The psychrometrics application calculates 35 thermodynamic properties of humid (moist) air in SI and English system of units. It’is based on the real gas formulation developed by Hyland and Wexler. It allows 21 different combinations of input variables to be used for calculations.
Input variables that can be used are;
Dry bulb temperature.
Wet bulb temperature.
Dew point tempertature.
The psychrometrics application uses the most accurate formulations of thermodynamic properties of moist air. Formulations are based on the study performed by Hyland and Wexler, and approved by ASHRAE (American Society of Heating, Refrigeration and Air-conditioning Engineers) as documented in the 1997 ASHRAE Handbook “Fundamentals”.
They presented the equation of state in;
Formulations for the thermodynamic properties of the saturated phases of H2O from 173.15 K to 473.15 K, W. Hyland and A.Wexler, ASHRAE Transactions, 89(2A) 500-519, 1983.
Formulations for the thermodynamic properties of dry air from 173.15 K to 473.15 K, and of saturated moist air from 173.15 K to 372.15 K, at pressures to 5 MPa, R. W. Hyland and A. Wexler, ASHRAE Transactions, 89(2A) 520-535, 1983.