules showed was stable and consistent with cosmic ray rate over an approximately 500 V operating range between 5400 to 5900 V. The count in some modules, however, was shown to unexpectedly spike near the operation point. In general, the modules through which the gas first flows did not show this problem, but those further along the gas chain were much more likely to do so. The suggestion was that this spike was due to higher humidity in the modules furthest from the fresh, dry inflowing gas, and that the water molecules in more humid modules were adversely affecting the modules' performance. This project studied the effect of humidity in the modules, using a small capacitive humidity sensor (Honeywell). The sensor provided a humidity-dependent output voltage, as well as a temperature measurement from a thermistor. A full-size hygrometer (Panametrics) was used for testing and calibrating the Honeywell sensors. First the relative humidity of the air was measured. For the full calibration, a special gas-mixing setup was used, where relative humidity of the LST gas mixture could be varied from almost dry to almost fully saturated. With the sensor calibrated, a set of sensors was used to measure humidity vs. time in the LSTs. The sensors were placed in two sets of LST modules, one gas line flowing through each set. These modules were tested for count rate v. voltage while simultaneously measuring relative humidity in each module. One set produced expected readings, while the other showed the spike in count rate. The relative humidity in the two sets of modules looked very similar, but it rose significantly for modules further along the gas chain.
Lang, M.I.; /MIT; Convery, M.; /SLAC; Menges, W.; /Queen Mary, U. of London
Climatology of Chicago Area Urban-Rural Differences in Humidity
Hourly measurements at an urban airport and at a rural laboratory have been used in a study of Chicago area urban-rural humidity differences. Although the relative humidity was usually lower in the city than in the country, largely a consequence ...
Bernice Ackerman
A New Empirical Model of the Temperature�Humidity Index
A simplified scale of apparent temperature, considering only dry-bulb temperature and humidity, has become known as the temperature�humidity index (THI). The index was empirically constructed and was presented in the form of a table. It is often ...
Carl Schoen
Outdoor Air, Heat Wheels and JCPenney: A New Approach to Retail Ventilation
JCPenney Construction Services department is responsible for the construction of new stores, takeover of existing facilities to create a new store, repairs to existing JCPenney facilities and the expansion and modernization of stores across the nation and the world. Each year, JCPenney Construction Services handles approximately 50 projects along these lines. After the implementation of ASHRAE 62- 1989 by JCPenney and many major building codes, including BOCA, mechanical engineers at JCPenney noticed a sharp increase in the percentage of cooling capacity required to cool the outdoor ventilation air. In an effort to limit this impact, both in first cost and in operational costs, JCPenney is beginning to make an effort to use enthalpy heat wheels in the hot and humid climate areas where it is economically feasible. This paper discusses the efforts of JCPenney to implement this option to the treatment of outdoor air in a store in Baton Rouge, LA while maintaining indoor air quality requirements as stated in ASHRAE Standard 62-1989 and maintaining energy efficiency. This paper also discusses the projected energy savings and operations of this alternative to the standard treatment of outdoor air.
Smith, C. S.; Bartlett, T. A.
Transparent Humidity Sensor Using Cross-Linked Polyelectrolyte Membrane
This paper describes the fabrication of a porous cross-linked polyelectrolyte membrane and the characterization of its humidity sensitivity performance. Electrostatic self-assembly, combined with acid treatment, and post-deposition annealing produced the membrane. The fabrication process offers the ability to control the thickness of the membrane, as well as enabling the engineering of the humidity sensitivity properties. A transparent humidity sensor was fabricated by integrating the membrane between two parallel electrodes. In order to improve the moisture absorption and diffusion, both the polyelectrolyte layer and the electrode were made porous. The membrane was cross-linked to enhance the durability in high humid environments. Such a polyelectrolyte membrane showed high sensitivity to relative humidity variation over a range of 25%�99%. The see-through property of the structure adds extra features and benefits to the sensor.
Zhang, Q.; Smith, James R.; Saraf, Laxmikant V.; Hua, Feng
Effect of refrigerant charge, duct leakage, and evaporator air flow on the high temerature performance of air conditioners and heat pumps
An experimental study was conducted to quantify the effect of several installation items on the high outdoor ambient temperature performance of air conditioners. These installation items were: improper amount of refrigerant charge, reduced evaporator airflow, and return air leakage from hot attic spaces. There were five sets of tests used for this research: two of them for the charging tests, two for the reduced evaporator airflow, and one for the return air leakage tests. For the charging tests, the indoor room conditions were 80'F (27.8'C) dry-bulb and 50% relative humidity. The outdoor conditions ranged from 95'F (350C) all the way up to 120'F (48.9'C). Charge levels ranged from 30% undercharged to 40% overcharged for the short-tube orifice unit. For the thermal expansion valve (TXV) unit, charge levels ranged from-36% charging to +27% charging. Performance was quantified with the following variables: total capacity, energy efficiency ratio (EER), and power. The performance of the orifice unit was more sensitive to charge than it was for the TXV unit. For the TXV unit on the -27% to +27% charging range, the capacity and EER changed little with charge. A TXV unit and a short-tube orifice unit were also tested for reduced evaporator airflow. As evaporator airflow decreased, the capacity and EER both decreased as expected. However, the drop was not as significant as with the charging tests. For the extreme case of 50% reduced evaporator airflow, neither unit's capacity or EER dropped more than 25%. 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 EER 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 perhaps the most detrimental effect of return air leakage on performance, which was the inability of the unit to absorb moisture from the environment.
Rodriguez, Angel Gerardo
Effect of Refrigerant Charge, Duct Leakage, and Evaporator Air Flow on the High Temperature Performance of Air Conditioners and Heat Pumps
An experimental study was conducted to quantify the effect of several installation
items on the high outdoor ambient temperature performance of air conditioners. These
installation items were: improper amount of refrigerant charge, reduced evaporator airflow,
and return air leakage from hot attic spaces. There were five sets of tests used for this
research: two of them for the charging tests, two for the reduced evaporator airflow, and
one for the return air leakage tests.
For the charging tests, the indoor room conditions were 80�F (27.8�C) dry-bulb
and 50% relative humidity. The outdoor conditions ranged from 95�F (35�C) all the way
up to 120�F (48.9�C). Charge levels ranged from 30% undercharged to 40% overcharged
for the short-tube orifice unit. For the thermal expansion valve (TXV) unit, charge levels
ranged from -36% charging to +27% charging. Performance was quantified with the
following variables: total capacity, energy efficiency ratio (EER), and power. The
performance of the orifice unit was more sensitive to charge than it was for the TXV unit.
For the TXV unit on the -27% to +27% charging range, the capacity and EER changed
little with charge. A TXV unit and a short-tube orifice unit were also tested for reduced
evaporator airflow. As evaporator airflow decreased, the capacity and EER both
decreased as expected. However, the drop was not as significant as with the charging tests. For the extreme case of 50% reduced evaporator airflow, neither unit's capacity or
EER dropped more than 25%.
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 EER 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 perhaps the most detrimental effect of return air leakage on
performance, which was the inability of the unit to absorb moisture from the environment.
Humidity-temperature relationships in the tropical troposphere
Based on the observed interannual variations of water vapor and temperature over the past 26 years the authors have examined the relationship between the variations of water vapor and temperature in the tropical troposphere. In both the lower and upper troposphere, tropical mean specific humidity increases with temperature. The rate of fractional increase of specific humidity with temperature at 500 mb is as large as that in the surface boundary layer. However, the rate of fractional increase of specific humidity with temperature is significantly smaller than that given by a model with a fixed relative humidity, particularly in the region immediately above the tropical convective boundary layer. The variations of tropical mean relative humidity show consistently a negative correlation with the temperature variations. The authors have further compared the spatial structure of the specific humidity variations with that of the temperature variations. Though the vertical structure of tropical mean specific humidity has more variability than that of the tropical mean temperature, the leading EOF for the normalized specific humidity variations is almost exactly the same as the leading EOF for the normalized temperature variations. The characteristic horizontal structure of the specific humidity variations at levels in the free troposphere, however, is very different from that of the temperature variations. The leading EOF for the normalized specific humidty variations at levels in the free troposphere is characterized by regions with alternating positive and negative signs, while the leading EOF for the corresponding temperature variations has a single sign throughout the Tropics. When the variations are averaged zonally, the leading EOF for the normalized specific humidity variations still differs significantly from that of the normalized temperature variations, but the leading EOF has the same sign from the deep Tropics to the subtropics. 31 refs., 15 figs., 1 tab.
Sun, D.Z. [Princeton Univ., NJ (United States); Oort, A.H. [NOAA, Princeton, NJ (United States)
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))
Secondary air interaction with main flow in axial turbines
Secondary air, known as purge air, is injected through seals in the hub and shroud of axial turbines to prevent hot gas ingestion into the endwall cavities. An investigation into the interaction of purge ow with turbine ...
The effects of roof reflectance on air temperatures surrounding...
the heating of condenser inlet air by the roof, and to assess the effects of condenser fan operation on the potential recirculation of hot discharge air from the condenser. The...
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.
Hot and Cold
What happens to neon gas when it gets very hot? In this experiment, liquid nitrogen and Tesla coils are used to study the effects of extreme temperatures on everyday objects. Don't...
Reactor hot spot analysis
The principle methods for performing reactor hot spot analysis are reviewed and examined for potential use in the Applied Physics Division. The semistatistical horizontal method is recommended for future work and is now available as an option in the SE2-ANL core thermal hydraulic code. The semistatistical horizontal method is applied to a small LMR to illustrate the calculation of cladding midwall and fuel centerline hot spot temperatures. The example includes a listing of uncertainties, estimates for their magnitudes, computation of hot spot subfactor values and calculation of two sigma temperatures. A review of the uncertainties that affect liquid metal fast reactors is also presented. It was found that hot spot subfactor magnitudes are strongly dependent on the reactor design and therefore reactor specific details must be carefully studied. 13 refs., 1 fig., 5 tabs.
Vilim, R.B.
DQO Summary Report for 324 and 327 Building Hot Cells D4 Project Waste Characterization
This data quality objective (DQO) summary report provides the results of the DQO process conducted for waste characterization activities for the 324 and 327 Building hot cells decommission, deactivate, decontaminate, and demolish activities. This DQO summary report addresses the systems and processes related to the hot cells, air locks, vaults, tanks, piping, basins, air plenums, air ducts, filters, an adjacent elements that have high dose rates, high contamination levels, and/or suspect transuranic waste, which will require nonstandard D4 techniques.
T.A. Lee
Effects of humidity during photoprocessing on thin film metallization adhesion
Humidity effects during photoprocessing on tantalum/chromium/gold thin film networks (TFNs) were investigated. Humidity conditions at various process steps were controlled by placing either desiccant or water in handling containers for the TFNs. The TFNs photoprocessed in humid conditions had a much higher occurrence of metallization failures compared to TFNs processed in dry conditions. Ceramic surface defects were shown to cause pores in the thin films, and these pores enhanced corrosion susceptibility for the films. This study resulted in a desiccated storage process for production of TFNs.
Norwood, D.P.
Dynamics of electrostatically driven granular media: Effects of humidity
We performed experimental studies of the effect of humidity on the dynamics of electrostatically driven granular materials. Both conducting and dielectric particles undergo a phase transition from an immobile state (granular solid) to a fluidized state (granular gas) with increasing applied field. Spontaneous precipitation of solid clusters from the gas phase occurs as the external driving is decreased. The clustering dynamics in conducting particles is primarily controlled by screening of the electric field but is aided by cohesion due to humidity. It is shown that humidity effects dominate the clustering process with dielectric particles.
Howell, D. W.; Aronson, Igor S.; Crabtree, G. W.
An Integrated Refrigeration, Humidity Control and HVAC Solution for Supermarkets: Field Demonstration at a Wal-Mart SuperCenter
This report describes a systematic approach to developing an energy efficient and cost effective solution for refrigeration, humidity control, indoor air quality, and space heating and cooling for large retail super centers. The report also presents the results of a field demonstration using a newly developed integrated system that achieved significant energy savings and other benefits compared to the state-of-the-art system.
Dry Bias in Vaisala RS90 Radiosonde Humidity Profiles over Antarctica
Middle to upper tropospheric humidity plays a large role in determining terrestrial outgoing longwave radiation. Much work has gone into improving the accuracy of humidity measurements made by radiosondes. Some radiosonde humidity sensors ...
Penny M. Rowe; Larry M. Miloshevich; David D. Turner; Von P. Walden
Mechanism for the Behavior of Hydroactive Materials Used in Humidity Sensors
The theory of operation of humidity sensors has not been widely discussed in the literature. In particular, no convincing explanation has been given as to why they respond to relative humidity (RH) rather than to an absolute measure of humidity, ...
P. S. Anderson
Closed loop air cooling system for combustion turbines
Convective cooling of turbine hot parts using a closed loop system is disclosed. Preferably, the present invention is applied to cooling the hot parts of combustion turbine power plants, and the cooling provided permits an increase in the inlet temperature and the concomitant benefits of increased efficiency and output. In preferred embodiments, methods and apparatus are disclosed wherein air is removed from the combustion turbine compressor and delivered to passages internal to one or more of a combustor and turbine hot parts. The air cools the combustor and turbine hot parts via convection and heat is transferred through the surfaces of the combustor and turbine hot parts.
