Chillers

Description

A chiller removes heat from a liquid using a vapor-compression or  absorption refrigeration cycle. The chilled liquid circulates through a heat exchanger to cool equipment or another process stream, such as air or process water. Air-cooled and evaporative-cooled chillers are designed for outdoor installation and operation. Air-cooled machines use ambient air, which circulates mechanically through the condenser coil, expelling heat into the atmosphere. Evaporative-cooled machines work similarly but add a mist of water over the condenser coil to enhance cooling, making these machines more efficient than traditional air-cooled models. These packaged air-cooled and evaporative-cooled chillers generally don’t require a remote cooling tower.

Chilled water cool and dehumidify air in mid- to large-size commercial, industrial, and institutional facilities. Chillers come in water-cooled, air-cooled, or evaporatively cooled systems. Water-cooled systems tend to offer better efficiency and environmental benefits than air-cooled ones.

In industrial settings, chilled water or other liquids from the chiller flow through process or laboratory equipment. Industries use industrial chillers for controlled cooling of products, machinery, and factory equipment. Common uses include plastic processing, injection and blow molding, metalworking cutting oils, welding equipment, die-casting, machine tooling, chemical processing, pharmaceutical formulation, food and beverage production, paper and cement processing, vacuum systems, X-ray diffraction, power supplies, power generation stations, analytical equipment, semiconductors, and compressed air or gas cooling. Chillers also cool specialized equipment such as MRI machines and lasers, as well as provide cooling in hospitals, hotels, and campuses.

Industrial chillers can be centralized, with a single chiller serving multiple needs, or decentralized, with individual machines or applications having their own chillers. Both approaches offer unique advantages. A combination of both centralized and decentralized systems can be beneficial when some cooling requirements are the same across different applications but not all.

Decentralized chillers are usually small in size and cooling capacity, usually from 0.2 to 10 short tons (0.179 to 8.929 long tons; 0.181 to 9.072 t).  Centralized chillers generally have capacities ranging from ten tons to hundreds or thousands of tons.

Dehumidifiers and chillers:

Chilled water is used to cool and dehumidify air in mid- to large-size commercial, industrial, and institutional (CII) facilities.  Water chillers can be water-cooled, air-cooled, or evaporatively cooled.  Water-cooled chillers incorporate the use of cooling towers which improve the chillers’ thermodynamic effectiveness as compared to air-cooled chillers.  This is due to heat rejection at or near the air’s wet-bulb temperature rather than the higher, sometimes much higher, dry-bulb temperature.  Evaporatively cooled offer higher efficiencies than air-cooled but lower than water-cooled chillers.

Water-cooled chiller is typically intended for indoor installation and operation, and are cooled by a separate condenser water loop and connected to outdoor cooling towers to expel heat to the atmosphere.

Air-cooled and evaporative cooled chiller is intended for outdoor installation and operation.  Air-cooled machines are directly cooled by ambient air being mechanically circulated directly through the machine’s condenser coil to expel heat to the atmosphere.  Evaporative cooled machines are similar, except they implement a mist of water over the condenser coil to aid in condenser cooling, making the machine more efficient than a traditional air-cooled machine.  No remote cooling tower is typically required with either of these types of packaged air-cooled or evaporatively cooled chillers.