EPA to Sponsor Low Global Warming Air-Conditioning Project

18 April 2007

The US Environmental Protection Agency (EPA) will sponsor a demonstration project for R-152a, a refrigerant for mobile air conditioners with lower global warming potential (GWP) than R-134a.

Kristen Taddonio, EPA Strategic Climate Manager, made the announcement during the SAE World Congress in Detroit.

R-152a has a GWP of 120 which is about 94% less than R134a (GWP = 1,300). In addition to lower GWP, R-152a has better thermal efficiency. With improved thermal efficiency, a lower system charge may be used in a direct expansion system to achieve satisfactory cabin cooling.

The main drawback of R-152a is that it is flammable and thermally decomposes to highly toxic HF (Hydrogen Fluoride) if exposed to a glowing filament. In liquid form, it can be ignited with open flame and therefore may pose some hazard to occupants. If it is used in the cooling circuit in the cabin, a system using sensors and safety releases must be included to guard against unwanted discharge.

Participants in the EPA project include SAE, Delphi, GM, Ford, Volvo, Fiat, the Mobile A/C Society and NREL.

Resources:

• Review and analysis of the reduction potential and costs of technological and other measures to reduce CO2-emissions from passenger cars (EC Report)