The installation of NIST REFPROP 9.1 (Reference Fluid Thermodynamic and Transport Properties) is a critical step for engineers and researchers who need high-accuracy fluid data. While now superseded by Version 10, Version 9.1 remains a staple in many legacy academic and industrial environments. 1. System Requirements & Preparation
Before beginning, ensure your system meets the baseline requirements for this legacy version:
Operating System: Windows 98, 2000, XP, Vista, 7, 8, or 10 (both 32-bit and 64-bit are supported). Storage: At least 10.0 MB of available hard disk space.
Administrative Rights: You typically need administrator privileges to write to the C:\Program Files\REFPROP directory. 2. Core Installation Steps
The installation process usually follows a standard executable wizard:
Run the Installer: Execute the nist2391.exe (or similar) file provided by NIST.
Default Directory: The program usually installs to C:\Program Files (x86)\REFPROP or C:\Program Files\REFPROP. Crucial: Avoid moving the REFPROP.DLL file to Windows system folders (like System32); it must remain in the application folder with its associated .FLD and .HMX fluid data files.
Registration (Optional): If using the CAPE-OPEN interface or certain COM objects, you may need to manually register the DLL using regsvr32.exe refpropco.dll in a command prompt. 3. Integrating with Excel
One of the most common uses for REFPROP 9.1 is within Microsoft Excel. Proper setup prevents the common #NAME? error.
Trusted Locations: Go to File > Options > Trust Center > Trust Center Settings > Trusted Locations. Add your REFPROP folder (e.g., C:\Program Files\REFPROP) and check "Subfolders of this location are also trusted".
Adding the Add-In: In Excel, go to File > Options > Add-Ins. At the bottom, select "Excel Add-ins" from the Manage dropdown and click Go. Browse to your REFPROP folder and select REFPROP.xlam.
Verify Links: If functions don't work immediately, go to the Data tab, click Edit Links, and ensure the source for the REFPROP add-in points to your local installation folder rather than a temporary or user-specific directory. 4. Troubleshooting Common Issues Potential Solution OCX Errors (339)
Run-time errors like MSHFLXGD.OCX missing often mean a firewall or antivirus blocked the registration of UI components. Missing Fluid Files
If Excel can't find fluid data, copy the *.FLD and HMX.BNC files into a default directory like C:\REFPROP\FLUIDS. Conflicting DLLs
If you previously had Version 7 or 8, search your computer for old Refprop.dll files (especially in System32) and delete them to prevent version conflicts. 64-bit Compatibility
Version 9.1 was the first to automatically include REFPRP64.dll, which is necessary for 64-bit versions of Excel or MATLAB. 5. Moving Forward refprop 91 install
The installation of REFPROP 9.1 (Reference Fluid Properties) follows a specific process depending on whether you are using the standalone program or integrating it with Microsoft Excel. Core Installation Steps
To install the base version of REFPROP 9.1, you typically need the original installation media (CD-ROM) or a digital installer purchased from NIST.
Run the Installer: Execute the nist2391.exe or Setup.exe file from your installation source.
Default Directory: The program usually installs to C:\Program Files\REFPROP (or C:\Program Files (x86)\REFPROP on 64-bit systems).
System Requirements: It is designed for Windows environments; older documentation suggests compatibility back to Windows 95/NT, but it remains functional on modern Windows 10/11 systems with proper user permissions. Linking to Microsoft Excel
Integrating REFPROP 9.1 with Excel is one of its most common uses, allowing you to use thermodynamic functions directly in spreadsheets. Trusted Locations:
Open Excel and go to File > Options > Trust Center > Trust Center Settings.
Under Trusted Locations, click Add new location and browse to your REFPROP folder (e.g., C:\Program Files\REFPROP). Add-in Setup: Go to File > Options > Add-ins.
At the bottom, select Excel Add-ins in the "Manage" box and click Go.
Click Browse and locate the REFPRP91.XLA file in your REFPROP folder. Ensure "Refprp91" is checked in the list. Special Cases: macOS and Version Conflicts
macOS Installation: Installing on Mac requires creating specific directory structures in the Group Containers folder for Office and manually copying fluids, mixtures, and the librefprop.dylib file.
Upgrading to Version 10: If you have REFPROP 10 installed, you can still use the 9.1 interface for backward compatibility. NIST provides a specific REFPRP91.XLA patch to help version 10 users run older spreadsheets without changing formula syntax.
Uninstallation Issues: If an installation fails, ensure you run the unins.exe utility in the REFPROP folder to clear registry entries before attempting a fresh install.
Are you planning to use REFPROP 9.1 primarily for Excel macros or as a standalone GUI for fluid property tables?
