Title: A study on the use of propane (R-290) in vending machines as a substitute for R-134a to minimise the global warming potential

Authors: Khaled A. Alkhaledi; Kenneth Means

Addresses: Department of Industrial and Management Systems Engineering, Kuwait University, P.O. Box 5969, Safat – 13060, Kuwait ' Department of Mechanical and Aerospace Engineering, West Virginia University, Engineering Science Building 335, P.O. Box 6106, Morgantown, WV 26506-6106, USA

Abstract: The refrigerant R-134a is widely used in vending machines, and it is a greenhouse gas with high global warming potential. The United States Environmental Protection Agency has mandated that R-134a be replaced with an environmentally friendly refrigerant. In this study, we compared the performance and safety of R-290 as a substitute for R-134a in vending machines. We compared the two refrigerants in a vending machine equipped with a single-stage compressor, four thermocouples, and a data log recorder. Our results demonstrate that R-290 performs as well as R-134a; in addition, it uses 31.4% less energy and 60% less refrigerant. The evaporator and condenser temperatures for R-290 were comparable to those for R-134a. Therefore, we conclude that R-290 is an excellent replacement for R-134a. In addition, R-134a's global warming potential is 1300, while R-290's global warming potential is 3, and its ozone depletion potential is zero. Finally, R-290 can be used safely and complies with Underwriter Laboratory^® safety standards.

Keywords: global warming potential; GWP; greenhouse gas; R-134a refrigerant; propane (R-290) refrigerant; vending machines.

DOI: 10.1504/IJGW.2018.088650

International Journal of Global Warming, 2018 Vol.14 No.1, pp.131 - 141

Received: 29 Jun 2015
Accepted: 17 Feb 2016
Published online: 14 Dec 2017 *

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