One of the best ways to ensure the efficiency of your air conditioner is to routinely replace and clean its filters. Clogged, dirty filters block normal airflow and significantly reduce a system's efficiency. With normal airflow obstructed, air that bypasses the filter may carry dirt directly into the evaporator coil and impair the coil's heat-absorbing capacity.
Some types of filters are reusable, but others must be replaced. They are available in a variety of types and efficiencies. Clean or replace your air conditioning system's filter every month or two during the cooling season. Filters may need more frequent attention if the air conditioner is in constant use or is subjected to dusty conditions.