Definition
Wildfire smoke infiltration is outdoor smoke entering a home through gaps in the building shell, open windows, leaky return ducts, and fresh-air intakes. EPA identifies fine particles as smoke's biggest health threat; they are small enough to pass indoors easily, so indoor air in an unprepared home can approach outdoor smoke levels.
Also called: Wildfire smoke, Smoke infiltration
Why it matters to you
SW Washington and the Portland metro see summer smoke episodes from regional fires that can be hundreds of miles away, with some summers clean and others hazy for weeks. Households with asthma, young children, or older adults feel it most, and filters and portable cleaners are hardest to find once the haze arrives.
Practical guidance
During smoke, homeowners can close windows and fireplace dampers, run the system fan with the best filter it can handle, set any fresh-air intake or HRV to recirculate, and run a portable HEPA cleaner in a closed clean room. A technician can verify before the season whether your system takes a MERV 13 filter and whether leaky return ducts are letting air bypass the filter.
About this definition
Written by the Home Energy Group team — a family-owned HVAC company celebrating 25 years of comfort & care across SW Washington and the Portland metro, licensed in Washington (WA LIC# HOMEEGI003J7) and Oregon (OR CCB# 184255). Definitions inform; an on-site diagnosis decides.
