"Consider ventilation system upgrades or improvements and other steps to increase the delivery of clean air and dilute potential contaminants" - cdc.gov
"Transmission of SARS-CoV-2 through the air is sufficiently likely that airborne exposure to the virus should be controlled. Changes to building operations, including the operation of heating, ventilating, and air-conditioning [HVAC] systems, can reduce airborne exposures." - ashrae.gov