The Quick Hack To Tell That It's Time To Replace An Air Conditioner Filter

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If you're looking to prolong the life of your AC system, maintain good air quality, and keep your space a comfortable temperature, it's necessary to give your unit a bit of TLC every now and then. Of course, more involved tasks like regular tune-ups, addressing odd noises, or repairing a refrigerant leak should be left to the pros, but a basic job like switching out a filter can be handled on your own in a matter of minutes. When you let this task fall to the wayside for too long, it can put unnecessary strain on your unit, but doing so too often is just a waste of money. Thankfully, there's an easy hack to determine when you should change your AC filter: Hold it up to the light.

While this advice might sound silly at first, it's a very reliable way to better understand how dirty your filter actually is. Rather than just looking at it in your home and making a vague judgment on its remaining lifespan, holding your filter in front of a light source — ideally the sun — can give you a much better perspective on what's able to get through the material. If it fully or almost entirely blocks the light behind it, it's a safe bet to assume that airflow is severely limited, too.

Your filter's appearance in the light should be enough to give you a good idea of its current state, but there are a few other factors you can consider if you want to confirm your decision. As a general rule of thumb, a standard 1 inch thick pleated filter should be changed around every one to three months, but this varies widely based on usage. As our article on how often to change your air conditioner filter suggests, there are different factors at play that will determine when to switch.

There are also a few other signs around the house you can look out for. If your electricity bills are soaring and there haven't been any major changes to the weather or your routine, a dirty filter might be to blame — your unit has to push harder to get air through the material, driving up energy usage. You could also notice a decrease in overall air quality. This can look like a bit more dust than usual, but to those who have increased allergies or sensitivities, the impacts will likely feel more direct.

Thankfully, changing your filter is an inexpensive and easy process. They're usually found behind a grill or directly on the unit, housed somewhere they can be removed without any tools. You can pick up a four pack of Filter King MERV 8 Air Filters for about $40 on Amazon, setting you up for anywhere from four months to a year of clean air. Make sure to add this task to your regular to-do list and you should reduce the chances of more serious problems down the line.