Released by NIST to accurately calculate fluid behavior across liquid, gas, and supercritical phases, REFPROP 9.1 relies on highly precise, mathematically intensive Helmholtz energy equations of state. mini-REFPROP - Version 10.0
Options are available for corporate or academic institutions, with pricing based on the number of users. 3. Key Features of REFPROP 9.1
Software fees fund equations of state updates.
This specific version includes several technical enhancements over its predecessors: refprop 91 free
Download the official, secure installer directly from the NIST repository.
While you may find links claiming “REFPROP 9.1 free,” they are unauthorized copies. For legitimate engineering work, consider using (free, open-source) or purchasing the latest REFPROP from NIST. If you need help setting up CoolProp or using NIST’s free online tools, I’m happy to provide a guide.
The most prominent example is CoolProp. CoolProp is an open-source thermodynamic database that matches the high-accuracy equations of state found in REFPROP. Crucially, CoolProp is free to use and easily integrates with Python, MATLAB, Excel, and other platforms. For the vast majority of users seeking a "free" solution, CoolProp offers comparable accuracy to REFPROP 9.1 without the legal and security risks associated with pirated software. It represents the democratization of thermodynamic data, ensuring that financial constraints do not impede scientific progress. Released by NIST to accurately calculate fluid behavior
You do not need to risk using pirated software. NIST and the open-source community provide several legal, free alternatives to access the REFPROP database. 1. NIST Webbook (Free Online Access)
The engineering community thrives on accuracy and reliability. NIST REFPROP costs money because maintaining the International Association for the Properties of Water and Steam (IAPWS) formulations and GERG-2008 mixtures requires expensive research.
: It includes properties for a restricted set of substances, typically water, CO2cap C cap O sub 2 R134acap R 134 a , nitrogen, methane, propane, hydrogen, and dodecane. Key Features of REFPROP 9
Because it integrates seamlessly with Excel, MATLAB, LabVIEW, and Python, many legacy workflows in engineering firms and academic labs were built specifically around the REFPROP 9.1 architecture. The Reality Behind "Free Download" Links
: The current version has superseded 9.1. It includes 147 pure fluids and significantly optimized Fortran code for faster calculations and better convergence.