Refprop 91 Install [new] -

. For those without the full version, a "mini" version was sometimes used as a starter. The Excel Trial

RefProp is a computer program for calculating thermophysical properties of fluids, developed by the National Institute of Standards and Technology (NIST). The software uses a comprehensive database of experimental and predicted data to calculate properties such as density, viscosity, thermal conductivity, and specific heat capacity. RefProp is widely used in various fields, including chemical engineering, mechanical engineering, and materials science.

By default, the installer suggests: C:\Program Files (x86)\REFPROP\ refprop 91 install

| Problem | Possible Cause | Solution | | :--- | :--- | :--- | | (e.g., trying to install v10 but v9.1 remains) | Leftover files from an older incomplete uninstallation | Perform a thorough manual cleanup as detailed in the Pre-Installation section, then reinstall | | Old DLL conflicts | An older REFPROP.DLL from version 7.0 or 8.0 is present in C:\Windows\System32 | Manually search for and delete any REFPROP.DLL in the C:\Windows\System32 folder (be very careful not to delete other system files) | | Excel linking fails | Missing 64-bit DLL or incorrect environment variables | Ensure REFPRP64.dll is in the REFPROP folder. If needed, set the RPprefix environment variable to your REFPROP installation path | | "Flash calculation" errors in mixtures | Using base version 9.1 instead of the updated 9.1.1 | Download and install the free 9.1.1 patch from NIST. Using 9.1 can lead to non-deterministic calculation behaviors | | MATLAB linking fails with "invalid MEX-file" | Using 64-bit MATLAB but missing the 64-bit thunking file | If not using the 9.1.1 patch, manually obtain REFPRP64_thunk_pcwin64.dll and rp_proto64.m and place them in the REFPROP directory |

: Permissions issue with Windows Registry. Solution : Run the installer under the hidden Administrator account. Enable it via: The software uses a comprehensive database of experimental

A: Yes, it supports binary and pseudo-binary mixtures. Use the “Mixture” menu in the GUI or the REFPROPm DLL.

Before beginning the installation, ensure your system meets the following requirements: If needed, set the RPprefix environment variable to

NIST Standard Reference Database 23 (REFPROP) Version: 9.1 Target Audience: Thermophysicists, Chemical Engineers, HVAC&R Engineers Prerequisites: Windows OS (7, 8, 10, or 11), Administrator Rights

Version 9.1, released in 2013, was a significant update. It enhanced most areas of the program, including its graphical interface, Excel spreadsheet integration, FORTRAN core routines, and sample code for other programming languages like C++ and MATLAB.

Press the , type Environment Variables , and select Edit the system environment variables .