The REFPROP 9.1 free version offers several key features:
“It begins with a search for free software and ends with a corrupted hard drive — or a polite reminder that NIST’s work supports global refrigeration standards, and pirating it only hurts the science.” refprop 91 free
Works with Python, C++, Excel, MATLAB, and Mathcad. The REFPROP 9
Before you risk your computer or career on a questionable "refprop 91 free" link, consider these alternatives. It is completely free for both academic and
CoolProp is the most prominent open-source alternative to REFPROP. It is completely free for both academic and commercial applications.
For some niche mixtures or extremely high-precision research, NIST’s proprietary models are still considered the "gold standard." B. NIST Webbook (Online Access)
NIST offers heavily discounted student and institutional licensing for universities. Check with your department to see if a site license is already available.