Performance assessment of an R32 commercial heat pump water heater in different climates

This study evaluates the performance of a heat pump water heater (HPWH) that uses low-global warming refrigerant in several climatic conditions. The performance assessment methodology adopted was based on the development and validation of a numerical simulator for the assessment of the performance of HPWH. The validation was achieved with dedicated experiments with a commercial R32 HPWH based on considerations of different climatic conditions, such as tropical climates, and summer, interim, and winter seasons, representative of temperate climates. The recorded deviations between the experimental and simulation for several system characterization were below 3%. The different climatic conditions were represented in terms of air temperature, humidity, and inlet water temperature. The influences of the climate on the system characterization is discussed based on experiments and simulations and based on the assessments of the temperature achievement, power consumption, P–h diagram, heating capacity, COP, and life-cycle climate performance (LCCP). The assessment results show that the system operation in the representative condition of a tropical climate yields the highest COP (approximately equal to 5.4) and according to the LCCP assessment, the lowest CO₂ emissions.