Field testing of natural ventilation in college student dormitories (Beijing, China)

Abstract

Human health demands and thermal comfort both require sufficient amounts of fresh outdoor air. Many university student dormitories in China have high residential density with no individual fresh air systems. In this kind of physical environment, natural ventilation is the primary way to obtain fresh outdoor air. However, few studies have explored ventilation under these conditions. In this paper, the ventilation rate in student dormitories (Beijing, China) was field-tested using carbon dioxide as a tracer gas. The test conditions were selected in accordance with the behavioral patterns of the occupants (students) throughout different seasons of the year. A stable CO2 release source was obtained from students in the sleep state. The results were used to create an empirical equation that could estimate the air change rate in a room. The CO2 concentration change in different dormitories was also discussed to evaluate the current ventilation and indoor air quality situation in the tested university student dormitories. Although sufficient outdoor air can be provided to dilute the indoor CO2 through single-sided natural ventilation in 82% of the testing period, nevertheless, for infiltration the indoor CO2 concentration exceeded the IAQ standard in 76% of the recorded times. The results were also factored into the design of student dormitories for better ventilation and indoor air quality.