Your air filter serves an extremely valuable purpose when it comes to your heating and cooling systems. Without it, your air handler (the blower fan and other indoor components of your furnace or air conditioner) could suffer damage due to the force of incoming debris. But the filter media blocks the way and keeps your equipment protected.
You must change the filter every 1-3 months if you expect your air conditioner or heater to do its job, and not for the reason many people think. A quality filter does keep many allergens out of the air, but the reason we recommend regular changeouts is to continue to protect your AC and heating equipment. A clogged filter could keep air from flowing into the system with ease.