This Special Publication is the result of two research projects sponsored and funded by the American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc.

The basic data on the thermodynamic properties of water, moist air and dry air, as well as an estimate of uncertainties in the calorimetric parameters of water, was done by Drs. Arnold Wexler and Richard Hyland of the National Bureau of Standards as part of ASHRAE Research Project 216, "Thermodynamic Properties of Moist Air and Water at Saturation".

A second Research Project entitled 257-RP, "New ASHRAE SI Psychrometric Chart", was completed by Dr. Richard Stewart of the Center for Applied Thermodynamic Studies at the University of Idaho using relationships generated by the previously described study.

This report combines the results of both projects into one document. The first chapter presents as formulae and in tabular form the thermodynamic properties of pure water substance, while the second chapter is an error analysis of this data.

The third chapter presents the thermodynamic properties of dry air and saturated moist air. The fourth chapter integrates the data from the previous chapters into seven psychrometric charts. It also presents the computer program used by calculating the various properties. This volume contains much detail which would not be found in any usual scientific presentation. It is hoped that this information will be helpful to researchers and/or authors in the future.