Acuity - Clarity In A Complex World
Data Center Terminology
A - B - C - D - E - F - G - H - I - K - L - M - N - P - R - S - T - U - V - W

  • Air-sampling: An air - sampling smoke detector, sometimes called a VESDA system, is capable of detecting microscopic particles of smoke.
  • Amps - ampere (A, amp) A unit of measurement of electric current. One ampere is equal to the current produced by one volt flowing through a resistance of one ohm.
  • BAS (Building Automation System)- A Building Automation System (BAS) is an example of a Distributed control system. Building automation describes the functionality provided by the control system. The control system is a computerized, intelligent network of electronic devices, designed to monitor and control the mechanical and lighting systems in a building. BAS core functionality keeps the building climate within a specified range, provides lighting based on an occupancy schedule, and monitors system performance and device failures and provides email and/or text notifications to building engineering staff. The BAS functionality reduces building energy and maintenance costs when compared to a non-controlled building. A building controlled by a BAS is often referred to as an intelligent building system.
  • Btu -
    1. The quantity of heat required to raise the temperature of one pound of water from 60° to 61°F at a constant pressure of one atmosphere.
    2. The quantity of heat equal to 1/180 of the heat required to raise the temperature of one pound of water from 32° to 212°F at a constant pressure of one atmosphere.
  • Category 6 - augmented balanced twisted-pair copper cable specifications characterized in a frequency range from 1 to 500 MHz. The augmentation from category 6 covers frequency range, insertion loss specifications, and alien crosstalk mitigation.
  • Category 6 Cable - commonly referred to as Cat-6, is a cable standard for Gigabit Ethernet and other network protocols that is backward compatible with the Category 5/5e and Category 3 cable standards. Cat-6 features more stringent specifications for crosstalk and system noise. The cable standard provides performance of up to 250 MHz and is suitable for 10BASE-T / 100BASE-TX and 1000BASE-T / 1000BASE-TX (Gigabit Ethernet). It is expected to suit the 10GBASE-T (10Gigabit Ethernet) standard, although with limitations on length if unshielded Cat 6 cable is used. Category 6 Cable can be identified by the printing on the side of the cable sheath.
  • CCTV Closed - circuit television (CCTV) A private television system, typically used for security purposes, in which the signal is transmitted to a limited number of receivers.
  • Cfm - Cubic feet per minute (CFPM or CFM) is a non-SI unit of measurement of the flow of a gas or liquid that indicates how much volume in cubic feet pass by a stationary point in one minute. The higher the CFPM the better the suction. In order to calculate Cubic Feet per minute from Air Flow (Cubic meter per Hour): We divide Airflow by 1.7 to get Cubic Feet per minute. Usable Amps- de-rating of available amps to usable amps to prevent circuit overloads and fires.
  • Chilled water pumps - A type of precision cooling system widely used in mid-sized to large IT environments. A chilled water system uses water as a cooling medium. Cold water is pumped from a chiller to computer room air handlers designed to cool the space. A chilled water air conditioner can be thought of as similar to a car radiator with a fan, with hot air being cooled by being blown through a cool radiator. In a chilled water system cooling an IT facility, the chilled water may be provided as a utility in the building, or special dedicated water chillers may be installed.
  • Chiller Feeders - A type of precision cooling system widely used in mid-sized to large IT environments. A chilled water system uses water as a cooling medium. Cold water is pumped from a chiller to computer room air handlers designed to cool the space. A chilled water air conditioner can be thought of as similar to a car radiator with a fan, with hot air being cooled by being blown through a cool radiator. In a chilled water system cooling an IT facility, the chilled water may be provided as a utility in the building, or special dedicated water chillers may be installed.
  • Condensate Piping - Water that results as a by-product of dehumidification. Condensate is usually pumped out of the IT room or data center (via a condensate pipe) into the building drainage system. Since maintaining humidity is a desired goal of a computer room air conditioning system, dehumidification is typically not a desired function. However, dehumidification and the resultant production of condensate commonly occur as a result of suboptimal design.
  • CRAC – Computer Room Air Conditioning - A computer room air conditioning (CRAC) unit is a device that monitors and maintains the temperature, air distribution and humidity in a network room or data center. CRAC units are replacing air-conditioning units that were used in the past to cool data centers. Climate control is an important part of the data center's infrastructure.
