The evaporator coil is the primary contact point for warm air in a central air conditioning system. The purpose of the evaporator coil is to remove the heat and humidity from the air that is passing over it.
The evaporator coil works by drawing hot air over the coil, which is filled with refrigerant, to cool the air. Once air has passed over the evaporator coil, a fan is used to circulate the cooled air throughout the building. The evaporator coil is located inside the building. Typically, it is located directly above the air handling unit of the furnace. The other half of the central air conditioning unit is located outside. The exterior portion contains the compressor, condenser and cooling fan.
A central air conditioning unit circulates refrigerant through a series of condensers and coils to remove heat from the air in a building. The evaporator coil contains refrigerant, which extracts the heat and humidity from the inside air. The refrigerant is then circulated to the external unit where the condenser is housed. The condenser allows the refrigerant to release the heat and humidity into the outside air. The refrigerant is once again cool and ready to be circulated to the interior.