Forest fire season in California can make breathing difficult, even inside your home! Find tips from the air quality experts at Cencal Mechanical Heating & Air, Inc. — including how to seal your home effectively, get an air filter with a high enough MERV rating, and invest in an effective air purifier.

Every year, thousands of wildfires burn across California, destroying millions of acres and creating thick smoke that drifts across the state. Peak forest fire season can start as early as June and last well into October, making the air potentially dangerous to breathe for nearly half the year—even when you’re at work or in your home.

By taking steps to improve your home’s indoor air quality, you can reduce the health risks associated with wildfire smoke, which include heart attacks, strokes, and asthma. Below, our team at Cencal Mechanical Heating & Air, Inc. has compiled a list of recommendations for making the air you breathe in your home or business clearer during the smokiest portions of the year.


Make sure your home is properly sealed to prevent outside air from entering. This includes:

  • Closing all windows and doors
  • Sealing gaps in window or door frames with weather stripping
  • Placing wet towels at the bottoms of doors to prevent air from coming in underneath
  • Monitoring Local Air Quality

You won’t want to keep wet towels under your doors all the time, but knowing when the air quality in your area is most impacted by wildfire smoke gives you an idea of when to take extra precautions. You can learn about your local air quality levels by:

  • Checking local air quality reports on
  • Monitoring local weather reports on TV or the radio
  • Using an app like IQAir or Breezometer

Improving Your HVAC Filters

Your furnace filter is designed to catch contaminants, but standard filters usually aren’t built to capture small particles—making them insufficient to protect you from wildfire smoke. You can upgrade your filter by purchasing a filter with a MERV rating of at least 13.

MERV stands for Minimum Efficiency Reporting Value and is a measurement scale specifically created for air filters by the American Society of Heating, Refrigerating, and Air Conditioning Engineers. You can install MERV 13 filters in most HVAC systems without needing to upgrade your equipment.

Maintaining Your HVAC System

Since your air filters play a critical role in maintaining your indoor air quality, you’ll need to make sure your HVAC system runs properly throughout forest fire season. Here are some tips:

  • Change your furnace filters regularly. Most filters with a MERV rating of 13 or higher should be changed every 30 to 90 days, but it’s best to change them monthly during fire season to be safe.
  • Keep the area around your air conditioner’s outdoor unit free from dust and debris, which can quickly accumulate during wildfire season. Sweeping away dust and moving twigs, branches, or other objects at least two feet away helps prevent them from entering your ducts and ensures proper airflow.
  • Schedule professional HVAC maintenance to make sure your equipment remains efficient and prevent breakdowns. It’s best to schedule an AC tune-up in the spring before wildfire season starts, and get a furnace tune-up at the end of wildfire season to make sure no damage has been done to your heating equipment before winter starts.

Buying A UV Air Purifier

UV air purifiers won’t catch particulate matter, but they do disrupt the DNA of potentially harmful microorganisms that can live in the air you breathe. The UV-C light these devices emit is harmless to humans, but effectively kills bacteria, mold, and viruses as they pass through your home’s ductwork.

Using a high-quality air filter with a high MERV rating is the best way to trap particulate matter from wildfire smoke and prevent it from entering your home’s air—but adding a UV air purifier to your HVAC system gives you the highest possible air quality at home.

The Health Benefits Of Improving Your Indoor Air Quality

Taking the steps above to protect yourself from the harmful effects of wildfire smoke can:

  • Reduce your risk of asthma and other respiratory problems
  • Reduce your risk of cardiovascular problems like heart attacks and lung cancer
  • Improve your sleep quality
  • Enhance your overall quality of life by providing peace of mind

For specific suggestions on how to improve the air quality at your home or business during California’s forest fire season, contact Cencal Mechanical Heating & Air, Inc.. Our experienced professionals will take your home’s features into consideration and provide an effective solution for helping you breathe easier.

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