Huber, David John (North Canton, OH); Briesch, Michael Scot (Orlando, FL)
Convective cooling of turbine hot parts using a closed loop system is disclosed. Preferably, the present invention is applied to cooling the hot parts of combustion turbine power plants, and the cooling provided permits an increase in the inlet temperature and the concomitant benefits of increased efficiency and output. In preferred embodiments, methods and apparatus are disclosed wherein air is removed from the combustion turbine compressor and delivered to passages internal to one or more of a combustor and turbine hot parts. The air cools the combustor and turbine hot parts via convection and heat is transferred through the surfaces of the combustor and turbine hot parts. 1 fig.
Huber, D.J.; Briesch, M.S.
Climate: monthly and annual average relative humidity GIS data at
relative humidity GIS data at relative humidity GIS data at one-degree resolution of the World from NASA/SSE Dataset Summary Description (Abstract): Relative Humidity at 10 m Above The Surface Of The Earth (%)NASA Surface meteorology and Solar Energy (SSE) Release 6.0 Data Set (Nov 2007)22-year Monthly & Annual Average (July 1983 - June 2005)Parameter: Relative Humidity at 10 m Above The Surface Of The Earth (%)Internet: http://eosweb.larc.nasa.gov/sse/Note 1: SSE Methodology & Accuracy sections onlineNote 2: Lat/Lon values indicate the lower left corner of a 1x1 degree region. Negative values are south and west; positive values are north and east. Boundaries of the -90/-180 region are -90 to -89 (south) and -180 to -179 (west). The last region, 89/180, is bounded by 89 to 90 (north) and 179 to 180 (east). The mid-point of
Eliminating Humidity and Condensation Problems in University Dormitories - Case Study
Krueger Hall, McFadden Hall and Rudder Hall are
dormitories used for housing on-campus students of
Texas A&M University (TAMU). These halls have
suffered with humidity problems for many years.
The Continuous Commissioning (CCSM) group of the
Energy Systems Lab in collaboration with the
Utilities Office of Energy Management, the TAMU
Physical Plant, was dispatched to perform
Continuous Commissioning on these three
dormitories in order to find viable solutions to the
humidity issues. The CC group performed extensive
field tests and analysis on building AHU systems,
exhaust systems, building construction, and the
Energy Management Control System (EMCS). This
paper presents the investigation and follow-up
efforts, which identified reasons and corrective
measures for the high humidity levels in the living
areas of McFadden and Rudder Halls, and
condensation in the bathroom ceilings of Krueger
Hall, transforming these inefficient, humid university
dormitories into comfortable environments.
Claridge, D.; Turner, W. D.; Zhu, Y.; Chen, H.; Bruner, H., Jr.; Hugghins, J.; Deng, S.
Threshold Relative Humidity Duration Forecasts for Plant Disease Prediction
Duration of high relative humidity periods is an important component of many plant disease development models. Performance of forecasts of this quantity, based on the model output statistics 3-h temperature and dewpoint forecasts produced by the ...
Daniel S. Wilks; Karin W. Shen
Response of Humidity and Clouds to Tropical Deep Convection
Currently available satellite data can be used to track the response of clouds and humidity to intense precipitation events. A compositing technique centered in space and time on locations experiencing high rain rates is used to detail the ...
Mark D. Zelinka; Dennis L. Hartmann
Diagnosis of Subtropical Humidity Dynamics Using Tracers of Last Saturation
A technique for diagnosing the mechanisms that control the humidity in a general circulation model (GCM) or observationally derived meteorological analysis dataset is presented. The technique involves defining a large number of tracers, each of ...
Joseph Galewsky; Adam Sobel; Isaac Held
Relative Humidity in Liquid, Mixed-Phase, and Ice Clouds
The results of in situ observations of the relative humidity in liquid, mixed, and ice clouds typically stratiform in nature and associated with mesoscale frontal systems at temperatures ?45�C < Ta < ?5�C are presented. The data were collected ...
Alexei Korolev; George A. Isaac
A Distribution Law for Free-Tropospheric Relative Humidity
The probability distribution of local relative humidity R in the free troposphere is explored by comparing a simple theoretical calculation with observations from the global positioning system (GPS) and the Microwave Limb Sounder (MLS). The ...
Steven C. Sherwood; E. Robert Kursinski; William G. Read
Electric Dehumidification and Humidity Control: Principles and Applications
This report summarizes a systematic approach to design and operation of electric dehumidification and humidity control system for a variety of end-use applications. The design and applications methodology is validated with a large number of field demonstrations.
Alternative Forms of Humidity Information in Global Data Assimilation
Global data analysis procedures were developed to perform data assimilation for observed geopotential heights wind components, and relative humidity. These procedures were implemented in conjunction with a global spectral forecast model (GSM) and ...
Donald C. Norquist
Vertical Correlation Functions for Temperature and Relative Humidity Errors
This article gives the details and results of an investigation into the properties of the temperature and relative humidity errors from the Navy Operational Global Atmospheric Prediction System for a 4-month period from March to June 1998. The ...
Richard Franke; Edward Barker
Orographic Flow Response to Variations in Upstream Humidity
The effects of upstream relative humidity (RH) on low-level wind and precipitation patterns for low-speed, statically stable flows over a mountain are investigated using idealized two- and three-dimensional numerical-simulation experiments in ...
Heather Dawn Reeves; Richard Rotunno
Relative Humidity over the West Florida Continental Shelf
Observed relative humidity variations on the coastal ocean of the West Florida Continental Shelf (WFS) are examined over the 5-yr period 1998�2003. Despite considerable daily variability within seasons, the monthly mean values are nearly constant ...
J. I. Virmani; R. H. Weisberg
An Analysis of Tropospheric Humidity Trends from Radiosondes
A new analysis of historical radiosonde humidity observations is described. An assessment of both known and unknown instrument and observing practice changes has been conducted to assess their impact on bias and uncertainty in long-term trends. ...
Mark P. McCarthy; P. W. Thorne; H. A. Titchner
Posters A Comparison of Model-Simulated Relative Humidity with...
71 Posters A Comparison of Model-Simulated Relative Humidity with Satellite-Derived Cloudiness R. J. Alliss and S. Raman Department of Marine, Earth and Atmospheric Sciences North...
Upper-Tropospheric Humidity from MLS and ECMWF Reanalyses
This paper compares upper-tropospheric humidity from the Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite with European Centre for Medium-Range Weather Forecasts (ECMWF) data. MLS measurements are not included in the ECMWF ...
H. L. Clark; R. S. Harwood
MOS structures with amorphous tungsten trioxide for capacitive humidity sensors
Electrical characteristics of the Al/a-WO{sub 3}/n-Si structure under conditions of water vapor sorption were studied. The parameters of this structure as a capacitive humidity sensor were determined.
Tutov, E. A. [Voronezh State University (Russian Federation)], E-mail: email@example.com
Radiation Dry Bias of the Vaisala RS92 Humidity Sensor
The comparison of simultaneous humidity measurements by the Vaisala RS92 radiosonde and by the Cryogenic Frostpoint Hygrometer (CFH) launched at Alajuela, Costa Rica, during July 2005 reveals a large solar radiation dry bias of the Vaisala RS92 ...
H. V�mel; H. Selkirk; L. Miloshevich; J. Valverde-Canossa; J. Vald�s; E. Kyr�; R. Kivi; W. Stolz; G. Peng; J. A. Diaz
A Numerical Method for Synthesizing Atmospheric Temperature and Humidity Profiles
A numerical technique is described for synthesizing realistic atmospheric temperature and humidity profiles. The method uses an ensemble of radiosonde measurements collected at a site of interest. Erroneous profiles are removed by comparing their ...
Maia S. Tatarskaia; Richard J. Lataitis; B. Boba Stankov; Viatcheslav V. Tatarskii
Temperature and Humidity Profiles in Mesoscale Unsaturated Downdrafts
Profiles of temperature and humidity beneath precipitating anvil clouds in tropical convective systems suggest the presence of a mesoscale unsaturated downdraft there. In this paper, a one-dimensional, steady-state, hydrostatic model of a ...
Colleen A. Leary
A New Approach to Homogenize Daily Radiosonde Humidity Data
Radiosonde humidity records represent the only in situ observations of tropospheric water vapor content with multidecadal length and quasi-global coverage. However, their use has been hampered by ubiquitous and large discontinuities resulting ...
Aiguo Dai; Junhong Wang; Peter W. Thorne; David E. Parker; Leopold Haimberger; Xiaolan L. Wang
Battelle Columbus Laboratories (BCL), located in Columbus, Ohio, must complete decontamination and decommissioning activities for nuclear research buildings and grounds at its West Jefferson Facilities by 2006, as mandated by Congress. This effort includes decommissioning several hot cells located in the Hot Cell Laboratory (Building JN-1). JN-1 was originally constructed in 1955, and a hot cell/high bay addition was built in the mid 1970s. For over 30 years, BCL used these hot cell facilities to conduct research for the nuclear power industry and several government agencies, including the U.S. Navy, U.S. Army, U.S. Air Force, and the U.S. Department of Energy. As a result of this research, the JN-1 hot cells became highly contaminated with mixed fission and activation products, as well as fuel residues. In 1998, the Battelle Columbus Laboratories Decommissioning Project (BCLDP) began efforts to decommission JN-1 with the goal of remediating the site to levels of residual contamination allowing future use without radiological restrictions. This goal requires that each hot cell be decommissioned to a state where it can be safely demolished and transported to an off-site disposal facility. To achieve this, the BCLDP uses a four-step process for decommissioning each hot cell: (1) Source Term Removal; (2) Initial (i.e., remote) Decontamination; (3) Utility Removal; and (4) Final (i.e., manual) Decontamination/Stabilization. To date, this process has been successfully utilized on 13 hot cells within JN-1, with one hot cell remaining to be decommissioned. This paper will provide a case study of the hot cell decommissioning being conducted by the BCLDP. Discussed will be the methods used to achieve the goals of each of the hot cell decommissioning stages and the lessons learned that could be applied at other sites where hot cells need to be decommissioned.
Weaver, Patrick; Henderson, Glenn; Erickson, Peter; Garber, David
Test Plan to Evaluate the Relationship Among IAQ, Comfort, Moisture, and Ventilation in Humid Climates
This experimental plan describes research being conducted by Pacific Northwest National Laboratory (PNNL), in coordinatation with Florida Solar Energy Center (FSEC), Florida HERO, and Lawrence Berkeley National Laboratory (LBNL) to evaluate the impact of ventilation rate on interior moisture levels, temperature distributions, and indoor air contaminant concentrations. Specifically, the research team will measure concentrations of indoor air contaminants, ventilation system flow rates, energy consumption, and temperature and relative humidity in ten homes in Gainesville, FL to characterize indoor pollutant levels and energy consumption associated with the observed ventilation rates. PNNL and FSEC have collaboratively prepared this experimental test plan, which describes background and context for the proposed study; the experimental design; specific monitoring points, including monitoring equipment, and sampling frequency; key research questions and the associated data analysis approach; experimental logistics, including schedule, milestones, and team member contact information; and clearly identifies the roles and responsibilities of each team in support of project objectives.
Widder, Sarah H.; Martin, Eric
Alloy 903 (FeNiCo+Nb) is currently used for certain components in industrial gas turbines for low coefficient of thermal expansion applications. A variance in creep behavior for material quality control evaluations suggested a possible effect of moisture level on stress rupture properties. To investigate the role of water vapor on the creep properties of alloy 903, controlled laboratory experiments were conducted at 650 C with 0 to 100% relative humidity. The water content was controlled by flowing dry air through a water bath at a constant temperature. A significant decrease of lifetime was observed in the presence of water vapor, which is likely related to grain boundary embrittlement by the inward diffusion of hydrogen. The increase of the microstructure grain aspect ratio by different forging processes generally improved the rupture lifetime and elongation in air. However, all specimens had reduced lifetime in the presence of water vapor despite the microstructure grain aspect ratios.
Dryepondt, Sebastien N [ORNL; Pint, Bruce A [ORNL; Mitchell, Ryan D [Solar Turbines, Inc.
Humidity effects on calibrations of radiation therapy electrometers
Purpose: To eliminate variation in electrometer calibration results caused by high humidity and suboptimal connectors on the standard capacitors and to implement hardware that prevents overloading of the input stage of electrometers during calibration. Methods: A humidity-controlled cabinet was installed to provide a low-humidity environment for the standard capacitors. All of the coaxial BNC connections were replaced with Triax (TRB) connectors with the exception of the output from the voltage source. A three-stage RC filter with cascaded RC low-pass sections was designed and tested. Results: The installation of the humidity cabinet resulted in a major improvement in the stability and reproducibility of the electrometer calibration system. For the three years since this upgrade, the Ionizing Radiation Standards (IRS) electrometer calibration results have been consistent regardless of the ambient relative humidity in the lab. The connector replacements improved grounding in the calibration circuit. The three-stage filter allows the voltage at the output to rise in an S-shaped waveform, resulting in a smooth rise of the current through the isolation resistor from zero and back again, with no abrupt transition. For the filter design chosen, 99.99% of the charge is delivered within 6 s. Conclusions: A three-way improvement to the calibration measurement system was successful in eliminating the observed variations, resulting in an electrometer calibration measurement system that is unaffected by humidity and allowing reliable year-round calibrations of any electrometer encountered since the implementation of these changes.
