A chilled water coil is a heat exchanger that cools air by circulating chilled water (typically 40°F to 50°F) supplied from a centralized chiller through its aluminum or copper tubing. Chilled water coils are prevalent in large commercial and industrial HVAC systems where multiple zones require independent temperature control from a single cooling source.
Technical Details
Chilled water coils operate with supply water temperatures between 40°F and 50°F and return water typically 10°F to 15°F warmer. Water flow rates are measured in gallons per minute (GPM), with capacity depending on water temperature differential and air volume. Coil selection considers entering water temperature, leaving air temperature, air quantity, and allowable pressure drop (typically 2 to 4 psi on the water side).
Applications and Significance
Chilled water systems serve high-rise buildings, hospitals, universities, and data centers where centralized cooling offers flexibility and efficiency. Multiple air handling units can draw from the same chiller, enabling zoned temperature control. These systems require more complex piping and controls than DX systems but provide superior performance in large installations with diverse cooling demands.