A Test and Simulation Comparison Study of the Atwhp Heating System and the Atahp Heating System Applied in the Non-Central Heating Buildings

Due to the different types of indoor condensers, air source heat pumps can be divided into air to air source heat pump ( ATAHP ) and air to water source heat pump ( ATWHP ). The two types of heat pumps are compared in the experiments and simulations in this paper. The experimental results show that the ATAHP heating system has an advantage on the actual operating performance over the ATWHP heating system during the entire heating season especially under low temperature conditions. As the ambient temperature drops from 7°C to -20°C, the ratio for the COP value of the ATWHP heating system and of the ATAHP heating system decreases from 0.83 to 0.62. Under the same ambient temperature conditions, the COP value of the ATAHP heating system is less affected by the current value of the unit, while the COP value of the ATWHP heating system is more affected by the current value of the unit. When the ambient temperature is -12°C, the COP value of the ATAHP heating system increases by 0.17 as the ratio of the hourly current value to the maximum current value decreases from 100% to 70%, while the COP value of the ATWHP heating system increases by 0.39. The simulation results show that the intermittent operation of the ATAHP heating system reduces the heating load demand by 35.0% and the power consumption by 65.7% compared with the ATWHP heating system running all day for a heating season under the same office building model. The intermittent operation of the ATAHP heating system reduces the heating load demand by 21% and the power consumption by 55.8% compared with the ATWHP heating system running all day for a heating season under the same apartment building model. Therefore, the ATAHP heating system is more energy-efficient in intermittent operation mode whether the ATAHP heating system is in office buildings or apartment buildings.