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Wildfire Smoke in Home? Improve Air Quality

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Wildfire Smoke in Home? Improve Air Quality

When wildfire smoke drifts into your home, the fine particles and gases can linger long after the outdoor air clears, affecting everyone’s breathing. This guide walks you through practical, effective steps to reduce indoor smoke levels, from quick actions to longer-term solutions. You’ll need a few basic supplies—many of which you may already have—and a bit of time to set up your home as a cleaner-air sanctuary.

What You’ll Need

  • Portable air cleaner with a HEPA filter (or a DIY box fan filter)
  • High-efficiency HVAC filter (MERV-13 or higher) if you have central air
  • Weather stripping or tape to seal gaps around windows and doors
  • Damp towels or rags to block drafts
  • N95 or N100 respirator masks (for when you must go outside)
  • Clean, damp cloth for wiping surfaces
  • Vacuum with a HEPA filter (optional but helpful)

Step-by-Step

  1. Check local air quality. Before you act, know the outdoor AQI (Air Quality Index) from a reliable source like AirNow.gov. This tells you how severe the smoke is and whether you need to take extra precautions.
  2. Close all windows and doors. Shut every window, exterior door, and even interior doors to rooms you’re not using. This is your first line of defense against smoke infiltration.
  3. Seal gaps and cracks. Use weather stripping or tape to cover gaps around window frames, door bottoms, and any other openings. For a quick fix, roll up damp towels and place them at the base of doors and windowsills.
  4. Turn off exhaust fans. Kitchen and bathroom exhaust fans, as well as clothes dryers, pull air out of your home, which can actually draw smoke in from outside. Turn them off until the air quality improves.
  5. Set up a portable air cleaner. Place a HEPA air purifier in the room where you spend the most time (often the bedroom or living room). Run it continuously on the highest setting that’s comfortable. Make sure it’s sized for the room—check the CADR rating (clean air delivery rate) against the square footage.
  6. Upgrade your HVAC filter. If you have central heating and cooling, replace your standard filter with a MERV-13 or higher filter. Set the fan to “ON” so it runs continuously, filtering the air even when the system isn’t heating or cooling.
  7. Create a clean room. Choose one room—ideally with a door and few windows—and focus your air-cleaning efforts there. Seal it off, run your air purifier, and spend most of your time in that room.
  8. Avoid adding indoor pollutants. Don’t smoke, burn candles, use gas stoves, or vacuum with a non-HEPA vacuum. These activities add particles to the air you’re trying to clean.
  9. Wipe surfaces with a damp cloth. Smoke particles settle on furniture and floors. Use a damp (not dry) cloth to wipe down surfaces, and mop hard floors. Dry dusting just stirs particles back into the air.
  10. Wear a mask if you must go outside. When you need to step out, wear an N95 or N100 respirator. Cloth masks and surgical masks do not block fine smoke particles.
  11. Monitor and adjust. Keep an eye on the AQI. Once it drops to a safe level (under 100), you can open windows and air out your home. Until then, keep your filtration running.

Common Mistakes

  • Opening windows “just a crack”—even a small opening lets in smoke. Keep them fully closed.
  • Using a fan without a filter—a regular fan just circulates smoky air, making it worse. Always use a filter.
  • Running exhaust fans—these create negative pressure that pulls smoke in through cracks.
  • Changing the HVAC filter too late—if the filter is clogged, it won’t capture particles effectively. Check it monthly during smoke events.
  • Ignoring the air purifier’s filter indicator—a dirty filter won’t clean air. Replace it as recommended.
  • Vacuuming with a non-HEPA vacuum—this kicks up dust and smoke particles into the air you breathe.

Tips

  • DIY box fan filter: Tape a MERV-13 filter to the back of a box fan. It’s a budget-friendly alternative to a commercial air purifier, but use it with caution—never leave it unattended.
  • Use a portable air conditioner wisely: If you have a window AC unit, close the vent to the outside and set it to recirculate. Ensure the seal around the unit is tight.
  • Keep a clean room ready: Prepare a room in advance with your air purifier, water, snacks, and entertainment so you can retreat there quickly.
  • Stay hydrated: Drinking water helps your body clear inhaled particles.
  • Use a damp cloth for dusting: A dry cloth just redistributes particles.

Troubleshooting

Air purifier isn’t helping? Check that the filter is clean and properly seated. If the room is larger than the purifier’s rating, you may need a second unit or to run it on high.

Smoke smell persists? Smoke odor can linger on fabrics. Wash curtains, bedding, and clothing. Wipe down walls and hard surfaces with a damp cloth.

Windows are drafty? Use plastic sheeting and tape to create a temporary seal. For a quick fix, use painter’s tape around the edges.

HVAC system is old or not working? If you can’t upgrade the filter, run a portable air purifier in the main living areas. Keep doors closed to concentrate the clean air.

Power outage? If you have no electricity, use a battery-powered air purifier if available. Otherwise, stay in the cleanest room and use damp towels to seal gaps.

Frequently Asked Questions

Q: Can I use a regular fan to blow smoke out?
A: No. A regular fan just circulates smoky air. If you must use a fan, attach a MERV-13 filter to it to create a makeshift air purifier.

Q: How long does smoke stay in a house?
A: It depends on the severity and how well you seal and filter. With continuous filtration, most particles settle within hours, but odors can linger for days. Wipe surfaces and wash fabrics to speed up the process.

Q: Is it safe to use a gas stove during a smoke event?
A: No. Gas stoves add carbon monoxide and nitrogen dioxide, which worsen indoor air quality. Use a microwave or electric kettle instead.

Q: Do houseplants help filter smoke?
A: While plants can remove some VOCs, they are not effective at filtering fine smoke particles. A HEPA air purifier is far more effective.

Q: Should I run my HVAC fan continuously?
A: Yes, if you have a MERV-13 filter installed. This helps filter the air throughout your home. Without a high-efficiency filter, it may just circulate particles.

Q: Can I use a wet towel in the window to block smoke?
A: Yes, a damp towel can help seal gaps, but it won’t filter the air. It’s a temporary measure until you can properly seal the window.

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