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Server Room
A server room is a room, usually air-conditioned, devoted to the continuous operation of computer servers. An entire building or station devoted to this purpose is a data center. The computers in server rooms are usually headless systems that can be operated remotely via KVM switch or remote administration software, such as Secure Shell, VNC, and remote desktop. Climate is one of the factors that affects the energy consumption and environmental impact of a server room. In areas where climate favours cooling and an abundance of renewable electricity, the environmental effects will be more moderate. Thus, countries with favourable conditions such as Canada, Finland, Sweden, and Switzerland are trying to attract companies to site server rooms there. Design considerations Building a server or computer room requires detailed attention to five main design considerations: Location Computer or server room location is the first consideration, even before considering the layout of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Handler
An air handler, or air handling unit (often abbreviated to AHU), is a device used to regulate and circulate air as part of a heating, ventilating, and air-conditioning ( HVAC) system. An air handler is usually a large metal box containing a blower, heating or cooling elements, filter racks or chambers, sound attenuators, and dampers. Air handlers usually connect to a ductwork ventilation system that distributes the conditioned air through the building and returns it to the AHU. Sometimes AHUs discharge (''supply'') and admit (''return'') air directly to and from the space served without ductwork Small air handlers, for local use, are called terminal units, and may only include an air filter, coil, and blower; these simple terminal units are called blower coils or fan coil units. A larger air handler that conditions 100% outside air, and no recirculated air, is known as a makeup air unit (MAU) or fresh air handling unit (FAHU). An air handler designed for outdoor use, typic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorinated Ethylene Propylene
Fluorinated ethylene propylene (FEP) is a copolymer of hexafluoropropylene and tetrafluoroethylene. It differs from the polytetrafluoroethylene (PTFE) resins in that it is melt-processable using conventional injection molding and screw extrusion techniques. Fluorinated ethylene propylene was invented by DuPont and is sold under the brandname Teflon FEP. Other brandnames are Neoflon FEP from Daikin or Dyneon FEP from Dyneon/ 3M. FEP is very similar in composition to the fluoropolymers PTFE (polytetrafluoroethylene) and PFA (perfluoroalkoxy polymer resin). FEP and PFA both share PTFE's useful properties of low friction and non-reactivity, but are more easily formable. FEP is softer than PTFE and melts at 260 °C; it is highly transparent and resistant to sunlight. Production FEP is produced by free-radical polymerization of mixtures of tetrafluoroethylene and hexafluoropropylene. The mixture is biased to compensate for the relatively low reactivity of the propylene compone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plenum Cable
__NOTOC__ Plenum cable is electrical cable that is laid in the plenum spaces of buildings. In the United States, plastics used in the construction of plenum cable are regulated under the National Fire Protection Association standard NFPA 90A: Standard for the Installation of Air Conditioning and Ventilating Systems. All materials intended for use on wire and cables to be placed in plenum spaces are designed to meet rigorous fire safety test standards in accordance with NFPA 262 and outlined in NFPA 90A. Plenum cable is jacketed with a fire-retardant plastic jacket of either a low-smoke polyvinyl chloride (PVC) or a fluorinated ethylene polymer ( FEP). Polyolefin formulations, specifically based on polyethylene compounding had been developed by at least two companies in the early to mid-1990s; however, these were never commercialized, and development efforts continue in these yet-untapped product potentials. Development efforts on a non-halogen plenum compound were announced in 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoxia (environmental)
Hypoxia refers to low oxygen conditions. Normally, 20.9% of the gas in the atmosphere is oxygen. The partial pressure of oxygen in the atmosphere is 20.9% of the total barometric pressure. In water, oxygen levels are much lower, approximately 7 ppm or 0.0007% in good quality water, and fluctuate locally depending on the presence of photosynthetic organisms and relative distance to the surface (if there is more oxygen in the air, it will diffuse across the partial pressure gradient). Atmospheric hypoxia Atmospheric hypoxia occurs naturally at high altitudes. Total atmospheric pressure decreases as altitude increases, causing a lower partial pressure of oxygen, which is defined as hypobaric hypoxia. Oxygen remains at 20.9% of the total gas mixture, differing from hypoxic hypoxia, where the percentage of oxygen in the air (or blood) is decreased. This is common in the sealed burrows of some subterranean animals, such as blesmols. Atmospheric hypoxia is also the basis of altitude ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FM200
