Skip to main content
U.S. flag

An official website of the United States government

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.

Options for Low-GWP Refrigerants



Mark O. McLinden, Andrei F. Kazakov, J S. Brown, Riccardo Brignoli, Ian H. Bell, Piotr A. Domanski


We summarize a systematic examination of possible low-GWP (global warming potential) replacements for the HFC (hydrofluorocarbon) refrigerants currently used in small air-conditioning systems. The methodology identified the optimal thermodynamic parameters for a refrigerant; this was based on an ideal- cycle analysis, which indicated a tradeoff between efficiency (COP) and refrigeration capacity depending largely on the refrigerant critical temperature. A more realistic analysis, which included an optimization of the heat exchangers, however, revealed that there was a maximum in COP at a relatively high refrigeration capacity, corresponding to refrigerants with a relatively low critical temperature and operating at moderately high pressures. A search in an exhaustive chemical database for fluids having the identified thermodynamic parameters as well as acceptable chemical stability, toxicity, and GWP identified a list of 28 candidate refrigerants. But none of these are a direct, nonflammable, low-GWP replacement for the R-410A currently used in the majority of small air- conditioning systems.
Proceedings Title
Proceedings of the Institute of Refrigeration
Conference Dates
November 6, 2019
Conference Location


GWP, Hydrofluoroolefins, Refrigerants, Refrigeration Cycle, Thermodynamic Properties


McLinden, M. , Kazakov, A. , Brown, J. , Brignoli, R. , Bell, I. and Domanski, P. (2019), Options for Low-GWP Refrigerants, Proceedings of the Institute of Refrigeration, London, -1, [online], (Accessed June 17, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created November 5, 2019, Updated July 8, 2020