A dirty filter reduces air flow to the system and may lead to noisy operation, reduced efficiency and even freezing in the system. Central HVAC system air handlers (the portion of the system in your attic or interior closet) need protection from soil and airborne particles by filtration.
Most systems are recommended to have disposable filters that should be replaced periodically. If a filter gets too dirty, soil, dander, pet hair and other airborne particles can enter the unit and, through condensation, bond with the copper cooling coils, which leads to corrosion of the unit.
Most Manufacturers Recommendations
- 1"-3" thick filters be changed every 60-90 days
- 4"-5" filters every 6-9 months.
If you have a large family, pets or live near ongoing construction or dry, windy locales, it is recommended to replace the filters more frequently.
Conversely, single occupant residences with no pets and no significant environmental elements may be able to wait longer between replacements.
Check the condition of your filter monthly and replace it when it becomes visibly dirty.