Cooling Tower Water Consumption: Where Does the Water Go?

Cooling towers use water continuously, but not all water leaving the system is lost in the same way. Understanding the main sources of water loss can help operators identify where efficiency improvements are possible.

Evaporation Is the Main Water Loss

The primary purpose of an evaporative cooling tower is to transfer heat through evaporation. As water evaporates, dissolved minerals remain in the circulating water, which gradually increases the concentration of dissolved solids.

For this reason, water consumption cannot be eliminated simply by changing the cooling tower fill. The operating strategy and water management system also need to be considered.

Blowdown Removes Concentrated Water

As dissolved solids build up in the circulating water, part of the water is intentionally discharged through blowdown. Fresh make-up water is then added to maintain the required water quality.

Controlling cycles of concentration can therefore have a direct effect on cooling tower water consumption. However, pushing concentration too high without appropriate water treatment can increase scaling, corrosion, or fouling risks.

Drift Is Different From Evaporation

Drift occurs when small water droplets are carried out of the tower with the exhaust air. Unlike evaporation, these droplets contain liquid water and dissolved substances from the circulating system.

Properly selected and installed drift eliminators can help reduce this type of water loss and limit water carryover from the cooling tower.

Where Does Cooling Tower Fill Come In?

The fill itself does not control all water consumption, but its condition can influence how effectively water is distributed and exposed to airflow. Damaged, heavily fouled, or poorly installed fill may affect cooling performance and force operators to change operating conditions to maintain the required outlet temperature.

Water Efficiency Requires More Than One Adjustment

A practical water-saving strategy should consider evaporation, blowdown, drift, water treatment, heat load, airflow, and cooling tower condition together. Simply reducing blowdown or changing one component may create another operating problem if the overall water chemistry is not controlled.

For projects where water consumption is a major concern, our team can review the cooling tower fill arrangement and operating conditions and help determine whether a different fill material, structure, or related component should be considered.

Related Cooling Tower Products

Drift Eliminators |Crossflow Film Fill |Counterflow Film Fill |Splash Grid Fill