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The Impact of an Air to Water Heat Pump in the Residence of a University Campus

Stephen Tangwe and Kusakana Kanzumba
Central University of Technology, Free State, P/SAK X20539, Bloemfontein, 9301, South Africa

Abstract—The implementation of an energy efficiency intervention in the students’ residence of the university campus may lead to a reduction in the energy consumed and electricity cost. The study focused on retrofitting a 1000 L, 12 kW boiler, with a 4.0 kW Air Source Heat Pump (ASHP) unit. A data acquisition system was built and deployed, to monitor the baseline performance of the electric boiler and the actual performance of the installed ASHP water heater (which was used to retrofit the electric boiler during the assessment period). The results show an annual electrical energy saving of 34805.94 kWh and load factor reduction of 0.124 due to the replacement of the electric boiler with the ASHP unit. The payback period of the ASHP system was 1.7 years, using the method of net present value of money. Wilcoxon rank sum test was employed to compare both the daily volume of water and energy consumed by the electric boiler and the ASHP water heater to test if their difference was of any significance. We concluded that, there exists a significant difference in the average daily energy consumed by the boiler and the ASHP water heater in both summer and winter season with the utilization of the Wilcoxon rank sum test. We could conclude that, a rollout of the ASHP units to retrofit the existing electric boiler in the students’ residence in the University campus is economically viable and calls for such an intervention is imperative. 
Index Terms—Load factor, Energy saving, Tariff hike, Air source heat pump, Electric boiler, Net present value payback period, Wilcoxon rank sum test

Cite: Stephen Tangwe and Kusakana Kanzumba, "The Impact of an Air to Water Heat Pump in the Residence of a University Campus," International Journal of Electrical and Electronic Engineering & Telecommunications