The answer to 'what does air filter do' is an air filter is an essential component of your HVAC system that helps improve indoor air quality and the efficiency of your heating and cooling equipment. Air filters trap airborne particles like dust, pollen, pet dander, and other debris before they can circulate through your home's ductwork and living spaces.
A clean, properly-sized air filter allows air to flow freely through your HVAC system, ensuring it operates at peak efficiency. This helps reduce your energy costs and extends the lifespan of your furnace, air conditioner, and other components. Replacing air filters on a regular schedule is an important part of HVAC maintenance that all homeowners should follow.