Nist Refprop 9

If you are still using REFPROP 9 (or maintaining legacy systems), these tips will maximize your productivity:

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.

hfile = c_char_p(b"REFPROP.txt") herr = c_char_p(b" ") ncomp = c_int(1) icomp = (c_int * 1)(1) # R134a index x = (c_double * 1)(1.0) RP.SETUPdll(hfile, herr) RP.SETREFdll(icomp, x, herr) # Set reference state nist refprop 9

Unlike many academic calculators, REFPROP 9 was designed for integration. It includes:

This made REFPROP 9 the backbone of many larger simulation environments, including Aspen Plus, EES (Engineering Equation Solver), and Dymola. If you are still using REFPROP 9 (or

| 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. This made REFPROP 9 the backbone of many

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