An Evaluation of the Energetic Performance of a Residential Hybrid Solar Assisted Air Source Heat Pump Water Heater

The study focused on the operational performance of an installed hybrid solar assisted air source heat pump (ASHP) water heater on a residence. The hybrid solar assisted ASHP water heater comprised of a 200 L solar water heater (SWH) that preheat the water and a 150 L, 1.2 kW ASHP water heater that heat the water to 55 oC. Temperature sensors, flow and power meters are installed at specific locations on the hybrid solar assisted ASHP water heater. These sensors measured the water and refrigerant temperatures, volume of hot water heated by the ASHP unit and the volume of hot water consumed by the occupants as well as the electrical power consumed by the ASHP unit. The preliminary results depict that in the month of February 2019, the average weekday volume of water consumed by the occupants was 238.75 L while the electrical energy consumed, the thermal energy gained and the coefficient of performance (COP) of the ASHP water heater was 1.73 kWh, 6.02 kWh and 3.43, respectively. The average weekday solar energy harnessed, the thermal energy gained by SWH and the solar fraction achieved by the SWH was 11.91 kWh, 6.17 kWh and 0.52, respectively. It can be concluded that, by implementing the hybrid solar assisted ASHP water heater for hot water heating, the overall performance was better compared to the conventional technology.