Performance of personalized ventilation in mitigating short-range airborne transmission under the influence of multiple factors

The effectiveness of using personalized ventilation (PV) in mitigating airborne transmission risk was found to be easily affected by multiple factors. The aim of this study was hereby to evaluate the impacts of several important factors on the performance of PV in airborne disease control for closely ranged occupants. Orthogonal experiments were designed for CFD simulations under different levels of four selected factors. Results indicated that the order of significance of these four factors affecting the intake fraction ( IF ) of the exposed occupant was as follows: mode of PV use > relative distance between occupants > PV airflow volume > background ventilation. The best combination of the four tested factors was PV of 15 L/s for both the infected source and the exposed occupant, with a relative distance of 2 m between them and mixing ventilation, which would yield an IF of merely 0.0246%. The worst combination was PV of 6 L/s for the exposed occupant only, with a relative distance of 0.86 m under displacement ventilation, indicating an elevated IF of 0.2919%. The increase of PV air volume and relative separation distance both contributed to lower exposure risk, but they were not as influential as the mode of PV use. PV integrated with mixing ventilation and utilized for both infected and susceptible occupants were recommended. The findings in this study will be helpful to provide guidance for the implementation of PV in indoor environment for airborne infection control.