Best Air Filters for Dealing With Wildfire Smoke in Your Home
Follow CR's advice for improving indoor air quality with filters for your HVAC system
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You don’t have to live in a wildfire zone to experience the bad effects of wildfire smoke, which can drift for hundreds, if not thousands, of miles, bringing unhealthy air conditions as it travels.
With such dirty air outside, it can be difficult to keep the air inside your home clean. Even if you keep your doors and windows closed, which is recommended, air can seep in through cracks and leaks. One way to clear the air is by running the fan on your central heating or cooling system so that it cycles through the filter. If your system has a fresh air intake, set it to recirculation mode or close the outdoor intake damper so that you do not draw polluted air inside, the Environmental Protection Agency advises.
An HVAC air filter will catch much of the smoke that’s in your home—assuming it’s a good one.
“You want a filter with a high MERV rating,” says Dave Trezza, an engineer who has tested air filters at Consumer Reports. MERV stands for minimum efficiency reporting value, and the higher it is, the more contaminants the filter removes. The top performers in our tests typically have a MERV rating higher than 10, and range in thickness from 1 inch to 5 inches.
Best Air Filters for Smoke Removal
More Ways to Keep Smoke Out of Your Home
In addition to using a high MERV filter in your HVAC system, follow these additional steps to keep healthy air in your home and smoke out.
What to Do Now if There’s Smoke in Your Area
• Keep all doors and windows closed.
• If air is seeping in around windows and under doors and you don’t have caulking or the other supplies you need to seal them, use duct or package tape to tape around your window frame where you feel a draft, and put towels in front of the doors.
• Even if you don’t need your central air conditioning for cooling, you can run just the fan on your HVAC system on a low setting to filter the air in your home. If your system has a fresh air intake, close it or set the system to recirculate to avoid drawing in bad outdoor air.
What to Do Before the Next Wildfire
Wildfire season seems to be getting longer, but when one subsides, there are a number of things you can do to prepare for the next one, Hamerly says.
• Seal all leaks. Walk around the house to see where you feel drafts, usually around windows and doors.
• Use caulk to seal your windows and doors from both the inside and outside. (You’ll need different types of caulk for the interior and exterior; ask at your hardware or home improvement store.) Always remove the old caulk before replacing it with new. Covering loose caulk is an exercise in futility because it won’t seal the leak.
• Consider upgrading your air filtration system. In our tests, we found that thicker air filters were more effective at removing impurities. If your system accommodates the basic 1-inch-thick filter, you’ll need to have a pro install a larger filter box to accommodate a thicker size.