How often do you need to clean air conditioner filters?

The question's a bit misleading - schedules like "every 2-4 weeks" only really work if you know your climate and how often your AC actually runs. It's better to go by the filter's actual condition rather than counting days.

Just check it yourself: open up the AC unit, pull out the filter, and see if it's clogged with dust. If you see a gray coating - time to clean it. If it's white or clear - it can keep going. At my place, during summer with the AC running, the filter gets clogged in about two or three weeks. In winter I forget about it for months. If you've got pets or your windows face the street, checking it every two weeks makes sense. If you live somewhere quiet, you can just peek at it once a month.

One thing worth paying attention to: when the filter gets really clogged, the AC doesn't cool as well and runs louder. That's a sign you should've cleaned it ages ago. You usually just rinse it under the tap or in the bathtub, let it dry, and pop it back in - takes five minutes tops.

Have you already noticed the air not blowing as well? The easiest thing is to just look at the filter itself: if it's already gray from dust and clogged up, it's time to clean it, regardless of the calendar. That said, it makes sense to check it visually at least once every week or two, so you don't let it get to a critical state where the air conditioner starts running on empty and putting unnecessary strain on itself.

I have an air conditioner that runs year-round, and I've noticed that if you don't clean the filters about once a month, the cooling power drops and your electricity bills go up. What works for me is a simple rule of thumb - when you can clearly see dust on the filter, it's time to wash it, even if it's only been two weeks.

What your climate is like and how often you run the AC - those are the deciding factors. In my case, it's on almost constantly during summer, and I've found that visually checking the filter works better than following some universal schedule. When the filter starts getting seriously clogged, the airflow noticeably weakens, even though it might look fine at first glance.

The main pitfall is that a lot of people mix up the main evaporator filter (the one inside the cassette) with the mesh screen at the inlet. You need to clean both, but they clog differently. The protective mesh can get blocked quickly, but the main filter sometimes needs replacing rather than just rinsing. Check both spots, or you might think you're cleaning the unit when you're barely doing anything.

Ideally, set a phone reminder for every two weeks, but not as a hard rule - just as a signal to visually inspect. If you don't live in a big city and there are no pets in the house, once a month might be enough. If the AC runs constantly and there's a lot of dust around - every 10 to 14 days. The main thing is don't wait until the air barely comes out at all.