Cooling towers are physically the largest individual pieces of energy using equipment usually found in an office building. They typically require 0.25 sq ft of floor area per 100 sq ft of total building area and can be from 12 to 40 feet high. When located on the roof, the building structure must support the added weight in the range of 120 to 150 lb per sq ft along the wind load stresses. If located at ground level, they are subject to vandalism and ground level dirt. If tower noise affects adjacent structures, acoustic treatment may be needed. Oversizing at added first cost reduces noise level due to lower fan speeds, and can be an excellent energy saving investment since it improves cooling system performance. If decorative screens are used, they must have sufficient free air so as not to interfere with good air flow. Tower location is critical to take advantage of prevailing winds and avoid air bypass conditions that will penalize tower performance and increase energy use.
Several types of cooling towers are available: