Nist Refprop 9 May 2026
NIST REFPROP 9 is a widely cited legacy database used for calculating high-accuracy thermodynamic and transport properties of fluids, often employed in cryogenics, power cycles, and aerospace applications. While version 10 is current, version 9 remains critical for validating against established technical reports and in legacy software applications. For more details, visit NIST.
NIST REFPROP 9 is a computer program and database for calculating thermodynamic and transport properties, documented primarily through its official User Guide rather than a single academic paper. It utilizes Helmholtz energy equations of state to model fluid properties, with documentation and citations provided by the National Institute of Standards and Technology. For documentation and technical information, visit the Official NIST REFPROP Page. Answers to Frequently Asked Questions - NIST Pages
What is NIST REFPROP 9?
NIST REFPROP 9 is a software program that implements the most accurate equations of state (EOS) available for a wide range of fluids. Unlike simple lookup tables or ideal gas laws, REFPROP uses complex Helmholtz energy formulations to predict properties across a broad spectrum of temperatures and pressures—including the critical region, two-phase conditions, and cryogenic temperatures. nist refprop 9
What is REFPROP?
Mixture Outputs:
- Vapor fraction.
- Composition of each phase in equilibrium.
- Excess properties (e.g., ( h^E )).
What is NIST REFPROP?
Developed by the National Institute of Standards and Technology (NIST), REFPROP is a computer program that provides tables and plots of thermodynamic and transport properties for a wide variety of fluids and fluid mixtures. NIST REFPROP 9 is a widely cited legacy
4. The Excel Add-In
For many engineers, the most valuable feature of Version 9 was its seamless integration with Microsoft Excel. REFPROP 9 installs as an Excel Add-In, allowing users to call fluid properties directly inside spreadsheet cells using custom formulas (e.g., =RP("TP","D", T, P, Fluid)). This functionality allows for rapid parametric studies and system modeling without learning a complex coding language.
Whether you are a student just learning about equations of state or a seasoned engineer maintaining legacy systems, understanding the capabilities of REFPROP 9 is essential. Vapor fraction
Stick with v9 if: You have legacy code, need only standard refrigerants, or prefer simple interface.
