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What is a Cooling Tower?

About Cooling Towers

HVAC technology continues to innovate year after year. Systems have become more efficient, longer-lasting, and more environmentally friendly. In modern systems, much of the energy-efficiency relies on cooling towers and their ability to reject and remove heat. Whereas many HVAC system components result in heat build-up, cooling towers work to counteract this and keep your system at a safe and functioning temperature.

How Cooling Towers Work – the Basics

Cooling towers bring together air and water to change the water’s temperature. The tower acts as a heat exchanger for water that has previously been heated, often in an air-conditioning system. Once it enters the cooling tower, water sprays into heat-transfer media – also called a “fill.” The goal is to slow the water flow and distribute it onto as much surface area of the fill as possible. At the same time, air flows through the tower. When the dry air meets the heated water, some water evaporates, cooling the remaining water. The system pumps the now cooled water to the original piece of equipment where it came from, where it eventually will be reheated through that system as needed.

Counterflow Vs. Crossflow

With cooling towers, there is a distinction based on which direction air flows compared to water flow. In a crossflow tower, air flows through the fill horizontally. As the name suggests, this means the air directionally crosses the water flowing downward. This type of tower relies on gravity to distribute water uniformly through the nozzles in its hot water basin. A fan then sends the now moist air back into the atmosphere.

In counterflow cooling towers, the air flows upward as water flows downward. With this, the towers can’t use gravity flow basins use in crossflow towers. They have pressurized systems which spray water towards the top of the tower to flow back down.

Choosing the Best Type of Cooling Tower

Both types of cooling towers are useful depending on the system and location as each has its pros and cons. Crossflow systems are generally lower in cost, both with initial purchase as well as required maintenance. The gravity distribution in these towers means they require smaller pumps. However, crossflow towers are more likely to freeze when temperatures dip below zero, so they are not ideal for areas with harsh winters.

Counterflow towers are less likely to freeze, because of their unique spray distribution of water. That spray also breaks up the water more than in crossflow towers, which allows for more efficient heat transfer. Greater efficiency does mean higher cost. Crossflow towers are the more expensive option and may produce more noise as water in these towers falls from a greater height.

Which tower you choose depends on your unique HVAC system, the building specifications, and even geographic location. A cooling tower expert can help you avoid choosing the wrong tower(s) and guide you through your project (installation, repair, or reconstruction) while keeping the timeline and budget in mind.

Maintaining a Cooling Tower for a Long Lifespan

Like any HVAC component, cooling towers require regular maintenance to ensure they continue to function properly and maintain their efficiency. Not only can a breakdown in the system cause headaches, but it can also be dangerous for those in the building and can result in costly repairs. The best solution is preventative maintenance, as this is a chance for a cooling tower expert to regularly assess the state of the tower, identify any small issues and determine a plan of action for repairs. Doing this regularly over time drastically reduces the chances of a system failure.

Cooling Tower Drift and Potential Effects

Beyond maintenance to keep cooling towers running efficiently, another crucial element deals with the resulting drift occurring in towers from continuous use. All cooling towers result in water sent back into the environment, occurring in two forms. The first is the pure water which evaporates once the dry air meets the heated water. This water is not harmful to the environment.  

On the other hand, “drift” refers to the liquid that does not evaporate. It ends up in a droplet form the exhaust air stream of the tower. It’s critical to control the amount of drift a system produces, as it often carries unwanted debris and microorganisms or bacteria. Drift eliminators help remedy this, as they force the combined air and droplets to separate, sending the air into the environment and the droplets back into the tower to have the chance to be evaporated as pure water. These eliminators must also be maintained over the lifespan of the cooling tower. Efficient or damaged drift eliminators can easily lead to high drift rates, which have negative effects on the environment and the health of those people exposed to the system.

Some towers additionally require the use of biocides or algaecides. Because microorganisms tend to grow in environments that are warm and humid, cooling towers are potential breeding grounds for rapid growth. Chemical treatments help to prevent the growth of these microorganisms. This ensures both that nothing harmful that may be growing gets distributed into the environment, but also that water flows in and out of the system as it should, maintaining efficiency.

Cooling Tower Experts – Equipped with Years of Industry Experience

The team at Cooling Tower Experts brings the knowledge and experience gained from years of fieldwork, project management experience, and training on products and industry standards. We serve as a reliable resource to its customers and consider them as partners. We strive to work with them to determine the best cooling tower solutions that will stand the test of time.  

From inspections to consulting to personalized training – our services ensure your system is running at its highest level of efficiency, you are well-versed on the inner workings of the cooling towers and how they function, and that you are set up to maintain it over the years to keep it that way.  Contact us today to learn more about partnering with Cooling Tower Experts.