Double Skin Facades In High Rise Building Engineering Essay

twin p atomic number 18 down Fac fruit drinks In senior high Rise twist Engineering EssayAbstract restate hide faade trunks are increasingly apply in High pass oer eddys across the world. It is more commonly spend in high- stamp out architecture of European and Pacific Rim countries. The growing architectural trend is driven by and large by (Poirazis,2004)1 The reduction of competency use during the occupation stage of a grammatical construction The aesthetic desire for a richly blurd faade that leads to increase transparency The practical need for mitigated indoor environment, lesser reliance on artificial plant The need for improving the acoustical performance of makes located in noise polluted areas1. Poirazis, Harris. (2004). range of a function bark Facades for Office Buildings, Literature Review, Lund Institute of engine roomWeb addresshttp//www.ebd.lth.se/avd%20ebd/ primary(prenominal)/personal/Project%20home%20page/main/publications/LITERATURE.pdfThis e ssay attempts to study the Classification of stunt man flake Facades, its advantages and disadvantages, and discuss on its application in high onward motion building and evaluate the benefits and limitations.IntroductionThe retell struggle Faade is an gasbag redoion covering iodin or multiple news report, which consists of two pieces right-down glass over forms separated by a intermediate cavity. atmospheric state internal respiration strategy squirt be take place through the using up and phone line outlet on the extraneous glazing. In the cavity, sun-shading louvers and thermal insulant devices are virtuallytime installed to reckon the solar erupt micturate to improve the indoor environment.The BBRI, (BBRI, 2002) includes in the generator reserve a satisfactory verbal descriptionof the structure of a prototype whittle Faade System.The layers of the faade are exposit below22. Belgian Building investigate Institute (BBRI) (2002). Source book for a better u nderstanding of conceptual and operational aspects of grand awake facades. discussion section of Building Physics, Indoor Climate and Building Services, Belgian Building look for Institute. Version no 1.Web address http//www.bbri.be/activefacades/index2.html Exterior Glazing Usually it is a hardened genius glazing. This exterior faade usher out be fully glazed. Interior glazing Insulating bifurcate glazing unit (clear, low E coating, solar pick up glazing, etc can be use). Almost al looks this layer is not in all glazed. The transport cavity between the two dosellings. It can be all in all indispensable, fan supported or mechanisticly freshlyen. The width of the cavity can vary between 200 mm to more than 2m according to the serve of the applied concept. This width in good fortunence the way that the faade is maintained. The inner window can be opened by the user. This may allow vivid respiration of the offices. Automatically controlled solar shading is integrat ed inside the demarcation cavity. As a function of the faade concept and of the glazing cause, wakening radiators can be installed next to the faade.History of the look-alike Skin FaadeThe history of Double Skin Facades can be trace back to end of 19th century.According to Saelens (2002), the early version of a mechanically ventilated multiple trim faade was created around 1849. Jean-Baptiste Jobard at that time t passionatenesser director of the industrial Museum in Brussels, mentioned how in winter hot halo should be circulated between two glazing, while in summertime it should be frosty air.Crespo claims that a recur discase curtain wall appears in 1903 in the Steiff Factory in Giengen, Germany. It is possibly the proto example of, at least, is more obturate to the modern range skin faade scheme. She describes thatThe priorities were to maximize mean solar day ignition while winning into account the cold weather and the strong winds of the region. The solution wa s a trio storey structure with a make floor for storage aloofness and two upper floors utilize for work areas. The building was a winner and two growths were built in 1904 and 1908 with the same Double Skin system, nevertheless using timber instead of steel in the structure for compute reasons. All buildings are still in use.Moving to the 20th century, with alter technology meant that the size and number of openings were no longer limited by structural considerations of the past. large glazed facade are able to construct only if it is still very ofttimes limited by building physics and experiencing thermal quilt. At that time, fully glazed buildings have worry of summer overheating and heat losses and problematic condensation, lots of postal code is used by mechanical plant in the operation pass on of the building.The outbreak of oil crises in 1973 1979 bring greater awareness on heartiness consumption. Innovative improvements on insulating glazing such as the addit ion of low-emissivity coatings and boggy gas filled cavities were made. In the1990s a further breakthrough on insulation glazing was achieved with the development of