To change the temperature in your home, your air-conditioning system sucks in air from a room, pulls it over AC coils to chill it, then blows the tempered air through ducts to the other rooms in your home. The air filter is stationed at the point where air is pulled into the system. It traps airborne particles that get sucked in with the air and keeps them from blocking the blower and clogging up the coils. Clogged coils can't heat or cool the air passing over them, and they may damage the system. So, the air filter helps your heating and cooling system do its job, keeps it running efficiently and protects it so it will last longer.
AC filters also help to keep dust from building up in your ducts, or being blown into other rooms of your house. In recent years, this air cleaning function has become more important to homeowners, and manufacturers have designed air conditioning filters that use your heating and air system to remove microscopic particles like dust, pollen, pet dander, bacteria, plant and mold spores, and even smoke from the air in your home. It's an often heard phrase: Clean AC filters save energy and money. Routinely changing or cleaning the filters from your home's air conditioning system helps the units run more efficiently and enjoy a longer lifespan.