NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Mixture Models for Refrigerants R-1234yf/134a, R-1234yf/1234ze(E), and R-134a/1234ze(E) and Interim Models for R-125/1234yf, R-1234ze(E)/227ea, and R-1234yf/152a
Published
Author(s)
Ian Bell
Abstract
In this work, new thermodynamic models for refrigerant mixtures are provided for the binary pairs R-1234yf/134a, R-1234yf/1234ze(E), and R-134a/1234ze(E) based on new reference measurements of speed of sound, density, and bubble-point pressures. Fitting the very accurate liquid-phase speed of sound and density data reproduces the bubble-point pressures to within close to their uncertainty, yielding deviations in density less than 0.1% and speed of sound deviations less than 1% (and less than 0.1% for R-1234yf/134a). Models are also presented for the binary pairs R-125/1234yf, R-1234ze(E)/227ea, and R-1234yf/152a based solely on bubble-point measurements.
Bell, I.
(2022),
Mixture Models for Refrigerants R-1234yf/134a, R-1234yf/1234ze(E), and R-134a/1234ze(E) and Interim Models for R-125/1234yf, R-1234ze(E)/227ea, and R-1234yf/152a, J. Phys. & Chem. Ref. Data (JPCRD), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.1063/5.0086060, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933859
(Accessed October 13, 2025)