**R22**

Fluid R22 implements the thermodynamic properties of refrigerant R22 using the fundamental equation state described by Wagner, W., Marx, V., Prob, A., "A New Equation of State for Chlorodifluoromethane covering the entire fluid region from 116 K to 550 K at pressures up to 200 MPa, *Int. J. Refrig*, 16:373, 1993.

The values of specific enthalpy and entropy are, by default, referred to 200 kJ/kg and 1.00 kJ/kg-K, respectively for the state of saturated liquid at 273.15 K. The reference state can be changed using the $Reference directive.

__Transport Properties:__

Liquid phase viscosity and conductivity data are from the generalized correlation described by:

M.J. Assael, N.K. Dalaouti, A.A. Griva, and J.H. Dymond

"Viscosity and Thermal Conductivity of Halogenated Methane and Ethane Refrigerants"

*Int. J. Refrig,* Vol. 22, pp. 525-535, 1999.

These property correlations are applicable over the same range as the equation of state.

Gas-phase viscosity: 230 K to 440 K

Gas-phase thermal conductivity: 230 K to 645 K

__Surface tension data are provided using the information in:__

Mulero, A., Cachadina, I, and Parra, M.

"Recommended Correlations for the Surface Tension of Common Fluids"

*J.Phys. Chem Ref. Data*, Vol. 41, No.4, 2012