5 Best Air Filters for the Wildfire Smoke in Your Home, Tested and Reviewed
CR's experts explain how to improve indoor air quality with the filters for your HVAC system
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For many people in the U.S., hazy skies and unhealthy air quality have become routine hazards. Just last month, the smoke from hundreds of wildfires in Canada and northern Minnesota drifted thousands of miles across the Midwest and Northeast, spiking the Air Quality Index to dangerous levels for millions of residents.
With such sweeping fallout, it can be difficult to keep the air inside your home clean. Even if you close all doors and windows, as recommended, pollutants can seep in through cracks and leaks. One way to clear the air is by using the fan on your central heating or cooling system to cycle the smog through a filter. If your system has a fresh-air intake, set it to recirculation mode or close the outdoor intake damper to avoid drawing polluted air inside, the Environmental Protection Agency says.
Best Air Filters for Smoke Removal
Here are five air filters from our tests that earn top or near-top scores for smoke removal at high speed. All still allow for plenty of airflow to your HVAC system.
How to Keep Smoke Out of Your Home
In addition to using a high-MERV filter (11 or above) in your HVAC system, follow these steps to keep healthy air in your home and smoke out.
What to Do If There’s Smoke in Your Area
• Keep all doors and windows closed.
• If air is seeping in around windows and doors, try using duct or package tape and towels to plug the openings (where you feel a draft).
• Run the fan on your central air conditioning system on a low setting to filter the air in your home. If the system has a fresh-air intake, close it or set the system to recirculate to avoid drawing poor outdoor air inside.
• Place an air purifier with a certified HEPA filter in the most frequented rooms of your home to trap additional smoke particles.
What to Do Before the Next Wildfire
• Seal all leaks. Walk around the house in search of drafts, usually around windows and doors.
• Use caulk to seal your windows and doors from the inside and outside. (You’ll need different types of caulk for the interior and exterior. Ask at your local hardware or home improvement store.) Always remove the old caulk before replacing it with new. Covering loose caulk won’t seal the leak.
• Look into upgrading your air filtration system. In our tests, we found that thicker air filters were more effective at removing impurities. If your system supports the standard 1-inch-thick filter, you’ll need a pro to install a larger box for a thicker filter.
Can a Window Air Conditioner Filter Out Wildfire Smoke?
Generally speaking, no. The overwhelming majority of window and portable air conditioners recirculate indoor air, rather than drawing fresh air from outside, and they lack a filter capable of sufficiently removing smoke particles.
If you rely on a window or portable unit and wildfire smoke is a concern, keep your windows shut, use the AC to cool the recirculating indoor air, and employ a portable air purifier, such as those listed below, to clean it.
Best Air Purifiers for Wildfire Smoke
For more options, see our article on models that excel at filtering out smoke particles.
