The ideal schedule for cleaning or replacing your air filter is based on a variety of factors, like the filter design and MERV rating as well as the existing indoor air quality. For conventional 1”-3” filters, most brands advise replacement every 30-90 days. Pets, health conditions and even local pollution sources can encourage replacing the filter more often.
A 1″ pleated air filter must be replaced every 30-60 days.
A 2″ pleated air filter should be swapped out every 3 months.
A 3” pleated air filter should be exchanged every 120 days.
A 4″ pleated air filter should be exchanged twice per year.
A 5” or 6″ pleated air filter ought to be replaced every 9-12 months.