Solar-air source heat pump water heater for scorching climatic condition: energy, exergy, economic and enviroeconomic (4E) exploration for sustainable future

As solar-powered air source heat pump is an emerging water heating technique in scorching climatic conditions, it is necessary to explore their performance in terms of energy, exergy, economic, and environeconomic (4E) perspective. Henceforth, current research experimentally investigates and reports on 4E of Direct Expansion Solar-Air Source Heat Pump water heater for hot regions. A heat pump with a dual source evaporator is proposed in two working modes: solar air source mode and air source mode. The impact of ambient conditions on the thermal performance, such as power consumption, evaporator and condenser capacity, heating time, coefficient of performance, and exergy efficiency of the heat pump water heating system in both the working modes, was experimentally investigated. Results depict the coefficient of performance of the proposed heat pump system in solar air source mode and air source mode in the range of 2.37-5.05 and 2.26-4.21, respectively. On average, the system heating time in solar air source mode is 16.5 % shorter than in air source mode. Based on the simulation results, compared to a conventional standard electric heating system, the payback period and lifetime carbondioxide mitigation savings cost of the proposed dual-source heat pump system are about 616 days and $179866, respectively.