**R455A**

R455A (also known as Honeywell Solstice) is a zeotropic mixture consisting of 75.5 weight% R1234yf, 21.5% R32 and 3% CO2. It is considered to be a replacement fluid for R404A.. It has a molar mass of 87.5 kg/kmol.

Thermodynamic data for R455A are provided using a pseudo-pure fluid model in the manner described by:

E. Lemmon

"Pseudo-Pure Fluid Equations of State for the Refrigerant Blends R-410A, R-404A,R-507A, and R-407C"

International Journal of Thermophysics, Vol. 24, No. 4, July 2003

The generalized equation of state was fitted by F-Chart Software using thermodynamic property data provided by the REFPROP 10 program. The reference state for enthalpy and entropy is the IIR recommendation in which the specific enthalpy and entropy of saturated liquid are 200 kJ/kg and 1.0 kJ/kg-K, respectively. The model is applicable for temperatures between 220 K and 420 K with pressures up to 50 MPa.

Transport properties are estimated using data from the manufacturer and a corresponding states approach as suggested in:

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