Which Cooling Tower System Is Best for You?
Cooling towers are used to cool and circulate water used in places such as refineries, petrochemical plants and other chemical plants, thermal power plants and building air conditioning systems. Cooling towers cool the water flow to a lower temperature by evaporation, rejecting the waste heat to the atmosphere.
There are two different types of industrial or HVAC cooling tower designs: closed circuit cooling tower systems and open circuit cooling tower systems. Both types of towers serve the same purpose, but they cool the water in different ways.
How do open cooling towers work?
A direct open circuit cooling tower is a closed structure that distributes warm water over a labyrinth of fill or packing, which provides an expanded air-water interface to heat the air and evaporate. The water is cooled as it flows through the packing and then collected in a cold water basin below. The heated, moist air that leaves the packing is discharged to the atmosphere.
More information on closed cooling towers
Closed circuit cooling towers, or dry cooling towers, involve no contact between the air and the fluid being cooled. This tower has two separate fluid loops, with the fluid in one loop recirculating outside the second loop, which is a bundle of tubes in which hot water flows. Air drawn through this cascading water provides evaporative cooling similar to an open cooling tower, except the cooling water never comes in direct contact with the air. A closed cooling tower requires more energy to achieve the same cooling effect as an open cooling tower.
Different Types of Closed Cooling Tower Systems
Another closed circuit cooling tower system includes a separate heat exchanger assembly and an open cooling tower. The fluid on the hot side of the heat exchanger also never comes in direct contact with the air. This allows the heat exchanger to be placed indoors, protected from outdoor weather elements, and offers other system advantages. This closed system has a much longer lifespan than an external coil closed circuit cooling tower.
Are Both Cooling Towers Effective?
There are so many factors and details to consider. You may be wondering, “Are both systems equally effective?” The answer is “Yes!” Both open and closed circuit cooling towers cool water effectively, but they work differently and use different amounts of energy.