Contents - Index



R134a provides thermodynamic properties for R134a using the fundamental equation of state developed by R. Tillner-Roth and H.D. Baehr, An International Standard Formulation for the Thermodynamic Properties of 1,1,1,2-Tetrafluoroethane (HFC-134a) for Temperatures from 170 K to 455 K and Pressures up to 70 MPa, J. Phys. Chem, Ref. Data, Vol. 23, No. 5, 1994.


The values of specific enthalpy and entropy are, by default, set to 0 kJ/kg and 0 kJ/kg-K at -40C (and -40F).  Another common reference state is the IIR reference for which h and s are 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.


Viscosity is correlated with a relation developed by:

Marcia Huber, Arno Laesecke, and Richard A. Perkins at NIST-Boulder, submitted in January 2003 to Industrial Engineering and Chemistry Research; 


Liquid phase thermal 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:  230 K to 475 K

Gas-phase thermal conductivity: 230 K to 475 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 


A computationally more efficient but potentially less accurate formulation for R134a properties is available with fluid name R134a_mh.



Fluid Property Information