How to Install an AC Filter

PDF download Download Article
PDF download Download Article

The filter for your AC unit helps keep the air in your home clean. It's important to change the filter regularly, as it collects dust, debris, and hair from pets and humans while pulling in air. A typical filter will be in a duct near the thermostat, though in a few cases, you may need to search a bit to find your filter.

Part 1
Part 1 of 3:

Changing a Typical Ceiling or Wall Filter

PDF download Download Article
  1. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/b\/ba\/Install-an-AC-Filter-Step-1.jpg\/v4-460px-Install-an-AC-Filter-Step-1.jpg","bigUrl":"\/images\/thumb\/b\/ba\/Install-an-AC-Filter-Step-1.jpg\/aid9464781-v4-728px-Install-an-AC-Filter-Step-1.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">Creative Commons<\/a><br>\n<\/p><p><br \/>\n<\/p><\/div>"}
    You can find air filters at home improvement stores and most big box stores. If you're not sure what to buy, look at the size you already have after you pull it out. Basic air filters take care of things like dust and dirt. You can also buy filters to help reduce allergies, as they filter out more particles. However, the more they filter out, the less efficient they are because AC has to work harder to get the air through the filter. [1]
  2. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/c\/c5\/Install-an-AC-Filter-Step-2.jpg\/v4-460px-Install-an-AC-Filter-Step-2.jpg","bigUrl":"\/images\/thumb\/c\/c5\/Install-an-AC-Filter-Step-2.jpg\/aid9464781-v4-728px-Install-an-AC-Filter-Step-2.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">Creative Commons<\/a><br>\n<\/p><p><br \/>\n<\/p><\/div>"}
    Usually, the return air is located near your thermostat, either on the same wall or nearby. It's often near the floor on the wall and looks like a vent/grate. [2] However, it may also be in the floor, ceiling, the furnace, or even the air conditioner. [3]
    Advertisement
  3. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/6\/60\/Install-an-AC-Filter-Step-3.jpg\/v4-460px-Install-an-AC-Filter-Step-3.jpg","bigUrl":"\/images\/thumb\/6\/60\/Install-an-AC-Filter-Step-3.jpg\/aid9464781-v4-728px-Install-an-AC-Filter-Step-3.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">Creative Commons<\/a><br>\n<\/p><p><br \/>\n<\/p><\/div>"}
    Find the fasteners to pull open your grill work. Often, you'll have little fasteners that pull out and allow you to open one side of the cover. Lean the cover out towards you. [4]
  4. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/6\/67\/Install-an-AC-Filter-Step-4.jpg\/v4-460px-Install-an-AC-Filter-Step-4.jpg","bigUrl":"\/images\/thumb\/6\/67\/Install-an-AC-Filter-Step-4.jpg\/aid9464781-v4-728px-Install-an-AC-Filter-Step-4.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">Creative Commons<\/a><br>\n<\/p><p><br \/>\n<\/p><\/div>"}
    Take the old filter out, being careful of the dust. Most filters will have a buildup of dust that will shake off everywhere if you're not careful. Place the filter in the trash. [5]
  5. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/d\/d3\/Install-an-AC-Filter-Step-5.jpg\/v4-460px-Install-an-AC-Filter-Step-5.jpg","bigUrl":"\/images\/thumb\/d\/d3\/Install-an-AC-Filter-Step-5.jpg\/aid9464781-v4-728px-Install-an-AC-Filter-Step-5.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">Creative Commons<\/a><br>\n<\/p><p><br \/>\n<\/p><\/div>"}
    Check for the airflow arrow on the vent. The arrow should point inward towards the duct not outward towards the grill. It should set right into the frame of the vent, as long as you have the right size. [6]
  6. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/a\/a4\/Install-an-AC-Filter-Step-6.jpg\/v4-460px-Install-an-AC-Filter-Step-6.jpg","bigUrl":"\/images\/thumb\/a\/a4\/Install-an-AC-Filter-Step-6.jpg\/aid9464781-v4-728px-Install-an-AC-Filter-Step-6.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">Creative Commons<\/a><br>\n<\/p><p><br \/>\n<\/p><\/div>"}
    Wipe down the grill with a damp rag to remove buildup of dust and hair. You can also use a vacuum cleaner if it's particularly dirty. Run the hose along the vent on the outside and inside to clean it. [7]
    7. Advertisement
Part 2
Part 2 of 3:

