It is estimated that over 95% of the air conditioned passenger rail equipment in the U.S. uses HCFC-22 Refrigerant (R-22), yet the USEPA has recently accelerated R-22's phase out schedule because of R-22's Ozone Depletion Potential (ODP). EPA has approved a list of suitable alternative refrigerants (refer to EPA's SNAP list for MVAC Class II refrigerants) that have been approved for end use in Buses and Passenger Trains.
All of these approved substitutes for R-22 in new or existing equipment are HFC compounds or HFC blends which all carry significant Global Warming Potential (GWP) values. It is suspected that the US may soon follow Europe's lead in the phaseout/ban of HFC refrigerants; which, if not carefully considered, could lead to NO EPA acceptable alternative refrigerants for new A/C systems or existing R-22 based systems.
What are the rail system and supply industry thoughts on these issues?