Downton, B.; Walker, S. [Ionizing Radiation Standards, National Research Council of Canada, Bldg. M35, Ottawa, Ontario K1A 0R6 (Canada)
Solar hot water heater
A solar hot water heater includes an insulated box having one or more hot water storage tanks contained inside and further having a lid which may be opened to permit solar radiation to heat a supply of water contained within the one or more hot water storage tanks. A heat-actuated control unit is mounted on an external portion of the box, such control unit having a single pole double throw thermostat which selectively activates an electric winch gear motor to either open or close the box lid. The control unit operates to open the lid to a predetermined position when exposed to the sun's rays, and further operates to immediately close the lid in response to any sudden drop in temperature, such as might occur during a rainstorm, clouds moving in front of the sun, or the like.
Melvin, H.A.
Beppu hot springs
Beppu is one of the largest hot springs resorts in Japan. There are numerous fumaroles and hot springs scattered on a fan-shaped area, extending 5 km (3.1 miles) from east to west and 8 km (5.0 miles) from north to south. Some of the thermal manifestations are called {open_quotes}Jigoku (Hells){close_quotes}, and are of interest to visitors. The total amount of discharged hot springs water is estimated to be 50,000 ton/day (9,200 gpm) indicating a huge geothermal system. The biggest hotel in Beppu (Suginoi Hotel) installed a 3-MW geothermal power plant in 1981 to generate electricity for its own private use.
Taguchi, Schihiro [Fukuoka Univ. (Japan); Itoi, Ryuichi [Kyushu Univ., Kasuga (Japan); Yusa, Yuki [Kyoto Univ., Beppu (Japan)
An Experimental Evaluation of HVAC-Grade Carbon-Dioxide Sensors: Part 3, Humidity, Temperature, and Pressure Sensitivity Test Results
This is the third paper in a four-part series reporting on the test and evaluation of typical carbon-dioxide sensors used in building HVAC applications. Fifteen models of NDIR HVAC-grade CO2 sensors were tested and evaluated to determine the humidity, temperature, and pressure sensitivity of the sensors. This paper reports the performance of the sensors at various relative humidity, temperature, and pressure levels common to building HVAC applications and provides a comparison with manufacturer specifications. Among the 15 models tested, eight models have a single-lamp, single-wavelength configuration, four models have a dual-lamp, single-wavelength configuration, and three models have a single-lamp, dual-wavelength configuration. The sensors were tested in a chamber specifically fabricated for this research. A description of the apparatus and the method of test are described in Part 1 (Shrestha and Maxwell 2009). The test result showed a wide variation in humidity, temperature, and pressure sensitivity of CO2 sensors among manufacturers. In some cases, significant variations in sensor performance exist between sensors of the same model. Even the natural variation in relative humidity could significantly vary readings of some CO2 sensor readings. The effects of temperature and pressure variation on NDIR CO2 sensors are unavoidable without an algorithm to compensate for the changes. For the range of temperature and pressure variation in an air-conditioned space, the effect of pressure variation is more significant compared to the effect of temperature variation.
Shrestha, Som S [ORNL; Maxwell, Dr. Gregory [Iowa State University
Humidity Dependence of Adhesion for Silane Coated Microcantilevers
This study examines adhesion between silane-coated micromachined surfaces that are exposed to humid conditions. Our quantitative values for interfacial adhesion energies are determined from an in-situ optical measurement of deformations in partly-adhered cantilever beams. We coated micromachined cantilevers with either ODTS (C{sub 18}H{sub 37}SiCl{sub 3}) or FDTS (C{sub 8}F{sub 17}C{sub 2}H{sub 4}SiCl{sub 3}) with the objective of creating hydrophobic surfaces whose adhesion would be independent of humidity. In both cases, the adhesion energy is significantly lower than for uncoated, hydrophilic surfaces. For relative humidities (RH) less than 95% (ODTS) and 80% (FDTS) the adhesion energy was extremely low and constant. In fact, ODTS-coated beams exposed to saturated humidity conditions and long (48 hour) exposures showed only a factor of two increase in adhesion energy. Surprisingly, FDTS coated beams, which initially have a higher contact angle (115{degree}) with water than do ODTS coated beams (112{degree}), proved to be much more sensitive to humidity. The FDTS coated surfaces showed a factor of one hundred increase in adhesion energy after a seven hour exposure to 90% RH. Atomic force microscopy revealed agglomerated coating material after exposed to high RH, suggesting a redistribution of the monolayer film. This agglomeration was more prominent for FDTS than ODTS. These findings suggest a new mechanism for uptake of moisture under high humidity conditions. At high humidities, the silane coatings can reconfigure from a surface to a bulk phase leaving behind locally hydrophilic sites which increase the average measured adhesion energy. In order for the adhesion increase to be observed, a significant fraction of the monolayer must be converted from the surface to the bulk phase.
ARM - Publications: Science Team Meeting Documents: AIRS retrievals of
AIRS retrievals of atmospheric profiles of temperature and humidity - AIRS retrievals of atmospheric profiles of temperature and humidity - comparisons with radiosondes and ship-based remote sensing during AEROSE Minnett, Peter University of Miami Szczodrak, Malgorzata University of Miami Feltz, Wayne University of Wisconsin Nalli, Nicholas NOAA/NESDIS The World Meteorological Organization (WMO) has determined that significantly improving weather forecasting would require global temperature and moisture soundings with at least the accuracy of the current radiosondes. The Atmospheric Infrared Sounder (AIRS) on board of the NASA EOS Aqua satellite, launched in 2002, is designed to provide high-accuracy atmospheric profiles of temperature and humidity. The validation of the AIRS atmospheric profile retrieval scheme is a continuing
Preconditioning Outside Air: Cooling Loads from Building Ventilation
HVAC equipment manufacturers, specifiers and end users interacting in the marketplace today are only beginning to address the series of issues promulgated by the increased outside air requirements in ASHRAE Standard 62- 1989, "Ventilation for Acceptable Indoor Air Quality", that has cascaded into building codes over the early to mid 1990's. There has been a twofold to fourfold increase in outside air requirements for many commercial building applications, compared to the 1981 version of the standard. To mitigate or nullify these additional weather loads, outdoor air preconditioning technologies are being promoted in combination with conventional HVAC operations downstream as a means to deliver the required fresh air and control humidity indoors. Preconditioning is the term applied for taking outside air to the indoor air setpoint (dry bulb temperature and relative humidity). The large humidity loads from outside air can now be readily recognized and quantified at cooling design point conditions using the extreme humidity ratios/dew points presented in the ASHRAE Handbook of Fundamentals Chapter 26 "Climatic Design Information". This paper presents an annual index called the Ventilation Load Index (VLI), recently developed by the Gas Research Institute (GRI) that measures the magnitude of latent (and sensible) loads for preconditioning outside air to indoor space conditions over the come of an entire year. The VLI has units of ton-hrs/scfm of outside air. The loads are generated using new weather data binning software called ~BinMaker, also from GRI, that organizes the 239 city, 8760 hour by hour, TMY2 weather data into user selected bidtables. The VLI provides a simple methodology for accessing the cooling load impact of increased ventilation air volumes and a potential basis for defining a "humid" climate location.
Kosar, D.
An indoor air perception method to detect fungi growth in flats
Located in the northwest coast of Spain, A Coruna has a mild climate where humidity is relatively high throughout most of the year, due to the effect of the Atlantic Ocean winds. This high relative humidity is related with mould exposure and allergy ... Keywords: Acceptability, Flats, Fungi, Indoor air, Water-damage
Jos� A. Orosa; Armando C. Oliveira
Guide to Energy-Efficient Ventilation Methods for Acceptable Levels of Indoor Air Quality Levels in Commercial Buildings
Indoor air quality is important in commercial buildings to maintain employee health, well-being, and productivity and avoid employer liability. The most common method to improve indoor air quality in commercial buildings is to use outside ventilation air for dilution of the inside air. Unfortunately, the conditioning of outdoor ventilation air may result in increased energy use for cooling, dehumidification, and heating; and humid outdoor ventilation air also can degrade indoor air quality. Some commerci...
Hot water supply system
A hot water supply system is described which consists of: a boiler having an exhaust; solar panels; and a frame supporting the solar panels and including a compartment beneath the solar panels, the boiler exhaust termining in the compartment beneath the solar panels, the boiler being within the compartment.
Piper, J.R.
Dehumidification and simultaneous removal of selected pollutants from indoor air by a desiccant wheel using a 1M type desiccant
Solid-desiccant dehumidifiers are increasingly becoming an integral part of desiccant based air-conditioning systems because of their effective handling of latent heat loads compared to conventional vapor compression units. In these units, either a silica gel or a molecular sieve is used for dehumidification of air. Both of them have the capability to co-adsorb various chemical pollutants during dehumidification of air. However, the shape of the isotherm for water vapor on these materials is not favorable for desiccant cooling applications. A mixture (1M desiccant) containing a silica gel, a molecular sieve, and a hydrophobic molecular sieve that was coated on an aluminum foil was studied for its capability for simultaneous removal of moisture and some selected pollutants from air. Experimental data were obtained in a fixed bed adsorber that simulated the operation of a rotary desiccant wheel. Air to be dehumidified and cleaned and the hot regeneration air were cycled in a specific time interval through this bed. The shape of the water isotherm on 1M desiccant was found to be in between that of silica gel and molecular sieve 13{times}, but its uptake capacity was significantly lower than that of either silica gel or molecular sieve. A flow rate of about 100 L/min that provided a face velocity of about 132 cm/s was used in the adsorption step. The flow rate during regeneration was about 50 L/min. The temperature of the inlet air was about 23 C and its relative humidity was varied between 20% and 80%. The concentrations of pollutants were as follows; carbon dioxide: 1050 and 2300 ppm; toluene: 32 ppm; 1,1,1-trichloroethane: 172 ppm, and formaldehyde: 0.35 ppm. A complete breakthrough of all the pollutants was observed during an adsorption cycle.
Popescu, M.; Ghosh, T.K. [Univ. of Missouri, Columbia, MO (United States)
Cornell University Hot Water Report
Hot Water System Hot Water System The production and delivery of hot water in the CUSD home is technologically advanced, economical, and simple. Hot water is produced primarily by the evacuated solar thermal tube collectors on the roof of the house. The solar thermal tube array was sized to take care of the majority of our heating and hot water needs throughout the course of the year in the Washington, DC climate. The solar thermal tube array also provides heating to the radiant floor. The hot water and radiant floor systems are tied independently to the solar thermal tube array, preventing the radiant floor from robbing the water heater of much needed thermal energy. In case the solar thermal tubes are not able to provide hot water to our system, the hot water tank contains an electric heating
Relative humidity in the near-field environment
The Yucca Mountain Site Characterization Project is investigating Yucca Mountain, Nevada, for its suitability as a potential repository for high-level nuclear wastes. United States federal regulation 10CFR60 requires that radioactive nuclides be substantially contained in waste packages for 300 to 1000 years after the emplacement. To meet the regulation, a waste package container should remain intact for several hundreds of years. It has been shown that high humidity increases the corrosion potential of metallic container materials. Relative humidity as a function of water saturation in intact rock is measured. The results of this test can be used to calibrate the relative humidity in the near-field environment predicted by model calculations using thermal-hydrological codes such as VTOUGH. This is a report on the progress of that experiment.
Lin, W.; Roberts, J.; Ruddle, D
Green Systems Solar Hot Water
Green Systems Solar Hot Water Heating the Building Co-generation: Heat Recovery System: Solar Thermal Panels (Trex enclosure) Hot Water Storage Tank (TS-5; basement) Hot Water Heaters (HW-1,2; basement) Pre-heats water so water heaters don't need to use as much energy Gas-powered, high efficiency
Schladow, S. Geoffrey
Temperature, Humidity, Wind and Pressure Sensors (THWAPS) Handbook
The temperature, humidity, wind, and pressure system (THWAPS) provide surface reference values of these measurements for balloon-borne sounding system (SONDE) launches. The THWAPS is located adjacent to the SONDE launch site at the Southern Great Plains (SGP) Central Facility. The THWAPS system is a combination of calibration-quality instruments intended to provide accurate measurements of meteorological conditions near the surface. Although the primary use of the system is to provide accurate surface reference values of temperature, pressure, relative humidity (RH), and wind velocity for comparison with radiosonde readings, the system includes a data logger to record time series of the measured variables.
Ritsche, MT
Humidity response of the Eberline model PAC-7 alpha instrument
Response of the Eberline Model PAC-7 alpha instrument under varying relative humidity (RH) and temperature conditions was studied in an environmental chamber. Electric discharges resulting in spurious counts or in instrument paralysis occurred at 35 to 50% RH. Improvement in the RH level tolerated by the PAC-7 alpha instrument was obtained by conformal coating of the high-voltage region of the printed circuit (PC) board. Following this treatment, electric discharges occurred only at relatively high humidity levels and then as a result of high-voltage breakdown within the AC-24C probe rather than within the PC board.
McAtee, J.L.
Solar and Thermal Radiation Errors on Upper-Air Radiosonde Temperature Measurements
Atmospheric temperature and humidity profiles are important for weather prediction, but climate change has increased the interest in upper-air observations asking for very high-quality reference measurements. This paper discusses an experimental ...
R. Philipona; A. Kr�uchi; G. Romanens; G. Levrat; P. Ruppert; E. Brocard; P. Jeannet; D. Ruffieux; B. Calpini
Atmospheric temperature and humidity profiles are important for weather prediction, but climate change has increased the interest in upper-air observations asking for very high quality reference measurements. Here we show an experimental approach ...
