Add your installation path to the existing Path variable to ensure Excel can always locate the required DLLs ( REFPROP.DLL or REFPRP64.DLL ). 4. Common Troubleshooting Answers to Frequently Asked Questions - NIST Pages
Click Install , wait for the progress bar to finish, and click Finish . Step 2: Configuring System Environment Variables
Tip: If you plan to interface REFPROP with Python, MATLAB, or Excel, consider changing this path to a simple, space-free directory like C:\REFPROP . This prevents file path syntax errors in external code. Step 4: Choose Components Ensure all components are selected, including: Core fluid files ( .FLD and .MIX ) Graphical User Interface (GUI) executable Help documentation and sample files refprop 91 install
A very common problem is that when users attempt to upgrade from an older version (like 9.1) to a newer one (like 10.0), the new installer fails or the new version is not functional.
The easiest way to use REFPROP 9.1 in Python is via the wrapper library ctypes or through the wrapper package ctREFPROP provided by NIST on GitHub. Add your installation path to the existing Path
Restart your computer if the installer prompts you to do so. 💻 Linking REFPROP to Other Software
[Pressure, Density] = refpropm('PD', 'T', 300, 'Q', 0, 'Water'); Use code with caution. Microsoft Excel Integration Open Excel and navigate to -> Options -> Add-ins . Step 2: Configuring System Environment Variables Tip: If
Step 1: Accept the agreement. The license text was long but familiar; I skimmed for the lines that mattered and clicked Accept. The installer asked where to place the files. Default was fine — C:\Program Files (x86)\REFPROP. I imagined folders stacking like neatly labeled canisters: mixture models, vapor tables, DLLs that would later answer frantic calls from MATLAB.
The calling software (e.g., 64-bit Python) is trying to access a 32-bit DLL, or the system path is missing.
Follow these steps to install the standalone REFPROP application on a Windows machine. Step 1: Run the Installer Locate your downloaded REFPROP91.EXE file. Right-click the file and select . If prompted by User Account Control (UAC), click Yes . Step 2: Navigate the Setup Wizard Welcome Screen: Click Next to begin.