Because cooling towers operate in outdoor environments, they are exposed to the weather which can cause debris and dirt to accumulate and local wildlife and pests to gather, which are attracted by the wet and warm environment. These two factors can cause serious operational problems. Below is a brief guide to 3 common problems which affect cooling tower systems.


Scaling occurs when minerals such as calcium carbonate which were dissolved in the water supply build up within the cooling tower system. The formation of scale can reduce the efficiency of the cooling tower's heat exchange process, which means that every part of the system must work harder in order to maintain the proper levels of cooling. Factors which can contribute to increased scaling include the pH level, quality and temperature of the water supply.


Fouling happens when particles such as oil, organic matter and silt, which have been suspended in the water supply fall out and form a deposit. The deposits created by the fouling process have a similar impact as scaling as they form an additional layer of insulation which reduces the system's heat exchange capability and places additional strain on the cooling tower. Causes of fouling include corrosion, leaks and low water velocities.

Microbiological Growth

Because they are warm and wet, cooling towers are the ideal environment in which microorganisms can grow. There are two types of microbiological growth which occur within cooling towers.

  • Planktonic: This type of growth is normally found floating within the water supply.
  • Sessile: This refers to biological growth which develops on surfaces within the cooling system.

Microbiological growth can cause problems within a cooling tower system because it has insulating properties and can also contribute to increased levels of corrosion within the system. Also, the byproducts produced by microbiological growths can contribute to the development of further microbiological activity. For this reason, it can be very difficult to kill and remove any microbiological growth. Microbiological activity can occur on the tower structure, on heat exchange surfaces and in the system's piping. It is important that you monitor and treat any outbreaks of biological activity in a cooling tower so its growth can be limited and controlled.

If you notice any of these conditions developing within your cooling tower, it is vital that you contact a professional cooling tower maintenance and repair service, who will be able to assess the problem and carry out any required work on the system.