Thermophysical Properties of 2,3,3,4,4,4-Hexafluoro-1-butene [R-1336yf]: Measurements and an Equation of State

Published

August 12, 2026

Author(s)

Tara Fortin, Marcia Huber, Andrei Kazakov, Stephanie Outcalt, Aaron Rowane

Abstract

We report thermodynamic property measurements for the refrigerant R-1336yf (2,3,3,4,4,4-hexafluoro-1-butene) which is being considered as a replacement for existing refrigerants. Density (ρ) data were measured in the compressed liquid phase at temperatures from 270 K to 410 K and pressures from 0.5 MPa to 30 MPa. Vapor pressure (p_sat) data were measured from 265 K to 360 K. Speed of sound (w) data were measured in the liquid phase from 230 K to 373 K and pressures up to 10 MPa. Relative combined, expanded (95% confidence level) uncertainties ranged from 0.04 % to 0.18 % for density, from 0.31 % to 0.59 % for vapor pressure, and from 0.27 % to 0.97 % for speed of sound. These data have been used to develop a new equation of state explicit in the Helmholtz energy. The equation of state represents the experimental data with an average absolute relative deviation (AARD) of 0.16 % for density, 1.15 % for vapor pressure, and 0.27 % for speed of sound.

Citation

Technical Note (NIST TN) - 2373

Report Number

2373

NIST Pub Series

Technical Note (NIST TN)

Pub Type

NIST Pubs

Download Paper

https://doi.org/10.6028/NIST.TN.2373

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Keywords

density, equation of state, hydrofluoroolefin, refrigerants, speed of sound, vapor pressure.

Citation

Fortin, T. , Huber, M. , Kazakov, A. , Outcalt, S. and Rowane, A. (2026), Thermophysical Properties of 2,3,3,4,4,4-Hexafluoro-1-butene [R-1336yf]: Measurements and an Equation of State, Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.TN.2373, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=961828 (Accessed August 13, 2026)

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