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Ductwork Airtightness
Ductwork airtightness can be defined as the resistance to inward or outward air leakage through the ductwork envelope (or ductwork shell). This air leakage is driven by differential pressures across the ductwork envelope due to the combined effects of stack and fan operation (in case of a mechanical ventilation system). For a given HVAC system, the term ductwork refers to the set of ducts and fittings (tees, reducers, bends, etc.) that are used to supply the air to or extract the air from the conditioned spaces. It does not include components such as air handlers, heat recovery units, air terminal devices, coils. However, attenuators, dampers, access panels, etc. are a part of the ductwork even if they have more functions than conveying the air and are therefore also referred to as technical ductwork products. Ductwork airtightness is the fundamental ductwork property that impacts the uncontrolled leakage of air through duct leaks. Metrics There are two major systems to classify ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duct (flow)
Ducts are conduits or passages used in heating, ventilation, and air conditioning (HVAC) to deliver and remove air. The needed airflows include, for example, ''supply air'', ''return air'', and ''exhaust air''. Ducts commonly also deliver '' ventilation air'' as part of the supply air. As such, air ducts are one method of ensuring acceptable indoor air quality as well as thermal comfort. A duct system is also called ''ductwork''. Planning (laying out), sizing, optimizing, detailing, and finding the pressure losses through a duct system is called ''duct design''. Materials Ducts can be made out of the following materials: Galvanized steel Galvanized mild steel is the standard and most common material used in fabricating ductwork because the zinc coating of this metal prevents rusting and avoids cost of painting. For insulation purposes, metal ducts are typically lined with faced fiberglass blankets (duct liner) or wrapped externally with fiberglass blankets (duct wrap). When ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASHRAE 90
The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE ) is an American professional association seeking to advance heating, ventilation, air conditioning and refrigeration (HVAC&R) systems design and construction. ASHRAE has over 57,000 members in more than 132 countries worldwide. ASHRAE's members are composed of building services engineers, architects, mechanical contractors, building owners, equipment manufacturers' employees, and others concerned with the design and construction of HVAC&R systems in buildings. The society funds research projects, offers continuing education programs, and develops and publishes technical standards to improve building services engineering, energy efficiency, indoor air quality, and sustainable development. History ASHRAE was founded in 1894 at a meeting of engineers in New York City, formerly headquartered at 345 East 47th Street, and has held an annual meeting since 1895. Until 1954 it was known as the A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distribution Of Ductwork Airtightness Classes
Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations *Probability distribution, the probability of a particular value or value range of a variable **Cumulative distribution function, in which the probability of being no greater than a particular value is a function of that value * Frequency distribution, a list of the values recorded in a sample *Inner distribution, and outer distribution, in coding theory *Distribution (differential geometry), a subset of the tangent bundle of a manifold *Distributed parameter system, systems that have an infinite-dimensional state-space * Distribution of terms, a situation in which all members of a category are accounted for * Distributivity, a property of binary operations that generalises the distributive law from elementary algebra *Distribution (number theory) *Distribution problems, a common type of problems in combinatorics where the goal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Between European (Eurovent And AMA) TightVent Classes A-D And American (ASHRAE) TightVent Classes CL3, CL6, Etc
Comparison or comparing is the act of evaluating two or more things by determining the relevant, comparable characteristics of each thing, and then determining which characteristics of each are similar to the other, which are different, and to what degree. Where characteristics are different, the differences may then be evaluated to determine which thing is best suited for a particular purpose. The description of similarities and differences found between the two things is also called a comparison. Comparison can take many distinct forms, varying by field: To compare things, they must have characteristics that are similar enough in relevant ways to merit comparison. If two things are too different to compare in a useful way, an attempt to compare them is colloquially referred to in English as "comparing apples and oranges." Comparison is widely used in society, in science and in the arts. General usage Comparison is a natural activity, which even animals engage in when dec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Law
In statistics, a power law is a functional relationship between two quantities, where a relative change in one quantity results in a proportional relative change in the other quantity, independent of the initial size of those quantities: one quantity varies as a power of another. For instance, considering the area of a square in terms of the length of its side, if the length is doubled, the area is multiplied by a factor of four. Empirical examples The distributions of a wide variety of physical, biological, and man-made phenomena approximately follow a power law over a wide range of magnitudes: these include the sizes of craters on the moon and of solar flares, the foraging pattern of various species, the sizes of activity patterns of neuronal populations, the frequencies of words in most languages, frequencies of family names, the species richness in clades of organisms, the sizes of power outages, volcanic eruptions, human judgments of stimulus intensity and many other quantit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duct Leakage Testing
