The Role Of Cooling Towers In Commercial Air Conditioning

17 August 2016
 Categories: , Blog

Commercial air conditioners, in cooling enormous volumes of air, themselves generate a good deal of heat. Cooling towers are one of the most effective--and the most common--means of safely dispelling this unwanted heat. If you would like to learn more about the various components utilized in a commercial air conditioning system, read on. This article will teach you all about the role that cooling towers play.


Cooling towers are used to reject unwanted heat into the atmosphere. They accomplish this feat through the conjunction of a water and an air stream. This water absorbs the excess heat and then transfers it to the air, usually through the process of evaporation. In the process, the temperature of the entire water stream is reduced.

An evaporative cooling system is able to ensure water temperatures that are much lower than those achieved by so-called "dry" systems, such as the radiator in your car. As a result, evaporative systems offer a much more efficient and cost-effective means of cooling. This makes them perfect for dealing with the unwanted heat generated by a commercial air conditioner's chiller.

Direct Vs. Indirect

Cooling towers can be broken down into two principal categories, direct and indirect, alternately known as open and closed circuit systems. A direct cooling tower is one in which the water and the air streams come into direct contact with one another. This contact takes place in the labyrinth-like system known as the fill. Air passes over the water as it is drawn downward through the fill by gravity. Once the cooled air has reached the bottom, it is pumped back to the top, thus keeping the cycle going perpetually.

An indirect cooling tower is one in which the water and air never come into direct contact. Here the water courses through the system along two distinct circuits. The hot water passes through the inner circuit. Through the outer circuit passes a mixture of cool water and air bubbles. Heat passes from the inner to the outer circuit, where it is carried out of the system by the air.

Crossflow Vs. Counterflow

Direct cooling towers can be further broken down into two types, crossflow and counterflow towers. In both types, water percolates downward through the fill. The difference is the direction in which the air stream moves. In a crossflow system, the air flows horizontally across the fill. This allows water to move downward through the system by means of gravity alone.

In a counterflow system, the air flows upward in a vertical direction. This brings it more forcefully into contact with the falling water, thus allowing it to accomplish more efficient cooling. Yet, because this upward air flow impedes the flow of falling water, gravity is not enough to keep the water moving. Instead, the system must be pressurized so that the water can continue to move downward through the fill.

For more information about what kind of cooling system will be most effective for your commercial air conditioner, contact a professional at D & R Service Inc.