Operating principle
Cooling towers - Indirect cooling towers

In indirect atmospheric refrigeration, the system is cooled by circulating a water flywheel in a closed circuit. Heat exchange between the hot source and the water takes place via a heat exchanger, which in the case of high-power plants is a condenser. The water is then cooled by an atmospheric cooler, also known as a cooling tower.

In this so-called indirect application, there is no contact between the hot primary fluid and the cooling water. There may, however, be contact between the cooling water and the air. This is known as wet indirect atmospheric cooling.