Do Air Conditioners Filter Dust? (Facts You Should Know)

Dust particles are a problem for everyone, not just those who suffer from allergies. They can aggravate asthma and other respiratory diseases, as well as cause eye irritation and damage furniture.

Indoor air quality

Dust accumulates in your home on everything from carpet to curtains to baseboards-and it’s the hardest thing to get rid of.

But what most people don’t know is that air conditioners can also remove dust particles from the air!

When we turn on our AC units, these dirt particles are sucked inside the AC unit and are trapped by a filter.

This is an important part of an air conditioner. It cleans your indoor air dust particles before the cool air is blown back into the room.

Most common filter types available for your home AC

  • Fiberglass filters are the cheapest and they do not cause as much strain on the HVAC system. They keep out large particles, but they do not work as well for dust and other small particles. If you have allergies or respiratory problems, this type of filter may not help because it will not stop these small things from getting in. The filter will have a MERV 4 rating.
  • Pleated air filters are made of cotton or polyester folds. They can be a little more expensive, but they do a better job at filtering dust and other small particles like pollen, mold spores, and pet dander. Filters with more pleats provide better filtering and help prevent dust from being recirculated in the air. The MERV rating for these filters is between 5-8.
  • If you or your family have allergies, the best air filter is a high-efficiency particulate air (HEPA) filter. The HEPA filters screen out 99.97% of dust, pollen, mold, pet dander, and other irritants in the air. Look for filters that are rated MERV 11 or higher. But be aware that HVAC systems find it hard to work with the higher MERVs because they need more power to pull in air and keep it circulating around your home.
  • UV filters are used in air cleaners that may be built into your HVAC system. They kill viruses, bacteria, and other microorganisms that come through the filter. The filters are not very good at removing dust and other contaminants but they help if you have concerns about indoor air quality issues.
  • An electronic air filter uses static electricity to make particles have an electric charge when they go inside the filter. The charge changes when it goes through different layers of the filter, and then it can get trapped. This means you don’t need to buy a new electronic air filter every few months as you do with a regular one. You do need to wash them, though.

What is an air conditioner filter?

An air conditioner filter is a device that removes dirt particles from the air before they enter back into your living space.
The filter traps dirt, dust, pet dander, mites, mold spores, or pollen in its pads or layers of fabric.

Why do I need to clean my AC filter?

Did you know your AC filter is one of the most important parts of the air conditioning system? The process of cleaning your filter can extend the life of your AC unit, and it also ensures cleaner indoor air.

How often should I change my air conditioner’s filter?

It’s always a good idea to change or clean your air conditioner’s filter at least once per month, especially during the spring and summer. Do this every 2 months during colder weather.
It is hard to say how often you need to replace your air filter. It could depend on the following:

  • Air filter model
  • The air quality inside your home
  • How many pets do you have in your house
  • The size of your house
  • The level of pollution in the surrounding area

For a basic 1″–3″ air filter, you should replace it every 30 days. If you have light to moderate allergies, then install a better filter or replace them even more often.

If you would like to know how regularly you should change your air filter at home, here are some averages that may help:

  • A home without pets or allergies could have its air filter changed every 6 months.
  • Homes with one pet or cat could change their air filter every 60 days.
  • A home with more than one pet could have its air filter changed for about 20 days.
  • Homes, where someone has allergies, should change the air filter for about 45 days.

When should I change my air conditioner’s filter during the year?

During the spring and fall, when the weather is not as hot, you might only need to change your filter once every six or eight weeks.
But during the summer, when it gets hotter outside, you will need to change your filter more often. This is because you will have the AC on more and it will be working harder to keep you cool.
So it’s important to change your filter in the summer about once a month or more often if you have allergies.

What are some other benefits of changing your AC filters regularly?

  • Keep your home cleaner and healthier.
  • Extend the life of your AC unit.
  • Keep your home cooler.
  • Save money by not having to replace or repair your unit as often.
  • Do not have to deal with the hassle of allergies.
  • Do not find yourself sneezing, coughing, or itching from allergic reactions.
  • Do not have to worry about people with allergies around you or who visit your home.

How can you tell if your air conditioning unit needs a new filter?

There are a few signs you can look for to know if your AC needs a new filter.

  • You may see more dust on the furniture or floors than usual.
  • You might smell an odor sometimes.
  • It takes longer for your AC to cool down your home.
  • The noise level of the unit has increased.
  • When the AC is on, if the back of the unit is too hot, it might mean that the filter needs replacing.
  • You are having more allergy attacks.

Do air conditioners bring in dust from outside?

People think that air conditioners bring in fresh air from outside the house. This is not true.
If you have a lot of pollen or pollution in the air, it is best to close the windows so no more dirt goes inside. An air conditioner will take room air and cool it down before passing it back into the room where you are.

Who manufactures the best AC filters on the market today?

Here are some trusted brands that have been in the air filter business for a long time.

  • Nordic Pure MERV 12
  • Honeywell’s FPR 9
  • Filtrete MPR 1500


Do air conditioners filter dust? Absolutely. An AC is designed to remove the large particles of dust in your home, which are often found on furniture and floors.

If you don’t change your AC filter, the air won’t be clean. Dust and other things will get into it. The moving parts of the AC won’t work well because there is dust in them. This makes the system work harder, which makes it less efficient and may cause a breakdown.

An air filter is designed to last about 1-6 months and can be changed easily and inexpensively by yourself or a professional. Do yourself and your family a favor and keep your AC filter clean so that everyone can stay healthy and comfortable.