REFPROP | NIST - National Institute of Standards and Technology The installation of NIST REFPROP 9
How to Install REFPROP 9.1: A Complete Step-by-Step Guide NIST’s REFPROP (Reference Fluid Thermodynamic and Transport Properties) is the gold standard for researchers and engineers needing accurate thermophysical properties of fluids. While newer versions exist, REFPROP 9.1 remains widely used due to its stability and compatibility with legacy academic and industrial software.
If you are looking to get REFPROP 9.1 up and running on your system, this guide covers the installation process and how to link it with common platforms like Excel, MATLAB, and Python. 1. Prerequisites and System Requirements Before starting, ensure you have the following:
The Installer: REFPROP is a commercial product. You must have the REFPROP91.EXE setup file or the physical media purchased from NIST.
Administrative Rights: You will need permission to write to the C:\Program Files (x86) directory.
Operating System: Windows 7, 8, 10, or 11 (32-bit or 64-bit). 2. Running the Core Installation Launch the Setup: Double-click the REFPROP91.EXE file. License Agreement: Read and accept the NIST license terms.
Destination Folder: By default, the installer suggests C:\Program Files (x86)\REFPROP.
Pro-tip: If you plan on using Python or MATLAB extensively, some users prefer installing to a simpler path like C:\REFPROP to avoid permission issues or "Space in filename" errors in code.
Select Components: Ensure that "Full Installation" is selected so that all fluid files (.fld) and mixture files (.mix) are included.
Finish: Click install. Once finished, you will see a "REFPROP" shortcut on your desktop. 3. Integrating REFPROP 9.1 with Microsoft Excel
Most users utilize REFPROP via the Excel Add-in. Here is how to enable it: Open Excel and go to File > Options > Add-ins.
At the bottom, select Excel Add-ins from the "Manage" dropdown and click Go.
Click Browse and navigate to your installation folder (usually C:\Program Files (x86)\REFPROP). Select REFPROP.xlam (for modern Excel) or REFPROP.xla.
Important: You must also copy the file REFPROP.DLL from the installation folder to your C:\Windows\SysWOW64 directory (for 64-bit Windows) or C:\Windows\System32 (for 32-bit Windows). This allows Excel to "see" the engine. 4. Connecting to MATLAB
To use REFPROP 9.1 in MATLAB, you need a wrapper file (often provided in the MATLAB subfolder of the installation). In MATLAB, use addpath('C:\Program Files (x86)\REFPROP'). Use the refpropm.m function to call properties.
Example: density = refpropm('D', 'T', 300, 'P', 101.325, 'water') Step-by-Step REFPROP 9
Ensure your MATLAB bit-version matches the DLL (use a 64-bit wrapper if using 64-bit MATLAB). 5. Connecting to Python
Python users typically use the ctypes based wrapper or the popular CoolProp interface to call REFPROP.
Via CoolProp: If you have CoolProp installed, you can call REFPROP fluids by setting the "Alternative Path."
Direct Call: You will need to point your script to refprop.dll. Ensure your Python environment is the same "bitness" (32-bit vs 64-bit) as the DLL you are calling. 6. Troubleshooting Common Errors
"File Not Found" for Fluids: This happens if the program doesn't know where the /fluids folder is. Go to the REFPROP GUI, select Options > Paths, and ensure the path points to your installation folder.
DLL Errors in Excel: If you see #NAME? in Excel, it usually means the REFPROP.xlam is active but it cannot find the REFPROP.dll in the Windows system folders.
Permission Denied: If you cannot save changes to fluid mixes, run the REFPROP GUI as an Administrator.
Installing REFPROP 9.1 is straightforward, but the real work lies in the path configurations for your specific external software. Always ensure your .dll files are in a location where your system's PATH environment variable can find them.
Here’s a helpful feature for installing REFPROP 9.1 (assuming you meant version 9.1, since REFPROP 10.x is more common now — but if you meant NIST REFPROP 9.1, the following applies):
Now, let’s walk through the actual refprop 91 install process. I will assume you have a legitimate installer named something like REFPROP91_setup.exe.
You have completed the refprop 91 install – but does it work? Run these checks:
Right-click the setup executable and select Run as Administrator. This ensures the installer can write to protected directories like Program Files and modify system registry keys.
Cause: The license file is in the wrong location or has wrong line endings (Unix vs. Windows).
Solution: Copy the license file directly into C:\Program Files (x86)\REFPROP\. Open it in Notepad, save as plain text with ANSI encoding.
The true power of REFPROP 9.1 lies in its use as a calculation engine for other programs. The installer automatically places the necessary files here:
refpropm.mexw32 and REFPROPn.m are found in the installation folder. Copy these to your MATLAB working directory. Use help refpropm in MATLAB for syntax.=REFPROP("water","T","P",300,101.325,"D") in a cell.REFPROP.DLL is in the same folder as EES.exe or in your system path.