Solid oxide fuel cell systems with hot zones having improved reactant distribution
A Solid Oxide Fuel Cell (SOFC) system having a hot zone with a center cathode air feed tube for improved reactant distribution, a CPOX reactor attached at the anode feed end of the hot zone with a tail gas combustor at the opposing end for more uniform heat distribution, and a counter-flow heat exchanger for efficient heat retention.
Poshusta, Joseph C.; Booten, Charles W.; Martin, Jerry L.
Hot Dry Rock Geothermal Energy Development in the USA David Duchane and Donald Brown
utility options such as pumped storage or compressed air energy storage (CAES) is that the HDR power plant1 Hot Dry Rock Geothermal Energy Development in the USA by David Duchane and Donald Brown Los energy resources lies right beneath our feet in the form of hot dry rock (HDR), the common geologic
Poshusta, Joseph C; Booten, Charles W; Martin, Jerry L
Air Flow Distribution in the Sales Area of a Supermarket
Many kinds of goods are displayed in a supermarket, which have their own particularities. The consumer flow rate is great and the type of shelved goods varies significantly, thereby influencing the objects that generate heat, and the demands of air temperature, air velocity and humidity in different zones. The results of a study of a sales area of a supermarket in Harbin are presented in this paper, including air temperature, air velocity and humidity. According to the assessment index of air flow distribution (EDT, ADPI, temperature efficiency, energy coefficient of utilization, coefficient of ununiformity and so on), the experimental data were analyzed. The rationality of airflow distribution was then evaluated. Suggestions for air conditioning system design are also presented in this paper.
Fang, X.; Song, C.; Zhao, J.; Wang, Z.
``Hot particle`` intercomparison dosimetry
Dosimetry measurements of four ``hot particles`` were made at different density thickness values using five different methods. The hot particles had maximum dimensions of 650 {mu}m and maximum beta energies of 0.97, 046, 0.36 and 0.32 MeV. Absorbers were used to obtain the dose at different depths for each dosimeter. Measurements were made using exoelectron dosimeters, an extrapolation chamber, NE extremity tape dosimeters, Eberline RO-2 and RO-2A survey meters, and two sets of GafChromic dye film with each set read out at a different institution. From these results the dose was calculated averaged over 1 cm{sup 2} of tissue at 18, 70, 125, and 400 {mu}m depth. Comparisons of tissue-dose averaged over 1 cm{sup 2} for 18, 70 and 125 {mu}m depth based on interpolated measured values, were within 30% for the GafChromic dye film, extrapolation chamber, NE Extremity Tape dosimeters, and Eberline RO-2 and 2A survey meters except for the hot particle with 0.46 MeV maximum beta energy. The results for this source showed differences of up to 60%. The extrapolation chamber and NE Extremity Tape dosimeters under-responded for measurements at 400 {mu}m by about a factor of 2 compared with the Gaf Chromic dye films for two hot particles with maximum beta energy of 0.32 and 0.36 MeV which each emitted two 100% 1 MeV photons per disintegration. Tissue doses determined using exoelectron dosimeters were a factor of 2 to 5 less than those determined using other dosimeters, possibly due to failures of the equipment.
Kaurin, D.G.L.; Baum, J.W. [Brookhaven National Lab., Upton, NY (United States); Charles, M.W.; Darley, D.P.J. [Birmingham Univ. (United Kingdom); Durham, J.S. [Pacific Northwest Lab., Richland, WA (United States); Scannell, M.J. [Yankee Atomic Electric Co., Bolton, MA (United States); Soares, C.G. [National Inst. of Standards and Technology, Gaithersburg, MD (United States)
Session: Hot Dry Rock
This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of four presentations: ''Hot Dry Rock - Summary'' by George P. Tennyson, Jr.; ''HDR Opportunities and Challenges Beyond the Long Term Flow Test'' by David V. Duchane; ''Start-Up Operations at the Fenton Hill HDR Pilot Plant'' by Raymond F. Ponden; and ''Update on the Long-Term Flow Testing Program'' by Donald W. Brown.
Tennyson, George P. Jr.; Duchane, David V.; Ponden, Raymond F.; Brown, Donald W.
Enabling Technologies for Ceramic Hot Section Components
Silicon-based ceramics are attractive materials for use in gas turbine engine hot sections due to their high temperature mechanical and physical properties as well as lower density than metals. The advantages of utilizing ceramic hot section components include weight reduction, and improved efficiency as well as enhanced power output and lower emissions as a result of reducing or eliminating cooling. Potential gas turbine ceramic components for industrial, commercial and/or military high temperature turbine applications include combustor liners, vanes, rotors, and shrouds. These components require materials that can withstand high temperatures and pressures for long duration under steam-rich environments. For Navy applications, ceramic hot section components have the potential to increase the operation range. The amount of weight reduced by utilizing a lighter gas turbine can be used to increase fuel storage capacity while a more efficient gas turbine consumes less fuel. Both improvements enable a longer operation range for Navy ships and aircraft. Ceramic hot section components will also be beneficial to the Navy's Growth Joint Strike Fighter (JSF) and VAATE (Versatile Affordable Advanced Turbine Engines) initiatives in terms of reduced weight, cooling air savings, and capability/cost index (CCI). For DOE applications, ceramic hot section components provide an avenue to achieve low emissions while improving efficiency. Combustors made of ceramic material can withstand higher wall temperatures and require less cooling air. Ability of the ceramics to withstand high temperatures enables novel combustor designs that have reduced NO{sub x}, smoke and CO levels. In the turbine section, ceramic vanes and blades do not require sophisticated cooling schemes currently used for metal components. The saved cooling air could be used to further improve efficiency and power output. The objectives of this contract were to develop technologies critical for ceramic hot section components for gas turbine engines. Significant technical progress has been made towards maturation of the EBC and CMC technologies for incorporation into gas turbine engine hot-section. Promising EBC candidates for longer life and/or higher temperature applications relative to current state of the art BSAS-based EBCs have been identified. These next generation coating systems have been scaled-up from coupons to components and are currently being field tested in Solar Centaur 50S engine. CMC combustor liners were designed, fabricated and tested in a FT8 sector rig to demonstrate the benefits of a high temperature material system. Pretest predictions made through the use of perfectly stirred reactor models showed a 2-3x benefit in CO emissions for CMC versus metallic liners. The sector-rig test validated the pretest predictions with >2x benefit in CO at the same NOx levels at various load conditions. The CMC liners also survived several trip shut downs thereby validating the CMC design methodology. Significant technical progress has been made towards incorporation of ceramic matrix composites (CMC) and environmental barrier coatings (EBC) technologies into gas turbine engine hot-section. The second phase of the program focused on the demonstration of a reverse flow annular CMC combustor. This has included overcoming the challenges of design and fabrication of CMCs into 'complex' shapes; developing processing to apply EBCs to 'engine hardware'; testing of an advanced combustor enabled by CMCs in a PW206 rig; and the validation of performance benefits against a metal baseline. The rig test validated many of the pretest predictions with a 40-50% reduction in pattern factor compared to the baseline and reductions in NOx levels at maximum power conditions. The next steps are to develop an understanding of the life limiting mechanisms in EBC and CMC materials, developing a design system for EBC coated CMCs and durability testing in an engine environment.
Venkat Vedula; Tania Bhatia
Hot Springs | Open Energy Information
Springs Springs Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Hot Springs Dictionary.png Hot Springs: A naturally occurring spring of hot water, heated by geothermal processes in the subsurface, and typically having a temperature greater than 37°C. Other definitions:Wikipedia Reegle Modern Geothermal Features Typical list of modern geothermal features Hot Springs Fumaroles Warm or Steaming Ground Mudpots, Mud Pools, or Mud Volcanoes Geysers Blind Geothermal System Mammoth Hot Springs at Yellowstone National Park (reference: http://www.hsd3.org/HighSchool/Teachers/MATTIXS/Mattix%20homepage/studentwork/Laura%20Cornelisse%27s%20Web%20Page/Yellowstone%20National%20Park.htm) Hot springs occur where geothermally heated waters naturally flow out of the surface of the Earth. Hot springs may deposit minerals and spectacular
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
Automated Temperature and Relative Humidity Calibrations for the Oklahoma Mesonetwork
A low-cost (under $12,000), fully automated, relative humidity calibration chamber capable of testing up to six probes simultaneously over a range of humidifies from 5% to approximately 95% is designed, constructed, and tested for use by the ...
Scott J. Richardson
Humidity-resistant ambient-temperature solid-electrolyte amperometric sensing apparatus
Apparatus and methods for detecting selected chemical compounds in air or other gas streams at room or ambient temperature includes a liquid-free humidity-resistant amperometric sensor comprising a sensing electrode and a counter and reference electrode separated by a solid electrolyte. The sensing electrode preferably contains a noble metal, such as Pt black. The electrolyte is water-free, non-hygroscopic, and substantially water-insoluble, and has a room temperature ionic conductivity [>=]10[sup [minus]4] (ohm-cm)[sup [minus]1], and preferably [>=]0.01 (ohm-cm)[sup [minus]1]. The conductivity may be due predominantly to Ag[sup +] ions, as in Ag[sub 2]WO[sub 4], or to F[sup [minus
Zaromb, S.
Investigations on Vapour Compression Air Conditioner with Direct Contact Desiccant Loop over Condenser and Evaporator
Perceived air quality increases when relative humidity is decreased till about 30% in the range of comfort temperature. In the present scenario, humidity is considered as a pollutant. Hence, a controlled environment not only at low temperature but also at low humidity is desired for many applications such as archives, data centers, etc. Either a separate dehumidifier or a precision air conditioning (AC) system needs to be employed for such an application. In fact, the latter forms a reheat AC system which happens to be energy inefficient. In view of this, a vapor compression window air conditioner is investigated with a superimposed liquid desiccant loop harnessing the advantages of both the compression system (high COP) and desiccant system (low humidity). Operation of such a novel system is explained, elucidating the operational feasibility. The results presented consider the characteristics of such a system with respect to changes in the evaporator inlet air temperature and humidity. The change in the specific humidity of air is compared for vapor compression system and the direct contact hybrid system for different values of inlet air temperature.
Maiya, M. P.; Ravi, J.; Tiwari, S.
Evaporative Enhancement for Air Cooled Condensers
This report summarizes research into condenser air evaporative pre-cooling technologies and the associated potential for energy and peak power savings. The interest in this project is evaluation of the specific application of evaporative cooling to the inlet air of condenser coils, particularly for large roof-top type air cooled chillers. While the technology is established and understood particularly well for hot, dry climates, this report is intended to also examine evaporative ...
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.
