Analysis Request – Cooling Towers

The most efficient way to remove heat from a system would be via Cooling towers. Commercial buildings, factories and other large buildings make use of cooling towers for comfort cooling. Manufacturing processes such as metal extrusion, refrigeration, food processing and storage also make use of cooling towers. Cooling towers remove heat from water by latent heat of evaporation performing an essential function. Risks associated with cooling towers include corrosion, scale and microbiological activity making cooling tower water testing essential.


Critical chemical parameters in testing cooling tower water include the pH, alkalinity, calcium concentrations, and total dissolved solids. These chemical parameters can be used to calculate the Langelier index, which provides an indication of the scaling or corrosion tendency of the water. Various other chemical parameters such as electrical conductivity, calcium hardness, iron, magnesium and copper are measured alongside the Langelier index. Critical microbiological parameters include Legionella and aerobic bacteria.


Frequent testing of cooling tower water enables the implementation of a chemical treatment plan preventing corrosion, scaling, and bacterial growth. Corrosion progresses when water conductivity increases, water hardness results in mineral build-up, and the hot, humid conditions present in the cooling towers environment encourage harmful bacterial contaminants to thrive. Understanding these chemical and microbiological factors is the only way to maintain and improve your cooling tower system and avoid unnecessary down time.

How often?

Cooling tower water should be tested monthly for aerobic bacteria and chemical parameters required. Sampling for Legionella should also take place monthly when commissioning a cooling tower or implementing a water treatment plan. Once it can be shown the system is under microbial control in terms of the presence of Legionella, Legionella sampling can take place quarterly.


Water sampling should not take place immediately after the addition of a biocide or any other water treatment chemicals. Once chemicals/biocides have had sufficient time to react sampling may commence.


Whether your cooling tower is for comfort cooling or manufacturing processes if a cooling tower is on site samples must be analysed for necessary chemical and microbiological parameters.