R-152a Refrigeration System for Mobile Air Conditioning

In recent years, climate protection has become as important as ozone layer protection was in the late 1980's and early 1990s. Concerns about global warming and climate change have culminated in the Kyoto Protocol, a treaty requiring its signatories to limit their total emission of greenhouse gases to pre-1990 levels by 2008. The inclusion of hydrofluorocarbons (HFCs) as one of the controlled substances in the Kyoto Protocol has increased global scrutiny of the global warming impact of HFC-134a (called R-134a when used as a refrigerant), the current mobile air conditioning refrigerant. Industry's first response was to begin improving current R-134a systems to reduce leakage, reduce charge, and increase system energy efficiency, which in turn reduces tailpipe CO₂ emissions. An additional option would be to replace the current R-134a with a refrigerant of lower global warming impact. This paper documents the use of another HFC, R-152a, in a mobile A/C system. It compares its cooling and energy performance with that of a comparable R-134a system. This paper also highlights the environmental benefit of R-152a and pinpoints safety issues that need to be addressed in the future.