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Celsius - A scale of temperature used by the metric system in which water freezes at 0C and boils at 100C. Degrees Celsius are abbreviated with the letter C. To convert to the Fahrenheit scale multiply by 1.8 and then add 32.
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Cabinet - Enclosure holding computing equipment such as IT, Network, and Storage devices. (also known as a \"rack\").
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Cold Aisle Containment (CAC) - A solution which segreggates and encloses cold air within the cold aisle and directs it to the front intake of computing equipment. This prevents unwanted air mixing thereby increasing cooling efficiency.
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Capital Expenditure (CapEx) - A capital expenditure is incurred when a business spends money either to buy fixed assets or to add to the value of an existing fixed asset with a useful life that extends beyond the taxable year. Capex is used by a company to acquire or upgrade physical assets such as equipment, property, or industrial buildings. CapEx can be contrasted with OpEx.
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Carbon Footprint - A measurement of the amount of Carbon Dioxide (CO2) generated by business operations. Generally measured in pounds or tonnes of CO2.
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Computational Fluid Dynamics (CFD) - Scientific calculations applied to airflow analysis. Often \"a CFD\" refers to a simulation showing the behavior\temperature of air throughout the data center. CFDs can be used to identify cooling problems and inefficiencies.
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Cubic Feet per Minute (CFM) - CFM measures the volume of liquid or gas (usually air) in cubic feet which passes a stationary point in one minute. In a typical data center facility that has conditioned air being delivered through a subfloor and via perforated tiles to cool down IT equipment in racks, it is useful to understand the relationship between CFM (air-flow), temperature rise, heat dissipation and the amount of cooling capacity required.
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Chiller Plant - A chiller plant cools water and pumps it through water-loop systems; fans are then placed to blow air over the pipes containing cooled water, which produces cooled air for a/c.
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Close-Coupled Cooling - Cooling technology that is installed adjacent to server racks and enclosed to direct airflow directly to the rack without mixing with Data Center room air.
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Coefficient of Effectiveness (CoE) - Uptime Institute metric based on the Nash-Sutcliffe model efficiency coefficient.
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Cold Aisle - An aisle where cold air is circulated. Equipment should be positioned so that the air intake in the front faces into the cold aisle where cold air is circulated.
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Cold Spot - An area where ambient air temperature is below expected setup and levels. Typically caused by cooling equipment capacity exceeding heat loads where the cold area is circulated. (Open area of data centers which do not need to be cooled or where not enough equipment is located where HIGH VOLUMES of Cold air is needed).
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Computer Room (CR) - A facility where the computing and telecommunication infrastructure (CTI) is housed. Computer Rooms are typically specially conditioned room for heating/cooling and power. Computer Room is often an alternate name for a data center.
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Computer Room Air Conditioner (CRAC; pronounced crack) - A device specifically manufactured for cooling computer equipment. These units can be purchased to handle 3 functions: 1) Cooling, 2) Heating, 3) Humidification
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Computer Room Air Handler (CRAH; pronounced craah) - A device specific manufactured for cooling computer equipment. These units can be purchased to handle 3 functions: 1) Cooling, 2) Heating, 3) Humidification
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Cut-out - An open area in a raised floor that allows airflow or cable feeds.
