Indoor environmental quality of high occupancy dormitory buildings in winter in Shanghai,China

Abstract

Maintaining acceptable air quality and providing adequate thermal comfort are conflicting goals for ventilation requirements in crowded, unheated rooms in winter. The former requires a maximal ventilation rate for indoor pollutant removal, but the latter prefers a minimal rate. To understand the indoor thermal environment in winter in the climatic zone that features hot summer and cold winter, the indoor environmental quality in three selected rooms of university dormitory buildings with high occupancy density in Shanghai, China was monitored simultaneously and continuously from December 2010 to January 2011. The results show that, without space heating equipment in winter, the quality of indoor thermal environment in the student dormitory was poor, and that the indoor temperature ranges of the sampling rooms were completely out of the thermal comfort zone as defined by ASHRAE. To maintain an endurable thermal environment, the occupants had to close the windows to reduce the heat loss, which resulted in elevated indoor CO₂ concentrations during sleeping hours due to a lack of ventilation. The indoor CO₂ levels exceeding 2000 ppm (4000 mg/m³) were observed in several occasions. To improve the indoor air environment, central heating systems or individual heating units should be provided for dormitory buildings in the Yangtze River Delta region.