Summer in Montana is one of the most beautiful times of the year! Montanans love to get outdoors, explore nature, and find fun things to do around the area. However, one of the biggest threats to our glorious summer weather is the wildfire season. Each year, wildfires inevitably make an appearance in late summer. Some years, the fires are small and easy for firefighting crews to handle, while other, drier years, cause evacuations or other major disruptions. Regardless of the size of the fire, though, Montanans know to expect some wildfire smoke.
Wildfire smoke may stick around for a few hours or last a week. Regardless of how long it is here, residents never want to smell the smokey air or breathe it for long. Each year, we receive questions from local residents about the health implications of running their HVAC systems during a smokey day. Is it possible to filter out wildfire smoke by running the air conditioning? Or will wildfire smoke damage air conditioners?
Should I Run My AC during a wildfire?
As wildfire season ramps up across Montana, many people may question what they should and should not do inside their home to protect their indoor air from wildfire smoke. It is understandable that homeowners may wonder if running their air conditioning unit will help prevent smoke particles, or if the smoke will damage the air conditioner.
The short answer is generally yes, it is safe to run your air conditioner during a wildfire. Even more so, your AC unit may help filter wildfire smoke out of your home. While the primary function of your HVAC system is to heat and cool your home, the system also helps purify the air in your home. When air is circulated through the heating and cooling system, it is run through a filter, which removes pollutants, pet dander and debris before recirculating the air back into your home. This filter will also help filter out wildfire smoke that may have gotten into your home.
How to Set Up Your HVAC System for Wildfire Smoke
The U.S. Environmental Protection Agency recommends these steps during smoky periods:
- Upgrade the filter. Use a filter rated MERV 13 or higher. Ask a technician whether your system can handle a higher-rated filter.
- Run the fan continuously. Switch the thermostat fan from Auto to On, so air passes through the filter even when the system is not cooling.
- Keep outdoor air out. If your system or a room air conditioner has a fresh air intake, close it or set it to recirculate.
- Check the filter often. Replace it when it looks dark brown or black.
- Add a portable air cleaner. A portable air cleaner in the room where you spend the most time adds a second layer of filtration.
Wildfire Smoke May Affect Your Filter
While your AC unit can help filter out wildfire smoke, the system is only as good as the filter you have installed. If the filter is old or full, your AC unit won’t be much help in purifying the air in your home. Check the air filter every month, and clean or replace it when it is dirty. During smoke events, check it more often. Have your system serviced annually to keep the filtration system working well.
Check AC Unit Settings To Keep Wildfire Smoke Outside
While your air conditioner unit will generally filter out any wildfire smoke (or other dangerous particles and debris) in your home, you will also want to ensure it is not bringing additional smoke into your home. Double check the settings on your air conditioning unit and HVAC system to ensure that any setting that allows the intake of outdoor air into the indoor space is turned off. If you use a window or portable air conditioner, close its fresh air vent or set it to recirculate.
Wildfire Smoke and AC FAQ
Does my air conditioner bring smoke into the house?
A central air conditioner recirculates indoor air. It only brings in outdoor air if the system has a fresh air intake, so close the intake or set the system to recirculate.
What filter is best for wildfire smoke?
The EPA recommends a filter rated MERV 13 or higher, if your system can handle it.
Should I run the fan on Auto or On during smoke?
On. Running the fan continuously keeps air moving through the filter.
Wildfires May Require More HVAC Maintenance
If you don’t know the last time you changed your air conditioner filter or had your HVAC system serviced, now is the time to schedule AC maintenance. Contact the team at Central Heating Cooling Plumbing Electrical. Our professional staff can help evaluate your system and get your AC unit ready for summer.
