The effect of student activity and outdoor conditions on particulate matter concentration in university classroom

The university lecture room is one of the places where the fine dust concentration can rise easily. Generally, since students move in each lecture, particulate matter formed in the outdoors is adsorbed on the clothes surface of the students and then re-suspended in the room. Also, university classrooms are often blocked for more than one hour of class, and the university's old buildings do not have a special ventilation system. In addition, when the number of students per unit area per class is large, much particulate matter can be re-suspended due to the activities of the students. The purpose of this study is to investigate the relationship between factors affecting the concentration of particulate matter in the classroom by long-Term field measurements. Particulate matter has been measured for long periods in two classrooms, hallway, and outdoor. At the same time, factors affecting the indoor particulate matter concentration such as cleaning status, window and door opening status, air conditioner operating status, and number of occupants per unit area were monitored. As a result, the increase and decrease of the outdoor particulate matter concentration had a great influence on the increase and decrease of particulate matter concentration in the classroom. At the beginning or end of the lesson, indoor and corridor particulate matter concentrations increased sharply with the movement of many students. The increased particulate matter concentration was maintained for a long time despite the window and door open condition.