  • CRAH - Computer room air handler (pronounced craah); a device usually installed in the data center or IT room that uses circulating chilled water to remove heat. The device must be used in conjunction with a chiller.
  • CRAH with VFD Chiller/Tower - Computer Room Air Handling Unit with a VFD (Variable Frequency Drive) allows your centrifugal chiller to achieve the most efficient part load performance possible by accurately matching the chiller’s motor performance to the actual cooling load requirement. Since most chillers operate at part load 99% of the time, your energy savings with a VFD can be significant, up to 30% annually. Additionally, a VFD may qualify for local utility rebates for even more savings.
  • Critical Power Distribution - Critical Load Equipment that must have an uninterrupted power input in order to prevent damage or loss to a facility, itself, or to prevent danger of injury to operating personnel.
  • Data Center Design Capacity - Capacity Planning is an essential aspect to creating, expanding, or optimizing a Data Center.
  • Distribution Cell - The cellular floor sections from which cables emerge into work areas.
  • Distributed Copper I nfrastructure - When networking gear is pushed out to copper connectivity to centralized switch instead of using distributed switches.
  • Distribution Frame - A structure with terminations for connecting the cabling of a facility in such a manner that interconnection or cross-connections may be readily made. (TIA)
  • Distribution Panel - A wiring board that provides a patch panel function, and mounts either in a rack or on a wall.
  • Distributed Switch Infrastructure - When networking gear is pushed into individual cabinets instead of providing copper or fiber connections back to a centralized switch.
  • Ecaro 25 - ECARO-25 utilizing HFC-125 as the fire-extinguishing agent, is the best, most cost-effective clean agent fire protection system available. ECARO-25 is perfect for NEW clean agent fire suppression applications, as well as for Halon replacement projects. This highly effective fire suppression system is safe for people, assets and the environment.
  • Electrical generator - is a device that converts mechanical energy to electrical energy, generally using electromagnetic induction. The reverse conversion of electrical energy into mechanical energy is done by a motor; motors and generators have many similarities. A generator forces electric charges to move through an external electrical circuit, but it does not create electricity or charge, which is already present in the wire of its windings.
  • Electrical Service - in building wiring, refers to the wiring that connects the electric utility's cables in the street to the building. Specifically, electrical service is the wiring from the street, through the meter and up to the panelboard, but no farther. Electrical service can be provided directly from the utility company's transformer or though service laterals. Besides referring to the physical wiring, the term electrical service also refers in an abstract sense to the provision of electricity to a building.
  • Firewall
    1. A continuous barrier used to prevent fire spreading from one fire zone or area to another.
    2. One or more security mechanisms (hardware and/or software) designed to prevent, detect, suppress, and/or contain unauthorized access to a network.
  • Floor Drains - A fixture that provides an opening in a floor that drains water into a plumbing system.
  • Generator Electrical Feeds - wires that feed from the electrical generator into the building structure.
  • Hall-POD - module or a room, segmented area of a datacenter.
  • Halon - Any of several compounds consisting of one or two carbon atoms combined with bromine and one or more other halogens. Halons are gases and are used as fire-extinguishing agents. They are between three and ten times more destructive to the ozone layer than CFCs are.
  • Horizontal Pathways - Horizontal Cabling connects telecommunications rooms to individual outlets on the floor.
  • HVAC - (pronounced either "H-V-A-C" or "H-vak") is an initialism or acronym that stands for "heating, ventilating, and air conditioning". HVAC is sometimes referred to as climate control and is particularly important in the design of medium to large industrial and office buildings such as skyscrapers and in marine environments such as aquariums, where humidity and temperature must all be closely regulated whilst maintaining safe and healthy conditions within. In certain regions (e.g., UK) the term "Building Services" is also used, but may also include plumbing and electrical systems. Refrigeration is sometimes added to the field's abbreviation as HVAC&R or HVACR, or ventilating is dropped as HACR (such as the designation of HACR-rated circuit breakers).
