Chiller
From Free net encyclopedia
A Chiller is a machine that produces chilled water (usually mixed with ~20% glycol and corrosion inhibitors) which is used to cool and dehumidify air in commercial and industrial facilities (see air conditioning). A typical chiller is rated between 15 to 1000 tons (180,000 to 12,000,000 BTU/h or 53 to 3,500 kW) in cooling power. There are basically four different types of chillers: Reciprocating, centrifugal, or screw-driven chillers are mechanical machines that can be powered by electric motors, steam, or gas turbines. Absorption chillers are powered by a heat source (such as steam or hot water). They have very low electrical power requirements - very rarely above 15kW combined consumption for both the solution pump and the refrigerant pump.
Chilled water is then distributed to air handling units as a refrigerant. The air handling unit is a heat exchanger consisting basically of a fan, a filter bank, and heating/cooling coil, inlet/outlet chilled water port, and air inlet port. These air handling units provide air conditioning to the building by running the incomming warm air through the coil of chilled water, transferring the heat from the air to the chilled water, thus, cooling the air.
Chillers can be air-cooled or water-cooled. Water-cooled chillers incorporate the use of cooling towers which improve heat rejection more efficiently at the condenser than air-cooled chillers.