Cooling Tower Types As Per Air Flow

Cooling towers can be differentiated as per the relative flow relationship of air and water.

Counterflow Cooling Towers: In counterflow towers air moves vertically upward through the fill, counter to the downward fall of water. The enclosed nature of a counterflow tower also restricts exposure of the water to direct sunlight, thereby retarding the growth of algae.

Crossflow Cooling Towers: This have a fill configuration through which that air flows horizontally across the downward fall of water. Water to be cooled is delivered to hot water inlet basins located atop the fill areas and is distributed to the fill by gravity through metering orifices in the floor of those basins. 

Crossflow towers are also sub-classified by the number of fill "banks" and air inlets that are served by each fan.

Spray-fill Cooling Towers: Spray-fill towers have no fill surface, depending only upon the water break-up afforded by the distribution system to promote maximum water-to-air contact.