Wildfire smoke is now an annual reality for the Portland metro. September 2020 taught everyone what a real event looks like. Whether the source is the Cascades, the Gorge, Southern Oregon, or Northern California, smoke drifts in, the terrain traps it, and Oregon DEQ posts unhealthy or hazardous AQI advisories for days.
This guide covers what is actually happening to your indoor air during a smoke event, what to do during the event to protect your family, and when professional smoke remediation is justified after the air clears.
Why Portland air gets so bad so fast
The Willamette Valley sits between the Coast Range and the Cascades. When wildfire smoke drifts in from the Gorge, Southern Oregon, or Northern California, the terrain and the summer inversion trap it near the surface for days. Oregon DEQ regularly issues unhealthy and hazardous AQI advisories during major fire seasons like September 2020.
How smoke gets inside a sealed home
Even a tightly built home is not airtight. Smoke enters through HVAC fresh air intakes, exhaust fan dampers, recessed lights, plumbing penetrations, dryer vents, attic vents, and the gap under every exterior door. By day two of a heavy smoke event, indoor PM2.5 in most Portland homes is well above safe levels unless you have actively filtered the air.
What to do during the event
- Run your HVAC system fan continuously with a MERV 13 (or higher) filter. Replace it weekly during smoke events.
- Add one or two HEPA portable air cleaners sized to your largest occupied rooms.
- Close fresh air intakes and economizer dampers temporarily.
- Skip running the dryer, range hood, and bathroom exhausts unless necessary; each pulls smoke in to replace exhausted air.
- Check on elderly neighbors, infants, and anyone with asthma or COPD.
When you need professional smoke remediation
A short smoke event handled with HEPA filtration usually leaves no lasting trace. A multi-day event, an event where you ran the HVAC without an upgraded filter, or any event where you can still smell smoke a week after the air clears outside often justifies a professional cleanup. Soot is acidic; it continues to etch glass, metal, and finishes if it is not properly removed.
- HEPA air scrubbing of indoor air
- Wipe-down of horizontal surfaces and electronics
- HVAC duct cleaning to stop recirculation
- Soft goods and contents cleaning if odor is in fabrics
- Hydroxyl or thermal fogging for residual odor
What professional smoke remediation actually does
Real post-event smoke remediation addresses ductwork, contents, and structural surfaces as separate work packages. HEPA air scrubbing during cleanup, soot-specific chemistry on surfaces, HVAC duct cleaning to stop recirculation, contents cleaning for fabrics and electronics, and hydroxyl or thermal fogging for residual molecular odor. Skipping any one of these typically leaves odor that re-emerges in Portland's humid weather months later.
Smoke residue in your Portland home after a wildfire event? IICRC certified cleanup and odor removal.
Call (503) 883-8429