Glossary
acre-foot
A unit of volume used to measure water; the amount of water needed to cover one acre of land (43560 square feet) to a depth of one foot. One acre-foot is equivalent to about 1,233 m³.
air cooling
A data center cooling method that uses exclusively air conditioning systems to circulate cool air over hardware to dissipate heat.
chiller
A machine that removes heat from a liquid coolant through vapor-compression, adsorption refrigeration, or absorption refrigeration cycles.
colocation center
Sometimes shortened to colo, a type of data center that rents out equipment, space, and bandwidth to retail customers, as opposed to single-tenant hyperscale data centers.
cooling tower
A device that rejects heat to the atmosphere by cooling a coolant stream (usually water) to a lower temperature, using either evaporation or air to cool the fluid.
CRAH
Computer Room Air Handler; an HVAC unit that provides precise cooling and humidity control for data centers and server rooms by circulating cold air, often through connection to an external chilling system.
evaporative cooling
A data center cooling method that passes hot air over a water-saturated pad or through a heat exchanger, causing water to evaporate and drawing heat from the air to cool the data center.
facility power
The total amount of electricity required by a given data center to run all of its equipment, including IT infrastructure and support systems like cooling and lighting; used to calculate PUE.