Field testing of natural ventilation in typical college student dormitories in beijing

In Beijing, China, most student dormitories have no individual fresh air systems. Therefore, the dorms can only use natural ventilation to gain fresh outdoor air. In order to evaluate indoor air quality of college dorms in China, it is necessary to measure air exchange rate. However, the existing softwares to simulate single-sided natural ventilation cannot analyze air exchange rate accurately. Therefore, field testing is necessary in order to calculate air exchange rate. This paper uses carbon dioxide exhaled by people as tracer gas to measure air exchange rate. From the measurement results with this method, different field influence factors are discussed. Then, the new modified testing method is applied in the large-scale field testing. Finally, a more convenient and reliable empirical equation to estimate air exchange rate is put forward.