An evaluation of energy savings potential on hot water production for a student residence

Abstract

This study focuses on evaluating the energy savings potential from decommissioning a 45 kW instant boiler and replacing it with two 9 kW air source heat pump (ASHP) water heaters for a student residence that uses central hot water heating. Baseline and actual energy performance of the instant electric boiler and the ASHP water heaters, respectively, was measured using a PQ-Box 100 power /quality analyser. The results showed that the instant electric boiler had an estimated annual energy consumption and a load factor of 187 050.52 kWh and 0.72. The annual energy consumed by the ASHP water heater was 58 795.30 kWh at a load factor of 0.59, with an estimated average coefficient of performance (COP) of 3. The study also revealed that the annual energy savings due to the hot water heating system change are estimated to be 128 255.22 kWh with avoided carbon dioxide emission of 125 Mt. Further analysis showed that the initiative achieved a load factor reduction of 0.12. Economic analysis of the ASHP system deduced an estimated payback period of 1.06 years.

Keywords: Heat pump water heater, energy savings, demand reduction, coefficient of performance, payback period