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Mark O. McLinden, Andrei F. Kazakov, J S. Brown, Riccardo Brignoli, Ian H. Bell, Piotr A. Domanski
Abstract
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.
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], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=928908
(Accessed October 9, 2025)