The typical air conditioner has an “Indoor Unit” consisting of an evaporator coil and a blower, and an “Outdoor Unit” that contains the compressor(s), an outdoor coil and a fan which is collectively called a Condensing Unit. The outdoor unit compressor pumps refrigerant through the system to gather heat from inside the home and remove it to the outside. In the process, heat and moisture are removed from the indoor air of the home by blowing warm, moisture-laden air over the cooled indoor evaporator coil. The moisture from the humid air condenses on the evaporator coil and drips down into the drain pan where the water collects and is piped to the condensate drain. The heat that gets transferred to the evaporator coil transfers to the refrigerant and is carried to the condensing unit outside where the refrigerant gives up its heat to the outside air by way of the outside coil and fan. The cooled refrigerant then goes back into the home to remove more heat and humidity.

There are many brands and configurations of air conditioners. The units described above are called a “Split System” and is typical in homes. In some homes all of the components are housed in the outside unit and only ductwork enters the home. This is referred to as a “Packaged Unit.”