Working with Odd Filters

PDF download Download Article
  1. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/9\/9f\/Install-an-AC-Filter-Step-7.jpg\/v4-460px-Install-an-AC-Filter-Step-7.jpg","bigUrl":"\/images\/thumb\/9\/9f\/Install-an-AC-Filter-Step-7.jpg\/aid9464781-v4-728px-Install-an-AC-Filter-Step-7.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">Creative Commons<\/a><br>\n<\/p><p><br \/>\n<\/p><\/div>"}
    With some units, especially indoor units, your filter may be inside the unit. Find the AC closet. Pull off the front panels. They should just slide off. Often, the air filter is at the bottom. [8]
    • Before pulling the filter out, check which direction the air flow arrow is pointed so you can install it correctly.
  2. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/5\/55\/Install-an-AC-Filter-Step-8.jpg\/v4-460px-Install-an-AC-Filter-Step-8.jpg","bigUrl":"\/images\/thumb\/5\/55\/Install-an-AC-Filter-Step-8.jpg\/aid9464781-v4-728px-Install-an-AC-Filter-Step-8.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">Creative Commons<\/a><br>\n<\/p><p><br \/>\n<\/p><\/div>"}
    Sometimes, you'll have a filter on the inside of the wall when your AC is outside. Often, the filter will just slide into a metal duct. You don't even need to open a grate. [9]
  3. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/2\/24\/Install-an-AC-Filter-Step-9.jpg\/v4-460px-Install-an-AC-Filter-Step-9.jpg","bigUrl":"\/images\/thumb\/2\/24\/Install-an-AC-Filter-Step-9.jpg\/aid9464781-v4-728px-Install-an-AC-Filter-Step-9.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">Creative Commons<\/a><br>\n<\/p><p><br \/>\n<\/p><\/div>"}
    Some ACs, particularly ductless filters, have a reusable filter. Switch the unit off, then remove the cover that houses the filter. Pull the filter out and wipe it clean before replacing it. [10]
    4. Advertisement
Part 3
Part 3 of 3:

Remembering to Change Your Filters

PDF download Download Article
  1. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/7\/70\/Install-an-AC-Filter-Step-10.jpg\/v4-460px-Install-an-AC-Filter-Step-10.jpg","bigUrl":"\/images\/thumb\/7\/70\/Install-an-AC-Filter-Step-10.jpg\/aid9464781-v4-728px-Install-an-AC-Filter-Step-10.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">Creative Commons<\/a><br>\n<\/p><p><br \/>\n<\/p><\/div>"}
    Take the new air filter out of its package. It's helpful to write the date on the edge of the filter in permanent marker. That way, you know when you changed it last.
  2. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/1\/19\/Install-an-AC-Filter-Step-11.jpg\/v4-460px-Install-an-AC-Filter-Step-11.jpg","bigUrl":"\/images\/thumb\/1\/19\/Install-an-AC-Filter-Step-11.jpg\/aid9464781-v4-728px-Install-an-AC-Filter-Step-11.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">Creative Commons<\/a><br>\n<\/p><p><br \/>\n<\/p><\/div>"}
    Filters should be changed often, at least 4 times a year. However, if you live in a particularly dusty area, change it more often. You'll also need to change it more if you have pets. [11]
  3. {"smallUrl":"https:\/\/www.wikihow.com\/images\/thumb\/f\/fc\/Install-an-AC-Filter-Step-12.jpg\/v4-460px-Install-an-AC-Filter-Step-12.jpg","bigUrl":"\/images\/thumb\/f\/fc\/Install-an-AC-Filter-Step-12.jpg\/aid9464781-v4-728px-Install-an-AC-Filter-Step-12.jpg","smallWidth":460,"smallHeight":345,"bigWidth":728,"bigHeight":546,"licensing":"<div class=\"mw-parser-output\"><p>License: <a target=\"_blank\" rel=\"nofollow noreferrer noopener\" class=\"external text\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/3.0\/\">Creative Commons<\/a><br>\n<\/p><p><br \/>\n<\/p><\/div>"}
    If you have trouble remembering to change your filter, try setting a reminder on your phone or computer calendar. You can also write it on a wall calendar three months from the day you change it.
    4. Advertisement

