High-efficiency particulate filtration in centralized HVAC systems reduces the airborne burden of infectious particles (Azimi and Stephens 2013). This strategy reduces the transport of infectious agents from one area to another, when they share the same centralized HVAC system through the supply of recirculated air.

When properly selected and implemented, high-efficiency filtration units in a single space (either roof-mounted or portable) can be highly effective in reducing or lowering concentrations of infectious aerosols in this space. Filtration will not eliminate all transmission risk from airborne particles because many factors other than the concentration of infectious aerosols contribute to disease transmission. (Level of Evidence A).