Indoor Air Quality During and After Wildfire Season

During a Smoke Event

Fine particulate matter (PM2.5) from wildfire smoke infiltrates homes through gaps in the building envelope, through HVAC systems that draw in outdoor air, and through any opening including bathroom exhaust fans and dryer vents. Closing windows reduces but does not eliminate infiltration. Running a HEPA air purifier in the rooms where you spend the most time, upgrading the HVAC filter to MERV 13 or higher, and sealing obvious gaps around doors and windows provides meaningful protection.

After the Smoke Clears

Smoke residue settles on surfaces, in carpet, in upholstery, and in HVAC ductwork. The smell may linger for weeks. Ventilating aggressively once outdoor air is clean, cleaning soft surfaces, and replacing HVAC filters removes the residual particulate. The assessment evaluates your home's infiltration vulnerabilities and filtration capacity.