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Damper (flow)
A damper is a valve or plate that stops or regulates the flow of air inside a duct, chimney, VAV box, air handler, or other air-handling equipment. A damper may be used to cut off central air conditioning (heating or cooling) to an unused room, or to regulate it for room-by-room temperature and climate control -- for example in the case of Volume Control Dampers. Its operation can be manual or automatic. Manual dampers are turned by a handle on the outside of a duct. Automatic dampers are used to regulate airflow constantly and are operated by electric or pneumatic motors, in turn controlled by a thermostat or building automation system. Automatic or motorized dampers may also be controlled by a solenoid, and the degree of air-flow calibrated, perhaps according to signals from the thermostat going to the actuator of the damper in order to modulate the flow of air-conditioned air in order to effect climate control. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Damper
The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing for liquid water to exist on the Earth's surface, absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation). By mole fraction (i.e., by number of molecules), dry air contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere. Air composition, temperature, and atmospheric pressure vary with altitude. Within the atmosphere, air suitable for use in photosynthesis by terrestrial plants and breathing of terrestrial animals is found only in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fireplace
A fireplace or hearth is a structure made of brick, stone or metal designed to contain a fire. Fireplaces are used for the relaxing ambiance they create and for heating a room. Modern fireplaces vary in heat efficiency, depending on the design. Historically, they were used for heating a dwelling, cooking, and heating water for laundry and domestic uses. A fire is contained in a firebox or fire pit; a chimney or other flue allows exhaust gas to escape. A fireplace may have the following: a foundation, a hearth, a firebox, a mantel, a chimney crane (used in kitchen and laundry fireplaces), a grate, a lintel, a lintel bar, an overmantel, a damper, a smoke chamber, a throat, a flue, and a chimney filter or afterburner. On the exterior, there is often a corbelled brick crown, in which the projecting courses of brick act as a drip course to keep rainwater from running down the exterior walls. A cap, hood, or shroud serves to keep rainwater out of the exterior of the chimney ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BACnet
BACnet is a communication protocol for building automation and control (BAC) networks that use the ASHRAE, ANSI, and ISO 16484-5 standards protocol. BACnet was designed to allow communication of building automation and control systems for applications such as heating, ventilating, and air-conditioning control ( HVAC), lighting control, access control, and fire detection systems and their associated equipment. The BACnet protocol provides mechanisms for computerized building automation devices to exchange information, regardless of the particular building service they perform. History The development of the BACnet protocol began in June, 1987, in Nashville, Tennessee, at the inaugural meeting of the ASHRAE BACnet committee, known at that time as SPC 135P, "EMCS Message Protocol". The committee worked at reaching consensus using working groups to divide up the task of creating a standard. The working groups focused on specific areas and provided information and recommendations to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spring (device)
A spring is an elastic object that stores mechanical energy. In everyday use the term often refers to coil springs, but there are many different spring designs. Modern springs are typically manufactured from spring steel, although some non-metallic objects like the bow are also springs. When a conventional spring, without stiffness variability features, is compressed or stretched from its resting position, it exerts an opposing force approximately proportional to its change in length (this approximation breaks down for larger deflections). The ''rate'' or ''spring constant'' of a spring is the change in the force it exerts, divided by the change in deflection of the spring. That is, it is the gradient of the force versus deflection curve. An extension or compression spring's rate is expressed in units of force divided by distance, for example or N/m or lbf/in. A torsion spring is a spring that works by twisting; when it is twisted about its axis by an angle, it produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternating Current
Alternating current (AC) is an electric current which periodically reverses direction and changes its magnitude continuously with time in contrast to direct current (DC) which flows only in one direction. Alternating current is the form in which electric power is delivered to businesses and residences, and it is the form of electrical energy that consumers typically use when they plug kitchen appliances, televisions, fans and electric lamps into a wall socket. A common source of DC power is a battery cell in a flashlight. The abbreviations ''AC'' and ''DC'' are often used to mean simply ''alternating'' and ''direct'', as when they modify '' current'' or '' voltage''. The usual waveform of alternating current in most electric power circuits is a sine wave, whose positive half-period corresponds with positive direction of the current and vice versa. In certain applications, like guitar amplifiers, different waveforms are used, such as triangular waves or square waves. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volt
The volt (symbol: V) is the unit of electric potential, electric potential difference (voltage), and electromotive force in the International System of Units (SI). It is named after the Italian physicist Alessandro Volta (1745–1827). Definition One volt is defined as the electric potential between two points of a conducting wire when an electric current of one ampere dissipates one watt of power between those points. Equivalently, it is the potential difference between two points that will impart one joule of energy per coulomb of charge that passes through it. It can be expressed in terms of SI base units ( m, kg, s, and A) as : \text = \frac = \frac = \frac. It can also be expressed as amperes times ohms (current times resistance, Ohm's law), webers per second (magnetic flux per time), watts per ampere (power per current), or joules per coulomb (energy per charge), which is also equivalent to electronvolts per elementary charge: : \text = \text\Omega = \fra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shaded-pole Synchronous Motor
