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Cooling towers are primarily used to cool water in air conditioning systems
Many people overlook the importance of the cooling tower to the overall energy efficiency of a building's cooling system. 

 

Consider if you will, that a cooling tower is nothing but a great big air washer. The outside air that is drawn into the tower is contaminated with pollutants, dust, pollen, exhaust byproducts, insects and whatever else is suspended in it. As the water falls through the air stream, it captures these contaminants and carries them into the basin. This water, in turn, is delivered to the chiller. As the cooling water is heated in the chiller by absorbing heat from the refrigerant, the contaminants precipitate out of the water and adhere to the chiller tube walls, reducing the efficiency of the chiller. The result of all this is increased energy and maintenance costs.
 

Heavier contaminants will tend to settle to the bottom of the cooling tower basin creating "dead" areas. These dead areas form a shield between the basin surface and corrosion-preventing chemicals that are added to the water. This leads to under-deposit corrosion of the metal surfaces. Once corrosion begins, blisters form which release oxide particles which add more suspended solids to the condenser water stream. In addition, mud, dirt and debris in the basin provide an ideal environment for microbiological organisms, some of which secrete an acidic solution that can contribute to additional corrosion. Some of these microorganisms represent a health risk to maintenance personnel, and if released from the tower in the form of aerosols present a risk to the general public. 

 

Having examined the effect a dirty cooling tower has on overall air conditioning system efficiency, it makes sense to keep the cooling tower as clean as possible as well as to perform maintenance on the tower at regular intervals.

 

We all know that with today's energy costs and the vulnerabilities of the power grid, it is in every maintenance professionals' interest to operate as efficiently as possible. Maintaining a clean cooling tower results in colder chilled water being delivered to the chiller increasing the efficiency of the chiller and making chiller tube cleaning easier. Economically it just makes sense. So let's keep those cooling towers clean.