  • HVAC system - is a computerized control system for climate control in buildings. Stand alone control devices may be pneumatic or electronic. Some may have microprocessors, but to be considered a "control system" for the context of this article, computerized and networked are expected requirements. HVAC stands for heating, ventilation, and air-conditioning. Often, these integrate fire, security, and lighting controls into one system. These systems typically use one or more central controllers to command and monitor the remote terminal unit controllers, and they communicate with one or more personal computers that are used as the operator interface. These control systems are typically used on large commercial and industrial buildings to allow central control of many HVAC units around the building(s). The latest systems use Ethernet for communications between central controllers--allowing remote access from a web browser.
  • Intrusion Detection - A network intrusion detection system (NIDS) is an intrusion detection system that tries to detect malicious activity such as denial of service attacks, port scans or even attempts to crack into computers by monitoring network traffic.
  • kVa – Kilovolt - ampere; amount of power in an alternating current (AC) circuit equal to a current flow of one ampere at an electromotive force of one volt.
  • kW per Cabinet - amount of electrical power available to a storage, network and server cabinet.
  • kWh - The kilowatt-hour (symbolized kWh) is a unit of energy equivalent to one kilowatt (1 kW) of power expended for one hour (1 h) of time. The kilowatt-hour is not a standard unit in any formal system, but it is commonly used in electrical applications.
  • Laser Smoke Detection - The Pinnacle Laser Smoke Detector senses the earliest particles of combustion. And that provides early warning of fire. Its high sensitivity is balanced with high stability to minimize false alarms. Like an -ionization detector, Pinnacle quickly senses a fast flaming fire. Laser technology gives you fast response detection in high sensitivity applications such as cleanrooms, telecommunications centers or computer rooms — areas where any damage is too much.
  • Low Voltage System - Low voltage is an electrical engineering term that broadly identifies safety considerations of an electricity supply system based on the voltage used. While different definitions exist for the exact voltage range covered by "low voltage", the most commonly used ones include "mains voltage". "Low voltage" is characterized by carrying a substantial risk of electric shock, but only a minor risk of electric arcs through air. "Low voltage" is distinguished from:
    • Extra low voltage – which carries a much reduced risk of electric shock
    • High voltage – where electrical arcing is a substantial additional risk.
    • Commonly used definitions include:
      • The International Electrotechnical Commission defines low voltage as any voltage in the range 50–1000 V AC or 120–1500 V DC.
      • The United States 2005 National Electrical Code (NEC) defines low voltage as any voltage under 600 V (article 490.2).
      • British Standard BS 7671:2008 defines low voltage as:
        • 50–1000 V AC or 120–1500 V ripple-free DC between conductors;
        • 50–600 V AC or 120–900 V ripple-free DC between conductors and Earth.
  • Low Voltage Systems - Low-voltage differential signaling, or LVDS, is an electrical signaling system that can run at very high speeds over inexpensive twisted-pair copper cables. It was introduced in 1994, and has since become very popular in computers, where it forms part of very high-speed networks and computer buses.
  • Modular, non-scalable UPS - based on incriminated growth based on size rating, can modularly increase power capacity.
  • Network Cabinets - A cabinet designed to hold a series of controllers, all connected via a telecommunications cable.
  • Network Operations Center (NOC) - A network operations center (or NOC, pronounced "nock") is one or more locations from which control is exercised over a computer, television broadcast, or telecommunications network. Large organizations may operate more than one NOC, either to manage different networks or to provide geographic redundancy in the event of one site being unavailable or offline. NOCs are responsible for monitoring the network for alarms or certain conditions that may require special attention to avoid impact on the networks performance. For example, in a telecommunications environment, NOCs are responsible for monitoring for power failures, communication line alarms (such as bit errors, framing errors, line coding errors, and circuits down) and other performance issues that may affect the network. NOCs analyze problems, perform troubleshooting, communicate with site technicians and other NOCs, and track problems through resolution. If necessary, NOCs escalate problems to the appropriate personnel. For severe conditions that are impossible to anticipate – such as a power failure or optical fiber cable cut – NOCs have procedures in place to immediately contact technicians to remedy the problem.
  • Packet Acceleration - TCP acceleration is the name of a series of techniques for achieving better throughput on an Internet connection than standard TCP achieves, without modifying the end applications. It is an alternative or a supplement to TCP tuning.
