In a central air conditioner, there is an indoor unit (typically a furnace and evaporator coil or fan coil) and an outdoor unit (often referred to as the air conditioning unit). Each of these units houses a coil that is vital to the air conditioning process (learn how ac works). Inside the home, the evaporator coil is located on the air intake side of the fan coil or the outlet side of the furnace. Its job is to remove heat from indoor air so the blower fan can return cool, refreshing air to the home. The condenser coil, found in the outdoor unit, releases that captured heat outside. Most evaporator and condenser coils are made of copper tubing which runs through a series of thin, aluminum strips called fins. If you need help, you can always contact a Carrier HVAC Dealer.