Is smoky air from wildfires a regular part of your life? If so, you're probably doing everything you can to keep it from infiltrating your home and making you and your family sick. You may resort to keeping windows and doors shut or purchasing portable air cleaners to improve indoor air quality. You might even consider battening down your home, but that can make the warmer months uncomfortable. Since you don't want to keep the windows open and let all that smoky air inside, you'll likely depend more on your air conditioning system to stay cool, but you might wonder if air conditioners can filter wildfire smoke. This raises an important question: Should you run your AC if it's smoky outside?
Causes of Smoky Air Outside
Wildfires are an all-too-common occurrence in the United States, and they're growing in frequency. The National Center for Environmental Information recorded 61,685 wildfires in 2024, which, perhaps surprisingly, is below the 25 year average. Unfortunately, wildfires have become more destructive in recent years, with an overall increase in acres burned per fire. This means that we are losing more land to fewer fires and driving more smoke into the atmosphere. Western states like California, Texas, Arizona and Montana present the highest wildfire risk, but fires are also prevalent in New Jersey, North Carolina, Florida and other East Coast states.Â
Even if you don't live close to a burning fire, the traveling smoke can affect people as far as 3,000 miles away. Fine smoke particles can enter your home in various ways, including through ventilation devices, small joints and cracks and improperly sealed windows and doors.
What to Do If There's a Wildfire Near Your Home
The actions you and your family should take during a wildfire threat depends on how close the flames and smoke are to your home:
Evacuation: If an active fire is very close to your house, moving to a safer location is the most prudent action. These raging infernos can spread quickly, making smoke infiltrating your residence the least of your concerns. Pay close attention to your TV, radio or phone for emergency alerts from local, state, and national authorities for the latest developments.
Preparation: A fire might be far enough away that it doesn't pose an imminent threat but still produces significant smoke levels. In this situation, you should implement preparatory steps like adjusting your HVAC unit or purchasing a portable air cleaner or even N95 respirator masks.
Monitoring from a distance: A fire that's several hundred or a thousand or more miles away may not be an immediate cause for concern. However, if it starts spreading in your direction, you should monitor your home's indoor air quality and developing a plan to fortify your home against the smoke.
Can Your AC Filter Smoky Air?
Running the AC with smoke outside can improve the air quality inside your home. You can keep the windows closed during hotter weather and keep everyone comfortable if smoky conditions keep you from going outside for extended periods. Most well-maintained AC systems can also remove other forms of air pollution and even pollen.Â
Central HVAC System
If you own a newer home, it probably has a central HVAC unit that distributes heated or chilled air throughout the structure via ductwork. To ensure your system is keeping as much smoky air out as possible, be sure to change the filter at least as often as the manufacturer recommends. Choose a filter with a minimum efficiency reporting value (MERV) of 13 or higher if your system can accommodate it. Make sure the filter fits snugly. If the unit has an outside air intake, use the damper to close it and prevent smoke infiltration. You can also set it to the recirculation mode if it contains this feature. You can typically find the air intake on the ceiling or in the attic.Â
Evaporative Cooler
Some homes use an evaporative cooler instead of an HVAC system to generate and distribute chilled air. Unlike an HVAC unit, which relies on refrigerants to remove heat and moisture and a fan to distribute the conditioned air, an evaporative cooling system needs only heat and water to operate. A water-soaked medium produces the cooling action, resulting in slightly moistened air. An evaporative cooler is not the ideal cooling equipment in a smoky environment, as its operating procedure can draw more smoky air inside. If you're considering purchasing a new cooling unit but live in a wildfire-prone area, it's best to avoid this option. If you already own one, keep it turned off during periods of heavy smoke.Â
Window Air Conditioner
You can use window air conditioners in heavy smoke, but you'll need to take some precautionary steps to keep the smoky air out. Most of these devices have an outdoor air damper located near the top to prevent entry of rain or snow. Closing the damper will also block the outside airflow. Check the seal between the unit and window for potential leaks.Â
Portable Air ConditionerÂ
If you use portable air conditioners, the number of hoses will dictate whether they're safe to use in smoky conditions. Models with a single hose can pull smoke inside, meaning you should avoid operating them in these environments. If yours is a two-hosed model, check for a secure seal between the window and vent kit before using it.Â
Other Steps to Take
Some air conditioners can filter wildfire smoke, but there are additional steps you can take to improve your home's indoor air quality:
Run your home's portable air cleaner (if you have one) at the highest speed as frequently as possible.
Avoid indoor activities like smoking, frying foods, burning candles, spraying aerosols or operating wood-burning stoves or furnaces.
Check the seals around all windows and doors and make upgrades such as installing new weatherstripping.
If you don't have air conditioning, use portable or ceiling fans to increase air circulation.
Designate a "clean room" — a place you can seek refuge if it becomes so hot that you need to open a window in another area of your home.
Should You Run Your AC If It's Smoky Outside? Yes and No
Some air conditioners filter wildfire smoke effectively, while others don't. If your current AC system isn't one of the better options, the home cooling experts at IWAE can help. We offer a wide range of HVAC options to provide the right choice for any homeowner.When you choose us, you can expect exceptional service. We offer flexible financing options, free quotes, price matching and fast, free shipping. You can always speak to a live human being whenever you have questions or need assistance.Â
Check out our broad selection of air conditioning options today.
