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How A Cooling Tower Works



A cooling tower is a simple piece of equipment designed to remove heat energy from water through the process of evaporation.  Because water removes heat energy more efficiently than air, cooling towers significantly outperform their air-cooled counterparts.

Although there are a variety of distinctive cooling tower designs, their basic operation remains the same.

Warm water from a heat source, such as commercial air conditioning systems or industrial equipment, is pumped to the top of the cooling tower.

The warm water enters the cooling tower and is evenly spread across the top.  It then flows down over the tower fill, which spreads the water over a larger surface area increasing the water to air contact, improving heat transfer through evaporation.

Large fans in the cooling tower draw air across the fill which further increases the evaporation rate.  As evaporation rapidly dissipates heat from the water, the cooled water continues to flow down into the tower sump.

The cooled water in the sump flows back through the system to cool the heat source, and the process is repeated.

To dilute the system, a bleed-off valve opens and dumps a portion of the system water to drain.

Fresh water flows into the cooling tower through the make-up line to replenish the water that has been lost to evaporation and bleed-off.

All of these functions occur simultaneously to create a continuous open loop.