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High-volume Low-speed Fan
A high-volume low-speed (HVLS) fan is a type of mechanical fan greater than in diameter. HVLS fans are generally ceiling fans although some are pole mounted. HVLS fans move slowly and distribute large amounts of air at low rotational speed– hence the name "high volume, low speed." Typical applications for HVLS fans fall into two classifications—industrial and commercial. In industrial applications, HVACR is often cost prohibitive or impractical, and is usually only used for refrigerated warehouses or the manufacture of refrigerated or frozen foods. Fans installed in spaces like warehouses, barns, hangars and distribution centers can prevent heat stress, increase worker comfort and the productivity of both workers and livestock. HVLS fans are also used in commercial spaces, where air conditioning is more common, but increased air movement from ceiling fans can cost-effectively augment occupant comfort or prevent stratification. Typical commercial applications include shopping m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HVLS Wood Ceiling
A high-volume low-speed (HVLS) fan is a type of mechanical fan greater than in diameter. HVLS fans are generally ceiling fans although some are pole mounted. HVLS fans move slowly and distribute large amounts of air at low rotational speed– hence the name "high volume, low speed." Typical applications for HVLS fans fall into two classifications—industrial and commercial. In industrial applications, Heating, ventilation, and air conditioning, HVACR is often cost prohibitive or impractical, and is usually only used for refrigerated warehouses or the manufacture of refrigerated or frozen foods. Fans installed in spaces like warehouses, barns, hangars and distribution centers can prevent heat stress, increase worker comfort and the productivity of both workers and livestock. HVLS fans are also used in commercial spaces, where air conditioning is more common, but increased air movement from ceiling fans can cost-effectively augment occupant comfort or prevent stratification. Typica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Office Buildings
An office is a space where an organization's employees perform administrative work in order to support and realize objects and goals of the organization. The word "office" may also denote a position within an organization with specific duties attached to it (see officer, office-holder, official); the latter is in fact an earlier usage, office as place originally referring to the location of one's duty. When used as an adjective, the term "office" may refer to business-related tasks. In law, a company or organization has offices in any place where it has an official presence, even if that presence consists of (for example) a storage silo rather than an establishment with desk-and-chair. An office is also an architectural and design phenomenon: ranging from a small office such as a bench in the corner of a small business of extremely small size (see small office/home office), through entire floors of buildings, up to and including massive buildings dedicated entirely to one c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Inventions ...
The following articles cover the timeline of United States inventions: *Timeline of United States inventions (before 1890), before the turn of the century * Timeline of United States inventions (1890–1945), before World War II *Timeline of United States inventions (1946–1991), for the post-war era *Timeline of United States inventions (after 1991), after the Fall of the Soviet Union {{DEFAULTSORT:Timeline of United States Inventions United States inventions United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Movement And Control Association
The Air Movement and Control Association International, Inc. (AMCA) is an American trade body that sets standards for Heating, Ventilation and Air Conditioning (HVAC) equipment. It rates fan balance and vibration, aerodynamic performance, air density, speed and efficiency. AMCA was formed in 1955 from several earlier trade associations which could be traced back to the fan-testing requirements of the US Navy in 1923. It is a nonprofit organization that issues over 60 publications and standards, including testing methods, a Certified Ratings Program (CRP), application guides, educational texts, and safety guides. Membership and Activities AMCA membership is open to any company that manufactures or holds the design of a product that falls under the AMCA scope. AMCA publications and standards are developed when sufficient interest has been expressed by AMCA members. Publication and standard writing committees are composed of volunteers, which include both AMCA members and intereste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drag (physics)
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers (or surfaces) or between a fluid and a solid surface. Unlike other resistive forces, such as dry friction, which are nearly independent of velocity, the drag force depends on velocity. Drag force is proportional to the velocity for low-speed flow and the squared velocity for high speed flow, where the distinction between low and high speed is measured by the Reynolds number. Even though the ultimate cause of drag is viscous friction, turbulent drag is independent of viscosity. Drag forces always tend to decrease fluid velocity relative to the solid object in the fluid's path. Examples Examples of drag include the component of the net aerodynamic or hydrodynamic force acting opposite to the di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Airfoils
An airfoil (American English) or aerofoil (British English) is the cross-sectional shape of an object whose motion through a gas is capable of generating significant lift, such as a wing, a sail, or the blades of propeller, rotor, or turbine. A solid body moving through a fluid produces an aerodynamic force. The component of this force perpendicular to the relative freestream velocity is called lift. The component parallel to the relative freestream velocity is called drag. An airfoil is a streamlined shape that is capable of generating significantly more lift than drag. Airfoils can be designed for use at different speeds by modifying their geometry: those for subsonic flight generally have a rounded leading edge, while those designed for supersonic flight tend to be slimmer with a sharp leading edge. All have a sharp trailing edge. Foils of similar function designed with water as the working fluid are called hydrofoils. The lift on an airfoil is primarily the result of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clark Y
