Which cooling tower type utilizes airflow created by natural convection?

The correct answer is the type of cooling tower that utilizes airflow created by natural convection, which is a natural draft cooling tower. These cooling towers are designed to use the natural buoyancy of warm air rising to draw cooler air into the tower. The heat from the water is transferred to the air, and as the warm air rises, it creates a negative pressure that pulls more air in at the bottom of the tower. This process occurs without the need for fans or mechanical devices, relying solely on the natural tendencies of hot air to rise and cool air to descend.

Natural draft cooling towers are often large and can accommodate significant temperature difference, making them efficient in terms of energy use. They are commonly found in power plants and large industrial settings where waste heat needs to be dissipated into the atmosphere.

While mechanical cooling towers also facilitate cooling, they rely on fans to actively move air through the system rather than using natural convection. Hyperbolic cooling towers are a type of natural draft cooling tower but the term 'natural draft cooling tower' is more precise and encompasses the concept of airflow created by natural convection. Evaporative cooling towers utilize the process of evaporation to cool water but are typically powered by mechanical units contributing to airflow.