**R1234yf**

R1234yf provides thermodynamic and transport property data for HFO-1234yf (2,3,3,3-tetrafluoropropene, MW 114.04116 g/gmole). The thermodynamic properties are based on the information provided in

Markus Richter, Mark O. McLinden, and Eric W. Lemmon

"Thermodynamic Properties of 2,3,3,3-Tetrafluoroprop-1-ene (R1234yf): Vapor Pressure and p-rho-T Measurements and an Equation of State"

*Journal of Chemical and Engineering Data*, 2011, 56, 3254-3264

The equation of state is valid for temperatures ranging from 220 K to 410 K at pressures up to 30 MPa. Enthalpy and entropy values are referenced to 200 kJ/kg and 1 kJ/kg-K respectively for saturated liquid at 273.15 K.

__Viscosity__

Viscosity is determined using the information from:

Huber, M.L., and Assael, M.J.,

"Correlations for the viscosity of 2,3,3,3-tetrafluoroprop-1-ene (R1234yf) and trans-1,3,3,3-tetrafluoropropene (R1234ze(E))"

*Int. J. of Refrigeration*, Vol 21, pp. 39-45, (2016)

__Thermal Conductivity__

Thermal Conductivity is obtained from the correlation provided by:

Perkins, R.A. and Huber, M.L, "Measurement and Correlation of the Thermal Conductivity of 2,3,3,3-Tetrafluorprop-1-end (R1234yf) and trans-1,3,3,3-Tetrafluoropropene (R1234ze(E))

J. of Chemical & Engineering Data, 56, 2011, pp. 4868-4874.

Note that the critical enhancement contribution is not implemented.

__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

Note: R1234yf replaces an earlier (less accurate) formulation which has been renamed to R1234yf_mh. R1234yf_mh has been retained for backward compatibility reasons.