Expert Q&A

Search
Add New Question
  • Question
    Can I fix a broken AC myself?
    Victor Belavus
    Air Conditioning Specialist
    Victor Belavus is an Air Conditioning Specialist and the Owner of 212 HVAC, an air condition repair and installation company based in Brooklyn, New York. In addition to HVAC and air conditioning units, Victor also specializes in furnace repair and air duct cleaning. He has over 10 years of experience working with HVAC systems.
    Victor Belavus
    Air Conditioning Specialist
    Expert Answer
    Outside of replacing the filter, it's typically not recommended for anyone outside of a trained professional to work on an AC unit. Just hire a professional to make sure the repair is done right.
    Thanks! We're glad this was helpful.
    Thank you for your feedback.
    If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission. Support wikiHow
    Yes No
    Not Helpful 2 Helpful 1
Ask a Question
200 characters left
Include your email address to get a message when this question is answered.
Submit
      Advertisement

      Tips

      Submit a Tip
      All tip submissions are carefully reviewed before being published
      Submit
      Thanks for submitting a tip for review!

      You Might Also Like

      How to
      Install a Split System Air Conditioner
      How to
      Install a Portable Air Conditioner
      How to
      Put Freon in an AC Unit
      How to Replace the Batteries in Most Models of Honeywell Thermostat
      How to
      Replace an Air Conditioning Unit's Run Capacitor
      How to
      Clean Split Air Conditioners
      How to
      Charge a Home Air Conditioner
      How to
      Use a Vacuum Pump
      How to
      Clean a Window Air Conditioner
      3 Easy Ways to Reset an Air Conditioning Unit That’s Not Working
      How to
      Clean a Central Air Conditioner
      How to
      Clean the Filter on Your Air Conditioner
      How to
      Install an Inwall Air Conditioner
      How to
      Clean the Outside of an AC Unit
      Advertisement

      References

      1. ↑ Victor Belavus. Air Conditioning Specialist. Expert Interview. 6 May 2020.
      2. ↑ https://www.youtube.com/watch?v=PLpsZplJx8M&feature=youtu.be&t=10
      3. ↑ https://energy.gov/energysaver/maintaining-your-air-conditioner
      4. ↑ https://www.youtube.com/watch?v=PLpsZplJx8M&feature=youtu.be&t=10
      5. ↑ https://www.todayshomeowner.com/video/changing-the-air-filter-in-your-home/
      6. ↑ https://www.todayshomeowner.com/video/changing-the-air-filter-in-your-home/
      7. ↑ https://www.todayshomeowner.com/video/changing-the-air-filter-in-your-home/
      8. ↑ https://www.youtube.com/watch?v=cZknWY1zAUk&feature=youtu.be&t=30
      9. ↑ https://www.youtube.com/watch?v=RnAwh2jJ6vA&feature=youtu.be&t=214
      1. ↑ http://time.com/4408512/air-conditioning-mistakes/
      2. ↑ Victor Belavus. Air Conditioning Specialist. Expert Interview. 6 May 2020.

      About This Article

      Article Summary X

      The filter for your air conditioning unit keeps the air in your home clean, and you should replace it every 3 months. You’ll find the filter on your return air duct, which is usually on the same wall as your thermostat or at least nearby. Look for small fasteners that pull out and let you open the cover. Alternatively, your filter might be inside the unit itself, behind a front panel. All you need to do is take out the old filter, replace it with the new one, and close the grate again. Wipe the grill down with a damp rag to get rid of any dust and you’re all set. For more tips, including how to clean reusable air conditioning filters, read on!

      Did this summary help you?
      In other languages
      Thanks to all authors for creating a page that has been read 61,528 times.

      Did this article help you?

      Advertisement