A Novel Improvement of the Performance Coefficient of a Residential Air Source Heat Pump Water Heater

Stephen L Tangwe (Central University of Technology, Free State, Bloemfontein & Fort Hare Institute of Technology, South Africa); Kanzumba Kusakana (Central University of Technology, South Africa)

Air source heat pump (ASHP) water heaters are efficient and renewable energy devices employed for sanitary hot water heating. The study focused on demonstrating that the coefficient of performance (COP) of an ASHP unit is always higher than the COP of the ASHP water heater. The setup involved the design and installation of a 1.2 kW, 150 L ASHP water heater and a data acquisition system (DAS). The DAS consist of a power meter, flow meters, temperature sensors, pressure sensors, ambient temperature and relative humidity sensor and were installed at precise locations of the ASHP water heater. Specific controlled volume of 150, 50 and 100 L were drawn off from the ASHP water heater during the morning, afternoon and evening for a full year. The results depicted that during the summer and winter periods, the average COP of the ASHP water heater was 3.04 and 2.32, respectively. On the contrary, the COP of the ASHP unit was 3.53 and 2.99, respectively. The implementation of electric motors in the prime movers (fan, pump and compressor) with better energy efficiency to replace the existing electric motors, can enhance the COPs of both the ASHP unit and the ASHP water heater.

Conference: UKSim-AMSS 22nd International Conference on Computer Modelling and Simulation, UKSim2020

Published: Mar 25, 2020

DOI: 10.5013/IJSSST.a.21.02.27