1,1,1,2,3,3,3-Heptafluoropropane, also called heptafluoropropane, HFC-227ea ( ISO name), HFC-227 or FM-200, as well as apaflurane ( INN), is a colourless, odourless gaseous halocarbon commonly used as a gaseous fire suppression agent. Chemistry Its chemical formula is CF-CHF-CF, or CHF. With a boiling point of −16.4 °C, it is a gas at room temperature. It is slightly soluble in water (260 mg/L). Use HFC-227ea is used in fire suppression systems that protect data processing and telecommunication facilities, and in fire suppression of many flammable liquids and gases. HFC-227ea is categorized as a Clean Agent and is governed by ''NFPA 2001 - Standard for Clean Agent Fire Extinguishing Systems''. Effective fire suppression requires introducing a concentration of the HFC-227ea agent between 6.25% and 9% depending on the hazard being suppressed. Its NOAEL for cardiac sensitization is 9%. The United States Environmental Protection Agency allows concentration of 9% vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Dioxide
Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. It is a trace gas in Earth's atmosphere at 421 parts per million (ppm), or about 0.04% by volume (as of May 2022), having risen from pre-industrial levels of 280 ppm. Burning fossil fuels is the primary cause of these increased CO2 concentrations and also the primary cause of climate change.IPCC (2022Summary for policy makersiClimate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA Carbon dioxide is soluble in water and is found in groundwater, lakes, ice ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argon
Argon is a chemical element with the symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third-most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice as abundant as water vapor (which averages about 4000 ppmv, but varies greatly), 23 times as abundant as carbon dioxide (400 ppmv), and more than 500 times as abundant as neon (18 ppmv). Argon is the most abundant noble gas in Earth's crust, comprising 0.00015% of the crust. Nearly all of the argon in Earth's atmosphere is radiogenic argon-40, derived from the decay of potassium-40 in Earth's crust. In the universe, argon-36 is by far the most common argon isotope, as it is the most easily produced by stellar nucleosynthesis in supernovas. The name "argon" is derived from the Greek word , neuter singular form of meaning 'lazy' or 'inactive', as a reference to the fact that the element undergoes almost no chemical reactions. The com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System. At standard temperature and pressure, two atoms of the element bond to form N2, a colorless and odorless diatomic gas. N2 forms about 78% of Earth's atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids ( DNA and RNA) and in the energy transfer molecule adenosine triphosphate. The human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes the movement of the element from the air, into the biosphere and organic compounds, then back into the atmosphere. Many indus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halomethane
Halomethane compounds are derivatives of methane () with one or more of the hydrogen atoms replaced with halogen atoms ( F, Cl, Br, or I). Halomethanes are both naturally occurring, especially in marine environments, and human-made, most notably as refrigerants, solvents, propellants, and fumigants. Many, including the chlorofluorocarbons, have attracted wide attention because they become active when exposed to ultraviolet light found at high altitudes and destroy the Earth's protective ozone layer. Structure and properties Like methane itself, halomethanes are tetrahedral molecules. The halogen atoms differ greatly in size and charge from hydrogen and from each other. Consequently, most halomethanes deviate from the perfect tetrahedral symmetry of methane.Günter Siegemund, Werner Schwertfeger, Andrew Feiring, Bruce Smart, Fred Behr, Herward Vogel, Blaine McKusick “Fluorine Compounds, Organic” Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. The ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Protection
Fire protection is the study and practice of mitigating the unwanted effects of potentially destructive fires. It involves the study of the behaviour, compartmentalisation, suppression and investigation of fire and its related emergencies, as well as the research and development, production, testing and application of mitigating systems. In structures, be they land-based, offshore or even ships, the owners and operators are responsible to maintain their facilities in accordance with a design-basis that is rooted in laws, including the local building code and fire code, which are enforced by the authority having jurisdiction. Buildings must be constructed in accordance with the version of the building code that is in effect when an application for a building permit is made. Building inspectors check on compliance of a building under construction with the building code. Once construction is complete, a building must be maintained in accordance with the current fire code, which is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperature Chaining
Temperature chaining can mean temperature, thermal or energy chaining or cascading. Temperature chaining has been introduced as a new concept at Datacentre Transformation in Manchester by the company Asperitas as part of a vision on a Datacentre of the Future. It is a method of transforming electrical consumption in datacentres into usable heat. The concept is based on creating high temperature differences in a water based cooling circuit in a datacentre. The premise is that every system in a datacentre can be equipped with a shared water infrastructure which is divided into multiple stages with different temperatures. The different temperatures are achieved by setting up different liquid cooling technologies with different temperature tolerances in a serial cooling setup as opposed to a single parallel circuit. This creates high temperature differences with a low water volume. This results in a datacentre environment which is capable of supplying constant temperature water to a re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
