The normal function of a condenser is to transform hot discharge gas from the compressor to a slightly sub-cooled liquid flow, by transferring heat from the refrigerant gas to the secondary cooling liquid.
The basic operation of condensers is divided into three parts: desuperheating, condensation and sub-cooling. All three operations can be carried out inside the condenser. The total heat transfer is called the Total Heat of Rejection (THR). Alternatively, the desuperheating or sub-cooling operation can be carried out in a separate heat exchanger.