How often should you change an AC Filter even if you are not running the AC?

Kelly
by Kelly
  1 answer
  • KMS Woodworks KMS Woodworks on Apr 06, 2011
    Some people swap them out monthly when being used and about every 6 months if not being used. Running the fans in an open recirculating mode will still cause the filters to "load" with dust and debris. Whether the AC is adding cooling or not. A lot of homes vary in the levels of "dust" that are prevent based on traffic patterns, pets, cleaning practices etc. The real test is to inspect and swap them out based on your particular case. When I worked in the Pharmaceutical industry we had scheduled Preventative Maintenance plans that varied from a few weeks to semi annual. Many of the large air handlers had pressure monitors that could detect when loading started to cause a reduction in air flow. A dirty or clogged filter makes the fans work harder, so keeping them free flowing put less stress on your fan motors.