Temporal and spatial distribution characteristics of nighttime air exchange rate and indoor air pollutants in university dormitories

Abstract

Indoor air quality of dormitories is significantly associated with physical health and learning efficiency among college students, but few studies have evaluated the long-term ventilation and indoor air pollutants in university dormitories. In this study, continuous monitoring of nighttime indoor air pollutants was conducted in 12 university dormitories in Chongqing, China, over a one-year period, and the air exchange rate (AER) of the dormitory at night was estimated. The results show that there are significant differences in the AER of dormitories across seasons, months, and orientations, with the lowest qualification rate (>0.7 h −1 ) in summer; the air change rate of south-facing dormitories is significantly higher than that of north-facing ones in all seasons. Nighttime Indoor air pollutants also exhibit significant differences across seasons, months, and genders. The concentrations of PM 2.5 and PM 10 are the highest in winter, with higher levels in male dormitories than in female dormitories, whereas the concentration of total volatile organic compound (TVOC) in female dormitories is significantly higher than that in male dormitories throughout the year. Increased natural ventilation was associated with lower formaldehyde and TVOC concentrations but may increase the infiltration of outdoor particulate matter.