There are several terms that people looking into industrial chillers should understand. Here is a brief glossary and some of the definitions of some of the popular terms you’re likely to hear regarding industrial chiller systems.
Chiller
A typical chiller is a water chiller that serves as a refrigeration apparatus that generates cold water to cool equipment or keep a building at a comfortable temperature for employees and others. A water chiller uses the evaporation of a specific refrigerant to cool fluid via a heat exchanger. The fluid passes through either a circuit or piping system to reach the equipment.
Central Chiller
A central chiller is any chiller used to cool multiple processes, either using water or air for cooling. It can also use a portable or stationary configuration.
BTU
British thermal units (BTU) are often used to describe the capacity of a chiller. A single btu is the amount of energy needed to raise a pound of water by one degree Fahrenheit.
Compressor
A compressor in a refrigeration circuit compresses cool low-pressure refrigerant gas to hot and highly pressurized gas that then turns back into a liquid for reuse.
Glycol
Glycol is added to water in chill water systems to prevent freezing. Glycol is available as Propylene Glycol or Ethylene Glycol and can either be bought with or without rust inhibitors. The freezing point of the fluid relies on the glycol concentration.
The higher the concentration of glycol the lower the freezing point, but the heat transfer properties are also reduced this way, thus reducing chiller capacity.
Low Ambient Kit Chiller
Modification enables proper chiller operation in low ambient conditions, and the modifications will vary based on the type of chiller, refrigerant, and temperatures involved.
Refrigerant
A refrigerant is a substance used to cool water in a chiller through an evaporator or heat exchanger. It typically has a low boiling temperature and includes both ammonia and Freon.
Hot Gas Bypass
Hot Gas Bypass is a specific valve that bypasses some of the hot gas that leaves the refrigeration compressor. This gas doesn’t enter the condenser and instead is reintroduced into the circuit after the expansion valve and prior to the evaporator.
This practice is normally intended for low-load applications and can also be used to help with low-ambient conditions.
Industrial Chiller
Industrial cooling system chillers are normally chillers used to process cool rather than comfort cooling. The head loads and exiting fluid temperatures may be different between both types of cooling, with different requirements for system pumps, fluid volumes, and components.
Reverse Flow
Reverse Flow is a portable water chiller that doesn’t include a tank. It’s used in open-loop cooling applications where an external tank or trough is used.
These are simply some of the many chiller terms you may need to know when looking for and working with a chilling system for many types of facilities. You’ll better understand what a specific application requires by knowing this terminology.