Evaluation of Refrigerant Mixtures in Three Different Cold Climates Residential Air-Source Heat Pumps (ST-16-006)

This paper addresses the challenge of improving the performance of Heat Pumps (HPs) in cold climate condition by applying refrigerant mixtures. The potential benefits of implementing R32/CO2 zeotropic refrigerant mixtures in three different residential air-source HPs for cold climates is studied. The cases studied are: conventional residential HP, HP with variable mixture control system and HP with variable compressor speed. The seasonal performance of a heating system with these air-source HPs, supplemented with an auxiliary electric heater is studied in the cold climate city of Montreal. To this aim, a detailed screening HP model previously developed is modified and used. The obtained results highlight the potential HP performance improvement of applying refrigerant mixtures.