First things first: Find out where it is.
- Filters are often located in ceilings or walls along the path of the ductwork that returns air to the air conditioning unit. Look for a removable metal cover in the ceiling, or low on a wall.
- Open the metal cover to expose the filter, remove the old filter and measure it.
- Buy a replacement filter the same size as the old one (as long as the old one fit).
- Notice that there will be an arrow on the side of the filter telling you which way the air flow is supposed to go through the filter. Install the new filter according to that air flow arrow and reinstall the metal cover. Remember you're installing
- Dispose of the old filter.
- Repeat the process every single month when the weather is hot, even if the filter’s instructions say you can wait two or three months before changing it. Our dusty Arizona air makes a/c filters extra-dirty, so they need changing more often than in other states.
If you have a window or wall mount air conditioner, the filter is located inside the unit. Here’s how to change it:
- Turn the air conditioner off.
- Take the cover off of the front of the air conditioner; you might be able to pop it off, but you might have to unscrew it. You’ll see the filter behind it.
- Remove the filter. Again, you might be able to push it out, but some models are screwed in.
- Most window and wall mount A/C filters are reusable, so instead of replacing the filter, you will clean it. Shake or vacuum the dust off of it, and then rinse it with soapy water in the laundry sink or with a hose outdoors.
- After the filter is completely dry, place it back into the unit and replace the front cover.