mini-REFPROP - Version 9.5

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 version here is now based on Refprop 10, and was initially built and placed here on May 14, 2019. This original version is in a beta stage and labeled 9.5 until such time as we feel that it is working properly. Once done, the official mini-Refprop installer will be placed here and labeled as version 10. The 9.5 beta version is set to expire at the end of 2019, so please bookmark this page so that you can obtain the official version once it has been released.

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: May 14, 2019