Chiller AC Systems: How Chilled Water Cooling Works

A chiller AC system cools buildings by producing chilled water that circulates to air handling units or fan coil units, where air is cooled and distributed. It differs from direct expansion systems, which cool air by refrigerant circulating directly through coils. This explainer covers the main components, including chiller, pumps, piping and terminal units, and where such systems are commonly used. It is written for readers who want a clear, non-technical introduction to chilled water air conditioning.