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
Performance of Variable Capacity Heat Pumps in a Mixed Humid Climate
Variable capacity heat pumps represent the next wave of technology for heat pumps. In this report, the performance of two variable capacity heat pumps (HPs) is compared to that of a single or two stage baseline system. The units were installed in two existing research houses located in Knoxville, TN. These houses were instrumented to collect energy use and temperature data while both the baseline systems and variable capacity systems were installed. The homes had computer controlled simulated occupancy, which provided consistent schedules for hot water use and lighting. The temperature control and energy use of the systems were compared during both the heating and cooling seasons. Multiple linear regression models were used along with TMY3 data for Knoxville, TN in order to normalize the effect that the outdoor air temperature has on energy use. This enables a prediction of each system's energy use over a year with the same weather. The first system was a multi-split system consisting of 8 indoor units and a single outdoor unit. This system replaced a 16 SEER single stage HP with a zoning system, which served as the baseline. Data was collected on the baseline system from August 2009 to December 2010 and on the multi-split system from January 2011 to January 2012. Soon after the installation of the multi-split system, some of the smaller rooms began over-conditioning. This was determined to be caused by a small amount of continuous refrigerant flow to all of the indoor units when the outdoor unit was running regardless of whether they were calling for heat. This, coupled with the fact that the indoor fans run continuously, was providing enough heat in some rooms to exceed the set point. In order to address this, the indoor fans were disabled when not actively heating per the manufacturer's recommendation. Based on the measured data, the multi-split system was predicted to use 40% more energy in the heating season and 16% more energy in the cooling season than the baseline system, for the typical meteorological year weather data. The AHRI ratings indicated that the baseline system would perform slightly better than the multi-split system, but not by as large of a margin as seen in this study. The multi-split system was able to maintain more consistent temperature throughout the house than the baseline system, but it did allow relative humidity levels to increase above 60% in the summer. The second system was a split system with an inverter driven compressor and a single ducted air handler. This unit replaced a 16 SEER two stage HP with a zoning system. Data was collected on the baseline system from July 2009 to November 2010 and on the ducted inverter system from December 2010 to January 2012. The ducted inverter system did not offer a zone controller, so it functioned as a single zone system. Due to this fact, the registers had to be manually adjusted in order to better maintain consistent temperatures between the two levels of the house. The predicted heating season energy use for the ducted inverter system, based on the measured energy use, was 30% less than that of the baseline system for the typical meteorological year. However, the baseline system was unable to operate in its high stage due to a wiring issue with the zone controller. This resulted in additional resistance heat use during the winter and therefore higher energy use than would be expected in a properly performing unit. The AHRI ratings would indicate that the baseline system would use less energy than the ducted inverter system, which is opposite to the results of this study. During the cooling season, the ducted inverter system was predicted to use 23% more energy than the baseline system during the typical meteorological year. This is also opposite of the results expected by comparing the AHRI ratings. After a detailed comparison of the ducted inverter system's power use compared to that of a recently installed identical system at a retro-fit study house, there is concern that the unit is not operating as intended. The power use and cycles indicate t
Munk, Jeffrey D [ORNL; Gehl, Anthony C [ORNL; Jackson, Roderick K [ORNL
Variable capacity heat pumps represent the next wave of technology for heat pumps. In this report, the performance of two variable capacity heat pumps (HPs) is compared to that of a single or two stage baseline system. The units were installed in two existing research houses located in Knoxville, TN. These houses were instrumented to collect energy use and temperature data while both the baseline systems and variable capacity systems were installed. The homes had computer controlled simulated occupancy, which provided consistent schedules for hot water use and lighting. The temperature control and energy use of the systems were compared during both the heating and cooling seasons. Multiple linear regression models were used along with TMY3 data for Knoxville, TN in order to normalize the effect that the outdoor air temperature has on energy use. This enables a prediction of each system's energy use over a year with the same weather. The first system was a multi-split system consisting of 8 indoor units and a single outdoor unit. This system replaced a 16 SEER single stage HP with a zoning system, which served as the baseline. Data was collected on the baseline system from August 2009 to December 2010 and on the multi-split system from January 2011 to January 2012. Soon after the installation of the multi-split system, some of the smaller rooms began over-conditioning. This was determined to be caused by a small amount of continuous refrigerant flow to all of the indoor units when the outdoor unit was running regardless of whether they were calling for heat. This, coupled with the fact that the indoor fans run continuously, was providing enough heat in some rooms to exceed the set point. In order to address this, the indoor fans were disabled when not actively heating per the manufacturer's recommendation. Based on the measured data, the multi-split system was predicted to use 40% more energy in the heating season and 16% more energy in the cooling season than the baseline system, for the typical meteorological year weather data. The AHRI ratings indicated that the baseline system would perform slightly better than the multi-split system, but not by as large of a margin as seen in this study. The multi-split system was able to maintain more consistent temperature throughout the house than the baseline system, but it did allow relative humidity levels to increase above 60% in the summer. The second system was a split system with an inverter driven compressor and a single ducted air handler. This unit replaced a 16 SEER two stage HP with a zoning system. Data was collected on the baseline system from July 2009 to November 2010 and on the ducted inverter system from December 2010 to January 2012. The ducted inverter system did not offer a zone controller, so it functioned as a single zone system. Due to this fact, the registers had to be manually adjusted in order to better maintain consistent temperatures between the two levels of the house. The predicted heating season energy use for the ducted inverter system, based on the measured energy use, was 30% less than that of the baseline system for the typical meteorological year. However, the baseline system was unable to operate in its high stage due to a wiring issue with the zone controller. This resulted in additional resistance heat use during the winter and therefore higher energy use than would be expected in a properly performing unit. The AHRI ratings would indicate that the baseline system would use less energy than the ducted inverter system, which is opposite to the results of this study. During the cooling season, the ducted inverter system was predicted to use 23% more energy than the baseline system during the typical meteorological year. This is also opposite of the results expected by comparing the AHRI ratings. After a detailed comparison of the ducted inverter system's power use compared to that of a recently installed identical system at a retro-fit study house, there is concern that the unit is not operating as intended. The power use and cy
Instrument uncertainty effect on calculation of absolute humidity using dewpoint, wet-bulb, and relative humidity sensors
As part of the US Department of Energy`s Advanced Desiccant Technology Program, the National Renewable Energy Laboratory (NREL) is characterizing the state-of-the-art in desiccant dehumidifiers, the key component of desiccant cooling systems. The experimental data will provide industry and end users with independent performance evaluation and help researchers assess the energy savings potential of the technology. Accurate determination of humidity ratio is critical to this work and an understanding of the capabilities of the available instrumentation is central to its proper application. This paper compares the minimum theoretical random error in humidity ratio calculation for three common measurement methods to give a sense of the relative maximum accuracy possible for each method assuming systematic errors can be made negligible. A series of experiments conducted also illustrate the capabilities of relative humidity sensors as compared to dewpoint sensors in measuring the grain depression of desiccant dehumidifiers. These tests support the results of the uncertainty analysis. At generally available instrument accuracies, uncertainty in calculated humidity ratio for dewpoint sensors is determined to be constant at approximately 2%. Wet-bulb sensors range between 2% and 6% above 10 g/kg (4%--15% below), and relative humidity sensors vary between 4% above 90% rh and 15% at 20% rh. Below 20% rh, uncertainty for rh sensors increases dramatically. Highest currently attainable accuracies bring dewpoint instruments down to 1% uncertainty, wet bulb to a range of 1%--3% above 10 g/kg (1.5%--8% below), and rh sensors between 1% and 5%.
Slayzak, S.J.; Ryan, J.P.
Energy from hot dry rock
The Hot Dry Rock Geothermal Energy Program is described. The system, operation, results, development program, environmental implications, resource, economics, and future plans are discussed. (MHR)
Hendron, R.H.
Dmplet Interaction with Hot Surfaces
... served at the NGP Technical Program Manager for ... contains a 10 mW, polarized Helium-Neon laser. ... with Hot Surfaces, NGP Annual Report, 1998. ...
Continuous Humidity Monitoring in a Tropical Region with the Equatorial Atmosphere Radar
A radar remote sensing technique that estimates humidity profiles using a wind profiler is applied to the equatorial atmosphere radar (EAR) to monitor detailed humidity variations in tropical regions. Turbulence echo power intensity is related to ...
Jun-ichi Furumoto; Toshitaka Tsuda; Satoshi Iwai; Toshiaki Kozu
Simple Procedures for Extrapolation of Humidity Variables in the Mountainous Western United States
A series of simple procedures are presented for extrapolating climatic averages of humidity variables from a reference location with long-term humidity measurements to nearby higher elevation locations. The extrapolation of monthly average ...
Kenneth E. Kunkel
Analysis of Relative Humidity Sensors at the WMO Radiosonde Intercomparison Experiment in Brazil
The quality of the vertical distribution measurements of humidity in the atmosphere is very important in meteorology due to the crucial role that water vapor plays in the earth�s energy budget. The radiosonde is the humidity measurement device ...
Luiz F. Sapucci; Luiz A. T. Machado; Reinaldo B. da Silveira; Gilberto Fisch; Jo�o F. G. Monico
Short-Term versus Climatological Relationship between Precipitation and Tropospheric Humidity
In this study the observed relationship of precipitation with column relative humidity (CRH), a metric of tropospheric humidity, is examined in order to address a known discrepancy inherent to past studies. A composite analysis of satellite data ...
Hirohiko Masunaga
Climatology and Trends of U.S. Surface Humidity and Temperature
Climatological annual and seasonal dewpoint, specific humidity, and relative humidity maps for the United States are presented using hourly data from 188 first-order weather stations for the period 1961�90. Separate climatologies were calculated ...
Dian J. Gaffen; Rebecca J. Ross
An Evaluation of Problems Affecting the Measurement of Low Relative Humidity on the United States Radiosonde
This paper explores the low-humidity problem that has plagued the radiosonde hygristor for nearly 30 years and that makes the hygristor appear to become insensitive at relative humidities (RH) below about 20% RH. The problem led the National ...
Charles G. Wade
Using Relative Humidity as a State Variable in Climate Feedback Analysis
An approach to climate change feedback analysis is described in which tropospheric relative humidity replaces specific humidity as the state variable that, along with the temperature structure, surface albedos, and clouds, controls the magnitude ...
Isaac M. Held; Karen M. Shell
Comparison of In Situ Humidity Data from Aircraft, Dropsonde, and Radiosonde
Results are presented from the Measurement of Tropospheric Humidity (MOTH) Tropic and MOTH Arctic airborne field experiments, comparing a number of in situ humidity measurements. Good agreement is shown between the Total Water Content probe on ...
A. K. Vance; J. P. Taylor; T. J. Hewison; J. Elms
Effects on Climate Records of Changes in National Weather Service Humidity Processing Procedures
The U.S. National Weather Service has recently corrected an error in radiosonde humidity data reduction algorithms, eliminated a sonde thats processing contained another error, and recently made a further change in the humidity data reduction ...
William P. Elliott; Rebecca J. Ross; Barry Schwartz
The Variational Assimilation Method for the Retrieval of Humidity Profiles with the Wind-Profiling Radar
Recently, a humidity estimation technique was developed by using the turbulence echo characteristics detected with a wind-profiling radar. This study is concerned with improvement of the retrieval algorithm for delineating a humidity profile from ...
Jun-ichi Furumoto; Shingo Imura; Toshitaka Tsuda; Hiromu Seko; Tadashi Tsuyuki; Kazuo Saito
A Method for Rescaling Humidity Sensors at Temperatures Well below Freezing
A method for extending the calibrated temperature rang of a solid-state capacitive humidity sensor is presented. This technique is applicable to relative humidity instruments that are based around solid-state sensors.
Surface Temperature and Humidity Trends in Canada for 1953�2005
Annual and seasonal trends in temperature, dewpoint, relative humidity, and specific humidity are presented for the period 1953�2005. The analysis uses hourly observations from 75 climatological stations across Canada. Data were examined for ...
Lucie A. Vincent; William A. van Wijngaarden; Ron Hopkinson
Subsurface monitoring of reservoir pressure, temperature, relative humidity, and water content at the CAES Field Experiment, Pittsfield, Illinois: system design
This subsurface-instrumentation design has been developed for the first Compressed Air Energy Storage (CAES) field experiment to be performed in porous media. Energy storage will be accomplished by alternating the injection and withdrawal of compressed air in a confined sandstone aquifer near Pittsfield, Illinois. The overall experiment objective is to characterize the reservoir's geochemical and thermohydraulic response to imposed CAES conditions. Specific experiment objectives require monitoring: air-bubble development; thermal development; cyclic pressure response; reservoir dehydration; and water coning. Supporting these objectives, four parameters will be continuously monitored at depth in the reservoir. They are: temperature; pressure; pore-air relative humidity; and pore-water content. Reservoir temperatures and pressures will range to maximum values approaching 200/sup 0/C and 300 psi, respectively. Both pore-air relative humidity and pore-water content will range from approx. 0 to 100%. This report discusses: instrumentation design; sensor and sensor system calibration; field installation and testing; and instrument-system operation. No comprehensive off-the-shelf instrument package exists to adequately monitor CAES reservoir parameters at depth. The best available sensors were selected and adapted for use under expected ranges of reservoir conditions. The instrumentation design criteria required: suitable sensor accuracy; continuous monitoring capability; redundancy; maximum sensor integrity; contingency planning; and minimum cost-information ratio. Three wells will be instrumented: the injection/withdrawal (I/W) well and the two instrument wells. Sensors will be deployed by wireline suspension in both open and backfilled (with sand) wellbores. The sensors deployed in the I/W well will be retrievable; the instrument-well sensors will not.
Hostetler, D.D.; Childs, S.W.; Phillips, S.J.
Why alite stops hydrating below 80% relative humidity
It has been observed that the hydration of cement paste stops when the relative humidity drops below about 80%. A thermodynamic analysis shows that the capillary pressure exerted at that RH shifts the solubility of tricalcium silicate, so that it is in equilibrium with water. This is a reflection of the chemical shrinkage in this system: according to Le Chatelier's principle, since the volume of the products is less than that of the reactants, a negative (capillary) pressure opposes the reaction.
Flatt, Robert J. [Sika Technology AG, Zuerich (Switzerland); Scherer, George W., E-mail: email@example.com [Princeton University, Eng. Quad. E-319, Princeton NJ 08544 (United States); Bullard, Jeffrey W. [National Institute of Standards and Technology, Gaithersburg MD (United States)
Dual Path HVAC System Demonstration in School: Leveraging Thermal Energy Storage and Cold Air Distribution to Enhance System Perform ance in a Florida Elementary School
This document reports on a novel dual-path, low-temperature air distribution system demonstrated in a Florida elementary school. This system addresses high humidity levels and indoor air quality problems normally found in schools due to their large ventilation requirements, especially in humid climates. The dual-path system is also integrated with synergistic use of thermal energy storage and low-temperature air distribution, reduced energy use, and initial cost. The field data confirmed that the system ...
A humidity temperature test on the HLNC (high-level neutron coincidence counter) instrument
This paper presents the findings of a laboratory study made to determine the effects of unusual climatic conditions on high-level neutron coincidence counters (HLNCs). The capability of the instrument, when undesirable temperatures and/or humidities are present, the change in count rate as temperature and humidity increase, and the extent of humidity/temperature interaction are examined.
Goldman, A.; Augustson, R.; Karlin, E.W.
Based on embedded database greenhouse temperature and humidity intelligent control system
The article based on embedded database of greenhouse temperature and humidity control system intelligent. Put forward by embedded database system set up in an ideal environment for data greenhouse temperature and humidity control, greenhouse crops in ... Keywords: control, data filtering, embedded database, greenhouse, microcontrollers, temperature and humidity
Sun Rong-gao; Wan Zhong; Sun De-chao
TRUEX hot demonstration
In FY 1987, a program was initiated to demonstrate technology for recovering transuranic (TRU) elements from defense wastes. This hot demonstration was to be carried out with solution from the dissolution of irradiated fuels. This recovery would be accomplished with both PUREX and TRUEX solvent extraction processes. Work planned for this program included preparation of a shielded-cell facility for the receipt and storage of spent fuel from commercial power reactors, dissolution of this fuel, operation of a PUREX process to produce specific feeds for the TRUEX process, operation of a TRUEX process to remove residual actinide elements from PUREX process raffinates, and processing and disposal of waste and product streams. This report documents the work completed in planning and starting up this program. It is meant to serve as a guide for anyone planning similar demonstrations of TRUEX or other solvent extraction processing in a shielded-cell facility.