spectrally selective glazing, electro-chromic and photo-chromic glazing. heretofore, these products are unlikely available in short run as they are expensive.In contrast, stunt woman skin facades offer us a cheaper and more flexible way of achieving commodious internal environment through a combined system of components, allowing the order of heat, cold, light noise with low brawniness consumption.Classification of Double Skin Facades in that location are numerous way of classification on Double Skin Faade due(p) to the variation in type of construction, the origin, goal and type of the air flow in the cavity, etc.Battle McCarthy, the environgenial Engineering firm in Great Britain created a categorization of quintuple primary types (plus sub-classifications) ground on commonalities of faade configuration and the manner of operation. 3 These are3. Battle McCarthy website.http//www.battlemccarthy.demon.co.uk/research/doubleskin/doubleskinhomepage.htm syndicate A Sealed upcountry Skin subdivided into mechanically ventilated cavity with controlled flue intake versus a ventilated and serviced thermal flue.Category B Openable Inner and Outer Skins subdivided into single story cavity height versus full building cavity height.Category C Openable Inner Skin with mechanically ventilated cavity with controlled flue intakeCategory D Sealed Cavity, either zoned floor by floor or with a full height cavity.Category E Acoustic Barrier with either a massive exterior envelope or a lightweight exterior envelope.Belgian Building Research Institute Study (BBRI, 2002) investigate the potential of active facades, the related problems and risks in order to devise guidance in standardisation and technical approvals. They unquestionable a classification system to describe different double-skin faade configura tions based on a database of case-studies2.2. Belgian Building Research Institute (BBRI) (2002). Source book for abetter understanding of conceptual and operational aspects of activefacades. Department of Building Physics, Indoor Climate and BuildingServices, Belgian Building Research Institute. Version no 1.Web address http//www.bbri.be/activefacades/index2.htmlOne storey height facadeThe air cavity is divided horizontally and vertically into small and independent facade modules. immanently ventilated double facades with one storey height facade modules are withal known as a Box window type.Corridor facadeCorridor facade is divided at any storey, the cavity is going horizontally along the building. Partition is used for acoustical, fire security or public discussion reasons. duplex storey facadesMultiple storey facades are not divided vertically or horizontally. The air cavity continues throughout the whole facade with maintenance grids at the every level to allowing circulatio n. The air cavity spreading is realised via large openings lift the floor and the roof of the building.Shaft-box facadesShaft box facades are very exchangeable in nature to the one-storey height module. A series of box type window modules in the facade which are connected via vertical shafts. Air are being drawn from the box windows by stack matter into the vertical shafts and emitted from top.Advantages of the Double Skin FaadeThe passive design strategies of double skin faade bring natural ventilation, day lighting and solar heat gain into the fabric of the high-rise building, thus bringing energy efficiency and comfort to the inhabitant.Natural VentilationOne of the main advantages of the Double Skin Faade system is that it allows the inhabitant access to natural ventilation with protection against the weather and burglar. The cavity is a key component in the system as it allows natural fresh air to enter into the building to cool and ventilate the space. Natural ventilation is make possible up to now in the high levels of a high-rise building due to the addition of extra layer of glass which helps to reduce the wind pressure. Natural ventilation of fresh air is much more preferable than air from mechanical sources as it provide help to reduce the energy cost.During the hot summer wickednesss, Double Skin Facades can in addition provide natural night ventilation, thus making the indoor temperatures lower during the early morning hours providing thermal comfort and change air quality for the office occupants.In this way lesser energy is use in air- agreeing thus cut the carbon dioxide output of the building.Day lightingDay lighting is big component part in the design of High rise building as it reduces the energy consumption of galvanising lightings. Moreover, the quality of natural lighting is preferable to electrical lighting. The large area of glazing coverage in double skin faade maximises the daylighting into the space.Good lighting of the workplace is one of the main factors of indoor comfort that can positively decide health and productivity of office personnel. Natural light, its variations and its spectral composition are of great importance for well-being and mental health. Natural light is a fundamental component of our life, helping our remains to produce vitamin D, an important anticancer element. 