Shaded-pole synchronous motors are a class of AC motors. Like a shaded pole induction motor, they use field coils with additional copper ''shading coils'' (see the illustration) to produce a weakly rotating magnetic field. But unlike a shaded pole induction motor (which uses a squirrel cage rotor), the synchronous version of this motor uses a magnetized rotor, e.g. a permanent magnet. This rotor rotates synchronously with the rotating magnetic field: if the rotor begins to lag behind the rotating field, driving torque increases and the rotor speeds up slightly until the rotor's position within the rotating field is a point where torque = drag; similarly, if the rotation of the field slows down, the rotor will advance relative to the field, torque will decline, or even become negative, slowing the speed of the rotor until it again reaches a position relative to the field where torque = drag. Because of this, these motors are often used to drive electric clocks and, occasionally, p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compressed Air
Compressed air is air kept under a pressure that is greater than atmospheric pressure. Compressed air is an important medium for transfer of energy in industrial processes, and is used for power tools such as air hammers, drills, wrenches, and others, as well as to atomize paint, to operate air cylinders for automation, and can also be used to propel vehicles. Brakes applied by compressed air made large railway trains safer and more efficient to operate. Compressed air brakes are also found on large highway vehicles. Compressed air is used as a breathing gas by underwater divers. It may be carried by the diver in a high pressure diving cylinder, or supplied from the surface at lower pressure through an air line or diver's umbilical. Similar arrangements are used in breathing apparatus used by firefighters, mine rescue workers and industrial workers in hazardous atmospheres. In Europe, 10 percent of all industrial electricity consumption is to produce compressed air—am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum
A vacuum is a space devoid of matter. The word is derived from the Latin adjective ''vacuus'' for "vacant" or " void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often discuss ideal test results that would occur in a ''perfect'' vacuum, which they sometimes simply call "vacuum" or free space, and use the term partial vacuum to refer to an actual imperfect vacuum as one might have in a laboratory or in space. In engineering and applied physics on the other hand, vacuum refers to any space in which the pressure is considerably lower than atmospheric pressure. The Latin term ''in vacuo'' is used to describe an object that is surrounded by a vacuum. The ''quality'' of a partial vacuum refers to how closely it approaches a perfect vacuum. Other things equal, lower gas pressure means higher-quality vacuum. For example, a typical vacuum cleaner produces enough suction to reduce air pressure by around 20%. But h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HVAC
Heating, ventilation, and air conditioning (HVAC) is the use of various technologies to control the temperature, humidity, and purity of the air in an enclosed space. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer. " Refrigeration" is sometimes added to the field's abbreviation as HVAC&R or HVACR, or "ventilation" is dropped, as in HACR (as in the designation of HACR-rated circuit breakers). HVAC is an important part of residential structures such as single family homes, apartment buildings, hotels, and senior living facilities; medium to large industrial and office buildings such as skyscrapers and hospitals; vehicles such as cars, trains, airplanes, ships and submarines; and in marine environments, where safe and healthy building conditions are regulated with respect to temperature and humidity, using fres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zone Damper 2
Zone or The Zone may refer to: Places Climate and altitude zones * Death zone (originally the lethal zone), altitudes above a certain point where the amount of oxygen is insufficient to sustain human life for an extended time span * Frigid zone, a geographical zone on Earth * Hardiness zone, a geographically defined zone in which a specific category of plant life is capable of growing * Temperate zone, a geographical zone on Earth * Torrid zone, a geographical zone on Earth Military zones * Zone, any of the divisions of France during the World War II German occupation * Zone, any of the divisions of Germany during the post-World War II Allied occupation *DMZ or DZ or demilitarized zone, an area in which treaties or agreements between nations, military powers, or contending groups forbid military installations, activities, or personnel * Green Zone, a military zone in Baghdad, Iraq * Korean Demilitarized Zone Place-names * Administrative divisions of India, known as Zones * Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zone Damper 1
Zone or The Zone may refer to: Places Climate and altitude zones * Death zone (originally the lethal zone), altitudes above a certain point where the amount of oxygen is insufficient to sustain human life for an extended time span * Frigid zone, a geographical zone on Earth * Hardiness zone, a geographically defined zone in which a specific category of plant life is capable of growing * Temperate zone, a geographical zone on Earth * Torrid zone, a geographical zone on Earth Military zones * Zone, any of the divisions of France during the World War II German occupation * Zone, any of the divisions of Germany during the post-World War II Allied occupation *DMZ or DZ or demilitarized zone, an area in which treaties or agreements between nations, military powers, or contending groups forbid military installations, activities, or personnel * Green Zone, a military zone in Baghdad, Iraq * Korean Demilitarized Zone Place-names * Administrative divisions of India, known as Zones * Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
