The function of a chiller, also known as a water-cooled chiller or water chiller, is to cool down water or other fluids to a desired temperature. It is commonly used in air conditioning systems, industrial processes, and manufacturing facilities.

The chiller works by removing heat from the water or fluid through the process of refrigeration. It uses a refrigeration cycle consisting of a compressor, condenser, expansion valve, and evaporator. The compressor compresses refrigerant gas, which raises its temperature and pressure. This high-pressure gas is then condensed into a liquid state in the condenser, releasing heat to the surrounding air or a cooling medium such as water.