Different Types of Cooling Towers

Cooling towers remove heat from process water during manufacturing, energy production and air-conditioning.

Natural Draft

Utility plants and nuclear facilities often utilize very large cooling towers.Utility plants and nuclear facilities often utilize very large cooling towers.
By removing this heat, cooling towers allow facilities to recirculate and reuse wastewater for additional processes. Cooling towers may also help conserve heat energy for reuse in the building, rather than simply exhausting this heat to the outdoors. Each type of cooling tower must be chosen based on the specific needs of an individual project or facility in order to maximize functionality and efficiency.

Natural draft cooling towers consist of large chimneys set on an extremely large base. The size of these towers makes them well suited to utility and power production plants which utilize large volumes of water. These large towers may also be found at nuclear facilities, or any structure that requires large amounts of cooling capacity. Natural draft cooling towers operate without the use of fans or blowers. Instead, they rely on principles of evaporation and water pressure to remove heat energy from process water.

Mechanical Towers

Mechanical cooling towers utilize large fans to remove or collect heat from process water used in the facility. These fans force air through the water to extract the maximum amount of heat energy from the water. This energy can then be used within the facility to provide HVAC heating or industrial process heat. It may also be exhausted outside in order to keep process water at the desired temperature.

Mechanical cooling towers can be divided into two different categories depending on the placement of the fan. In a forced draft tower, the fan sits at the base of the tower to drive air up against the downward flow of the water. These units minimize erosion, condensation and noise issues. Induced draft units feature a fan placed at the top of the tower, which draws air down through the water. Induced draft cooling towers offer a high level of energy efficiency and effective heat exchange.

Hybrid Cooling Towers

Hybrid cooling towers rely on natural evaporation and water pressure during cooling but may also use a fan to assist the process as needed. These towers are specifically designed to minimize mechanical energy and maximize the efficiency of the cooling process. Fans may be used to handle peak loads or to redirect airflow when natural forces are insufficient. Fans may be placed anywhere within or around the tower as needed to maximize function.

About the Author

Emily Beach works in the commercial construction industry in Maryland. She received her LEED accreditation from the U.S. Green Building Council in 2008 and is in the process of working towards an Architectural Hardware Consultant certification from the Door and Hardware Institute. She received a bachelor's degree in economics and management from Goucher College in Towson, Maryland.