**R457A**

R457A is an zeotropic mixture consisting of 70 weight% R1234yf, 18% R32, and 12% R152a. It is considered to be a replacement fluid for R22. It has a molar mass of 87.60 kg/kmol.

Property data for R457A are provided using a generalized equation of state fitted by F-Chart Software using thermodynamic property data generated by REFPROP. The model is applicable for temperatures between 180 K and 420 K with pressures up to 20 MPa. The reference state is saturated liquid at 0 C for which specific enthalpy and entropy are 200 kJ/kg and 1.0 kJ/kg-K, respectively.

__Transport Data__

The viscosity and thermal conductivity were estimated using the corresponding states approach described the following references with propane as the reference fluid.

Klein, S.A., McLinden, M.O., and Laesecke , A.,

"An improved extended corresponding states method for estimation of viscosity of pure refrigerants and mixtures",

*Int. J. of Refrigeration*, 20, pp. 208-217, 1997

McLinden et al.,

"An extended corresponding states model for the thermal conductivity of refrigerants and refrigerant mixtures",

*Int. J. of Refrigeration*, 23, pp. 43-63, 2000

The correlation are valid over the same range of temperature as the equation of state.

Surface tension data were fit to data obtained from the REFPROP.