Interim And Long-Term Low-GWP Refrigerant Solutions For Air Conditioning

This paper will update on the feasibility status from the global test research efforts for ‘interim’ near drop-in refrigerants with low global warming potential (LGWP) with focus on R410A replacement for Unitary A/C & H/P. R32 and the HFO blends offer near drop-in solutions with a reasonable balance of trade-offs among GWP, efficiency, A2L flammability, and cost after  the building codes are available for commercialization. With the advent of further GWP phase down driven by the December 2015 Climate Change Agreement in Paris coupled with the imminent U.S. EPA SNAP de-listing and the U.S. DOE mandating new higher efficiency standards taking effect in 2020+, there is even more pressure for finding ‘long-term’ refrigerant solutions to meet the 15-20% GWP cap for 2030+ that can sustain efficiency, reduce charge requirement and are affordable. Theoretical and test results from various compressor and system tests with R32 and the HFO blends will be presented as ‘interim’ 2020+ solutions. Long-term 2030+ solutions and their tradeoffs are conceptualized and discussed for typical A/C residential and commercial applications from both GWP and LCCP standpoint including implications on HVAC system architecture.