Investigation of the influence of ventilation systems and components on the personal aerosol spread and transmission of SARS-CoV-2, taking into account the indoor air flow and the likelihood of infection for selected ventilation concepts
The Federal Institute for Occupational Safety and Health (Bundesanstalt für Arbeitsschutz und Arbeitsmedizin, BAuA) is significantly involved in the work being done on room ventilation for infection control. Proven methods and central findings have already been incorporated into the SARS-CoV-2 occupational safety and health regulation, the recommendations issued by the German Federal Government, and practical guidance documents. Against the background of the diversity of ventilation systems found in the real world, however, there is a lack of reliable findings about some aspects of the transmission risks from virus-contaminated aerosols in indoor spaces and the influence of ventilation and air purification.
When assessing the relevance of indoor air as a transmission path, a wide variety of factors come into play, which vary depending on the structural/technical conditions and how the room is used. The outside air exchange rate and flow conditions in the room, the effectiveness of air treatment methods (filtration/disinfection), and the room climate, with its effects on the stability/infectivity of virus aerosols, are of decisive importance.
BAuA is cooperating on this project with the TU Dresden to bundle existing competences, developed program systems, and models in the fields of indoor air flow simulation, indoor air technology, and particle/aerosol dispersion and relate them to current approaches to the assessment of transmission risks from virus-contaminated aerosols.
The goal of this collaborative research is to investigate the influence of various ventilation systems and components (window ventilation, different types of mechanical ventilation, personal ventilation) and common air treatment methods (filtration, heating, cooling) on the distribution of and inhalation exposure to virus-contaminated aerosols in multi-occupied rooms. This will allow a basic classification of such settings considered from the point of view of infection control.
In addition to general issues, it is necessary to address further questions about concrete hazards and suitable occupational safety measures in operational practice. Authorities will be able to draw on the study’s results both when drafting recommendations for action and practical advice on the use of specific air handling units or concepts and when defining minimum requirements. These will be concerned, among other things, with the design of devices, their positioning in rooms, and their appropriate operation.
Unit 2.4 "Workplaces, Safety of Machinery, Operational Safety"