The function of cooling towers is to remove residual heat from water that is circulated through a series of pipes and equipment. Though there are several design types of towers, they all function using the same principals of evaporating water to cause a cooling effect. By nature, cooling towers use large quantities of water. Evaporation obviously accounts for a large portion of this loss. Drift, actual drops of water that are drawn off the tower, likewise account for large quantities of water loss.
Drift also carries chemical treatments with it.
This causes an environmental problem as well as a potential liability problem. Cooling towers are normally chemically treated for control of algae, bacteria, corrosion and scale. Hard water scale will form both on the baffles of the tower, and on the equipment that the cooled water is used for, such as evaporators, chillers, condensers, heat exchangers etc. Towers using spray nozzles will frequently experience clogging of these nozzles also. It is common for hard water scale to form even with a chemical treatment program.