Can You Run Your Air Conditioner When It is Smoky Outside?

Sep 14, 2020Air Conditioning, Blog

If you have looked outside anytime in the past few weeks in California, you’ve noticed the air filled with smoke from wildfires. This fire season is especially bad, as it is affecting residents of Oregon and Washington state as well.

Right now, in September 2020, three of the top 15 major cities in the world with the worst air quality are in California, due to the wildfires.

The smoke from these fires can be particularly bad, as they contain toxins that can affect your respiratory health.

What Health Risks Does Breathing Smoky Air Pose?

According to the CDC, breathing wildfire smoke can worsen chronic heart and lung diseases. Because the smoke contains small particles from burning vegetation and toxins from burned houses, inhaling this smoke can exacerbate cardiovascular and respiratory conditions.

The groups that should be particularly careful about breathing smoky air are:

  • Young children, as their lungs and cardiovascular system is still developing. Children usually spend more time outdoor, and proportionately breathe more air than adults.
  • Older people, because they are more susceptible to respiratory, cardiac, and cardiovascular issues.
  • – People who already have heart and lung diseases, such as asthma, coronary artery disease, or pulmonary heart disease.

When air quality is poor, and it is smoky and hazy outside, you should spend as much time inside as possible. You can check the current Air Quality for any city at .

The Air Quality Index

The Air Quality Index has different levels.

0 to 50 (Good):  Air quality is satisfactory, poses little or no risk to anyone.

51 to 100 (Moderate) : Air quality is normal for most people. People with very high sensitivity to air quality conditions may be affected.

101 to 150 (Unhealthy for Sensitive Groups): Those with health conditions may be affected, but most of the general public may not be affected.

151 to 200 (Unhealthy): Some people may have health risks, the individuals with existing health conditions will be at risk.

201 to 300 (Very Unhealthy): The health risk for everyone is affected.

301 or higher (Hazardous): An emergency warning is in place, anyone who breathes the air will be affected.

So when it is fire season, and the outside air is smoky and hazy, and you are indoors, how can you get wildfire smoke out of your home?

Can You Run Your Air Conditioner When It is Smoky Outside?

You might think that if you run your air conditioner during fire season, that the smoke and ash particulate would move indoors to your home. This is not the case.

It is safe to run your AC system when the air quality outside is poor. Here’s why.

Central AC units are heat exchangers. The heat from inside your home is absorbed and transported through the refrigerant line, then deposited outdoors. An air handler or furnace, stored in am out-of-the-way place like an attic, basement, or utility room, blows the air that had heat removed (chilled air) throughout the home.

Air conditioners use air filters to remove pollutants from any air that is circulated in the house. Running the air conditioner circulates indoor air, removing heat, and also filtering some particulates from the air. If you want to ensure that your air filtration is operating at maximum efficiency, get the highest level of filters you can. HEPA filters trap very small particulate. Change the air filters often so they stay working at peak performance.


At Ventwerx HVAC, we understand your family’s health and well-being is your primary concern. If you have any questions, or need to schedule a service call, contact us at (408) 422-2987.

Get a Free Estimate from Ventwerx

Our HVAC technicians at Ventwerx HVAC Heating & Air Conditioning are here to help if your heating and cooling system is operating unusually. Give us a call at 408-422-2987 in San Jose or at 408-710-9595 in Morgan Hill for a free estimate.