How to Maintain Healthy Indoor Air in Spokane During Fire Advisories

Wildfire smoke is now a predictable part of late summer in Eastern Washington, and Spokane homes need a plan before advisories arrive. At Air Duct Cleaning Spokane in Spokane, WA, we prioritize a clean-air strategy built on current public-health guidance, correct HVAC settings, right-sized filtration, and room-level protection so families can breathe easier when PM2.5 spikes.

Check Local AQI First—and act on the number, not the view

Monitor the Air Quality Index (AQI) hourly and act when it climbs above key thresholds. AQI above 100 is unhealthy for sensitive groups; higher values quickly become unhealthy for everyone. Rely on Spokane Regional Clean Air Agency’s hourly readings, sign up for smoke alerts, and track regional plumes through statewide smoke updates. Use current dashboards; avoid outdated screenshots circulating on social media.

Set your home to keep smoke out (tighten the envelope and recirculate)

When advisories hit, close windows and doors, seal obvious gaps, and switch your HVAC to recirculate. If your system has a fresh-air intake (or a window A/C with an outdoor damper), close the intake; leave the indoor fan On to continuously pass air through the filter. Avoid devices that draw outdoor air (single-hose portable A/Cs, evaporative coolers) unless cooling is a safety issue.

For Spokane’s smoke-ready season, local officials echo the same message: “Preparing now is prudent… including steps to reduce your exposure to harmful smoke particles.”

Upgrade whole-home filtration (MERV 13 or higher—if the system can handle it)

During smoke periods, a MERV 13 return filter (or better, where compatible) improves capture of fine particles. Evaluate static pressure and blower capacity before upgrading; disable economizers temporarily so they don’t pull smoky air inside. Replace filters more often than usual during heavy smoke—inspect visually and don’t wait for the calendar.

Add room-level protection with the right CADR

Pair whole-home filtration with a portable HEPA air cleaner sized to the room. A practical rule: select a Smoke CADR that’s at least two-thirds of the room’s square footage (width × length). Example: a 20 ft × 20 ft room (400 sq ft) needs at least 267 CFM Smoke CADR. Prefer AHAM-verified units and run them on high during advisories.

Create a “clean room” for the worst days

Designate one closed room (often a bedroom or den) to maintain the lowest particle levels: shut windows, block obvious leaks, run a HEPA cleaner continuously, and avoid exhaust fans in that space. The clean-room approach is standard guidance for heavy smoke days.

DIY option: Corsi-Rosenthal boxes—effective with modern box fans

For additional capacity or budget builds, a Corsi-Rosenthal box (box fan plus four MERV-13 filters) meaningfully reduces indoor PM2.5. Follow practical safety guidance—use 2012-or-newer, UL/ETL-listed box fans, don’t use overnight or unattended, and avoid damaged cords.

Minimize indoor particle sources while it’s smoky

Don’t add to the load you’re trying to filter. Skip candles, incense, fireplaces, indoor smoking, high-heat frying/broiling, and vacuuming unless your vacuum has a HEPA filter.

If you must go outside: wear a proper respirator

Choose a NIOSH-approved N95 (or P100) and wear it tightly sealed over nose and chin. Cloth and surgical masks do not filter fine smoke particles effectively.

Spokane-specific readiness checklist

• Before fire season: stock MERV 13 filters, a HEPA cleaner matched by CADR, and materials to seal gaps (door sweeps, weather-strip). Review system ability to handle higher-efficiency filters; plan to disable economizer modes during smoke.

• During advisories: close openings, set HVAC to recirculate, keep the fan On, run room HEPA on high, and monitor AQI changes from local agencies.

• For businesses & multi-family: follow recognized building-readiness guidance—minimize outdoor air, maintain and verify filtration and controls, and consider pressure strategies to limit infiltration.

• After smoke clears: replace or clean filters as needed and use HEPA-equipped cleaning (wet-wipe/mop, HEPA vacuum) to avoid resuspending ash.

What levels trigger action?

• AQI 101–150 (Unhealthy for Sensitive Groups): sensitive people (children, older adults, those pregnant, heart/lung conditions) should stay indoors and start clean-room/HEPA use.

• AQI ≥ 151 (Unhealthy): everyone should reduce time outdoors; keep recirculation and filtration running until AQI returns to Moderate or Good.

Devices to avoid

Skip ozone or ionizing “air purifiers.” Ozone is a lung irritant and these devices do not effectively remove smoke; choose filtration-based solutions instead.

Spokane case notes & monitoring resources

Spokane’s health agencies regularly issue joint smoke updates and urge residents to set HVAC to recirculate and use HEPA or DIY filters when orange/red AQI days are forecast. Bookmark local air-quality and wildfire resources for localized forecasts and incident notes.

CONCLUSION

We protect indoor air during Spokane fire advisories by acting on current AQI, sealing the envelope, recirculating through MERV 13+ filtration, adding room-level HEPA or Corsi-Rosenthal capacity, and creating a clean room for the worst days. For families seeking a professional inspection of duct hygiene, filter upgrades, or smoke-season hardening, Air Duct Cleaning Spokane applies these evidence-based steps so indoor air stays as healthy as possible while smoke persists.

This post explains how UV lights enhance summer duct sanitation—reducing microbial growth and improving indoor air quality: The Role of UV Lights in Summer Duct Sanitation.

FAQs

1) Do I really need a portable air cleaner if I already upgraded to MERV 13? 

Yes—whole-home filters protect the entire system, but a HEPA unit sized by Smoke CADR to the room gives fast, local particle reduction where people actually spend time (bedrooms, nursery, home office). Use the two-thirds rule for CADR versus room area.

2) Are “ionizer/ozone” air purifiers helpful for wildfire smoke? 

No. Ozone generators can worsen respiratory symptoms and do not effectively remove smoke particles. Stick with HEPA or high-MERV filtration and verified CADR ratings.

3) How often should I change filters during and after a smoke event? 

More often than the normal schedule. Replace HVAC and air-cleaner filters more frequently during heavy smoke and inspect for heavy loading afterward; start the next advisory with a clean filter.