A water chiller is a device used to lower the temperature of the water. Most chillers use refrigerant in a closed-loop system to facilitate heat exchange from the water where the refrigerant is then pumped to a location where the waste heat is transferred to the atmosphere.

Dairy processing factories use large chillers to keep milk from spoiling before it is bottled. Large food processing chillers can be found in factories where food is being prepared for packaging and shipment to grocery stores and distribution centers.