Changing rules around the use of highglobal warming potential (GWP) refrigerants have been one of the hottest topicsin the HVAC&R industry in the last few years. Following the phaseout ofozone-depleting refrigerants starting in the 1990s, the U.S. EPA, acting underthe Significant New Alternatives Policy (SNAP) program, has recently changedthe status of certain high GWP refrigerants. In the next several years,refrigerants such as R-404A, R-507A, R-134a, and others will be prohibited foruse in some types of new or retrofit commercial refrigeration installations.