humidity ratio line of 0.0126, either in kg water per kg dry air or pounds water per pound dry air. A common variation of this problem is determining the final humidity of air leaving an air conditioner evaporator coil then heated to a higher temperature. Assume that the temperature leaving the coil is 10°C (50°F) and is heated to room temperature (not mixed with room air), which is found by following the horizontal humidity ratio from the dew point or saturation line to the room dry bulb temperature line and reading the relative humidity. In typical practice the conditioned air is mixed with room air that is being infiltrated with outside air. Determining the amount of water to be removed or added in lowering or raising relative humidity: This is the difference in humidity ratio between the initial and final conditions times the weight of dry air. Mollier diagram The "Mollier i-x" (Enthalpy - Humidity Mixing Ratio) diagram, developed by Richard Mollier in 1923, is an alternative psychrometric chart, preferred by many users in Germany, Austria, Switzerland, the Netherlands, Belgium, France, Scandinavia, Eastern Europe, and Russia. The underlying psychrometric parameter data for the psychrometric chart and the Mollier diagram are identical. At first glance there is little resemblance between the charts, but if the chart is rotated by ninety degrees and looked at in a mirror the resemblance becomes apparent. The Mollier diagram coordinates are enthalpy and humidity ratio. The enthalpy coordinate is skewed and the lines of constant enthalpy are parallel and evenly spaced. The ASHRAE psychrometric charts since 1961 use similar plotting coordinates. Some psychrometric charts use dry-bulb temperature and humidity ratio coordinates. See also Air Air conditioning Dalton's law of Partial Pressures Dew point Dry-bulb temperature Evaporative cooling Humidity Operative temperature Relative humidity Wet-bulb temperature References External links Western Cooling Efficiency Center Psych: An Open Source Psychrometric Plug-in for Microsoft Excel by Kevin Brown. Xchanger Inc, webpage Calculator for humidity, dew point, mass flows & heat flux for variable pressure systems with compressors, blowers, vacuum pumps and heat exchangers. Corwin's Calculators Calculator for humidity, dew point. How to read and use a psychrometric chart Free Online Interactive Psychrometric Chart Psychrometric Chart Calculator and Sketcher Humidity and hygrometry Heating, ventilation, and air conditioning