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.
Evaluation of binary and ternary refrigerant blends as replacements for R134a in an air-conditioning system
Published
Author(s)
Ian H. Bell, Piotr A. Domanski, Gregory T. Linteris, Mark O. McLinden
Abstract
We investigate refrigerant blends as possible low-GWP (global warming potential) alternatives for R134a in an air-conditioning application. We carried out an exhaustive screening of the binary and ternary blends possible among a list of 10 pure refrigerants comprising three hydrofluoroolefins (HFOs), six hydrofluorocarbons (HFCs), and carbon dioxide. The screening was based on a simplified cycle model, but with the inclusion of pressure drops in the evaporator and condenser. The metrics for the evaluation were nonflammability, low-GWP, high COP (coefficient of performance), and a volumetric capacity similar to the R134a baseline system. While no mixture was ideal in all regards, we identified 12 ``best" blends that were nonflammable (based on a new estimation method by Linteris, et al., presented in a companion paper at this conference) and with COP and capacity similar to the R134a baseline; the tradeoff, however, was a reduction in GWP of, at most, 56\% compared to R134a. An additional seven blends that were estimated to be ``marginally flammable" (ASHRAE Standard 34 classification of A2L) were identified with GWP reductions of as much as 90\%. These 17 ``best" blends were then simulated in a more detailed cycle model.
Proceedings Title
17th International Refrigeration and Air Conditioning Conference at Purdue, July 9-12, 2018
Bell, I.
, Domanski, P.
, Linteris, G.
and McLinden, M.
(2018),
Evaluation of binary and ternary refrigerant blends as replacements for R134a in an air-conditioning system, 17th International Refrigeration and Air Conditioning Conference at Purdue, July 9-12, 2018, West Lafayette, IN, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=925576
(Accessed October 14, 2025)