Cooling Tower
CSI Division 23, HVAC
A large mechanical unit, typically located on a rooftop or at grade, that rejects heat from a building's chilled water system to the outside air by evaporating a portion of the water passing through it, the outdoor heat-rejection component that works together with a building's [[concept-chiller|chiller]] to provide cooling.
Why it matters
A cooling tower's warm, standing water is a documented environment where Legionella bacteria can grow and spread through the tower's mist, which is why a written water treatment and maintenance program, following ASHRAE 188 guidance, is a genuine public health requirement rather than an optional maintenance nicety.
On a real project
A hospital's facilities team maintains a documented water treatment program for its rooftop cooling towers, including regular biocide treatment and water testing specifically to control Legionella risk, following ASHRAE guidance for building water systems.
Who this matters most to
A HVAC Technician maintains the cooling tower's mechanical components. A Facilities Manager is typically responsible for ensuring the required water treatment program is actually followed, not just documented on paper.
Where this goes wrong
A building's facilities team lets its cooling tower's water treatment program lapse for several months to cut costs, skipping the routine biocide treatment and testing. A subsequent water test reveals Legionella bacteria at levels well above the acceptable threshold, forcing the tower to be shut down and disinfected before it can be safely restarted.
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