Impact analysis of human emission on total volatile organic compound concentration in university classrooms: A field study

 Randomly selects ten in-use densely populated classrooms of a university in Nanjing, continuously monitors and compares the concentrations of indoor total volatile organic compound (TVOC) and CO2, air temperature and humidity, as well as the indoor occupancy rate and human activities (such as opening doors and windows). The results show that, the indoor TVOC concentration in the test classrooms is 363.1±121.7, 218.4±11.5, 583.3±38.9 μg/m3 in winter, spring and summer, respectively. The indoor TVOC concentration increases at first and then decreases, which is similar to that of CO2, and has a significantly positive correlation with the change of the indoor occupancy rate. In addition, seasonal difference of indoor TVOC concentration is significant among those classrooms. The estimated results of indoor total emission rate indicate that both indoor TVOC concentrations and human emission rates vary with sample population size, with the trends of increasing at first, then keeping relatively stable, and finally decreasing gradually.