REFPROP 10 (Reference Fluid Thermodynamic and Transport Properties) is the gold standard for researchers and engineers needing high-accuracy thermophysical property data for fluids. Version 10, released by NIST, introduced significant improvements over previous versions, including new equations of state and expanded fluid mixtures. Because it is a highly specialized, proprietary software developed by the National Institute of Standards and Technology, it is not available as a free download.

This write-up summarizes what REFPROP is, the legal and practical considerations around obtaining it, why searching for a “free download” (especially for a specific year like 2021) is problematic, and recommended legitimate options.

Key 2021 Update Info

: While REFPROP 10 was released in 2018, its official documentation and FAQ were significantly updated on March 29, 2021 . This update introduced better Excel examples, optimized Fortran code for speed, and expanded fluid data for refrigerants like R1123 and R1233zd(E). REFPROP | NIST

REFPROP

(Reference Fluid Thermodynamic and Transport Properties) is proprietary software developed by the National Institute of Standards and Technology (NIST) . It is not legally available as a free download, especially not for the 2021 version (REFPROP 10.0). NIST provides a free evaluation version with limited fluid packages, but full versions require a paid license.

CanteraCantera is an open-source suite of tools for problems involving chemical kinetics, thermodynamics, and transport processes. It is highly favored in combustion research and complex fluid systems. How to Legally Access REFPROP

Alternative Sources for Refprop 10 Free Download