**R152a**

R152a uses the fundamental equation of state to determine thermodynamic properties developed from the following reference:

"Equation of State from 1-1-DiFluoroethane, R152a", Y. Kim, C. Borgnakke, and R. Sonntag, Intl. Journal of Energy Research, Vol. 21, 575-589, 1997. This equation is valid for temperatures between 213 K and 433 K at pressures up to 20 MPa.

The values of specific enthalpy and entropy are referred to 200 kJ/kg and 1.00 kJ/kg-K, respectively for the state of saturated liquid at 273.15 K.

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.

Krauss, R., Weiss, V.C., Edison, T.A., Sengers, J.V. and Stephan, K.,

"Transport Properties of 1-1-Difluoroethane (R152a), I

ntl. Journal of Thermophysics, Vol. 17, No. 4, 1996, pp. 731-757.

The range of the gas phase data were extended with information from the NIST REFPROP 6 program (M.O. McLinden, S.A. Klein, E.W. Lemmon and A.P. Peskin, Physical and Chemical Properties Division, National Institute of Standards and Technology, Boulder, CO 80303, 1995.)

Gas-phase viscosity: 180 K to 433

Gas-phase thermal conductivity: 180 K to 433 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.