Psychrometric Calculator

The formulations used here to calculate moist air properties are based on perfect gas relations published in 1989 ASHRAE Fundamentals Handbook, which should be accurate. Nevertheless, It is strongly recommend that you to compare the results calculated by this worksheet with a psychrometric chart. There is no error checking so you should use reasonable input values.

Inputs
Unit Chosen: SI IP
Parameter Name Value Unit
Dry Bulb Temp.:
Wet Bulb Temp.:
Relat. Humidity:  
Dew Point Temp
Altitude
Outputs
Atmospheric Press
Sat. Vapor Press.
Partial Vapor Press.
Humidity Ratio
Enthalpy
Specific Volume

Unit Conversion

°C °F
WTD(°C) WTD(°F)
m ft
mm in
kW Btuh
L/S CFM
L/S GPM
kPa ft H2O
Pa in H2O
kW/m Btuh/ft
m/s fpm
kg lb
Q (Air) = 1.085 x  
cfm x  
°F =    Btu/hr
Q (H2O) = 500 x  
gpm x  
°F =    Btu/hr