: The current industry standard is REFPROP 10.0 .
Version 9.1 was a major release in 2013, but it has since been superseded by Version 10 . While some third-party sites might list "free trials" for 9.1, these are often just installers for the "mini" version or unofficial files that NIST does not support. Why People Still Search for 9.1
If you need a completely free tool capable of handling complex mixtures and fluids not included in Mini-REFPROP, the following open-source alternatives are highly recommended: CoolProp (The Best Free Alternative) refprop 91 free
Many universities and educational institutions have site licenses. If you are a student or a professor, you likely have access to REFPROP through your university’s software portal at no cost to you personally. Check with your IT department or engineering library before attempting to find unauthorized versions online.
You cannot integrate it into Excel or automated scripts; it is for manual lookups only. C. Mini-REFPROP : The current industry standard is REFPROP 10
The REFPROP 9.1 free version is a valuable resource for anyone working with fluids and thermodynamics. Its robust features, comprehensive fluid database, and user-friendly interface make it an excellent choice for a wide range of applications. While limitations exist, the free version still offers significant capabilities for engineering design, research, and education. For those requiring more advanced features or customization, the full commercial version of REFPROP may be necessary. Overall, the REFPROP 9.1 free version is a useful tool that can benefit both individuals and organizations working with fluid thermodynamics.
REFPROP (Reference Fluid Thermodynamic and Transport Properties) is a critical software database developed by the National Institute of Standards and Technology (NIST) . It is the gold standard for engineers and researchers who need accurate thermodynamic properties—such as density, viscosity, enthalpy, and vapor pressure—for pure fluids and mixtures. Why People Still Search for 9
NIST provides a known as mini-REFPROP . While it doesn't include the full library of 147+ fluids, it serves as an excellent entry point for: Students: Perfect for introductory thermodynamics courses.
NIST historically provided a limited "Mini-REFPROP" for educational use, though full version 9.1 functionality typically requires purchase. Free Alternatives to REFPROP
