It is generally recommended that you change your air filter once a month or every 3 months. However, the exact frequency will depend on several factors:
• Air filter type:
Higher filters tend to get clogged more quickly and require more frequent replacement. MERV 6-8 filters can last 3 months, MERV 9-11 may need monthly change, and MERV 12-16 should be changed monthly.
• Indoor air quality:
If you have pets, smokers, pollen, or other allergens in the home, more frequent change air filter are needed, around once a month. Dirty or clogged filters can’t effectively filter these contaminants.
• HVAC system type:
Larger and more powerful HVAC systems with higher air flow require more frequent filter changes. A smaller window unit filter may only need changing once every 3-6 months.
• HVAC runtime hours:
The more your HVAC system runs, the faster filters will get dirty. So you may need monthly filter changes in very hot or cold climates where the system runs most of the time. In moderate seasons, 3 monthly filter changes may suffice.
• Noticing decreased airflow or performance:
If you notice your HVAC isn’t blowing as strongly, isn’t cooling/heating as well, or is running noisier, it is likely time for a new filter. Clogged or dirty filters reduce performance and energy efficiency.
• Seeing visible dirt or damage:
Inspect filters regularly and change immediately if they look visibly dirty or damaged. Even if not due for scheduled change, a failing filter should be replaced right away.
Some recommendations to help keep good filter maintenance:
• Check your filters at least once a month and change them before they get too clogged.
• Keep extra filters on hand so you can change them on schedule. This avoids running out and going longer between changes.
• Choose high-quality, high-MERV rated filters for the best filtration. Cheaper filters get clogged faster and don’t filter as well.
• Consider electronic or pleated filters which tend to stay cleaner longer before needing replacement.
• Be sure to also perform regular duct cleaning and disinfecting, especially in homes with allergens or illnesses. Filters work with ducts and HVAC components to properly filter the air.
• Consult your HVAC equipment manual for any specific recommendations on filter type or change schedules. The guidelines may vary depending on your system model and size.