Chamberlain, D.B.; Leonard, R.A.; Hoh, J.C.; Gay, E.C.; Kalina, D.G.; Vandegrift, G.F.
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.
Temperature, humidity and air flow in the emplacement drifts using convection and dispersion transport models
Storage Capacity At Yucca Mountain Favors Thermal ManagementConfiguration Management, Yucca Mountain Project � STN:and condensation . Yucca Mountain Project Report, MDL-EBS-
Danko, G.
Effects of ambient humidity on the energy use of air conditioning equipment
els to the solar measurements from the ebu weather stationels to the solar measurements from the ebu weather stationto the hourly solar data from the cz07 weather file. The
related to fan electricity demand. All of these equationsmeasurements. The electricity demand outputs of all modelsonly overall building electricity demand measurements. The
An Analysis of Low Cost, Energy Efficient, Housing for Low-income Residents of How and Humid Climates
The purpose of this research is to develop methods that will enable the reduction of owning and operating costs of low-income housing in the hot-humid climates of the U. S. The objectives include investigating various scenarios that will enable the implementation of cost-effective construction of low-income housing using volunteer labor. The research uses a case study approach where a base-line energy use is established using a comparative Princeton Score Keeping Method (PRISM) analysis and measurements from a case study house. A prototype house is then simulated with the DOE-2 building simulation program, and the energy savings calculated by comparing simulated energy and water conservation design measures (E&WCDMs) with the calibrated baseline energy simulation. The cost and maintenance of the house are analyzed with the real cost of construction of a case study house in Bryan/College Station, Texas.
Kootin-Sanwu, Victor
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
Ga Air Compressor, Ga Air Compressor Products, Ga Air ...
U.S. Energy Information Administration (EIA)
Ga Air Compressor, You Can Buy Various High Quality Ga Air Compressor Products from Global Ga Air Compressor Suppliers and Ga Air Compressor ...
Managing the Drivers of Air Flow and Water Vapor Transport in Existing Single Family Homes (Revised)
This document focuses on managing the driving forces which move air and moisture across the building envelope. While other previously published Measure Guidelines focus on elimination of air pathways, the ultimate goal of this Measure Guideline is to manage drivers which cause air flow and water vapor transport across the building envelope (and also within the home), control air infiltration, keep relative humidity (RH) within acceptable limits, avoid combustion safety problems, improve occupant comfort, and reduce house energy use.
Cummings, J.; Withers, C.; Martin, E.; Moyer, N.
Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems
The objective of this study is to develop standardized air blown fixed bed gasification hot gas cleanup integrated gasifier combined cycle (IGCC) systems.
Sadowski, R.S.; Brown, M.J.; Hester, J.C.; Harriz, J.T.; Ritz, G.J.
Analysis of Innovative HVAC System Technologies and Their Application for Office Buildings in Hot and Humid Climates.
??The commercial buildings sector in the United States used 18 percent (17.93 Quads) of the U.S. primary energy in 2006. Office buildings are the largest� (more)
Residential Attic Ventilation In A Hot And Humid Climate: Effects Of Increased Ventilation On Thermal Performance And Moisture Control.
?? The reality of the effect of natural ventilation in a residential attic cavity has been the topic of many debates and scholarly reports since� (more)
Atherton, Stanley Arthur
Whole-House Design and Commissioning in the Project Home Again Hot-Humid New Construction Community
BSC has been working with Project Home Again since 2008 and has consulted on the design of around 100 affordable, energy efficient new construction homes for victims of hurricanes Katrina and Rita. This report details the effort on the final two phases of the project: Phases V and VI which resulted in a total of 25 homes constructed in 2011. The goal of this project was to develop and implement an energy efficiency package that will achieve at least 20% whole house source energy savings improvement over the B10 Benchmark.
Kerrigan, P.
An experimental investigation of an air cooling scheme for removing environmentally imposed heat loads from the multiplicity and vertex detector`s main enclosure
This report presents a summary of an experimental investigation of a closed loop air cooling system designed to control the temperature and humidity in the main enclosure of the multiplicity and vertex detector (MVD). Measurements of the cooling air flow rate, the humidity levels inside and outside of the MVD, and the cooling air temperatures were used to assess the performance of the system and to characterize the system limitations and potential assembly problems. The results of the study indicate that several design changes are needed in the final design to meet the temperature and humidity operating requirements. A thorough set of design change recommendations that satisfy these operating criteria completes this report.
Cunningham, R.; Bernardin, J.D.; Simon-Gillo, J.
Waste heat from kitchen cuts hot water electricity 23%
Heat recovered from the Hamburger Hamlet's kitchen in Bethesada, Maryland and used to pre-heat the million gallons of hot water used annually reduced hot water costs 23% and paid off the investment in 1.5 years. Potomac Electric initiated the installation of an air-to-water heat pump in the restaurant kitchen above the dishwasher at a cost of about $5300, with the restaurant obliged to reimburse the utility if performance was satisfactory. Outside water recirculates through storage tanks and the ceiling heat pump until it reaches the required 140/sup 0/F. The amount of electricity needed to bring the preheated water to that temperature was $3770 lower after the installation. Cooled air exhausted from the heat pump circulates throughout the kitchen.
Barber, J.
Hot Hydrogen Test Facility
The core in a nuclear thermal rocket will operate at high temperatures and in hydrogen. One of the important parameters in evaluating the performance of a nuclear thermal rocket is specific impulse, ISp. This quantity is proportional to the square root of the propellant�s absolute temperature and inversely proportional to square root of its molecular weight. Therefore, high temperature hydrogen is a favored propellant of nuclear thermal rocket designers. Previous work has shown that one of the life-limiting phenomena for thermal rocket nuclear cores is mass loss of fuel to flowing hydrogen at high temperatures. The hot hydrogen test facility located at the Idaho National Lab (INL) is designed to test suitability of different core materials in 2500�C hydrogen flowing at 1500 liters per minute. The facility is intended to test non-uranium containing materials and therefore is particularly suited for testing potential cladding and coating materials. In this first installment the facility is described. Automated Data acquisition, flow and temperature control, vessel compatibility with various core geometries and overall capabilities are discussed.
W. David Swank
New and Underutilized Technology: Liquid Desiccant Air Conditioner |
Liquid Desiccant Air Conditioner Liquid Desiccant Air Conditioner New and Underutilized Technology: Liquid Desiccant Air Conditioner October 4, 2013 - 4:40pm Addthis The following information outlines key deployment considerations for liquid desiccant air conditioners (LDACs) within the Federal sector. Benefits Liquid desiccant air conditioners deeply dry air using natural gas, solar energy, waste heat, bio-fuel, or other fossil fuels to drive the system. By providing mostly latent cooling, the LDAC controls indoor humidity without overcooling and reheating. This unit is supplemented by an electric chiller or DX air conditioner that sensibly cools the building's recirculation air. The liquid desiccant is a concentrated salt solution that directly absorbs moisture. Application LDACs are applicable in hospital, office, prison, school, and service
Line Heat-Source Guarded Hot Plate
Line Heat-Source Guarded Hot Plate. Description: The 1-meter guarded hot-plate apparatus measures thermal conductivity of building insulation. ...
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.
Tips: Air Conditioners | Department of Energy
Tips: Air Conditioners Tips: Air Conditioners Tips: Air Conditioners June 24, 2013 - 6:31pm Addthis Bigger isn't always better for an air conditioner. Learn effective ways to stay cool while saving energy. | Photo courtesy of ©iStockphoto/galinast. Bigger isn't always better for an air conditioner. Learn effective ways to stay cool while saving energy. | Photo courtesy of ©iStockphoto/galinast. Buying a bigger room air conditioner won't necessarily make you feel more comfortable during the hot summer months. In fact, a room air conditioner that's too big for the area it is supposed to cool will perform less efficiently and less effectively than a smaller, properly sized unit. The reason: an oversized unit will cool the room(s) to the thermostat set-point before proper dehumidification occurs, making the area feel "clammy"
Sensitivity of Low Sloped Roofs Designs to Initial Water and Air Leakage
Liquid water in low sloped roofs almost always causes problems. Roofs are designed only to control the migration of vapor, if at all. Small amounts of water leakage/penetration, may cause mold growth or catastrophic corrosion in current roofs systems. In a recent paper by the authors the effect of exterior surface emissive and absorptive properties was found to have a significant effect on the moisture performance of a roof that had a leak. Depending on the surface characteristics, roof systems can be designed to effectively manage water penetration, but at an energy cost. In the roofs system examined previously, air leakage was not included. In the present study, the authors reinvestigated the effect of water penetration and the influence of air leakage on the hygrothermal performance of a few selected roofs. The drying potential of a groove ventilated roof is examined. The performance concept is based on the fact that warming up of air in the groove increases it's ability to transport moisture to the outside. Solar radiation raises the temperature of air in the grooves and on average, during a sunny summer day 0.5 L of water can be ventilated out of the roof per 1m width of the roof. In this paper, one climatic condition was investigated; a hot and humid Climate representative of Houston, TX. The specific questions that the paper addresses are: What are the vapor and liquid control dynamic involved in the moisture migration of a roof in Houston TX? and how does airflow influence the performance of a roof that is initially wet ? A state-of-the-art numerical model was used to address these issues. Results showed that the drying potential depends on the ventilation rates. The roof system with ventilation grooves dried out faster from the initially wet stage than the roof without the ventilation grooves. The total increase in heat loss of the roof was found to be between 0 - 5 % depending on the thickness of the insulation. The ventilation can cool down the temperature of the roof in the middle of a hot and sunny day thus reducing the heat load to the inside.
Karagiozis, A.; Desjarlais, A.; Salonvaara, M.
Alternatives for reducing hot-water bills
A two stage approach to reducing residential water heating bills is described. In Stage I, simple conservation measures were included to reduce the daily hot water energy consumption and the energy losses from the water tank. Once these savings are achieved, Stage II considers more costly options for further reducing the water heating bill. Four alternatives are considered in Stage II: gas water heaters; solar water heaters (two types); heat pump water heaters; and heat recovery from a heat pump or air conditioner. To account for variations within the MASEC region, information on water heating in Rapid City, Minneapolis, Chicago, Detroit, and Kansas City is presented in detail. Information on geography, major population centers, fuel prices, climate, and state solar incentives is covered. (MCW)
Bennington, G.E.; Spewak, P.C.
Five-Year Climatology of Midtroposphere Dry Air Layers in Warm Tropical Ocean Regions as Viewed by AIRS/Aqua
Many studies have commented on the presence of midtroposphere dry air layers in normally moist areas of the warm-pool region in the tropical western Pacific Ocean. In this study, 5 yr of relative humidity (RH) observations from the Atmospheric ...
Sean P. F. Casey; Andrew E. Dessler; Courtney Schumacher
NREL: Learning - Solar Hot Water
Hot Water Hot Water Photo of solar collectors on a roof for a solar hot water system. For solar hot water systems, flat-plate solar collectors are typically installed facing south on a rooftop. The shallow water of a lake is usually warmer than the deep water. That's because the sunlight can heat the lake bottom in the shallow areas, which in turn, heats the water. It's nature's way of solar water heating. The sun can be used in basically the same way to heat water used in buildings and swimming pools. Most solar water heating systems for buildings have two main parts: a solar collector and a storage tank. The most common collector is called a flat-plate collector. Mounted on the roof, it consists of a thin, flat, rectangular box with a transparent cover that faces the sun. Small tubes
Virginia Tech Hot Water Report
The team chose to use a water-to-water heat pump (WWHP) connected to an earth coupled heat exchanger to provide water heating. This system provides not only domestic hot water...
The decay of hot nuclei
The formation of hot compound nuclei in intermediate-energy heavy ion reactions is discussed. The statistical decay of such compound nuclei is responsible for the abundant emission of complex fragments and high energy gamma rays. 43 refs., 23 figs.
Moretto, L.G.; Wozniak, G.J.
Assessment of coal gasification/hot gas cleanup based advanced gas turbine systems
The major objectives of the joint SCS/DOE study of air-blown gasification power plants with hot gas cleanup are to: (1) Evaluate various power plant configurations to determine if an air-blown gasification-based power plant with hot gas cleanup can compete against pulverized coal with flue gas desulfurization for baseload expansion at Georgia Power Company's Plant Wansley; (2) determine if air-blown gasification with hot gas cleanup is more cost effective than oxygen-blown IGCC with cold gas cleanup; (3) perform Second-Law/Thermoeconomic Analysis of air-blown IGCC with hot gas cleanup and oxygen-blown IGCC with cold gas cleanup; (4) compare cost, performance, and reliability of IGCC based on industrial gas turbines and ISTIG power island configurations based on aeroderivative gas turbines; (5) compare cost, performance, and reliability of large (400 MW) and small (100 to 200 MW) gasification power plants; and (6) compare cost, performance, and reliability of air-blown gasification power plants using fluidized-bed gasifiers to air-blown IGCC using transport gasification and pressurized combustion.
