Indoor environment quality in a low-energy residential building in winter in Harbin

Harbin is located in the severe cold area of China with the outdoor mean air temperature reaching lower than −10 °C in January in winter. A passive ultra-low energy residential building was built in Harbin in compliance with the German passive house standard, the first passive house project in the severe cold climate zone of China. A post-occupancy evaluation of indoor environmental quality was conducted in the passive building (PB) during the 2015/2016 heating season. The physical parameters of indoor thermal environment and air quality were measured, in parallel with a subjective occupant survey. For comparative purposes conventional buildings (CBs) in the same community were also evaluated with the same protocols. The results show that the average indoor temperature was higher than the upper limit of thermal comfort range in the PB and low relative humidity resulting from the overheating was observed. The indoor temperature fluctuation is small, and the difference between the inner surface temperature and the air temperature in the PB is lower than that of the CBs due to the high performance envelopes, so that cold radiation was minimized. The air quality in the PB was improved compared to the CBs due to the additional mechanical ventilation system. The fresh air volume was sufficient and CO2, PM10 and PM2.5 concentrations in the PB significant lower than those in CBs. In general, passive house technologies applied in Germany are applicable in the severe cold area of China, but the overheating problem should be avoided by proper operational strategies.