Another essential job that your air conditioner filter does is helps to keep dust from collecting on the evaporator coil of your air conditioning system http://www.alaskanhomeservices.com/ac-repairs/ . It is found inside the air handler, and is one of the 4 main components of any air conditioning system. The air filter is typically found somewhere just before the evaporator coil.
Any dust that passes through the filter ends up back in your living space, and can be really irritating to allergy sufferers, and anyone else who is sensitive to dust. The filter also prevents the evaporator coil from becoming congested with dust, and decreasing the efficiency of the equipment.
This evaporator coil is very similar to the radiator in an auto. Like your vehicle radiator, it will not be able to do its job without proper airflow. The reason Im comparing it to an automobile radiator is because many of us know exactly what a radiator does, however, an evaporator coil works to cool air as it passes through.
It could take months or even years for dust to build up on the fins of the evaporator coil. If your air conditioner is serviced routinely, the technician will check this and inform you when it has to be cleaned. If this is not done, it will result in pricey repairs.
So the perks of an effective air conditioner filter would not only be cleaner air, but also save you money, since the air conditioning unit will perform at a higher efficiency.