LAXENBURG, Austria, 15 August 2022: A study led by IIASA researcher, Pallav Purohit, in collaboration with researchers from the United Nations Environment Programme and the University of Leeds, showed that by switching to propane, an alternative low (<1) global warming potential refrigerant for space cooling, we could avoid a 0.09 degree C increase in global temperature by the end of the century, thereby making a significant contribution towards keeping the global temperature rise below 1.5 degrees C.

In the study published in Proceedings of the National Academy of Sciences of the United States of America (PNAS), researchers used the IIASA Greenhouse Gas – Air Pollution Interactions and Synergies (GAINS) model to compare the baseline halogenated refrigerant emission scenarii with scenarii of switching to HFC-32 or propane. While the switch to HFC-32 also lessened the global temperature increase (0.03°C by the end of the century), propane proved to be the superior solution in terms of sustainability, according to IIASA.

“Propane exhibits significant environmental advantages through good energy performance and a global warming potential of less than 1,” Purohit said. “In split-ACs, up to 7 kW, propane can be classified as a technically valid alternative to HFC-driven split-ACs.”

Energy-efficient split-ACs, using propane, are already available commercially in the Chinese and Indian markets, IIASA said. Despite performing similarly to split-ACs using HFC-32, and even better than the currently widespread appliances using HFC-410A and HCFC-22, some national regulations prohibit their use, primarily due to standards and codes restricting the use of refrigerants with higher flammability, hindering their wider adoption, IIASA said.

“To achieve the EU’s ambitious 2050 climate-neutrality targets, early and aggressive action is needed,” Purohit said. “In the short term, converting new air conditioning systems to more environmentally friendly refrigerants can reduce their climate impact significantly, underlining the urgency of updating standards for policymakers.”

Reference

Purohit, P., Höglund-Isaksson, L., Borgford-Parnell, N., Klimont, Z., Smith, C.J. (2022). The key role of propane in a sustainable cooling sector. Proceedings of the National Academy of Sciences (PNAS)  119 (34) e2206131119. DOI: 10.1073/pnas.2206131119 [pure.iiasa.ac.at/18153].