Southern California’s fire season isn’t just dangerous for your family – it can also wreak havoc on your home’s heating and cooling system.
September and October are actually the most damaging months for California wildfires, with Southern California’s fire season extending into November or December due to delayed rainfall. San Bernardino County has seen its share of devastating fires, including the Line Fire in September 2024 that burned over 21,000 acres and threatened more than 36,000 structures. The recent January 2025 Los Angeles area wildfires reminded us all that fire season can strike at unexpected times, burning over 57,000 acres and destroying more than 18,000 homes.
While you’re focused on keeping your family safe during fire season, don’t forget about your AC system. Wildfire smoke and ash can seriously damage your heating and cooling equipment, leaving you without climate control when you need it most.
How Wildfire Smoke Damages Your AC System
Wildfire smoke contains dangerous gases, fine particulates, and pollutants that can be extremely hazardous. When this toxic cocktail gets into your AC system, it doesn’t just affect your indoor air quality – it can also damage expensive equipment.
The particles in wildfire smoke, called PM2.5, are so small they can sneak past your body’s defenses, but they’re also small enough to clog up your AC filters and components. Think of it like trying to breathe through a dirty sock – your system has to work much harder to move air through clogged filters.
Ash is another problem. Unlike regular dust, wildfire ash is often acidic and can corrode metal components in your system. It can also coat your outdoor unit’s coils, reducing efficiency and potentially causing overheating.
Your AC Filter: The First Line of Defense
Most home systems use a low efficiency fiberglass filter with a MERV rating of 1-4, but upgrading to a MERV 13 or higher filter can remove as much as 95% of particles that pass through it. During fire season, this upgrade isn’t just recommended – it’s essential.
MERV 13 air filters are specifically designed to capture fine particles as small as 0.3 microns, which include the PM2.5 particles found in wildfire smoke. These filters can remove up to 98% of airborne particles, including soot and ash.
However, there’s a catch. During active forest fire events, you may need to change your AC filter as often as every 2 to 4 weeks, depending on the severity of smoke exposure. If the air quality is really bad, you might even need to change filters every few days.
Protecting Your System During Fire Season
Here are the steps you should take before and during wildfire events:
Before Fire Season:
- Upgrade to MERV 13 filters (have a professional confirm your system can handle them)
- Stock up on extra filters – you’ll go through them quickly during smoke events
- Have your system professionally serviced to ensure it’s running efficiently
- Consider upgrading to a higher-capacity filter system if you’re in a high-risk area
During a Fire Event:
- Set your system to recirculation mode and close the outdoor air intake to prevent drawing polluted air inside
- Run your system’s fan continuously to filter air, even if you don’t need heating or cooling
- Check your filter every few days and replace it when it looks dirty
- Keep windows and doors closed to minimize contamination
After the Fire:
- Replace filters immediately, even if they were recently changed
- Have a professional inspect your outdoor unit for ash buildup on coils
- Consider having your ductwork cleaned if smoke infiltration was severe
When Your System Needs Professional Help
Some situations require more than just filter changes. Call for professional service if you notice:
- Unusual odors coming from vents after a fire event
- Reduced airflow even with a clean filter
- Strange noises from your outdoor unit
- Higher than normal energy bills
- Visible ash or soot buildup on your outdoor unit
The Long-Term Investment
Investing in a high-efficiency, high-quality air filter has lasting health benefits beyond just wildfire protection. Better filtration helps with everyday allergens, dust, and other pollutants year-round.
For homes in high-risk fire areas, consider upgrading to a whole-house air purification system. While the upfront cost is higher, it provides superior protection and can actually extend the life of your AC equipment by keeping it cleaner.
Don’t Wait for the Smoke to Clear
Fire season preparation isn’t something you can put off until you see flames on the horizon. Fire potential across California is expected to increase steadily through summer, with above-normal large fire activity forecasted. The time to protect your AC system is now, before the next fire starts.
Your AC system works hard to keep your family comfortable and safe. During fire season, return the favor by giving it the protection and maintenance it needs to do its job effectively.
Ready to fireproof your AC system? Call Ballard at 909-297-1914 or schedule service on our website. Because when wildfire smoke fills the air, you want to be sure your home’s air stays clean and your system keeps running strong.
