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20 October 2016

Cooling Terms for Industrial Chillers: Data Centres

Industrial coolers are an integral part of business for a surprising mixture of professional fields. The behind-the-scenes refrigeration systems are responsible for ensuring correct operations in pharmacies, food/beverage facilities, produce and medicine preservation, aerospace/electronics activities, medical/research industries, and data/communication centres. Varied and unrelated, this motley crew of commercial and industrial businesses are unified in their need for a specific temperature. Cue the industrial chillers.

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Today we will learn about some of the terms used when dealing with refrigeration systems placed in data centres. The first step towards understanding chillers is familiarising yourself with some basic terms related to the machinery and cooling process.

BTU – 
British thermal unit, a unit of heat energy. One BTU is quantified as the heat energy necessary to increase/decrease the temperature of 1 lb. of water by 1°F in one hour. In data centres, BTU is a measurement of the heat energy used to calculate heat loads.
1 kW/h = 3412btu
1 W = 3.4129btu

Chilled Water System – 
A precision cooling system used in mid-sized to large environments. Using chilled water (CW) or glycol, the system pumps cold water from a chiller to computer room air handlers, thereby cooling the area.

Chiller – 
A cooling unit comprised of a compressor, condensing and expansion sections where water is chilled and air dehumidified using a cooling medium (water, glycol) as the heat transfer agent. As the unit’s main function is to cool water, it is constantly cycling through large volumes. A cooling cycle supplies cold water to the chiller where it is then directed to the Computer Room Air Handlers (CRAH) within the data centre. The CRAH units remove heat.

Compressor – 
A component in the chiller, the compressor uses motorised energy to compress a gaseous cooler. This compression allows the air cooler to attract heat of a certain level and dispel it outside at a higher temperature.

Condenser Coil – 
A method of heat elimination used in air-cooling systems. It transmits heat energy from a cooler to the external environment.

Dehumidification – 
The process of removing moisture from the air. In data centres, dehumidification is not desired, but occurs when the moisture-filled air runs through a cold evaporator coil.

Energy Efficiency Ratio (EER) – 
A measurement using a compressor’s operations in relation to its power consumption to calculate a threshold for efficiency.

Evaporator Coil – 
Resembling a vehicle radiator, this coil is used to facilitate heat removal. Cool air from the air conditioning unit carries heat energy to the flashing cooler after going through the evaporator coil. 

Jacqui Litvan

Jacqui Litvan, wielding a bachelor's degree in English, strives to create a world of fantasy amidst the ever-changing landscape of military life. Attempting to become a writer, she fuels herself with coffee (working as a barista) and music (spending free time as a raver).