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Closed-Circuit Cooling Towers

The tried and true method used for process waste heat removal has long been the cooling tower. There are several types of traditional open cooling towers – natural draft or mechanical draft, crossflow or counterflow – but open cooling towers share some common drawbacks. An alternative type that solves some of these inherent problems is growing in popularity: the closed-circuit cooling tower.


Though effective and simple in design, open cooling towers expose process cooling water to the outside atmosphere, which contains contaminants. These contaminants can cause a variety of cooling tower problems, namely scale, corrosion and biological fouling. To control these issues, these systems require frequent maintenance and costly chemical treatment.


Closed-circuit cooling towers are similar in operation to open cooling towers, but process fluid flowing through a heat exchange coil is isolated from the atmosphere in a closed loop, preventing airborne contaminants from entering the system. A second, external circuit sprays water over the coil, transferring heat to the atmosphere through evaporation. While closed-loop systems are initially more expensive than traditional cooling towers, they pay for themselves within a few years with reduced maintenance requirements, reduced water treatment costs, conservation of water, and increased energy efficiently. Closed-circuit towers also allow for free cooling operation during the winter, a feature that is not possible with an open tower.


For more information on closed-circuit cooling towers, please call MSC / Mechanical Service Corp. at 973-884-5000.