SARS-CoV-2 airborne infection risk in venues with different ventilation strategies – a comparison between experimental, numerical and analytical approaches

Abstract

The COVID-19 pandemic demonstrated that reliable risk assessment of venues is still challenging and resulted in the indiscriminate closure of many venues worldwide. Therefore, this study used an experimental, numerical and analytical approach to investigate the airborne transmission risk potential of differently ventilated, sized and shaped venues. The data were used to assess the effect size of different mitigation measures and to develop recommendations. In general, positions in the near field of an emission source were at high risk in all ventilation systems studied, while the risk of infection from positions in the far field varied depending on the ventilation strategy. Occupancy rate, airflow rate, residence time, SARS-CoV-2 virus variants, a high activity level and face masks affected the individual and global infection risk in all venues. The global infection risk was lowest for the displacement ventilation case and highest for the naturally ventilated venue. Therefore, in our study, a properly designed displacement ventilation system is the most effective ventilation strategy to keep airborne transmission and the number of secondary cases low, compared to mixing or natural ventilation.