One of the least expensive things that can be done in order to maintain the air conditioning system is to change its air filters. When air pollutants and dirt get lodged into the air filter, it can not only damage your health, but it can damage your equipment. If your equipment becomes damaged, it can be expensive to replace or repair your cooling system. Luckily, taking the steps to change your air filter are relatively painless and simple.Find the furnace and its filter compartment. Usually, this part if covered by a piece of metal that can easily slide out of its position and back in again.Figure out how large the air filter is. The size will probably be noted on the size, appearing as 15x15x1 or a size similar to that format.Go to the store and buy a filter to replace the old one, and