Condensers are heat exchangers that transfer heat from the refrigerant to the air. There are different types of condensers including round tube serpentine condensers, oval/flat tube serpentine condensers, and oval/flat tube parallel flow condensers. Flat tube condensers are more efficient. Serpentine condensers have refrigerant flowing back and forth through tubes, while parallel flow condensers have groups of parallel tubes with some carrying refrigerant left to right and others right to left. The purpose of the condenser is to change the refrigerant vapor to a liquid by decreasing its temperature and pressure.