Protecting Your Home from Wildfire Smoke: HVAC Strategies

Bay Area residents have become all too familiar with wildfire smoke. When outdoor air quality drops, your home should be a refuge. Here's how.

Immediate Steps During Smoke Events

Close Up the House - Keep windows and doors closed - Seal gaps around windows and doors if possible - Avoid activities that bring outdoor air inside

Run Your HVAC Set the fan to ON (continuous) rather than AUTO. This keeps air circulating through your filter even when not heating or cooling.

Upgrade Your Filter If smoke is forecast, install the highest MERV rating your system can handle—typically MERV 13 for most residential systems. Check the filter more frequently during smoke events.

Create a Clean Room If you can't filter the whole house, focus on one room: - Run a portable HEPA air purifier - Keep the door closed - Spend time there when smoke is worst

Longer-Term Preparations

Know Your Filter Limits Standard HVAC filters aren't designed for wildfire smoke. MERV 13 helps, but won't capture the smallest particles. MERV 16 or HEPA are better but may not fit your system.

Consider a Portable Air Purifier HEPA air purifiers sized for the room can significantly reduce particulate matter. Run them continuously during smoke events.

Seal Your Home The less outdoor air that infiltrates, the better. Weatherstripping, caulking, and addressing obvious gaps helps.

Understand Your HVAC - Know where fresh air intake is located - Learn how to switch to recirculation if possible - Understand your fan settings

What About Masks?

N95 masks help when you must go outside but aren't a substitute for clean indoor air. Ensure proper fit for effectiveness.

After the Smoke Clears

Ventilate Once outdoor air quality improves, open windows to flush out accumulated indoor pollutants.

Replace Your Filter Extended smoke exposure clogs filters quickly. Replace it even if it's not at the usual interval.

Clean Surfaces Smoke particles settle on surfaces. Damp-wipe furniture and vacuum floors.

Special Considerations

Medical Needs People with respiratory conditions, heart disease, older adults, and children are more vulnerable. Be extra cautious.

Pets Pets are affected too. Keep them inside during smoke events.

Don't Create More Pollution Avoid burning candles, incense, or using gas stoves more than necessary during smoke events.