Theory and operation - Evaporative cooling
The closed circuit cooling tower exploits the same physical principle of the open circuit cooling tower in order to dissipate the heat: the forced evaporation of a minimal quantity of water produces a lowering of the temperature of the main mass of water.
The fluid to be cooled enters the upper header of a coil which is constantly wetted by the recirculating water of the small, pre-assembled evaporative circuit of the unit.
The evaporation of a part of the recirculating water removes the heat from the heat exchanging surface of the coils.
The cooling performance of a closed circuit cooling tower depends on the ambient wet bulb temperature.