**R32**

The thermodynamic properties of refrigerant R32 are provided using the fundamental equation state described by R. Tillner-Roth and A. Yokozeki, *"An International Standard Formulation for Difluoromethane (R-32) for Temperatures from the Triple Point at 136.34 K to 435 K and Pressures up to 70 MPa", *J. Phys. Chem. Ref. Data, Vol. 26, No. 6, 1997.

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.

__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",

IJR, Vol. 22, pp. 525-535, 1999.

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

Gas-phase viscosity: 190 K to 350 K

Gas-phase thermal conductivity: 190 K to 350 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.