AC Air Exchanger Explained

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Updated May 18, 2023

If you are new to the world of indoor cooling, you may wonder what is the air exchanger on an air conditioner. Many of the best air conditioners, after all, feature an air exchanger as part of the overall design. An AC air exchanger helps make the air in your home cleaner and saves energy. It exchanges stale indoor air with fresh outdoor air while transferring heat and humidity. In the summer, it cools and dehumidifies the air. In the winter, it heats and humidifies the air. It reduces energy costs and improves air quality by reducing pollutants and moisture in the home.

Now you might be wondering if you need an AC exchanger to maintain the best central air conditioner? Keep reading to find out.


  • Air exchangers are a vital component of many modern AC units, as they blow in air from the outside.
  • Using an exchanger to slightly cool your home or deliver a breeze helps cut down on energy costs with air conditioning.
  • Exchangers also improve indoor air quality by reducing excess humidity and mold, in addition to eliminating odorous gasses and pollutants from the home.

What is an Air Exchanger?

Before you learn about what types of AC motors are used in air conditioners, and related queries, it is helpful to understand the function of an air exchanger. An air conditioner’s air exchanger allows you to switch between cool air and outside air at will if you are wondering what a fan does within an air conditioner. This allows you to refrain from actual cooled air to experience a cool breeze instead, leading some to wonder how to vent a portable air conditioner.

Insider Tip

Some air exchangers include air filters that must be cleaned or replaced regularly to maintain efficacy.

Exchangers are found with many modern air conditioning types, such as window units, portable air conditioners, central AC units, and more.

Benefits of an Air Exchanger

Exchangers are nifty pieces of technology and a big part of how modern air conditioners work. Here are some of the most significant benefits you’ll receive from going with a model featuring an exchanger.

Decreased Energy Costs

You’ll experience a fairly significant decrease in your monthly energy bill with the regular use of an exchanger. When the exchanger is simply pushing outdoor air into your home, instead of cooling it, you’ll only expend energy on the fan, as none of the other components are activated. It should go without saying that a fan uses less energy than a condenser and a compressor. Of course, this option is not so appealing when the temperatures reach the 90s and above.

Reduces Humidity

If you are looking for an energy-efficient way to reduce the humidity in your home, look to the humble exchanger. Not only do these AC components naturally limit humidity, with functionality not entirely dissimilar to a dedicated dehumidifier, but they also reduce the chances of mold and mildew. If you ever notice that your AC is not cooling, it may be due to a faulty exchanger that needs to be inspected and possibly repaired.

Removes Pollutants and Gases

If you want to decrease odorous gasses and other pollutants from the home, switch on the exchanger. These air conditioner components do the job without adding too much to your energy bill.


Should I run the air exchanger during winter?

It depends on whether or not you have heat pumps running through the same vents, otherwise, there could be a conflict with the heat exchanger. Otherwise, pay attention to outdoor temperatures and use as needed.

Do I need an air exchanger?

This depends on personal preference, though many modern AC designs include an integrated exchanger. However, if you desire the proper humidity level in your home and are concerned about the air exchange rate, go for one of these atmospheric exchangers.

How much ventilation do I need in my home to improve indoor air quality?

It depends on the cubic foot size of your home and other factors such as the embedded air filter and ventilation rates. Central ventilation helps in this regard but check with a pro for actual numbers.

STAT: The rate at which outdoor air replaces indoor air is described as the air exchange rate. (source)

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