How Often Should You Replace Your AC Filters?

If you don't suffer from allergies, it's recommended to replace your air conditioner filters every 90 days. However, air conditioning professionals usually suggest changing them every 45 days for maximum efficiency. It's important to use the correct size and type of air cleaner when replacing the filter. If your air conditioner is working properly, you can remove the filter and buy one that is identical.

In general, most air filter manufacturers and HVAC companies recommend changing the air filter every 90 days or 3 months. This may vary depending on the location of your home, if you have pets, and the age of your system and equipment. If you have pets at home, it's best to change the filter every 60 days or 2 months. For households with several pets or people with allergies or respiratory conditions, it's recommended to change the filter every 20 to 45 days.

Vacation homes or empty houses that aren't used much can wait to change filters every 9 to 12 months. The more you use your home, the more often you'll need to change your air filter. A general rule for pleated air filters (such as those manufactured by FilterBuy) is to change them every 90 days. As the filter traps more dirt, dust and allergens from the air, its efficiency decreases. If you live in a “smaller house”, your air conditioners and ovens must pump less air with the same temperature change, which could mean fewer filter changes.

The usual recommendations range from every 30 days for cheaper fiberglass filters (which are often not very useful when filtering), to 6 months for high-end pleated filters. One of the most important things you can do on your own to take good care of your air conditioning system is to simply change your air filter regularly. Air filters are usually made of spun fibreglass (the same thing that forms the insulation of the attic) or 26% pleated paper framed with cardboard for greater stability and rigidity. Filters with higher MERV values trap small particles more effectively than filters with lower MERV scores. How often you change your home's HVAC air filter depends on how long the filter is expected to last and the different qualities in your home that affect the filter. Households with a pet generally need to replace filters after two months; those with more than one pet may need to replace the filter once a month.

When you change your air filter, you allow more air to flow through the system with lower energy consumption, which translates into better circulation, cleaner air and a lower electricity bill. Estimating how often an air filter should be changed can be complicated because of the many different variables involved. However, if you live in a smaller house, your air conditioners and ovens must pump less air with the same temperature change, which could mean fewer filter changes. The only type of filters that capture allergens and spores are HEPA, or high-energy particulate air filters. The replacement cycle of the air filter and oven filter is also affected by air outside and inside the house. The usual recommendation is that if the filter shows only a subtle layer of dirt under which the filter material is still visible, then it works properly.

Much of that hair is carried through the air and passes through the AC filters, clogging them up quickly.

Cora Koci
Cora Koci

Certified travel expert. Subtly charming web trailblazer. Devoted coffee fanatic. Amateur tv specialist. Wannabe coffee fanatic.