Airborne transmission of infectious diseases in rooms ventilated by mixing ventilation

BUILD, Aalborg University, Copenhagen, Denmark

^* Corresponding author: pvn@civil.aau.dk

Abstract

This study aims to explore the parameters influencing the mixing level in rooms with mixing ventilation based on experimental results and CFD predictions. An increased concentration will be present close to sources in mixing ventilated rooms and almost fully mixed concentration will be found in some distance. In case of point sources, as an infected person, it will likewise give a distribution ranging from a high concentration in very close to face, down to a low concentration in the long distance in the room due to the turbulent mixing process and the fresh air supply. This distribution may change in the room when the point source change position, room temperature is changed, or the air supply rate is changed together with temperature.

High ventilation rate is suggested for post-COVID ventilation design because it can provide a low concentration of pathogens. However, it often causes discomfort due to draught. In the last part of the study, we will compare five ventilation systems. We will identify conditions and systems that can handle high ventilation rate while minimizing draught rate.