5 Best Air Purifiers for Wildfire Smoke, According to Our Testing

According to our testing, air purifiers with HEPA filters can help rid your home of these harmful particulates. In fact, the aforementioned study suggests they may cut the level of such irritants by half. But not all air purifiers do a good job of removing smoke particulates. (For proof of that, see our air purifier ratings.) The most effective options for battling smoke have a HEPA filter and a large fan that forces air through a fine mesh to trap particles.

The best air purifiers with HEPA filters can reduce particle concentrations by as much as 85 percent, according to the EPA. If you want to get rid of the smoke smell, too, you’ll want an air purifier that has a large carbon filter for odor absorption.

HEPA air purifiers can range from $50 to more than $1,000, and it often makes sense to scale up. Large purifiers, rated for rooms bigger than 350 square feet, tend to be better at removing smoke. Most of CR’s recommended air purifiers fall into that category.

These five air purifiers (listed in order of Overall Score) top our ratings and pass CR’s particle-reduction tests with flying colors at both high and low fan speeds. All are rated for use in rooms 350 square feet or larger.

To evaluate how well these machines trap small particulates from smoke, we inject cigarette smoke particles into a sealed room and use a particle counter to measure the number and size of particles, as small as 0.1 micrometer, in the room as an air purifier works. Because air purifiers typically have a number of speed settings, we test for smoke removal at the highest speed and at a lower speed. (Some models that perform well at high speeds don’t do as well at low speeds.)

We also measure noise levels at every speed a machine has because you’ll need to run it 24 hours a day for it to be effective. And we calculate annual operating costs, which include filter replacements and energy use.

Smoke can travel hundreds of miles from the source, so even if you live far away from a fire and are in no immediate danger, you could still have harmful smoke coming into your home. Using an air purifier helps, but there’s more you can do to keep your dwelling as smoke-free as possible.

• Close all your windows and doors and seal any air leaks (including the mail slot, if you have one) with weather stripping, if available. Even masking tape is better than nothing.
• If it’s too hot to go without using a window air conditioner, close the outdoor air damper if you can, and tightly seal any gaps between the unit and the window.
• If you need to leave your house, wear goggles and a face mask approved by the National Institute for Occupational Safety and Health that’s designed to block particles from entering your mouth and nose. If you don’t have an air purifier and the smoke is very bad, consider wearing this protective gear indoors as well, whenever you can. While surgical masks protect against exposure to viruses, they do not protect against smoke inhalation.
• Try to spend the bulk of your time in a room with the fewest windows and no fireplace or ventilation ducts that connect to the outside. If you have a fireplace, shut the chimney flue.
• If you have an air purifier, use it in this room and keep it running 24/7.
• Change the air purifier filter as soon as the indicator light comes on or according to the time frame specified in the manual. If you can’t change it right away, continue to use the air purifier until you can make the switch. A dirty filter is still better than not using the air purifier at all.
• If you have central heating, ventilating, and air conditioning, you can install a high-efficiency filter (MERV 13 or higher) in the system. Run the system’s fan as much as possible to get the most out of the filter. If your system has a fresh air option, turn it off or close the intake.
• Shut doors to the laundry room and bathrooms because those rooms often have ventilation ducts that lead to the outside.
• Vacuum cleaners with HEPA filters can help remove and trap smoke particles that have settled on carpet and furniture. But don’t use a vacuum that doesn’t have a HEPA filter; it’ll just kick up more particles into the air. For the same reason, clean hard surfaces with a damp cloth or mop.