|
Passive Ventilation
Passive ventilation is the process of supplying air to and removing air from an indoor space without using mechanical systems. It refers to the flow of external air to an indoor space as a result of pressure differences arising from natural forces. There are two types of natural ventilation occurring in buildings: '' wind driven ventilation'' and ''buoyancy-driven ventilation''. Wind driven ventilation arises from the different pressures created by wind around a building or structure, and openings being formed on the perimeter which then permit flow through the building. Buoyancy-driven ventilation occurs as a result of the directional buoyancy force that results from temperature differences between the interior and exterior. Since the internal heat gains which create temperature differences between the interior and exterior are created by natural processes, including the heat from people, and wind effects are variable, naturally ventilated buildings are sometimes called "brea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infiltration (HVAC)
Infiltration is the unintentional or accidental introduction of outside air into a building, typically through cracks in the building envelope and through use of doors for passage. Infiltration is sometimes called air leakage. The leakage of room air out of a building, intentionally or not, is called exfiltration. Infiltration is caused by wind, negative pressurization of the building, and by air buoyancy forces known commonly as the stack effect. Infiltration measures The infiltration rate is the volumetric flow rate of outside air into a building, typically in cubic feet per minute (CFM) or liters per second (LPS). The air exchange rate, (''I''), is the number of interior volume air changes that occur per hour, and has units of 1/h. The air exchange rate is also known as air changes per hour (''ACH''). ACH is the hourly ventilation rate, divided by the building volume. It can be calculated by multiplying the building's CFM by 60, and then dividing by the building volume. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravitational Acceleration
In physics, gravitational acceleration is the acceleration of an object in free fall within a vacuum (and thus without experiencing drag (physics), drag). This is the steady gain in speed caused exclusively by gravitational attraction. All bodies accelerate in vacuum at the same rate, regardless of the masses or compositions of the bodies; the measurement and analysis of these rates is known as gravimetry. At a fixed point on the surface, the magnitude of gravity of Earth, Earth's gravity results from combined effect of gravitation and the centrifugal force from Earth's rotation. At different points on Earth's surface, the free fall acceleration ranges from , depending on altitude, latitude, and longitude. A conventional standard gravity, standard value is defined exactly as 9.80665 m/s² (about 32.1740 ft/s²). Locations of significant variation from this value are known as gravity anomaly, gravity anomalies. This does not take into account other effects, such as buoyancy or d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
English Units
English units were the units of measurement used in England up to 1826 (when they were replaced by Imperial units), which evolved as a combination of the Anglo-Saxons, Anglo-Saxon and Ancient Roman units of measurement, Roman systems of units. Various standards have applied to English units at different times, in different places, and for different applications. Use of the term "English units" can be ambiguous, as, in addition to the meaning used in this article, it is sometimes used to refer to the units of the descendant Imperial system as well to those of the descendant system of United States customary units. The two main sets of English units were the Winchester measure, Winchester Units, used from 1495 to 1587, as affirmed by Henry VII of England, King Henry VII, and the Exchequer Standards, in use from 1588 to 1825, as defined by Queen Elizabeth I. In England (and the British Empire), English units were replaced by Imperial units in 1824 (effective as of 1 January 1826) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windcatcher
A windcatcher, wind tower, or wind scoop () is a traditional architectural element used to create cross ventilation and passive cooling in buildings. Windcatchers come in various designs, depending on whether local prevailing winds are unidirectional, bidirectional, or multidirectional, on how they change with altitude, on the daily temperature cycle, on humidity, and on how much dust needs to be removed. Despite the name, windcatchers can also function without wind. Neglected by modern architects in the latter half of the 20th century, the early 21st century saw them used again to increase ventilation and cut power demand for air-conditioning. Generally, the cost of construction for a windcatcher-ventilated building is less than that of a similar building with conventional heating, ventilation, and air conditioning (HVAC) systems. The maintenance costs are also lower. Unlike powered air-conditioning and fans, windcatchers are silent and continue to function when the electr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computational Fluid Dynamics
Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis and data structures to analyze and solve problems that involve fluid dynamics, fluid flows. Computers are used to perform the calculations required to simulate the free-stream flow of the fluid, and the interaction of the fluid (liquids and gases) with surfaces defined by Boundary value problem#Boundary value conditions, boundary conditions. With high-speed supercomputers, better solutions can be achieved, and are often required to solve the largest and most complex problems. Ongoing research yields software that improves the accuracy and speed of complex simulation scenarios such as transonic or turbulence, turbulent flows. Initial validation of such software is typically performed using experimental apparatus such as wind tunnels. In addition, previously performed Closed-form solution, analytical or Empirical research, empirical analysis of a particular problem can be used for compa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windcatcher
