A chilling plant is a mechanical device used to facilitate heat exchange from water to a refrigerant in a closed loop system. The refrigerant is then pumped to a location where the waste heat is transferred to the atmosphere.

A water-cooled chilled water plant usually consists of a shell and tube type water-cooled condenser. The condenser is a heat exchanger that removes heat from refrigerant vapour and transfers it to the water. Cooling towers are outside of the building with a make-up water circuit to evaporate condensed water.