What’s the Best Air Purifier for Wildfire Smoke?

HVAC Logo IconBy Tom MoorAugust 16, 2023

Have your sunny summer days suddenly turned hazy and gray? In many areas of the country, it’s not from an incoming weather front – it’s the smoke from Canadian wildfires thousands of miles away.

At any given time this summer, as many as 100 million Americans across more than a dozen states spanning Montana to Vermont have been under air quality alerts due to the worst wildfire season in Canadian and North American history. In some cases, wildfire smoke has turned the sky a yellow or orange hue, a tell-tale sign of compromised air quality.

Installing the right indoor air quality solutions such as whole-house air purifiers and high-efficiency air filters can help filter wildfire smoke indoors to keep you and your family safe.

Recapping the Canadian Wildfire Season

Since the start of 2023, more than 4,000 wildfires have been reported in Canada, far above the 10-year average. The fires have burned more than 10 million hectares, or the equivalent of 24.7 million acres, across Canada. As of Monday (July 17), more than 900 active fires burned in Canada, with 600 deemed "out of control."

The wildfires have led to more than 150,000 evacuations and caused cities across Canada and the United States to issue indoor air quality warnings, including New York City, Washington D.C., and Chicago.

By the end of June, the wildfire smoke reached Western European countries such as France, the United Kingdom, and Spain, making the 2023 Canadian wildfire season a truly international event.

With fires continuing to burn across Canada, areas of the United States are expected to be at risk for smoke for the foreseeable future. The specific regions are unknown as fire flare-ups in Canada and weather patterns determine the smoke’s path.

"What is kind of extraordinary this year is that the fire season started early and in multiple areas at the same time," Jennifer Kamau, a spokeswoman for the Canadian Interagency Forest Fire Center, told the New York Times. "(In the past,) fires would flare up in one part of the country, then die down and then start in another area."

How Do Canadian Wildfires Affect Your Health?

According to the U.S. Environmental Protection Agency, the majority of healthy children and adults quickly recover from smoke exposure from wildfires and will not have any long-lasting health effects. However, millions of Americans who suffer from asthma, allergies, other respiratory illnesses, lung disease, or cardiovascular disease are at a higher risk of developing serious health effects. Children, pregnant women, and people ages 65 or older are also at a heightened risk of health effects.

Some common signs of wildfire smoke inhalation include:

  1. Coughing
  2. Difficulty breathing
  3. Eye irritation
  4. Sore throat
  5. Wheezing
  6. Runny nose
  7. Chest pain
  8. Headaches
  9. Fatigue

On days the smoke level is high in your area, consider taking appropriate steps. "I think it’s really important to wear a mask," Kenneth Mendez, CEO and president of the Asthma and Allergy Foundation of America (AAFA), recently told DailyMail.com. "If you have to be outside, then wear a mask."

Particulate matter with a diameter of 10 micrometers or less is considered dangerous and is small enough to be inhaled into the lungs and into the bloodstream, causing health effects for susceptible groups of people. Particles from wildfire smoke are generally tiny, with diameters of 2.5 microns or less. According to the EPA, the size of smoke particles are mostly in the 0.4 to 0.7 microns range.

"These particulates are particularly irritating to your upper airway, your nose or your throat and your eyes, so if you feel any of this, it is a warning sign," Dr. David Rosenberg, a specialist in pulmonary disease at UH Ahuja Medical Center in Cleveland, told CNN Health. "We have sensitive neurological sensors that can act like an alarm that means you’re potentially breathing something harmful, so you should heed that warning and go inside."

Is Wildfire Smoke a Threat Indoors?

According to the EPA, wildfire smoke can enter your home in a few different ways, including:

  • Open doors and windows.
  • Small openings, cracks, joints, and through a process called infiltration around closed doors and widows.
  • Mechanical ventilation equipment including HVAC systems with a fresh air intake or kitchen and bathroom exhaust fans.

Installing Air Purifiers and Air Filters to Treat Wildfire Smoke

Using portable air purifiers or air cleaners coupled with installing high-efficiency air filters in your heating and air conditioning system can help filter out indoor smoke from Canadian wildfires to improve the health of your indoor environment.

Air purifiers and air filters eliminate common particles and contaminants including pollen, dust, pet dander, mold spores, and – depending on their efficiency – smoke.

MERV, or minimum efficiency reporting value, determines the efficiency of an air filter, including those installed in an air purifier or air cleaner, and is based on a scale of 1 to 20. The higher the rating, the more efficiently the filter captures the smallest particles.

An HVAC air filter with a minimum MERV rating of 13 is recommended to filter out smoke. However, high-efficiency particulate absorbing, or HEPA filters, offer the greatest defense against smoke and smaller particles, as they can filter out particles as small as 0.3 microns.

Activated carbon filters are also effective at filtering smoke. They attract and capture particles like smoke but aren’t as efficient at filtering other fine air particles including dust, pollen, and mold spores. If you use an activated carbon filter, consider pairing it with a portable or whole-house air purification system with a HEPA filter.

The ideal solution to protect people with allergies, asthma, or other health ailments in your home is installing an HVAC air filter with a MERV 13 rating and an air purification device.

The Best Air Purifiers for Wildfire Smoke

According to Consumer Reports, the best air purifiers for wildfire smoke include:

These air purifiers range in price from $280 to $1,000.

How to Monitor Indoor Air Quality Levels

Online sites such as PurpleAir and AirNow allow you to check your area’s indoor air quality level. The Air Quality Index (AQI) value scale is between 0 to 500; a higher number indicates increased air pollution.

According to the EPA, an AQI of 151 to 200 is unhealthy, a value of 201 to 300 is very unhealthy, and an AQI of 301 to 500 is considered hazardous.

To measure indoor air quality in and around your home, consider installing indoor and outdoor air quality sensors. Companies such as PurpleAir sell these devices which measure dust, smoke, and air pollution to determine if you need to improve your air quality by installing an air purifier.

Other Steps to Avoid Smoke Exposure Indoors

According to the American Lung Association, consider taking the following precautions if you have a lung disease or other respiratory condition:

  1. Stay indoors
  2. Keep doors and windows closed
  3. Do not smoke indoors
  4. Avoid burning wood or candles
  5. Do not vacuum
  6. Use damp towels to block outside air from entering through the bottom of windows or doors
  7. Keep pets indoors as much as possible