In-Row Cooling
Cooling technology installed between racks in a row that draws warm air from the hot aisle and delivers cool air to the cold aisle, minimizing the path of the air (see close coupled cooling).
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Leave a Comment (0) →Hybrid Cable
An assembly of two or more cables, of the same or different types or categories, covered by one overall sheath.
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Leave a Comment (0) →Hot Spot
An area, typically related to a rack or set of racks, where ambient air temperature is above acceptable levels. Typically caused by poor airflow management (insufficient cool air supply or an excess of recirculation).
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Leave a Comment (0) →Hot Aisle Containment (HAC)
A system that directs heated air from the outlet side of racks to air conditioning equipment return ducts in a highly efficient manner.
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An aisle where rack backs face into the aisle. Heated exhaust air from the equipment in the racks enters this aisle and is then directed to the CRAC return vents.
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Leave a Comment (0) →Horizontal Distribution Area (H.D.A.)
Horizontal Distribution Area, a space in a computer room where a horizontal cross-connect is located as defined by TIA 942 specifications.
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Leave a Comment (0) →Heat Exchanger
A device used to transfer heat energy from one medium to another. Common uses of heat exchangers are water to air heat exchangers in air handling units, plate and frame heat exchangers in economizers, etc.
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Leave a Comment (0) →Harmonic distortion
Distortion in the line voltage waveform. Any cyclical waveform can be described as the sum of sine waves of various magnitudes which are integer multiples of the root frequency (60 Hz, 120 Hz, 180 Hz, etc.). Harmonics are often the result of the non-linear loading of the power distribution system due to the nature of solid state power supplies. Harmonics are detrimental to the efficiency and capacity of power delivery equipment and rotating equipment due to increased eddy current losses and non-fundamental frequency torques.
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Leave a Comment (0) →GbE
Gigabit Ethernet
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Leave a Comment (0) →Gateway
A network element interconnecting two otherwise incompatible networks, network nodes, subnetworks or devices. A gateway is often associated with both a router, which knows where to direct a given packet of data that arrives at the gateway, and a switch, which furnishes the actual path in and out of the gateway for a given packet.
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Leave a Comment (0) →Flywheel UPS
A flywheel is a heavy shaft-mounted rotating disc that absorbs and stores twisting or spinning motion and then releases it as rotational kinetic energy to provide motion to a stationary, or nearly stationary object.
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Leave a Comment (0) →Firewall
The primary method for keeping a computer secure from intruders. A firewall allows or blocks traffic into and out of a private network or the user’s computer. Firewalls are widely used to give users secure access to the Internet as well as to separate a company’s public Web server from its internal network. Firewalls are also used to keep internal network segments secure; for example, the accounting network might be vulnerable to snooping from within the enterprise.
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Leave a Comment (0) →External Network Interface
Interface between the computer room cabling and external cabling coming from a telecommunications carrier or campus cabling.
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Leave a Comment (0) →Equivalent Full Cabinets (EFC)
The number of full cabinets that would exist if all the equipment in the data center were concentrated in full cabinets.
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Leave a Comment (0) →Equipment Room (ER)
An environmentally controlled centralized space for telecommunications equipment that usually houses Distributor B or Distributor C.
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Leave a Comment (0) →Equipment Distribution Area (EDA)
The computer room space occupied by equipment racks or cabinets [TIA 942]
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Leave a Comment (0) →Entrance Room
(do not use acronym) – use Entrance Facility to avoid confusion with Equipment Room
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Leave a Comment (0) →Entrance Point
The point of emergence for telecommunications cabling through an exterior wall, a floor, or from a conduit.
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Leave a Comment (0) →Entrance Facility (EF)
An entrance to a building for both public and private network service cables (including wireless) including the entrance point of the building and continuing to the entrance room or space. (569)
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Leave a Comment (0) →Electrostatic Discharge (ESD)
More commonly ‘static discharge’.
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