For proper charging, performance and energy efficiency of the machinery, it is important that the property tables used are accurate. Variations in dew point temperatures from different sources are of order of 5 to 7 F. Such large differences are unacceptable.

In an effort to standardize data, the refrigerant industry and ASHRAE TC 3.1 is moving towards using REFPROP 6.0 as the thermodynamic property reference database. However the properties of these widely used refrigerants found in the manufacturers’ bulletins are very different from what is currently in the REFPROP database. Additional experimental data are required to resolve these differences.

The objective of this research is to provide critically evaluated accurate thermodynamic property data on some key HCFC refrigerant mixtures that are in wide use today (R-401, R-402 and R-409 series). This is to be achieved through:

1. Measuring the vapor-liquid equilibrium properties of selected compositions of these blends between 30 C to 50 C.
2. Critical evaluation of the measured data along with data on these systems from the literature and any other sources willing to share data. The investigator will then fit the data to the mixture model used in REFPROP 6.0 in order to obtain the interaction parameters.
3. Preparation of tables of saturation properties suitable for publication as a stand-alone properties pamphlet and as an article to ASHRAE Journal. These data are also expected be incorporated into the 2005 update of the Handbook of Fundamentals, but that task is outside the scope of the present project.