  • Perimeter Cooling - A solution that enables monitoring and maintenance of temperature and humidity design conditions which is critical to the smooth operation of a data center or computer room. Tight tolerance temperature control is essential as temperature fluctuations can cause thermal stresses and premature failures in IT equipment. Low humidity can cause static discharge and high humidity can cause condensation – both extremes creating treacherous conditions for IT and networking equipment. Additionally, Perimeter Cooling solutions are highly manageable with controls to ensure optimized operation, alarms to provide visibility into the health of the unit, and an easy-to-use display allowing the operator to select options from the device's menu-driven interface to control and monitor the connected air conditioning system.
  • Power - Electric power is defined as the rate at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt. Electrical power is distributed via cables and electricity pylons like these in Brisbane, Australia. When electric current flows in a circuit, it can transfer energy to do mechanical or thermodynamic work. Devices convert electrical energy into many useful forms, such as heat (electric heaters), light (light bulbs), motion (electric motors), sound (loudspeaker) or chemical changes. Electricity can be produced mechanically by generation, or chemically, or by direct conversion from light in photovoltaic cells, also it can be stored chemically in batteries.
  • Power Density - Electrical power used in a space divided by the area of the space.
  • Power Factor - Amount of power loss due to the amount of power conversion.
  • PDU - Power Distribution Unit. This electrical device is used to control the distribution of power to the individual loads.
  • PreAction - An Action involved in a dry system prior to actually flooding the pipe with water and potentially discharging into the protected space.
  • Primary Core Switch & Redundant Core Switch - Each PCR room has two core switches, one is primary and the other is redundancy. Between PCR room's core switches, every building's core switch has two links to other building's core switches. One link to core switches of primary and the other link to core switches of redundancy.
  • Pumps - A pump and enclosure used to circulate condenser water or glycol on applicable systems. Pump packages are specified based on desired flow rate and piping losses for each application.
  • Rack unit (RU) - a unit of measure of vertical space in an equipment rack. One rack unit is equal to 45 mm (1.75 in).
  • Raised Floor -
    1. the raised floor acts as a supply plenum to deliver conditioned air into the room to cool the equipment and can also serve as wire management for power, data, or both. Air-conditioning units (ACUs) also sit on the raised floor and provide cool air into the raised floor plenum to cool the room and take their return air directly from the room.
    2. A raised floor is a type of floor used in office buildings (such as IT data centers) with a high requirement for servicing to carry cables, wiring, electrical supply, and sometimes air conditioning or chilled water pipes. Additional structural support and lighting are often provided when a floor is raised enough for a person to crawl or even walk beneath.
  • Raised Floor Height - This type of floor consists of a gridded metal framework or understructure of adjustable-height legs (called "pedestals") that provide support for individual floor panels, which are usually 2×2 feet or 60×60cm in size. The height of the legs/pedestals is dictated by the volume of cables and volume of air necessary to provide air network and power connectivity to the cabinet. Typically arranged for a clearance of at least six inches or 15cm.
  • Ceiling to Deck Height - the space between a suspended or false ceiling and the structural surface above used as a distribution system that provides a pathway for cables serving the work area outlets from above.
  • Router - Router An internetworking device, operating at the Network layer of the Open Systems Interconnection model, used to direct packets from one network to another.
  • Row-based cooling - Row-Based Cooling solutions provide cooling directly to multiple adjacent cabinets. These solutions are typically deployed in locations that do not have traditional computer room air conditioning. They may also be implemented to augment existing cooling, especially in areas where cabinets are densely populated. Options range from medium-density (5 to 7kW per cabinet) to high-density (20+ kW per cabinet).
  • Satellite Head End System - An equipment rack filled with active electronics capable of receiving, processing and delivering digital satellite TV signals to an entire community over coaxial cable and/ or fiber optic infrastructure. Head end systems are used by both franchised and non-franchised cable companies to provide video, Internet and telephone services to customers.
  • Server Cabinets -A cabinet designed to hold a network device that combines hardware and software to provide and manage shared services and resources on the network.
  • Step Down Transformers - a transformer that reduces voltage - an electrical device by which alternating current of one voltage is changed to another voltage
  • Switch 1. A network access device that provides a centralized point for LAN communications, media connections, and management activities where each switch port represents a separate communications channel. Sometimes referred to as a multi-port bridge. See also bridge. 2. A voice communications device that utilizes switching technology to establish and terminate calls.
