How Cooling Tower Fan Works

A cooling tower fan works by moving air through hot water so heat is removed by evaporation. Here’s the simplest explanation:

How a Cooling Tower Fan Works

1. Hot water enters the tower

  Warm water from a chiller or industrial process is pumped to the top of the cooling tower.

2. Water spreads over the fill

  The water flows through spray nozzles and across fill media, forming thin films or droplets.

3. The fan moves air through the tower

  The fan, driven by a motor, pulls or pushes large amounts of air through the falling water.

  * Most towers use an induced-draft fan at the top that pulls air upward.

4. Evaporation removes heat

  A small portion of the water evaporates into the air.

  Evaporation absorbs heat, cooling the remaining water.

5. Cooled water is reused

  The cooled water collects in the basin and is pumped back to the system.

Why the Fan Is Important

* Controls airflow and cooling capacity

* Improves heat transfer efficiency

* Helps reach the lowest possible water temperature (limited by wet-bulb temperature)

* Saves energy when used with a VFD

One-Line Summary

> A cooling tower fan moves air through warm water, causing evaporation that carries heat away and cools the water.