Energy efficiency assessment of heat pump system for centralized hot water system in buildings

Abstract

Heat pump (HP) is an efficient, energy-saving alternative for centralized hot water system in buildings. Using heat pump can save up to 75% in energy consumption comparing to traditional resistive water heating techcology. The present study aims to assess real energy efficiency of heat pump system through Coefficient of Performance (COPsys). The heat pump system works to heat the water in the swimming pool. The experimental results show that the COPsys depends on the temperature distance between temperature of the hot water in the pool and the ambient temperature; and the number of heat pumps operating simultaneously in the system. In the condition of the average ambient temperature of 18.6oC, the swimming pool has a capacity of 507m3 and an open surface area of 390m2, the water temperature maintained in the swimming pool is from 25oC-30oC. The COP coefficient reached 4.01 with 06 heat pumps and 4.56 with 02 heat pumps. This COP is lower than the value provided by the manufacturer which is 5.0 but still higher than the minimum value specified in QCVN 09: 2013 / BXD which is 3.0. Due to the high energy efficiency, the heat pump system are regarded a promising technology for centralized hot water supply systems in buildings.