mini-REFPROP - Version 10.0

The mini-REFPROP program is a free sample version of the full REFPROP program (located at and is meant for use as a teaching tool in the introduction of thermodynamics to students. It contains a limited number of pure fluids (water, CO2, R134a, nitrogen, oxygen, methane, propane, helium, hydrogen, and dodecane), along with air as a pseudo-pure fluid. It also allows mixture calculations of a 50/50 molar mix of nitrogen and methane or of a 79/21 molar mix of nitrogen and oxygen for teaching vapor-liquid equilibrium (VLE). Please note carefully that the 79/21 N2/O2 mixture is not meant for air calculations, but as a teaching tool to study composition changes as the mixture passes through the two phase. For actual air properties, please select Substance/Pseudo-Pure Fluid/Air when running the GUI.

To install the program, right-click on the file below and select "Save Target As..." Place this file in a temporary directory (which is not labeled Refprop), then run the executable to install mini-REFPROP to your harddrive.

The executable for Version 10 of mini-Refprop was set to expire on Dec. 31, 2019. If your version no longer works, please download the exe below and place it in your mini-Refprop directory AFTER you have installed the program from the setup file above. This version does not expire, but may contain new bugs. If you find them, please report them to us. (

Unfortunately, because there is no charge for the mini-Refprop software, we are not able to provide technical support due to the limited number of staff available at NIST in the thermophysical properties division. Support is available only with the full version.

Last updated: Feb. 5, 2020