Refprop 9.1 //free\\ Jun 2026

Prior to version 9.0, mixture calculations relied on mixing rules (like van der Waals or Wong-Sandler). REFPROP 9.1 fully leverages the . This multi-parameter EOS was developed by the European Research Group on Gas (GERG) and is valid for natural gas mixtures and hydrocarbon refrigerants. It covers components such as methane, nitrogen, carbon dioxide, ethane, propane, and many more with unprecedented accuracy—often within ±0.1% for density in the gas phase.

It added support for hydrofluoroolefins (HFOs) like R1234yf and R1234ze(E) , which are vital for low-GWP (Global Warming Potential) applications. Software Integration

If you are looking for a topic for a new paper involving REFPROP 9.1, the software is most commonly used for: Refrigerant Performance refprop 9.1

To use the DLL in external programs, the installer registers REFPROP.DLL (32-bit) or REFPROP64.DLL . Users must set the environment variable REFPROP_PATH to the installation folder (e.g., C:\Program Files (x86)\REFPROP ). This is a common stumbling block—failure to set the path results in "DLL not found" errors.

: Calculation of 49 thermophysical properties for 100+ pure substances and 145+ mixtures. Phase Diagrams : Automated generation of T-s, P-h, and T-p diagrams. Advanced Models : Implementation of the model for natural gas and the model for natural gas calculations. Current Status Please note that Version 9.1 has been superseded by Version 10.0 Prior to version 9

A common question is: Why not just use the newest version?

REFPROP 9.1 is designed to be highly accessible beyond its graphical user interface (GUI): It covers components such as methane, nitrogen, carbon

ORC systems use organic fluids (like R245fa or R1233zd) to generate power from low-temperature heat sources (solar, geothermal, industrial waste heat). REFPROP 9.1 provides the precise superheated vapor properties and two-phase expansion behavior needed to optimize turbine inlet conditions.