Wet Coolers are heat exchangers when water and air together are used as heat transfer medium. In such coolers the water falls downwards over the tubes relying on latent heat of water evaporation and the fresh ambient air passes upward due to induced draft fans over the wet coils exchanging the heat and which is released in to the atmosphere.
The Closed circuit cooling towers operate similar to open cooling towers, however The heat to be rejected is transferred from the process fluid (inside the tubes which is to be cooled) to the ambient air through a heat exchange coil.
Water scarcity is a growing concern and freshwater is becoming a critical natural resource; hybrid cooling solutions where applicable can significantly reduce process water consumption. Hybrid cooling tower combines dry cooling and evaporative cooling to provide heat rejection and reduce water and energy consumption.