Effects of internal airflow on IAQ and cross-infection of infectious diseases between students in classrooms

Abstract

A full-scale school ventilation performance test-bed is newly constructed to evaluate the effects of internal airflow on IAQ and cross-infection among students. The indoor airflow is controlled by return diffusers installed on the ceiling or the floor of a classroom. The removal performance of PM2.5 is measured according to the location of return diffusers in the school classroom, and the indoor airflow is analyzed using numerical simulation. The airflow angle is introduced to evaluate the possibility of cross-infection of infectious diseases between students at the height of their respiratory line. It is confirmed that the floor return is successfully reduced compared to the upper return at the height of the students' breathing line in the horizontal airflow, which has a high possibility of infection between students. The floor return reduces the dust removal time by 35% from the ‘Unhealthy’ level to the ‘Good’ level for PM2.5 compared to the upper return, which is due to the optimal control of airflow inside the classrooms. Through a study on the optimization of the direction of indoor airflow in school classrooms, this paper can provide a basic design guide for the direction of airflow that can improve classroom air quality, which can improve students' right to learn, and reduce cross-infection between students due to infectious diseases.