Cooling towers are heat exchangers that use water and air to transfer process waste heat into the atmosphere. Most commonly, they are used to provide cooled water for large-scale heating, ventilation, and air conditioning (HVAC) systems, electric power generation, and industrial purposes.
Legacy Mechanical sells, installs and services many different brands and models of cooling towers. These towers come in a variety of designs, and can vary in size from small rooftop units, to very large towers that are over 600 feet tall. While not all types of cooling towers operate in the exact same way, they all function on the principle of removing heat from water by evaporating a small portion of water that is recirculated through the system and reused. The mixing of warm water and cooler air releases latent heat of vaporization, creating a cooling effect on the water.
In general, there are four main types of cooling towers that are manufactured today:
Natural draft towers use natural convection to circulate air inside the tower and cool the water. The warm, moist air will naturally rise through the tower, while the dry, cool air from outside will fall, creating a constant cycle of air flow. Because these towers take advantage of natural processes, they’re relatively inexpensive to operate, but must be located outdoors. They are most often used at large power plants and industries with infinite cooling water flow.
Mechanical draft towers use propeller or centrifugal fans to circulate air through the tower. They are lower in height than natural draft towers, so they can be placed inside a building, which can be a plus for some operations. Also, the air flow can be regulated. A potential disadvantage is these kind of cooling towers tend to be more costly to operate. Mechanical draft towers can have different types of air flow configurations, with counter-flow and cross-flow being two of the most common.
Cross-flow towers are designed so that air the flows horizontally through the tower’s structure while hot water flows vertically through the fill. This allows gravity to filter the hot water into the basins, eliminating the need for air to flow through the distribution system.
Counter-flow towers are designed so that air flows vertically upwards through the tower as hot water falls downwards, releasing the extracted heat out of the top of the tower. This type of configuration is typically more compact and has a smaller footprint than a cross-flow configuration.
There are many, many other types of cooling tower types that are available, each with its own pluses and minuses. Exactly which type of cooling tower is right for your facility is a major decision, one with potentially huge financial implications.
If you are looking for a cooling tower or you’re unsure what type of tower you should choose, we can help you with your decision. We’ll be happy to work with you every step of the way, from design, budgeting and planning, to installation, maintenance and servicing. Give us a call at 770-432-1171 to set up a meeting with one of our customer service representatives. We are dedicated to your complete satisfaction and to your success in finding a cooling tower that runs effectively and efficiently.