The results of ASHRAE Research Project 743-RP, "Pressure-Enthalpy Graphs for the Alternative Refrigerants R-32, R-123, R-124, R-125, R-134a and R-141b," are summarized. Thermodynamic property formulations selected for this work are reported. All equations of state were converted into a common form, explicit in dimensionless Helmholtz energy. The common functional form allows for property calculation from a core set of previously tested and verified computer subprograms.

The pressure-enthalpy diagrams were drawn using several in-house and commercial software packages. Line weights, graph size, label size and label fonts were selected in consultation with ASHRAE Technical Committee 3.1 members. Final diagrams were printed using a 2400 dpi image setter. The procedure for producing the diagrams is summarized in this report.