A windcatcher, wind tower, or wind scoop () is a traditional architectural element used to create cross ventilation and passive cooling in buildings. Windcatchers come in various designs, depending on whether local prevailing winds are unidirectional, bidirectional, or multidirectional, on how they change with altitude, on the daily temperature cycle, on humidity, and on how much dust needs to be removed. Despite the name, windcatchers can also function without wind. Neglected by modern architects in the latter half of the 20th century, the early 21st century saw them used again to increase ventilation and cut power demand for air-conditioning. Generally, the cost of construction for a windcatcher-ventilated building is less than that of a similar building with conventional heating, ventilation, and air conditioning (HVAC) systems. The maintenance costs are also lower. Unlike powered air-conditioning and fans, windcatchers are silent and continue to function when the electr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Institute Of Building Sciences
The National Institute of Building Sciences is a non-profit, non-governmental organization that identifies and resolves problems and potential issues in the built environment throughout the United States. Its creation was authorized by the U.S. Congress in the Housing and Community Development Act of 1974. Board of directors The Institute is governed by a board of directors which consists of 21 members. All members serve for terms of three years, with a third of the board up for new terms each year. The President, with the advice and consent of the Senate, appoints six members to represent the public interest. The remaining 15 members are elected from the nation's construction industry, including representatives of construction labor organizations, product manufacturers, and builders, housing management experts, and experts in building standards, codes, and fire safety, as well as public interest representatives including architects, professional engineers, officials of Federal, Sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whole Building Design Guide
The Whole Building Design Guide or WBDG is guidance in the United States, described by the Federal Energy Management Program as "a complete internet resource to a wide range of building-related design guidance, criteria and technology", and meets the requirements in guidance documents for Executive Order 13123. The WBDG is based on the premise that to create a successful high-performance building, one must apply an integrated design and team approach in all phases of a project, including planning, design, construction, operations and maintenance. The WBDG is managed by the National Institute of Building Sciences. History The WBDG was initially designed to serve U.S. Department of Defense (DOD) construction programs. A 2003 DOD memorandum named WBDG the “sole portal to design and construction criteria produced by the U.S. Army Corps of Engineers (USACE), Naval Facilities Engineering Command (NAVFAC), and U.S. Air Force.” Since then, WBDG has expanded to serve all building in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urban Planning
Urban planning (also called city planning in some contexts) is the process of developing and designing land use and the built environment, including air, water, and the infrastructure passing into and out of urban areas, such as transportation, communications, and distribution networks, and their accessibility. Traditionally, urban planning followed a top-down approach in master planning the physical layout of human settlements. The primary concern was the public welfare, which included considerations of efficiency, sanitation, protection and use of the environment, as well as taking account of effects of the master plans on the social and economic activities. Over time, urban planning has adopted a focus on the social and environmental "bottom lines" that focuses on using planning as a tool to improve the health and well-being of people and maintain sustainability standards. In the early 21st century, urban planning experts such as Jane Jacobs called on urban planners to take ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chimney
A chimney is an architectural ventilation structure made of masonry, clay or metal that isolates hot toxic exhaust gases or smoke produced by a boiler, stove, furnace, incinerator, or fireplace from human living areas. Chimneys are typically vertical, or as near as possible to vertical, to ensure that the gases flow smoothly, drawing air into the combustion in what is known as the stack, or chimney effect. The space inside a chimney is called the '' flue''. Chimneys are adjacent to large industrial refineries, fossil fuel combustion facilities or part of buildings, steam locomotives and ships. In the United States, the term '' smokestack industry'' refers to the environmental impacts of burning fossil fuels by industrial society, including the electric industry during its earliest history. The term ''smokestack'' (colloquially, ''stack'') is also used when referring to locomotive chimneys or ship chimneys, and the term ''funnel'' can also be used. The height of a chim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Door
A door is a hinged or otherwise movable barrier that allows ingress (entry) into and egress (exit) from an enclosure. The created opening in the wall is a ''doorway'' or ''portal''. A door's essential and primary purpose is to provide security by controlling access to the doorway (portal). Conventionally, it is a panel that fits into the doorway of a building, room, or vehicle. Doors are generally made of a material suited to the door's task. They are commonly attached by hinges, but can move by other means, such as slides or counterbalancing. The door may be able to move in various ways (at angles away from the doorway/portal, by sliding on a plane parallel to the frame, by folding in angles on a parallel plane, or by spinning along an axis at the center of the frame) to allow or prevent ingress or egress. In most cases, a door's interior matches its exterior side. But in other cases (e.g., a vehicle door) the two sides are radically different. Many doors incorporate lock ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
