Airborne infection risk in venues with different ventilation strategies – a comparison between experimental, numerical and analytical approaches

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 total infection risk in all venues. The total 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. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was funded by the Ministry of Science, Energy, Climate Protection and Environment of the Federal State of Saxony-Anhalt, the Federal Government Commissioner for Culture and the Media and Berlin University Alliance. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethics Committee of the Martin Luther University (Halle, Germany) gave ethical approval for this work. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors.