New Copper-based Heat Exchangers for Alternative Refrigerants

The ongoing global effort to replace current refrigerants with zero Ozone Depletion Potential (ODP) and virtually zero Global Warming Potential (GWP) refrigerants has important implications for heat exchangers, air conditioning system design, and the materials choices in these designs. Natural refrigerants with higher flammability, CO2, HFOs, and HFC – HFO blends each place different requirements on the heat exchanger design, whether it be for higher equipment efficiency, to reduce refrigerant charge, to operate to much higher operating pressures or temperatures, to prevent corrosion or to avoid leakage. This paper presents critical information on how heat exchangers based on round inner-grooved small-diameter copper tube and newly-developed flat copper microchannel tube can be applied in air conditioning equipment using new alternative refrigerants. These technologies have synergies with key refrigerant performance characteristics enabling multiple application opportunities, and they address operating energy efficiency degradation from mold growth on total Life Cycle Climate Performance (LCCP).