An air conditioner’s condenser is a component which turns gas into liquid via a cooling process. Warm gas in the form of refrigerant vapour from the compressor enters the condenser coils at the top end; as it is condensed, it drains down to the bottom of the coils and into a receiver unit.
The receiver unit holds any surplus liquid refrigerant. The condenser’s function in an air conditioner is to release the heat from the refrigerant to the air surrounding the coils. Split system air conditioners have a separate condenser unit located outdoors.
There are various designs of condenser used in air conditioners; these include tube coils, finned tube, plate, series-pass and parallel-pass. Condensers can be further classified by cooling method employed, either water cooled, air cooled, or combined air and water cooled condensers.
Air cooled is the most common type in residential applications, and consists of a coil across whose surface air is passed, either by a fan or through natural draft. In a water cooled condenser, the cooling is done entirely by water circulating through enclosed coils or tubes.
The refrigerant to be cooled circulates in the annular space between tubes or coils. Combined air and water cooled condensers, also known as evaporative condensers, use water sprayed on the coils to cool them as well as cold air.
The problems that are seen in condensers typically are that the pressure in the compressor is too high or the condenser pressure is too low. The causes of pressure being too low in the compressor include a faulty discharge or suction valve in the compressor, a refrigerant change that is too low and needs recharging, or the evaporator’s entering temperature set too low.
Causes of too high a pressure in the compressor could include a dirty air conditioning condenser which needs cleaning, refrigerant charge which is too high, and air in the system which should be purged.