The general consensus among HVAC professionals is that you should replace your oven filter every 90 days or every three months. However, this may vary depending on the thickness of the filter. Thicker filters have more room to capture dirt and dust, so they don't need to be changed as often. For 3- and 4-inch filters, it's recommended to replace them every six to nine months.
If you have larger 5- or 6-inch filters, they should be changed every nine to 12 months. If you suffer from allergies or are sensitive to dust and pet dander, you should change your air filters more frequently than every 90 days. Try replacing them after 60 days and, if your allergies continue to worsen, consider changing them every month or switching to pleated filters. In general, most air filter manufacturers and HVAC companies suggest changing the air filter every 90 days or 3 months. This may differ depending on the location of your home (e.g. dry and dusty climates), if you have pets, and the age of your system and equipment.
If you have pets in the house, you should consider changing the filter every 60 days or 2 months, and for households with multiple pets or people with allergies or respiratory conditions, it's recommended to change the filter every 20 to 45 days. Vacation homes or vacant homes that don't get much use can usually wait to change filters every 9-12 months. The more you use your home, the more often you need to change the air filter. Air filters are usually made of spun fiberglass (the same as attic insulation) or pleated paper framed with cardboard for added stability and rigidity. If outdoor temperatures are extremely cold or hot and your oven or air conditioner is running non-stop to keep up to date, filters that should have lasted 90 days will need to be changed every 30 days to ensure your HVAC system is working properly. Having multiple animals means you need to change a one- or two-inch filter every month, a four-inch filter every two months, and a five-inch filter every three months.
Not many homeowners set their calendars for the next furnace filter replacement, but it's an essential step in keeping their heating and cooling system in top shape. Another fundamental consideration is air quality, which is affected by the amount of pollutants floating in the air. Doors and windows open frequently can also contribute to a buildup of dust and outdoor air pollutants in your home, adding an extra layer of dirt to air filters. If you're a pet owner, you'll want to change the air filter every 2 months, especially when winter turns to spring and summer to fall. For an animal that lives at home, you should change the filter every two months for a one- or two-inch filter, four months for a four-inch filter, and six months for a five-inch filter. These air filters act as barriers to prevent contaminants from entering the HVAC system or circulating in the air.
But what happens if you let that time go by a little? Before we talk about WHEN the air filter should be changed, let's start with the WHY. One of the most important things you can do on your own to take good care of your HVAC system is to simply change your air filter on a regular basis. If you answer yes to this question, you'll want to change your filter every 6 weeks to maintain the best indoor air quality. In general, filters with a MERV 16 rating or lower are considered HVAC system grade filters for residential, commercial, and general hospital use. Because filters with higher MERV ratings are denser, your oven must work harder to draw air through them, and not all ovens are powerful enough to do so.