REFPROP revision control method.

NIST released REFPROP v10 in June 2018, but no new version has been released in nearly seven years. Since that time, updated properties for numerous refrigerants have been made available from peer-reviewed publications, both equation of state models and interaction parameters for mixture models. NIST made some of these available on the Frequently Asked Questions web page in October 2024. While this provides users with a means to use updated properties that have been vetted by NIST, some users may now have the dilemma of how to manage “old” and “new” properties. REFPROP does not have revision control functionality at the fluid level, independent of the software version. A method is presented that allows users to utilize both “old” and “new” properties within REFPROP and a means to document the source, through a file naming convention and a few tweaks to the *.FLD, *.MIX, and HMX.BNC files.