The general consensus among HVAC professionals is that you should replace your 16x20x1 air filter every 90 days or every three months. However, this depends on the thickness of the filter. Fiberglass air filters are the more affordable option, but they are less efficient at capturing dust and particles from the air. It is usually recommended to change these filters every 30 days or as recommended by the manufacturer.
Pleated air filters should be replaced approximately every three to six months, depending on several factors such as your home, occupants, and location. Thicker filters have more room to accumulate dirt and dust, so they don't need to be changed as often. Thomas & Galbraith Heating, Cooling and Plumbing, of Ohio, recommends changing filters less than 2 inches thick every 30 to 90 days. Three- or 4-inch filters can last 6 to 9 months, and filters up to 6 inches thick can be replaced once a year.
If you live alone, don't have pets, and the outdoor air around you is of good quality, the manufacturer's recommendations for changing filters will probably work well for you. Because filters with higher MERV ratings are denser, your oven must work harder to get air through them, and not all ovens have enough power to do so. On average, you should change a fiberglass air filter about once every 30 days, while you can leave a pleated air filter for three to six months before having to replace it. If you have allergies, you can reduce symptoms by using a high-quality air filter and adopting a more frequent replacement program.
Be careful not to confuse Honeywell oven filters with HEPA air filters for purifiers, which last much longer. The filters are designed to trap dust and particulates suspended in the air as the air passes through the filter and into the furnace system. After a period of smoke-filled days and poor outdoor air quality, inspect the air filter to see if it needs to be changed. Use a filter with a MERV rating of 12, such as the Nordic Pure Filter (available on Amazon), if your oven can handle it.