A duct leakage tester is a diagnostic tool designed to measure the airtightness of forced air heating, ventilating and air-conditioning (HVAC) ductwork. A duct leakage tester consists of a calibrated fan for measuring an air flow rate and a pressure sensing device to measure the pressure created by the fan flow. The combination of pressure and fan flow measurements are used to determine the ductwork airtightness. The airtightness of ductwork is useful knowledge when trying to improve energy conservation. Uses Duct leakage testers are used in residential single family, residential multi-family, and commercial buildings that have a forced air delivery systems for heating and cooling. Operation A basic duct leakage testing system includes three components: a calibrated fan, a register sealing system, and a device to measure fan flow and building pressure. Supply registers or return air grills are sealed using adhesive tapes, cardboard, or non-adhesive reusable seals. One register o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TightVent Europe
TightVent Europe is a platform, formed in 2011, with a focus on building and ductwork airtightness issues.BUILD UP energy solutions for better buildings,Launching of TightVent Europe - the Building and Ductwork Airtightness platform, 2011 The creation of the platform was triggered by the need for a strong and concerted initiative to meet the Directive on the energy performance of buildings The Energy Performance of Buildings Directive (EPBD) is the European Union's main legislative instrument aiming to promote the improvement of the energy performance of buildings within the European Union. It was inspired by the Kyoto Protocol which ... ambitious targets for the year 2020 and overcome the challenges in relation to the envelope and ductwork leakage towards the generalization of nearly zero-energy buildings.BUILD UP energy solutions for better buildings:TightVent Newsletter 1, May, 2011 The platform’s main activities, among others, include the production and dissemination of po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Infiltration And Ventilation Centre
Air Infiltration and Ventilation Centre (AIVC) is the International Energy Agency information centre on energy efficient ventilation of buildings. History The AIVC started in 1979 in the context of the first and second oil crisis in 1973 and 1979. The Centre was established as the 5th research project (Annex 5) in the context of the implementing agreement Energy in Buildings and Communities Programme (at that time called ECBCS) of the International Energy Agency. Since its inauguration, in 1979, the AIVC has been running without interruption. In November, 2020 the executive committee of the International Energy Agency Technical Collaboration Programme Buildings and Communities, approved a 5-year extension period for the AIVC from 2022 till 2026. In the first years, the AIVC's primary focus was understanding and finding ways to limit the energy impact of air infiltration in buildings.P. Wouters,The new AIVC - your companion in the ventilation world, 22nd AIVC Conference "Market O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testing, Adjusting, Balancing
In heating, ventilation, and air conditioning (HVAC), testing, adjusting and balancing (TAB) are the three major steps used to achieve proper operation of heating, ventilation, and air conditioning systems. TAB usually refers to commercial building construction and the specialized contractors who employ personnel that perform this service. In general, the TAB specialist performs air and hydronic measurements on the HVAC systems and adjusts the flows as required to achieve optimum performance of the building environmental equipment. The balancing is usually based upon the design flow values required by the Mechanical Engineer for the project, and the TAB contractor submits a written report which summarizes the testing and balancing and notes any deficiencies found during the TAB work. Many times facility managers will use a TAB contractor to assist in identifying preexisting or common issues with a facility. While not necessary to be a TAB contractor, many contractors tend to hold pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventilation
Ventilation may refer to: * Ventilation (physiology), the movement of air between the environment and the lungs via inhalation and exhalation ** Mechanical ventilation, in medicine, using artificial methods to assist breathing *** Ventilator, a machine designed to move breathable air into and out of the lungs * Ventilation (architecture), the process of "changing" or replacing air in any space to provide high indoor air quality * Ventilation (firefighting), the expulsion of heat and smoke from a fire building * Ventilation (mining), flow of air to the underground workings of a mine of sufficient volume to dilute and remove noxious gases See also * Heating, ventilation, and air conditioning, the technology of indoor and vehicular environmental comfort * Mechanical fan * Reebok Ventilator, a shoe * Vent (other) Vent or vents may refer to: Science and technology Biology *Vent, the cloaca region of an animal *Vent DNA polymerase, a thermostable DNA polymerase Geology * H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Energy Conservation
Energy conservation is the effort to reduce wasteful energy consumption by using fewer energy services. This can be done by using energy more effectively (using less energy for continuous service) or changing one's behavior to use less service (for example, by driving less). Energy conservation can be achieved through energy efficiency, which has a number of advantages, including a reduction in greenhouse gas emissions, a smaller carbon footprint, and cost, water, and energy savings. Energy conservation is an essential factor in building design and construction. It has increased in importance since the 1970s, as 40% of energy use in the U.S. is in buildings. Recently, concern over the effects of climate change and global warming has emphasized the importance of energy conservation. Energy can only be transformed from one form to another, such as when heat energy is converted into vehicle motive power or when water flow's kinetic energy is converted into electricity in hydroelectr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
