Experimental research on the cross-infection control performance of different ventilation strategies

Sustained pandemics have awakened the growing need to select appropriate indoor ventilation strategies to create a healthy environment. Hence, this study experimentally evaluated the cross-infection control performance of different ventilation strategies, namely mixing ventilation with outlets installed in the bottom of the side wall (MV-BR) and at ceilings (MV-CR), stratum ventilation with outlets installed in the side wall (SV-SR) and at ceilings (SV-CR), interactive cascade ventilation with outlets installed in the side wall (ICV-SR) and at ceilings (ICV-CR). The supply air flow rate of the studied ventilation strategies remains the same (6.51 h-1) for fair comparison. The infection risk and maximum cumulative exposure are introduced as the evaluation indicators. The research results show that the mean infection risk in the respiratory zone of susceptible individuals who are standing in the sidewind directions of the infected people under ICV-SR has the lowest potential infection risk (Pi) value of 0.012, which is consistently lower than ICV-CR by 8.3%, MV-CR by 42%, MV-BR by 45%, SV-CR by 50%, and SV-SR by 55%, respectively. And the average max long-term exposure of MV-BR is 15.2% lower than MV-CR. Compared with SV-CR and ICV-CR, SV-SR and ICV-SR can also realize to reduce the max long-term exposure by 21.3% and 25%, respectively. The integrated scenario index calculation results demonstrate that ICV presents excellent cross-infection control performance than SV and MV, obtaining 53.5% and 61.2% lower cross-infection risk. The conclusions got from this study can provide guide for the design of indoor airflow organization with the epidemic normalizing.