Cooling towers are an integral
part of temperature control systems in modern plants, offices, shopping
centers and apartment structures. The increased efficiency of a cooling
unit that combines water and air evaporation makes such equipment the method
of choice for commercial cooling.These recirculating cooling
devices function through the evaporation of a small portion of the water
by a stream of air that absorbs enough heat so that the remainder of the
water is cooled. This cooled water is then circulated through heat exchangers
that reduce the air or liquid temperature of the system.Such cooling towers or evaporators
are similar to air scrubbers. They remove chemicals and biological contamination
from the air and trap it in the cooling liquid. Without antimicrobials,
such systems can rapidly become contaminated with a variety of microorganisms.
The presence of slime deposits reduces heat transfer and increases energy
requirements.The occurrence of possible
pathogenic organisms is a secondary concern in cooling towers and evaporative
condenser systems. Most microorganisms in cooling towers are of environmental
origin and non-pathogenic to most humans and animals.However, each cooling season,
some people develop pulmonary disease due to Legionella pneumophila.
Antimicrobials are used in these systems to prevent illness in persons exposed
to mists from such units. An additional benefit is optimum operational efficiency.