  • Switching 1. Networking protocol in which a station sends a message to a hub, which then routes the message to the specified destination station. 2. Establishing a direct signal path form one device to another. Establishing a direct signal path from one device to another.
  • Switchgear - Electrical Distribution hat breaks out power from high to medium to low voltage.
  • Telco - In the United States and possibly other countries, "telco" is a short form for Telephone Company. Sometimes it means a local telephone company, such as a Bell operating company or an independent local telephone company. Sometimes it means any telephone company, including one offering long-distance services.
  • Telephony - (pronounced teh-LEH-fuh-nee) encompasses the general use of equipment to provide voice communication over distances, specifically by connecting telephones to each other.
  • Tier I - composed of a single path for power and cooling distribution, without redundant components, providing 99.671% availability.
  • Tier II - composed of a single path for power and cooling distribution, with redundant components, providing 99.741% availability
  • Tier III - composed of multiple active power and cooling distribution paths, but only one path active, has redundant components, and is concurrently maintainable, providing 99.982% availability
  • Tier IV - composed of multiple active power and cooling distribution paths, has redundant components, and is fault tolerant, providing 99.995% availability.
  • Tons - Ton (Cooling) A measurement of heat energy commonly used historically to measure heat loads in data centers and IT rooms in North America. A ton is equal to 12,000 BTUs and is the amount of heat energy required to melt 2000 pounds (907kg) of ice in one hour. This is an archaic term typically used to specify heat output when expressed in Tons/day, where the use of the more modern term Watts is the simpler and more universal measure that should be used.
  • Traditional, non-scalable UPS - based on a particular size rating. It is fixed and cannot be increased or decreased.
  • Transformer- Designed to increase or decrease available voltage by electromagnetic conversion. (Exception: can also convert AC- DC)
  • Transition Operating System - An operating system (commonly abbreviated to either OS or O/S) is an interface between hardware and user; it is responsible for the management and coordination of activities and the sharing of the limited resources of the computer. The operating system acts as a host for applications that are run on the machine. As a host, one of the purposes of an operating system is to handle the details of the operation of the hardware. This relieves application programs from having to manage these details and makes it easier to write applications. Almost all computers, including handheld computers, desktop computers, supercomputers, and even video game consoles, use an operating system of some type. Some of the oldest models may however use an embedded operating system, that may be contained on a compact disk or other data storage device.
  • TVSS - Transient volt surge suppression; shunt to ground over volt spikes to prevent electrical fires and/or system failures.
  • UPS - An uninterruptible power supply (UPS) is a device that allows your computer to keep running for at least a short time when the primary power source is lost. It also provides protection from power surges. When power surges occur, an UPS intercepts the surge so that it doesn't damage your computer.
  • Usable VA per Circuit - de-rating of available volt-amps to usable amps to prevent circuit overloads and fires.
  • Usable KVA per Circuit - de-rating of available Kilo-volt-amps to usable amps to prevent circuit overloads and fires.
  • Usable kW per Circuit - de-rating of available Kilo-watts to usable amps to prevent circuit overloads and fires.
  • Volt (V) - A unit of electromotive force or potential difference that will cause a current of one ampere to flow through a resistance of one ohm.
  • WAN connection - A wide area network (WAN) is a computer network that covers a broad area (i.e. any network whose communications links cross metropolitan, regional, or national boundaries [1]). Less formally, a WAN is a network that uses routers and public communications links [1]. Contrast with personal area networks (PANs), local area networks (LANs), campus area networks (CANs), or metropolitan area networks (MANs), which are usually limited to a room, building, campus or specific metropolitan area (e.g., a city) respectively. The largest and most well-known example of a WAN is the Internet. A WAN is a data communications network that covers a relatively broad geographic area (i.e. one city to another and one country to another country) and that often uses transmission facilities provided by common carriers, such as telephone companies. WAN technologies generally function at the lower three layers of the OSI reference model: the physical layer, the data link layer, and the network layer. wide area network (WAN) A data communications system that uses telecommunications circuits to link LANs that are distributed over large geographic distances.
  • Watts per sq ft - watts per square foot