Finding non-fluorinated alternatives to fluorinated gases used as refrigerants.

Hydrofluorocarbons (HFCs) and so-called hydrofluoroolefins (HFOs) are used as refrigerants in air conditioning, refrigeration, chillers, heat pumps and devices for dehumidification and drying. However, many HFCs, including R-134a and R-125, have a high global warming potential and some of the HFCs and HFOs degrade atmospherically and form trifluoroacetic acid (TFA) as a persistent degradation product. Rising levels of TFA around the globe reveal an urgent need to replace fluorinated refrigerants with non-fluorinated working fluids to avoid direct emissions due to leakage, incorrect loading or removal. It is important, however, also to select refrigerants with high efficiencies to avoid increasing indirect CO