NIST REFPROP 9.1 is a professional engineering software for calculating the thermodynamic and transport properties of industrially important fluids. It is not a lifestyle or entertainment application. If you have encountered a download link for this software categorized under "lifestyle and entertainment," it is likely a misleading or illegitimate source National Institute of Standards and Technology (.gov) Legitimate Software Overview
Here’s where it gets surprising. REFPROP 9.1 has found its way into in three specific ways: nist refprop 91 download hot
Entertainment has a price. A full commercial license for REFPROP is expensive (hundreds to thousands of dollars). However, for the lifestyle enthusiast, a student evaluation license or a legacy access pass through academic alumni portals is the path of honor. Avoid illegal "warez" sites; they are the antithesis of the NIST ethos (accuracy and traceability). NIST REFPROP 9
NIST REFPROP 9.1 is a legacy version of the Reference Fluid Thermodynamic and Transport Properties Database that has been officially superseded by Version 10 REFPROP 9