Do Air Conditioners Remove and Reduce Dust in Homes?

I’ve been looking for ways to reduce dust in my house and I found some people are asking if air conditioners reduce dust. So, I decided to write an article on to answer it.

Air conditioners reduce dust in the house by circulating the air through the air filter inside the air conditioner. The air filter remove the dust from the air every time the air passes through it. Dust is collected on the air filter and regular washing of the air filter is essential to maintain the performance of the air filter.

Many people want to further reduce dust in their house and thinking if adding more filters or putting a more expensive filter helps. Although it sounds like a good idea, it may do more harm than good. I’ve included some tips to reduce dust in your house in this article.

How Air Conditioners Reduce Dust?

Air conditioners provide cooling by circulating air through their cooling coil. The air in the house draws into the air conditioner and comes out a few degrees Celsius colder. Through continuous circulation of the air, the room temperature gradually reduced and eventually reach the set temperature.

A typical air conditioner has an air filter located at the return air section. Every time an air conditioner is turned on, it draws in air. The air returns to the air conditioner pass through a filter first before going through the cooling coil and comes out as colder air.

High-grade filters can block finer particles and reduce more dust in the house. However, an air conditioner must equip with a suitable filter. Any alternation may cause damage to the air conditioner

Wall Mounted Air Conditioner

The air filter in a typical wall-mounted type air conditioner is a piece of plastic with fine mesh, designed to capture up to a certain size of dust.

Dust that can’t pass through the fine mesh will stay on the filter. However, they can’t capture finer particles such as smoke, fumes, bacterias, and viruses.

Ceiling Cassette Air Conditioner

A ceiling cassette air conditioner.

The ceiling cassette often uses a plastic mesh air filter as well. Sometimes, a primary filter can be found in one of these ceiling cassette air conditioners too.

Central Air Conditioner: Fan Coil Unit / Air Handling Unit

Central air conditioners such as a fan coil unit and an air handling unit usually have a better filter than a typical wall-mounted air conditioner. They mostly used in commercial buildings such as hotels and shopping malls.

A very dirty filter of an air handling unit.

However, some large houses also use fan coil units in large rooms such as the living room and master bedroom. Occasionally, small air handling units can be found in large houses too.

Central air conditioners have at least a primary filter. Some have a secondary filter such as bag filter, pocket filter, and HEPA filter to further block not just dust only but smoke, bacterias, and viruses.

Ways to Reduce More Dust in Your House

Although air conditioners reduce dust in the house, sometimes our house still has too much dust, especially when we or our kids are allergic to dust. Thus, consider the following ways to reduce more dust in your house. The obvious way such as vacuum your house frequently is not included tho.

1. Don’t go in and out of your house too frequently

The main reason for a dusty house is the introduction of outside air into the house. We go in and out of our house every day and very frequently. Naturally, we carry a lot of dust from outside into our house. Don’t go in and out of your house too frequently will help to reduce dust in your house.

2. Close all windows, use a fresh air duct

Another way to reduce dust in your house is don’t open the windows to allow dusty outside air to come inside your house. Consider to add-on a fresh air duct to your existing air conditioning system so that outside air can be filtered by the air conditioner before supplying it to your house.

Take note that wall-mounted type air conditioner mostly unable to attach to a duct. The ceiling cassette, fan coil unit, and air handling unit all can be attached to a duct to bring in outside air. The outside air will be filtered by the air conditioner before supplying into your house.

One caution to this method is to be sure to check and wash your air conditioner filter much more frequently. The introduction of outside air brings in more dust.

3. Use an air purifier to reduce dust in a particular room

An air purifier is a great way to further reduce dust in your house. However, air purifiers often have lesser airflow compared to air conditioners. This means that they circulate lesser air and reduce lesser dust.

On the bright side, air purifiers mostly have a better filter than most air conditioners. Thus, they give a much cleaner air, especially for allergy people. They serve best in a small area unless you are willing to buy a bunch of air purifiers.

4. Install a high filtration grade air conditioning system

If you are serious about reducing dust in your house, you can seek a local air conditioning expert to assess your house and have them propose an air conditioning system that focuses on air filtration. This air conditioning system will have a high-grade filter and a higher air change rate.

An air conditioning system with a higher air change rate circulates the air within a room much more than they typically do. At the same time, the air conditioners are equipped with a high-grade filter such as a bag filter or a HEPA filter.

By increasing the frequency of air circulation in a room, the air passes through the filter much more often and with a high-grade filter, the air comes out much cleaner. Therefore, more dust and other micro-particles can be removed from the air in the room.

The downside of this method is the air conditioning system is much more expensive. In addition, the bag filter and HEPA filter can’t be washed. They need to be replaced once in a few months depending on the air quality and they are not cheap either.


Air conditioners are very good in reducing dust in the house. Different types of air conditioner reduces different amount of dust. Air purifiers are a complimentary product to reduce more dust in a particular room.

Enclose your house all the time and use a fresh air duct to introduce outside air to your house to maintain a healthy oxygen level. Outside air must go into your air conditioning system before supply into your house. The wall-mounted air conditioner is unable to introduce fresh air.

Lastly, seek local expert advice for a high filtration grade air conditioning system to greatly reduce dust in your house.

What’s Next?

  1. Find out if the air conditioner provides oxygen.
  2. Read about does an air conditioner makes the air dry.
  3. Check out my recommended products:

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Yu Chang Zhen

Yu worked as a professional in the HVAC industry for more than 7 years. He is an engineer who has a passion for blogging. Ever since he created this website, Yu has helped hundreds of homeowners and engineers on HVAC related matters.

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