Clark Y is the name of a particular airfoil profile, widely used in general purpose aircraft designs, and much studied in aerodynamics over the years. The profile was designed in 1922 by Virginius E. Clark using thickness distribution of the German-developed Goettingen 398 airfoil.Piccirillo, Albert, "The Clark Y Airfoil - A Historical Retrospective," SAE/AIAA paper 2000-01-5517, presented at the World Aviation Congress & Exposition, October 10, 2000, San Diego, California. The airfoil has a thickness of 11.7 percent and is flat on the lower surface aft of 30 percent of chord. The flat bottom simplifies angle measurements on propellers, and makes for easy construction of wings. For many applications the Clark Y has been an adequate airfoil section; it gives reasonable overall performance in respect of its lift-to-drag ratio, and has gentle and relatively benign stall characteristics. But the flat lower surface is not optimal from an aerodynamic perspective, and it is rarely used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NFCC
The PFF National Challenge Cup is an annual semi-professional Single-elimination tournament, knockout association football, football competition in men's domestic Football in Pakistan, Pakistani football within the Pakistan football league system. It is organized by and named after the Pakistan Football Federation. Khan Research Laboratories F.C., Khan Research Laboratories have won the most titles (six). WAPDA F.C., WAPDA are the current champions, winning the 2020 PFF National Challenge Cup, 2020 edition courtesy of a 1-0 win against SSGC F.C. in the final. Background Although it is an annual competition, it has not been held on a few occasions. The competition was not held from (1980–83, 1986, 1988–89, 1995, 1997, 2004, 2006–07, 2017, 2021–22). The tournament has seen various name changes throughout its establishment. Names Finals ;Wins by club Results by team Since its establishment, the National Challenge Cup has been won by 15 different teams. Teams shown in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schools
A school is an educational institution designed to provide learning spaces and learning environments for the teaching of students under the direction of teachers. Most countries have systems of formal education, which is sometimes compulsory. In these systems, students progress through a series of schools. The names for these schools vary by country (discussed in the '' Regional terms'' section below) but generally include primary school for young children and secondary school for teenagers who have completed primary education. An institution where higher education is taught is commonly called a university college or university. In addition to these core schools, students in a given country may also attend schools before and after primary (elementary in the U.S.) and secondary (middle school in the U.S.) education. Kindergarten or preschool provide some schooling to very young children (typically ages 3–5). University, vocational school, college or seminary may be availabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Church (building)
A church, church building or church house is a building used for Christian worship services and other Christian religious activities. The earliest identified Christian church is a house church founded between 233 and 256. From the 11th through the 14th centuries, there was a wave of church construction in Western Europe. Sometimes, the word ''church'' is used by analogy for the buildings of other religions. ''Church'' is also used to describe the Christian religious community as a whole, or a body or an assembly of Christian believers around the world. In traditional Christian architecture, the plan view of a church often forms a Christian cross; the center aisle and seating representing the vertical beam with the Church architecture#Characteristics of the early Christian church building, bema and altar forming the horizontal. Towers or domes may inspire contemplation of the heavens. Modern churches have a variety of architectural styles and layouts. Some buildings designe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Fan
A fan is a powered machine used to create a flow of air. A fan consists of a rotating arrangement of vanes or blades, generally made of wood, plastic, or metal, which act on the air. The rotating assembly of blades and hub is known as an ''impeller'', ''rotor'', or ''runner''. Usually, it is contained within some form of housing, or case. This may direct the airflow, or increase safety by preventing objects from contacting the fan blades. Most fans are powered by electric motors, but other sources of power may be used, including hydraulic motors, handcranks, and internal combustion engines. Mechanically, a fan can be any revolving vane, or vanes used for producing currents of air. Fans produce air flows with high volume and low pressure (although higher than ambient pressure), as opposed to compressors which produce high pressures at a comparatively low volume. A fan blade will often rotate when exposed to an air-fluid stream, and devices that take advantage of this, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shopping Malls
A shopping mall (or simply mall) is a North American term for a large indoor shopping center, usually anchored by department stores. The term "mall" originally meant a pedestrian promenade with shops along it (that is, the term was used to refer to the walkway itself which was merely bordered by such shops), but in the late 1960s, it began to be used as a generic term for the large enclosed shopping centers that were becoming commonplace at the time. In the U.K., such complexes are considered shopping centres (Commonwealth English: shopping centre), though "shopping center" covers many more sizes and types of centers than the North American "mall". Other countries may follow U.S. usage (Philippines, India, U.A.E., etc.) and others (Australia, etc.) follow U.K. usage. In Canadian English, and oftentimes in Australia and New Zealand, 'mall' may be used informally but 'shopping centre' or merely 'centre' will feature in the name of the complex (such as Toronto Eaton Centre). The te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
