How to Change Your AC Filter in Minutes

You're just a commercial break or two away from a fresh, new air filter

Lydia Schapiro
Written by Lydia Schapiro
Updated May 11, 2022
woman resting on sofa turning on air conditioner
Photo: fizkes / Adobe Stock


Flex your DIY muscles.

Time to complete

15 minutes

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What you'll need:


  • Tape measure or ruler
  • AC manual
  • New AC filter

HVAC filters help maintain your home’s air purity and quality, so it’s important to show yours some TLC. Regularly replacing your AC filter is a great way to help improve your home’s air and maximize your HVAC unit’s functionality. 

Luckily, changing your AC filter is an extremely doable project for almost anyone and won’t take longer than a few minutes once you get the correct filter. For maximum efficiency, aim to change your filter every one to two months.

  1. Locate the AC Filter

    woman locating filter in ac
    Photo: Andrey Popov / Adobe Stock

    One of the most involved parts of this process is finding the AC filter since it could be in various places. With some systems, the filter is located in the return air duct, the vent that’s attached to the wall, or somewhere near or within the HVAC unit. Try looking above or below it or on the air return side of the HVAC unit. If you’re stumped on finding yours, this is a great time to break out the manual.

  2. Identify the AC Filter Type

    To ensure you get the proper replacement, it’s important to note what type of air filter you currently have. You can usually find a label on the side of the filter that indicates its type. Take a photo of the label to bring to the store, and show it to an employee who can help you find the correct replacement.

    If you can’t find the label, look in the manual to see if it indicates what type of air filter you’ll need. If there’s no label or instructions in the manual, it won’t hurt to take a photo of your current air filter to see if a sales associate can help.

  3. Determine the Filter’s Size

    You’ll also have to make sure you know the size of your current air filter. Ensuring a tight filter fit is crucial to its functionality.

    You’ll often find instructions in your AC manual for which size air filter to purchase. If you can’t find any, you can usually find the filter’s dimensions printed on the filter frame. If all else fails, you can manually measure the dimensions with a tape measure or ruler. Write down the dimensions so you can take them to the store when purchasing your new filter.

  4. Turn Off Your Unit

    Make sure your thermostat is off before changing your AC filter. Doing so helps protect the HVAC system from debris getting inside and accumulating. Plus, it reduces the chance of dirty air circulating your home.

  5. Remove the Old Filter

    Removing the old filter is simple—just slide it out of its place. If you can, immediately place it in a garbage bag so the dust doesn’t scatter around the room.

  6. Insert Your New AC Filter

    man changing/replacing ac filter
    Photo: Александр Поташев / Adobe Stock

    Inserting the new air filter is easy: you just have to place it back in. It is, however, crucial that you slide it in the right direction according to airflow arrows. 

    Air filters are designed to filter the air from one direction so that as they become loaded with dirt, they don’t collapse. If you’re having trouble, arrows on the filter’s frame show you the direction the air should flow, which will be away from the return air duct and toward the air handler mechanism. 

    There should be a snug fit—if you notice any gaps, the filter is probably the wrong size.

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