Performance test and analysis of heat pump air conditioning units of a passive house in severe cold zone in winter

Because the passive house envelope has good thermal insulation performance, and the winter time in severe cold zone is long, the indoor and outdoor temperature difference is large, and the specific enthalpy difference is large, so the energy consumption of the outdoor air system accounts for a large proportion of the total energy consumption of the heating and air conditioning system. In this paper, the operating parameters of the outdoor air system of a passive house in severe cold zone are tested in winter, and the operation effect of the air-source heat pump unit in the severe cold zone is analysed. The results show that in actual operation, the air supply temperature and air supply volume of the unit can meet the requirements of design standards and comfort when there are few occupants. As the outdoor air temperature decreases, the heating capacity of the heat pump unit is insufficient. When the outdoor air temperature rises to -7 ℃, the coefficient of performance of the unit reaches 1.87, which is higher than the standard lower limit. The unit is recommended to work when the outdoor air temperature is higher than -7 ℃.