Air conditioning filters are one of the most important parts of the unit. Dirty or clogged filters can cause loss of efficiency, overwork, and ultimately failure of the unit completely.
However, AC filters are one of the easiest things to work on within any given air conditioner, whether it is a room type model or a whole house central air conditioning unit.
Types of filters
Portable room type of air conditioners will generally have a foam filter installed behind the grill. These types are easily cleaned by a thorough rinsing, or if they become damaged, they can be purchased at any hardware store and cut down to size.
Central air filters look much like a standard furnace filter and would be located in a return duct, usually next to the furnace itself. These are not easily cleanable and would be better off by being replaced.
Clean or replace monthly
Both AC manufacturers and the US government stress cleaning or replacing filters on a monthly basis for optimum efficiency, and energy savings. However, take into consideration facts like pets, living in dusty conditions or constant usage as a sign that cleaning or replacement may have to be done more often.