chillers

A chiller is a machine that removes heat from a process or space by circulating a cooled liquid, usually water or glycol. The chilled liquid is circulated to equipment such as heat exchangers, data centers, or air handling systems to provide continuous cooling.

Chillers come in several designs, most commonly air-cooled and water-cooled. Air-cooled chillers reject heat to the ambient air via condensing coils, while water-cooled chillers reject heat to a separate water loop and cooling tower. Absorption chillers use heat instead of electricity to drive cooling.

Most modern chillers operate on a vapor-compression refrigeration cycle. A refrigerant is compressed, releasing heat in a condenser, then expanded to a low pressure before evaporating in the evaporator. The evaporator absorbs heat from the chilled liquid, which is then circulated back to equipment.

Key components include the compressor, condenser, evaporator, expansion device, and controls. Supporting elements may include cooling towers or water circuits, pumps, heat exchangers, and filtration or water treatment systems. Efficiency is commonly described by COP or EER; SEER is used for building chillers.

Applications span commercial air conditioning, industrial process cooling, plastics and metalworking, pharmaceuticals, and data centers. Environmental considerations focus on refrigerant choice and leakage, with industry moves toward lower-GWP refrigerants and inverter-driven, variable-speed drives to improve part-load efficiency.