Hot Dry Rock - Summary
Hot Dry Rock adds a new flexibility to the utilization of geothermal energy. Almost always the approach has been to limit that utilization to places where there is a natural source of water associated with a source of heat. Actually, the result was that steam was mined. Clearly there are much larger heat resources available which lack natural water to transport that energy to the surface. Also, as is found in hydrothermal fields being mined for steam, the water supply finally gets used up. There is a strong motive in the existing capital investment to revitalize those resources. Techniques for introducing, recovering and utilizing the water necessary to recover the heat from below the surface of the earth is the subject of this session. Implicit in that utilization is the ability to forecast with reasonable accuracy the busbar cost of that energy to the utility industry. The added element of supplying the water introduces costs which must be recovered while still supplying energy which is competitive. Hot Dry Rock technology can supply energy. That has been proved long since. The basic barrier to its use by the utility industry has been and remains proof to the financial interests that the long term cost is competitive enough to warrant investment in a technology that is new to utility on-grid operations. As the opening speaker for this session states, the test that is underway will ''simulate the operations of a commercial facility in some ways, but it will not show that energy from HDR can be produced at a variety of locations with different geological settings''. Further, the Fenton Hill system is a research facility not designed for commercial production purposes, but it can give indications of how the system must be changed to provide economic HDR operations. And so it is that we must look beyond the long term flow test, at the opportunities and challenges. Proving that the huge HDR resources can be accessed on a worldwide scale must involve the construction of additional sites, preferably to the specifications of the now Federal geothermal community. These facilities will have to be engineered to produce and market energy at competitive prices. At the same time, we must not rest on our technological laurels, though they be many. Design and operational techniques have been conceived which could lead to improved economics and operations for HDR. These must be pursued and where merit is found, vigorously pursued. Accelerated research and development ought to include revolutionary drilling techniques, reservoir interrogation, and system modeling to assure the competitiveness and geographical diversity of applications of HDR. Much of this work will be applicable to the geothermal industry in general. More advanced research ought to include such innovations as the utilization of other operating fluids. Supercritical carbon dioxide and the ammonia/water (Kalina) cycle have been mentioned. But even as the near and more distant outlook is examined, today's work was reported in the HDR session. The start-up operations for the current test series at the Fenton Hill HDR Pilot Plant were described. The surface plant is complete and initial operations have begun. While some minor modifications to the system have been required, nothing of consequence has been found to impede operations. Reliability, together with the flexibility and control required for a research system were shown in the system design, and demonstrated by the preliminary results of the plant operations and equipment performance. Fundamental to the overall success of the HDR energy resource utilization is the ability to optimize the pressure/flow impedance/time relationships as the reservoir is worked. Significant new insights are still being developed out of the data which will substantially affect the operational techniques applied to new systems. However, again, these will have to be proved to be general and not solely specific to the Fenton Hill site. Nevertheless, high efficiency use of the reservoir without unintended reservoir grow
Tennyson, George P. Jr.
Guides and Case Studies for Mixed-Humid Climates | Department of Energy
Guides and Case Studies for Mixed-Humid Climates Guides and Case Studies for Mixed-Humid Climates Guides and Case Studies for Mixed-Humid Climates Map of the Mixed-Humid Climate which reaches from the coast of Maryland through North Carolina and sprawls to cover most of Kansas and Oklahoma. The Department of Energy (DOE) has developed a series of best practices and case studies to help builders improve whole-house energy performance in buildings found in mixed-humid climates. Best Practice Guides New Construction Case Studies Improvements to Existing Homes Case Studies Best Practice Guides 40% Whole-House Energy Savings in the Mixed-Humid Climates - Volume 16 New Construction Case Studies Maryland Project: North Point Lot 5 - Frederick Builder: Nexus EnergyHomes Profile: This urban infill community with 24 duplexes, 19 townhomes, and 7
Response of bean and tobacco to ozone: effect of light intensity, temperature and relative humidity
Pinto bean (Phaseolus vulgaris, L.) and Bel W/sub 3/ tobacco (Nicotiana tabacum, L.) were grown and exposed to 40 pphm ozone for 1 hr under a range of light intensities, temperatures, and relative humidities. Foliar injury to the more sensitive plant leaves was determined on the third day after exposure. Each atmospheric factor was independently assessed. Two significant three-way interactions were found: exposure light intensity by growth light intensity by species, and growth temperature by exposure temperarture by species. Three significant two-way interactions were found for humidity: growth humidity by exposure humidity, growth humidity by species, and exposure humidity by species. The sensitivity of each species to ozone changed with changes in each environmental condition.
Dunning, J.A.; Heck, W.W.
Effects of Temperature and Humidity on Wilethane 44 Cure
Wilethane 44 is a polyurethane adhesive developed by the Materials Team within ESA-MEE at Los Alamos National Laboratory as a replacement for Hexcel Corporation Urethane 7200. Urethane 7200 is used in numerous weapon systems, but it was withdrawn from the market in 1989. The weapons complex requires a replacement material for use in the W76-1 LEP and the W88, as well as for assembly of JTAs for other warheads. All polyurethane systems are susceptible to moisture reacting with unreacted isocyanate groups. This side reaction competes with the curing reaction and results in CO{sub 2} formation. Therefore, a polyurethane adhesive can exhibit foaming if appropriate environmental controls are not in place while it cures. A designed experiment has been conducted at TA-16-304 to determine the effects of ambient conditions on the properties of cured Wilethane 44. Temperature was varied from 15 C to 30 C and relative humidity from 15% to 40%. The density, hardness at 24 hours, and butt tensile strength on aluminum substrates were measured and fitted to quadratic equations over the experimental space. Additionally, the loss and storage moduli during cure were monitored as a function of cure temperature. These experiments provide a stronger basis for establishing appropriate environmental conditions and cure times when using Wilethane 44. The current guidelines are a working time of 90 minutes, a cure time of 18 hours, and a relative humidity of less than 25%, regardless of ambient temperature. Viscosity measurements revealed that the working time is a strong function of temperature and can be as long as 130 minutes at 15 C or as short as 90 minutes at 30 C. The experiments also showed that the gel time is much longer than originally thought, as long as 13 hours at 15 C. Consequently, it may be necessary to extend the required cure time at temperatures below 20 C. Allowable humidity varies as a function of temperature from 34% at 15 C to 15% at 30 C.
John C. Weigle
Method and apparatus for extracting water from air
The present invention provides a method and apparatus for extracting liquid water from moist air using minimal energy input. The method comprises compressing moist air under conditions that foster the condensation of liquid water (ideally isothermal to a humidity of 1.0, then adiabatic thereafter). The air can be decompressed under conditions that do not foster the vaporization of the condensate. The decompressed, dried air can be exchanged for a fresh charge of moist air and the process repeated. The liquid condensate can be removed for use. The apparatus can comprise a compression chamber having a variable internal volume. An intake port allows moist air into the compression chamber. An exhaust port allows dried air out of the compression chamber. A condensation device fosters condensation at the desired conditions. A condensate removal port allows liquid water to be removed.
Spletzer, Barry L. (Albuquerque, NM)
A modification to the AMT-4 radiosonde transmitter and modulator which permits the use of a new aluminum oxide humidity element is described. The modification is simple enough to be made by relatively unskilled personnel in the field and involves: using the newly developed aluminum oxide humidity element, slightly modifying the transmitter, and slightly revising the modulator circuitry. The polarization problem usually associated with using humidity elements in a direct-current circuit is also minimized by this modification. (auth)
constructed with ?-inch plywood with a vinyl or PVC skin ortile, gypsum board, shiplap, plywood, terracotta brick) thatsamples are all made from plywood. Humidity Equilibration
Parthasarathy, Srinandini
Humidity-resistant ambient-temperature solid-electrolyte amperometric sensing apparatus and methods
Apparatus and methods for detecting selected chemical compounds in air or other gas streams at room or ambient temperature includes a liquid-free humidity-resistant amperometric sensor comprising a sensing electrode and a counter and reference electrode separated by a solid electrolyte. The sensing electrode preferably contains a noble metal, such as Pt black. The electrolyte is water-free, non-hygroscopic, and substantially water-insoluble, and has a room temperature ionic conductivity .gtoreq.10.sup.-4 (ohm-cm).sup.-1, and preferably .gtoreq.0.01 (ohm-cm).sup.-1. The conductivity may be due predominantly to Ag+ ions, as in Ag.sub.2 WO.sub.4.4AgI, or to F- ions, as in Ce.sub.0.95 Ca.sub.0.05 F.sub.2.95. Electrical contacts serve to connect the electrodes to potentiostating and detecting circuitry which controls the potential of the sensing electrode relative to the reference electrode, detects the signal generated by the sensor, and indicates the detected signal.
Zaromb, Solomon (9 S 706 William Dr., Hinsdale, IL 60521)
Zaromb, Solomon (9S 706 William Dr., Hinsdale, IL 60521)
Evaluation of ANSI N42-17A by investigating the effects of temperature and humidity on the response of radiological instruments
The American National Standards Institute (ANSI) N42.17A-1989 standard`s performance criteria and test methods has been evaluated by investigating the effects of temperature and humidity on the response of 105 portable direct-reading radiological instruments (45 beta-gamma survey meters, 32 neutron rem meters, 1O alpha contamination and 18 tritium-in-air monitors). The US Department of Energy (DOE) mandates the use of ANSI standards for the calibration and performance testing of radiological instruments, and requires that instruments be appropriate for existing environmental conditions. Random tests conducted in an environmental chamber determined the effects of temperatures ranging from {minus}10{degree}C to 50{degree}C and humidity at levels of 40% RH and 95% RH on the response of a cross section of instruments used in routine health physics operations at Los Alamos. The following instruments were tested: Eberline RO-2 and RO-C ionization chambers, Eberline E-530 survey meter with the Model HP-C stainless steel Geiger-Muller (G) wall probe, Eberline PIC-6A and PIC-6B ion chambers, Eberline ESP-1 survey meter with the Model HP-260 pancake G detector, Ludlum 3 survey meter with the Model 44-6 stainless steel G wall probe, Eberline ESP-1, ESP-2 and PAR-4 survey meters with the neutron rem detector, Health Physics Instruments 2080 survey meter with the moderator detector, Ludlum 139 survey meter with the Model 43-32 air-proportional alpha detector, and the Overhoff 394-C, Johnston J-111 and J-110 tritium monitors. Experimental results encompass 1128 temperature tests (1269-hours exposure in the chamber) and 735 humidity tests (1890-hours exposure in the chamber). The study shows the standard`s test requirement for temperature at or near the extreme conditions, and the standard`s test requirement for humidity at 95% RH may be too restrictive for instruments used in the work environment.
Clement, R.S.
Promethus Hot Leg Piping Concept
The Naval Reactors Prime Contractor Team (NRPCT) recommended the development of a gas cooled reactor directly coupled to a Brayton energy conversion system as the Space Nuclear Power Plant (SNPP) for NASA's Project Prometheus. The section of piping between the reactor outlet and turbine inlet, designated as the hot leg piping, required unique design features to allow the use of a nickel superalloy rather than a refractory metal as the pressure boundary. The NRPCT evaluated a variety of hot leg piping concepts for performance relative to SNPP system parameters, manufacturability, material considerations, and comparison to past high temperature gas reactor (HTGR) practice. Manufacturability challenges and the impact of pressure drop and turbine entrance temperature reduction on cycle efficiency were discriminators between the piping concepts. This paper summarizes the NRPCT hot leg piping evaluation, presents the concept recommended, and summarizes developmental issues for the recommended concept.
AM Girbik; PA Dilorenzo
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
A New Ventilation System Integrates Total Energy Recovery, Conventional Cooling and a Novel 'Passive' Dehumidification Wheel to Mitigate the Energy, Humidity Control and First Cost Concerns Often Raised when Designing for ASHRAE Standard 62-1999 Compliance
This paper introduces a novel, ''passive" desiccant based outdoor air preconditioning system (PDH) that is shown to be significantly more energy-efficient than all known alternatives, and has the unique ability to dehumidify outdoor air streams to very low dewpoints unattainable with conventional cooling approaches. The system allows for precise control of the indoor space humidity while delivering high quantities of outdoor air, at both peak and part load conditions, and during both occupied and unoccupied modes. Low operating cost, reasonable first cost and a significant reduction in cooling plant capacity requirements provide a life cycle cost that is substantially less than that of more conventional system approaches.
Fischer, J. C.
Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems. Volume 1, Final report
Hot Gas Halos in Galaxies
We use Chandra and XMM-Newton to study how the hot gas content in early-type galaxies varies with environment. We find that the L{sub X}-L{sub K} relationship is steeper for field galaxies than for comparable galaxies in groups and clusters. This suggests that internal processes such as supernovae driven winds or AGN feedback may expel hot gas from low mass field galaxies. Such mechanisms are less effective in groups and clusters where the presence of an intragroup or intracluster medium may confine outflowing material.
Mulchaey, John S. [Carnegie Observatories (United States); Jeltema, Tesla E. [UCO/Lick Observatories (United States)
Hot conditioning equipment conceptual design report
This report documents the conceptual design of the Hot Conditioning System Equipment. The Hot conditioning System will consist of two separate designs: the Hot Conditioning System Equipment; and the Hot Conditioning System Annex. The Hot Conditioning System Equipment Design includes the equipment such as ovens, vacuum pumps, inert gas delivery systems, etc.necessary to condition spent nuclear fuel currently in storage in the K Basins of the Hanford Site. The Hot Conditioning System Annex consists of the facility of house the Hot Conditioning System. The Hot Conditioning System will be housed in an annex to the Canister Storage Building. The Hot Conditioning System will consist of pits in the floor which contain ovens in which the spent nuclear will be conditioned prior to interim storage.
