ABSTRACT
Faced with epidemic risks, ensuring an exchange of air and sufficient direction of airflow is essential to reduce the air-borne transmission of infectious agents in buildings. In this study, we strove to identify effective ventilation strategies to reduce the risk of infection by COVID-19 inside buildings. To do so, we developed a multi-route transmission model of SARS-CoV-2 (INDALO (R)-COVID) which estimates a risk of infection.This study enabled us to quantify the impact of two preventive measures (installation of a mobile air purifier and increase in the renewal of air by the air purification unit) on the risk of COVID-19 infection in a nursing home. In the configuration used in this study, the use of an air purifier in the rooms of residents with COVID-19 appears to be the most effective measure to reduce the viral load potentially transported to other areas of the building, and thus to reduce the risk of COVID-19 infection among all residents.The digital model developed is a versatile and ready-to-use solution, which can compare preventive measures and design/renovation choices for different types of buildings and uses.