Intervention of personalized ventilation on interpersonal airborne disease transmission

Personalized ventilation (PV) has been integrated to reduce the risk of interpersonal infection exposure in the office environment. Some studies showed that PV systems may increase occupants’ risk of airborne infection. Therefore, the aim of this study is to investigate the intervention of PV on interpersonal airborne disease transmission in office environment. A three-dimensional computational fluid dynamics model (CFD) was developed and experimentally validated in a clean chamber. Then the validated CFD model was used to calculate the diffusion of exhaled droplets under different particle size. Results showed at the size of 0.7μm particles, compared to pure mixing ventilation, the personal ventilation of 6L/s reduced the inhalation fraction （IF）from 0.121% to 0.092%，and the reduction ratio of IF is 23.96%. As of 5μm, the IF also decreased from 0.165% to 0.102%, and the reduction ratio of IF is 38.18%. The percentage of 50μm particles deposited on the ground rises from 6.29% to 43.22% of exhaled particles. Therefore, the personalized ventilation can reduce the risk of inhalation in exposed person, and for large size particles, the number of particles falling on the floor increased greatly, which lead to the risk of resuspension increases. The results may be helpful for maximizing the effect of PV in interpersonal airborne disease control.