You may have heard of a cooling tower, but you may not know what one does, or where to find it. Cooling towers actually remove waste heat from the water used in industrial processes, making it so that that same water can be conserved and reused.

A cooling tower can be one of several different types. There are dry or closed circuit cooling towers, and open circuit or wet cooling towers. The main difference between the two is that while an open circuit is one circuit, a closed circuit towers have two separate fluid circuits, so that the water to be cooled, and the water doing the cooling do never come in contact.

Closed circuit towers work by cascading water onto a tube full of water to be cooled, which then cools the tube, cooling the water inside. Open circuit towers cascade the water to be cooled over some packing, which provides more surface area for water-to-air-contact and evaporation.

There are also both natural draft and forced draft cooling towers. A natural draft tower makes use to nature’s natural draft in the tower, allowing the warmer air filled with droplets of water to rise up out of the tower. Forced draft systems use a fan to help things along.

But where do you find these towers? They actually come in a number of different sizes, and are used in a number of different settings. The largest towers are called hyperboloid towers, and they are usually found at nuclear power plants, chemical plants, or other processing plants. They are very large, to process the large amount of fluid used by these factories.

However, most towers are much smaller, and are found on or near rooftops as part of their air conditioning system. If you’ve ever wondered where the cool air that’s pumped into your office on a hot day comes from, now you know. Continue reading here.