Spaces that have either no windows, or windows that are not designed to be opened and closed, are provided mechanical ventilation. Mechanical ventilation systems use fans to bring fresh outdoor air into a building, through a process that filters, conditions, and delivers it to occupied interior spaces.
All mechanical ventilation systems have been reviewed for modifications consistent with CDC and ASHRAE recommendations. These modifications include upgraded filtration to clean air, extended run times of systems that deliver outdoor fresh air continuously before and after room occupancy, and increases to the percentages of outdoor air in total supply to serve interior spaces.