Bradshaw, F.W., Westinghouse Hanford
Ceramic filters for removal of particulates from hot gas streams
The primary goal is to demonstrate the performance of a new ceramic filter in removing particulate matter from hot gas streams produced in advanced coal conversion processes. The specific objectives are threefold: (1) Development of full size ceramic filters suitable for hot gas filtration; (2) Demonstration of ceramic filters in long term (ca. 1000 hrs) field trials; and (3) Development of full-scale hot gas filter system designs and costs. To date, field tests of the ceramic filter for particulate removal have been conducted at seven sites on a variety of gas streams and under a variety of test conditions. In general, the following performance characteristics have been observed: 1. Filtration face velocity (equivalent to an ``air to cloth ratio``) for flue gas tests is comparable to that for pulse jet bags operating at the same pressure drop. In hot gas tests, flow-pressure drop characteristics have been observed to be comparable to those for other ceramic filters. 2. Complete regeneration by a simple backpulse technique is achieved; i.e., no increase in clean filter resistance over repetitive cycles is observed. 3. No plugging of the filter passageways by badly caking particulates is observed. 4. Essentially complete particulate removal, including submicron particulate matter, is achieved.
Goldsmith, R.L.
The primary goal is to demonstrate the performance of a new ceramic filter in removing particulate matter from hot gas streams produced in advanced coal conversion processes. The specific objectives are threefold: (1) Development of full size ceramic filters suitable for hot gas filtration; (2) Demonstration of ceramic filters in long term (ca. 1000 hrs) field trials; and (3) Development of full-scale hot gas filter system designs and costs. To date, field tests of the ceramic filter for particulate removal have been conducted at seven sites on a variety of gas streams and under a variety of test conditions. In general, the following performance characteristics have been observed: 1. Filtration face velocity (equivalent to an air to cloth ratio'') for flue gas tests is comparable to that for pulse jet bags operating at the same pressure drop. In hot gas tests, flow-pressure drop characteristics have been observed to be comparable to those for other ceramic filters. 2. Complete regeneration by a simple backpulse technique is achieved; i.e., no increase in clean filter resistance over repetitive cycles is observed. 3. No plugging of the filter passageways by badly caking particulates is observed. 4. Essentially complete particulate removal, including submicron particulate matter, is achieved.
From earlier results on the measurement of soil humidity an apparatus was constructed and calibrated for the measurement of the humidity of soils by diffusion of a beam of thermal neutrons. The construction and calibration of this apparatus are described in detail. (J.S.R.)
Wack, B.
Enviropower hot gas desulfurization pilot
The objectives of the project are to develop and demonstrate (1) hydrogen sulfide removal using regenerable zinc titanate sorbent in pressurized fluidized bed reactors, (2) recovery of the elemental sulfur from the tail-gas of the sorbent regenerator and (3) hot gas particulate removal system using ceramic candle filters. Results are presented on pilot plant design and testing and modeling efforts.
Ghazanfari, R.; Feher, G.; Konttinen, J.; Ghazanfari, R.; Lehtovaara, A.; Mojtahedi, W.
The Chilled Water and Hot Water Building Differential Pressure Setpoint Calculation - Chilled Water and Hot Water Pump Speed Control
More and more variable frequency devices (VFD)
are being installed on the chilled water and hot water
pumps on the TAMU campus. Those pump speeds
are varied to maintain chilled water or hot water
building deferential pressure (DP) or return
temperature or flow rate at their setpoints. The chilled
water and hot water DP setpoint or return
temperature setpoint or flow rate setpoint was a
constant value or reset based on outside air
temperature. In some buildings, the chilled water and
hot water DP setpoints were reset based on flow rate,
but in many instances those setpoint schedules were
either too low to maintain enough building DP
requirement or too high and consumed excess energy.
The building DP reset schedule based on flow rate is
studied and compared with the other pump speed
control methods. Because the building DP setpoint
based on flow rate method is achieved by tracking the
load change, it saves energy than the other methods.
In this paper its calculation procedure is generated
and the example of the building DP calculation is
Turner, W. D.; Bruner, H., Jr.; Claridge, D.; Liu, C.; Deng, S.
Relative Humidity Sensing Properties Of Cu{sub 2}O Doped ZnO Nanocomposite
In this paper we report application of Cu{sub 2}O doped ZnO composite prepared by solid state reaction route as humidity sensor. Pellet samples of ZnO-Cu{sub 2}O nanocrystalline powders with 2, 5 and 10 weight% of Cu{sub 2}O in ZnO have been prepared. Pellets have been annealed at temperatures of 200-500 deg. C and exposed to humidity. It is observed that as relative humidity increases, resistance of the pellet decreases for the humidity from 10% to 90%. Sample with 5% of Cu{sub 2}O doped in ZnO and annealed at 500 deg. C shows best results with sensitivity of 1.50 M{omega}/%RH. In this case the hysteresis is low and the reproducibility high, making it the suitable candidate for humidity sensing.
Pandey, N. K.; Tiwari, K.; Tripathi, A.; Roy, A.; Rai, A.; Awasthi, P. [Sensors and Materials Research Laboratory, Department of Physics, University Of Lucknow, U.P., Pin-226007 (India)
What's hot on woodburning cookstoves? Emerging opportunities from the new
What's hot on woodburning cookstoves? Emerging opportunities from the new What's hot on woodburning cookstoves? Emerging opportunities from the new generation of dissemination programs and devices Speaker(s): Omar Masera Date: February 25, 2010 - 12:00pm Location: 90-3122 Reducing traditional fuelwood and charcoal use with improved cookstoves is key for a whole range of critical issues including climate change mitigation (e.g., black carbon emissions and emissions of short-lived GHG such as methane and CO), indoor air pollution and health (as 1.6 million excess deaths per year are attributable to cooking with open fires), forest conservation (as woodfuels constitute 60% of total demand from wood products), energy use (with 9% of worldwide energy supply) and, more than anything, for improving the living conditions of poorest households on
Hot Diggity Dog CFC Fundraiser | Department of Energy
Sites Power Marketing Administration Other Agencies You are here Home Hot Diggity Dog CFC Fundraiser Hot Diggity Dog CFC Fundraiser Hot Diggity Dog CFC Fundraiser December...
Acord 1-26 hot, dry well, Roosevelt Hot Springs hot dry rock prospect, Utah
The Acord 1-26 well is a hot, dry well peripheral to the Roosevelt Hot Springs known geothermal resource area (KGRA) in southwestern Utah. The bottom-hole temperature in this 3854-m-deep well is 230/sup 0/C, and the thermal gradient is 54/sup 0/C/km. The basal 685 m, comprised of biotite monzonite and quartz schist and gneiss, is a likely hot, dry rock (HDR) prospect. The hole was drilled in a structural low within the Milford Valley graben and is separated from the Roosevelt KGRA to the east by the Opal Mound Fault and other basin faults. An interpretation of seismic data approximates the subsurface structure around the well using the lithology in the Acord 1-26 well. The hole was drilled with a minimum of difficulty, and casing was set to 2411 m. From drilling and geophysical logs, it is deduced that the subsurface blocks of crystalline rock in the vicinity of the Acord 1-26 well are tight, dry, shallow, impermeable, and very hot. A hydraulic fracture test of the crystalline rocks below 3170 m is recommended. Various downhole tools and techniques could be tested in promising HDR regimes within the Acord 1-26 well.
Shannon, S.S. Jr.; Pettitt, R.; Rowley, J.; Goff, F.; Mathews, M.; Jacobson, J.J.
In-situ characterization of free-volume holes in polymer thin films under controlled humidity conditions with an atmospheric positron probe microanalyzer
A pulsed, slow positron beam, with a diameter of 200 {mu}m, was extracted into air through a thin SiN window of an atmospheric positron probe microanalyzer (PPMA), and used to measure the ortho-positronium lifetimes {tau} in polyvinyl alcohol and polycaprolactam sub-{mu}m-thick films. By measuring the variation of {tau} as a function of relative humidity, the effect of water molecules on the hole sizes, deduced from {tau}, was examined for the films with consideration to the chain mobility. The results demonstrate the usefulness of the atmospheric PPMA to the in-situ characterization of nanoscopic holes in thin films under practical conditions.
Zhou Wei; Oshima, Nagayasu; O'Rourke, Brian E.; Kuroda, Ryunosuke; Suzuki, Ryoichi [Research Institute of Instrumentation Frontier (RIIF), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Chen Zhe; Ito, Kenji [Metrology Institute of Japan (MIJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565 (Japan); Yanagishita, Hiroshi [Research Institute for Innovation in Sustainable Chemistry (ISC), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565 (Japan); Tsutsui, Takuro; Uedono, Akira [Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Hayashizaki, Noriyosu [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Meguro, Tokyo 152-8850 (Japan)
Early Guarded-Hot-Plate Apparatus
... published a recommended plan advocating the ... with the US Department of Energy, completed measurements ... hot plate apparatus described above. ...
Commonwealth Solar Hot Water Commercial Program | Department...
Commercial Program Commonwealth Solar Hot Water Commercial Program Eligibility Agricultural Commercial Fed. Government Industrial Local Government Multi-Family Residential...
Corrosion of well casings in compressed air energy storage environments
The goal of this study was to determine corrosive effects of compressed air energy storage (CAES) environments on several well casing materials to aid in material selections. A literature search on corrosion behavior of well casing material in similar environments revealed that corrosion rates of 0.20 to 0.25 mm/y might be expected. This information was employed in designing the laboratory study. Unstressed electrically isolate samples of various carbon steels were autoclaved at varying humidities, temperatures, and exposure durations to simulate anticipated environments in the well bore during CAES operation. All compressed air tests were run at 12.1 MPa. Temperatures varied from 323/sup 0/K to 573/sup 0/K, and humidity varied from 100% to completely dry air. The effects of salts in the humidified air were also studied. Results indicated that typical well casings of carbon steel as used in oil, gas, and water production wells adequately withstand the anticipated CAES reservoir environment. An acceptable corrosion rate arrived at by these laboratory simulations was between 0.0015 and 0.15 mm/y. Corrosion was caused by metal oxidation that formed a protective scale of iron oxide. Higher temperatures, humidity rates, or salinity content of the humid air increased corrosion. Corrosion also increased on a metal coupon in contact with a sandstone sample, possibly due to crevice corrosion. For each of these factors either singularly or collectively, the increased corrosion rates were still acceptable with the maximum measured at 0.15 mm/y. When coupons were reused in an identical test, the corrosion rates increased beyond the anticipated values that had been determined by extrapolation from one-time runs. Fine cracking of the protective scale probably occurred due to thermal variations, resulting in increased corrosion rates and a greater potential for particulates, which could plug the reservoir.
Elmore, R.P.; Stottlemyre, J.A.
Improved intake air filtration systems
This report comprises the results of a project sponsored by the Pipeline Research Committee of the American Gas Association (Improved Intake Air Filtration Systems). The quality of the inlet air consumed by pipeline gas turbines plays a significant role in the performance, maintenance, and economy of turbine operations. The airborne contaminants may cause degradation of compressor blades and hot gas path components, primarily by erosion, corrosion, and fouling. Machines in the pipeline fleet have a typical average loss of 3.5% in output, chiefly caused by fouling of the gas turbine compressor. It also showed that: Air contamination could be significantly reduced by the use of more efficient air filtration systems, especially through the reduction of the quantity of smaller particles ingested.'' Filters which incorporated electrostatically charged fibers (achieved through the use of triboelectric [TE] effects) offered the most promising means for developing an improvement over paper media. The purpose of this program was to validate the use of new technology for self-cleaning air inlet filtration on gas turbine pumping applications. An approach utilizing triboelectrification of fabric filters was examined by testing to determine the penetration (efficiency), cleanability, pressure drop vs flow, and dust-holding capacity of seven pairs of filter cartridges: six fabric and one paper.
Lawson, C.C. (Lawson (Calvin C.), North Wildwood, NJ (United States))
In order to carry out adequately controlled studies on the effects of temperature and humidity on the behavior of bacteria and viruses suspended in the air under various experimental conditions, it became necessary to have available enclosed spaces in which any desired atmospheric state could be produced and maintained. The use of conventional methods of air conditioning is unsuitable for this purpose because all of these depend upon exchange of the air inside the experimental space with conditioned air. Hence, two identical air-tight, glass-walled rooms 8 feet X 10 feet and 8 feet high were built each within a separate air-conditioned shell which can be kept constantly at any temperature and relative humidity likely to be encountered in spaces occupied by human beings. Rapid circulation of the conditioned air over all surfaces of the inner room provides a sufficiently high rate of heat transfer to insure constant temperature conditions within that space. The relative humidity of the inner room can be maintained at the same level as the air of the outer shell or can be increased by the introduction of steam. Two rooms provide much greater
O. H. Robertson; Theodore T. Puck, Ph.D.; Henry Wise
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
How Do You Stay Cool and Comfortable in Hot Weather? | Department of Energy
Cool and Comfortable in Hot Weather? Cool and Comfortable in Hot Weather? How Do You Stay Cool and Comfortable in Hot Weather? May 28, 2009 - 5:25pm Addthis As you may have read on the blog over the past few weeks, the Stay Cool, Save Money site offers no-cost and low-cost tips for saving energy during the warm summer months, as well as ideas for long-term investments to help you save year round. Whether you rely on an air conditioner, strategically opened windows (and closed shades), fans, regular dips in the pool, or some other strategy entirely, tell us: How do you stay cool and comfortable in hot weather? Each Thursday, you have the chance to share your thoughts on a topic related to energy efficiency or renewable energy for consumers. Please comment with your answers, and also feel free to respond to other comments.
Compact Liquid Waste Evaporator for Cleanup on Hanfords Hot Cells [FULL PAPER