How to Change an Air Conditioner Filter

How to Change an Air Conditioner Filter

It’s important to change an air conditioner filter at least once every few months to guarantee your air conditioner works at its optimal level of performance. The filter acts as a barrier between unwanted debris and the air conditioner system . Over time dirt and debris can cause an air conditioner to run poorly and can reduce the life of the unit. A properly changed filter can also prevent allergens from getting into the house and keep the air inside the house cleaner.





Change an Air Conditioner Filter Step 1.jpg
1. Locate the filter in the air conditioner or furnace unit.While the central air conditioning unit, or condenser, is located outside the home and connected to the home through an electrical and airflow system of wires and tubes, the filter is usually located in the home’s ductwork or furnace unit.

Read the owner’s manual to find out where the filter is located.


Change an Air Conditioner Filter Step 2.jpg
2. Pull the filter compartment out of the duct or furnace.Some filters are covered by a metal strip that must be removed to gain access to the filter.

Remove any screws holding the compartment in place, and store them in a safe place so you have them after you replace the filter.


Change an Air Conditioner Filter Step 3.jpg
3. Measure the filter’s outer dimensions, and look for any identifying numbers or letters on the casing.Take measurements or the old filter with you if you’re not sure what size filter you need.

Filters come in many different varieties from the more inexpensive unit that you will need to change an air conditioner filter more often to a higher-grade filter that will trap many smaller particles and can prevent allergens from entering the air system in your home.


Change an Air Conditioner Filter Step 4.jpg
4. Slide the air filter into your air conditioning unit the same way the old one came out.Make sure the filter is placed into the compartment with the correct side facing out.

Follow the directions on the package. The sides are usually marked as air-in and air-out.


Change an Air Conditioner Filter Step 5.jpg
5. Replace any filter cover or door that you took off to gain access to the filter compartment.If you took any screws out to access the compartment, make sure they are all tightly replaced to prevent unwanted debris inside the filter compartment.


  • Another type of filter is an electrostatic filter. This filter will cost more, but it does a good job of filtering dust and particles. It also is reusable. It only needs to be cleaned with water, dried and replaced.
  • Not all filters need to be replaced. Some air conditioning units have filters that must be cleaned and reused. These can be cleaned with an air compressor or water and replaced.
  • Some of the best replaceable filters can filter out almost all fine particles and allergens. These fine filters need to be replaced more often than their counterparts because they collect so much more.

Source: How to Change an Air Conditioner Filter