For your average residential filter 1” – 3”, manufacturers basically tell you to change them bi-monthly which is a great rule of thumb but may not suit your individual needs. Here are some guidelines:
Vacation home or single occupant homes without pets or allergies: change 6-12 months
Typical suburban home without pets: change every 90 days
House with a pet: change every 60 days
Multiple pets or allergies: change every 30-45 days
When choosing what kind of filter you need, it is important to remember that airflow is a critical component of your system. Disposable pleated filters are constructed of paper and polyester and do a good job at filtering most household particles and allergens, however, they may limit airflow. Disposable fiberglass filters filter out less allergens and finer particles though will allow greater airflow. The higher the cost of the filter, the more dust and particles it will collect. We recommend finding a balance that works for you between indoor air quality and the frequency in which you change filters.