Ventilation, Filtration, and Air Cleaning Guidance

The purpose of this document is to recommend ventilation, filtration, and air cleaning strategies for reducing exposures indoors and limiting the spread of SARS-CoV-2, the virus that causes COVID-19. These strategies are also useful for reducing exposure to other indoor air pollutants, viruses, and bacteria. More comprehensive guidance is available from the Centers for Disease Control and Prevention (CDC) Ventilation in Buildings guidelines, U.S. Environmental Protection Agency (USEPA), and American Society of Heating Refrigerating and Air Conditioning Engineers (ASHRAE).

The Illinois Department of Public Health supports CDC's recommendation that schools, child care programs, workplaces, congregate living facilities, and other locations use a layered approach to risk reduction. This includes the use of face coverings where applicable, in addition to vaccination and environmental control measures to reduce the spread of COVID-19. The strategies recommended for ventilation, filtration, and air cleaning include: