What is an outdoor condenser coil?

expert EXPERT April 26, 2007

The outdoor condenser coil transfers heat from the refrigerant into the outdoor air (or into water if it's a water-cooled system). The refrigerant enters the condenser coil from the compressor as a hot (e.g.,150F) gas. The gas condenses to a liquid as the 95F outdoor air (for example) is pushed past the coil by the condenser fan. The air coming off the condenser coil may be 110F.

The condenser coil is in a cabinet often call the condenser unit although it contains the compressor and the condenser fan as well as the condenser coil. This cabinet is not normally opened or serviced by the homeowner. Live 240-volt electrical connections are accessible inside the cabinet. A good deal of information can be gained by opening the cabinet but this should only be done by someone familiar with air conditioner systems and experienced in working around live electrical equipment. In some jurisdictions an outdoor electrical disconnect is required so the outdoor unit can be serviced safely. Removing the access panel to the compressor allows you to examine the compressor shell and determine the compressor age from its data plate. You can also look for a failed capacitor (bulging or leaking), oil leaks (which indicate refrigerant leaks) or corroded and obstructed coil fins, for example.

Condensers are typically copper tubes with aluminum fins. The bottom of some condensers are liquid receivers that collect the condensed refrigerant. Some receivers are separate from the condenser. Some modern coils are all aluminum; these may have a shorter life span than copper tube coils.

The condenser unit can be noisy. Its location should take this into consideration. A condenser unit that is adjacent to a patio, for example, may be a nuisance.