Nist Refprop 9 🆕 No Sign-up

| Problem | Solution | |---------|----------| | "Fluid not found" | Check fluid name spelling (e.g., R134a not 134a). Use Fluids → List. | | Mixture phase error | Ensure T,P are within envelope; use Calculate → Phase boundary first. | | DLL not loading in Python | Run 32-bit Python, set working directory to REFPROP folder. | | Plot window blank | Save data to .txt first, then plot in Excel/origin. | | License error | Reinstall refprop.lic; ensure path has no spaces. |

NIST REFPROP 9 remains a respected tool in thermodynamics and fluid property calculation. While newer versions exist, version 9's reliability, broad fluid coverage, and programming interfaces make it a solid choice for many engineering projects, especially those requiring verified refrigerant and mixture data.

If accuracy in thermophysical properties is critical to your work — REFPROP is the benchmark.

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 9.0 (REFerence PROPerties) is a legacy version of the industry-standard software developed by the National Institute of Standards and Technology (

) for calculating the thermophysical properties of fluids. While newer versions (like REFPROP 10) are currently available, Version 9.0 remains widely cited in research for its accurate modeling of refrigerants, industrial chemicals, and natural gas mixtures. National Institute of Standards and Technology (.gov) Key Features of REFPROP 9 Property Calculations

: It provides high-accuracy data for thermodynamic properties (density, enthalpy, entropy) and transport properties (viscosity, thermal conductivity). Phase Coverage

: Supports calculations across liquid, gas, and supercritical phases, as well as subcooled and metastable regions. Fluid Support

: Includes models for pure fluids and complex multi-component mixtures. Integration

: Commonly used as an Excel add-on or linked with engineering software like MATLAB and ANSYS for cycle design and numerical simulations. National Institute of Standards and Technology (.gov) Common Applications nist refprop 9

NIST REFPROP 9 (REference Fluid PROPerties) is a standard reference database developed by the National Institute of Standards and Technology (NIST) to calculate the thermophysical properties of industrially important fluids and their mixtures. Released in 2010 (v9.0) and updated in 2013 (v9.1), it is a critical tool for researchers and engineers in refrigeration, natural gas, and chemical processing. Core Capabilities

The software provides highly accurate calculations for a wide range of properties over various conditions (liquid, gas, and supercritical phases):

Thermodynamic Properties: Pressure, temperature, density, enthalpy, entropy, heat capacity, and speed of sound. Transport Properties: Viscosity and thermal conductivity.

Phase Equilibrium: Calculations for vapor-liquid (VLE), liquid-liquid, and solid-liquid systems.

Specialized Models: Implements high-accuracy Helmholtz energy equations, the GERG-2008 model for natural gas, and the AGA8 equation. Fluid and Mixture Library

REFPROP 9 significantly expanded the database from previous versions:

Pure Fluids: Includes 105 to 121 pure fluids, covering HFCs, CFCs, "natural" refrigerants (like ammonia and CO2), hydrocarbons, cryogens (like helium and nitrogen), and water.

Mixtures: Supports over 200 predefined mixtures (e.g., R410A, air) and allows users to define custom mixtures with up to 20 components. Software Features & Access

The program is designed for versatility across different technical environments: | Problem | Solution | |---------|----------| | "Fluid

NIST REFPROP 9 (REFerence PROPerties) is a premier software program and database developed by the National Institute of Standards and Technology (NIST) for calculating the thermodynamic and transport properties of industrially important fluids and their mixtures. Released originally in 2010, Version 9.0 (and its 2013 update, 9.1) remains a critical standard in engineering, research, and academia for its high-accuracy property modeling. Key Features of NIST REFPROP 9

NIST REFPROP 9 provides a comprehensive suite of tools for thermophysical property prediction across a wide range of fluid conditions, including liquid, gas, and supercritical phases.

Extensive Fluid Library: Includes 105 pure fluids and 5 pseudo-pure fluids (like air), allowing for the creation of mixtures with up to 20 components.

Property Calculations: It predicts over 40 properties, such as density, enthalpy, entropy, heat capacity, viscosity, thermal conductivity, surface tension, and speed of sound.

Advanced Modeling: Uses high-accuracy Helmholtz energy equations of state (EOS), the modified Benedict-Webb-Rubin (MBWR) EOS, and extended corresponding states (ECS) models for fluids with limited data.

Phase Equilibrium: Capable of calculating vapor-liquid, liquid-liquid, and solid-liquid systems.

Interoperability: Beyond its graphical user interface (GUI), it is accessible via an Excel spreadsheet add-in, FORTRAN DLL, and sample code for Python, C++, and MATLAB. Industry Applications

The precision of REFPROP 9 makes it indispensable across several high-stakes engineering sectors: IJoT Author Guidelines - DergiPark

For mixtures not explicitly calibrated (e.g., a proprietary blend), REFPROP 9 uses a mixing rule for viscosity. Always validate against a single experimental data point if possible, or simply note the increased uncertainty in your reports. NIST REFPROP 9 remains a respected tool in

For a given state (e.g., temperature and pressure), REFPROP 9 calculates:

Engineers designing compressors, expansion valves, and heat exchangers use REFPROP 9 to model the exact refrigerant behavior. For example, calculating the isentropic efficiency of a compressor requires precise entropy values at the inlet and outlet. Using REFPROP 9 reduces design margin risks from 10% (using ideal gas tables) to under 1%.

The GUI in v9 is menu-driven with separate windows for:

| Feature | REFPROP 8 | REFPROP 9 | |--------|-----------|-----------| | Fluids | ~105 | 120+ | | Mixture model | Mostly mixing rules | GERG-2008 added | | GUI | Basic | Improved interface | | HFOs | Few | R1234yf, R1234ze(E) | | Transport props | Limited | Expanded models | | 64-bit support | No | Yes |

Note: REFPROP 10.0 is now available (2023+), but version 9 remains widely used due to licensing and compatibility in legacy systems.

| Feature | REFPROP 9 | REFPROP 10+ | |---------|-----------|--------------| | GUI | Classic, functional | Modern, tabbed | | Fluids | ~105 | ~150+ | | Mixture model | GERG-2008 | GERG-2008, EOS-CG, others | | Python support | Manual DLL | Official refprop Python package | | Plotting | Basic 2D | Enhanced 2D + 3D | | Cost | One-time purchase (legacy) | Subscription or perpetual |

Stick with v9 if: You have legacy code, need only standard refrigerants, or prefer simple interface.

Upgrade to v10+ if: You need new fluids (R1234yf, low-GWP), better mixture handling, or Python integration.