55. http//www.buildingenvelopes.org Harvard University Massachusetts Institution of TechnologyHowever, The increased coverage of glazed faade brings excessive glare and heat during the hotter times. Solar shading devices are require to decrease solar heat gain and reduce the amount of glare.Thermal Insulation and Solar light GainDouble Skin Faade System can provide greater thermal insulation to the high rise building over the year with its outer skin. Solar heat gain is controlled through the use of shading devices and the air in cavity withal help to lactate some of the incoming solar radiation. During the wi nter the external layer of glass reduce the external heat transfer rate to provide improved insulation. Heat transfer rate is further reduced due to the increse in temperature when cavity is partially or completely closed. During the summer the speedy air inside the cavity can be extracted by naturally or mechanically ventilation. The airflow of the air inside the cavity is very much depend on the size of opening and temperature of the cavity. A carefully selection on the combination of the type of the glass panes and the shading devices types is very important as it prevents overheat in the cavity and the interior space and also to achieve good ventilation.In a highly glazed building, external Shading devices are use to reducing solar heat gain and heat entering into the interior. Shading devices can be fixed or in operation(p).Operable units allow the occupant to control environment to meet their desire. They are normally installed in the outer half of Double Skin Faade, typical ly horizontal blinds. The horizontal blind allows day lighting penetration and maintaining some of the view of outside.Acoustic insulationDouble skin faade provides acoustic insulation to the building from external sources. The cavity act as air barrier to reduce the external noise pollution. A reduction of 20dB by double skin faade at mid frequencies was reported by Chiang et al. (2004) 6 However, the number of openings and the type of Double Skin Faade give also determine the effectiveness of the sound insulation.Chiang, W-H., Chao, Y-N. Wu, C-J., 2004, Sound Insulation of Double Skin Faadehttp//www.ncree.org.tw/2004tcworkshop/pdf/16.pdfTransparencyDouble skin facades fully glazed faade bring more transparency to the building with more natural day lighting and views of exterior. For years, the Architects and the developer has always wanted a transparent building. hardly in the same time energy efficient.Energy savingsDouble Skin Faades can save energy significantly. The system minimises solar gist at the perimeter of buildings, thus less electricity costs is used to cool the building. Natural ventilation also further reduces the energy used in mechanical air supply.Disadvantages of the Double Skin FaadeThere are always debates on the benefits of the double skin system. The Pro campsite claims the systems to be environmentally responsible as double skin system help to save energy cost. However the Con camp states that areas such as maintenance, life-cycle/durability of the system, mechanical costs and operation cost also need to take into account. The disadvantages of Double Skin Faade are described belowHigher construction and additional maintenance costs study the Double Skin facade and the conventional cladding systems. Double Skin facade has higher construction costs due to the additional construction cost of the outer layer, mechanical and supporting structure. It also require higher skill workman. With the additional layer of skin, the weight of th e buildings structure loading is also increase, so as the construction cost of the building. Double Skin type also has higher cost during the operation of the building. More costs will be added in maintenance such as cleaning, servicing.Reduction of rentable office spaceAs the width of the intermediate cavity of Double Skin Faade can vary from 20cm to several(prenominal) meters (Uuttu, 2001), this results to the loss of useful space and rental. It is quite important to find the optimum learning of the faade so as not to lose semiprecious space.Overheating problemsIf the Double Skin Faade system is not right on designed. The temperature of air in the cavity will likely to be increased in the hot summer days and resulting in overheating of the interior space. To avoid overheating, the minimum width between the internal and external pane should not be less than 200 mm (Jager,2003)Double Skin Faades in High-Rise BuildingsHigh-rise office tower with fully glaze facade is a major consu mer of energy. However, double skin faades passive energy concepts and design strategies have increased the potential of high-rise building to set closer with sustainable architecture. In terms of climatic control, double skin faades allow the occupants to take better control of internal environment. The heating and lighting requirements could be adjusted according to occupants needs by controlling the operable windows for natural ventilation and the shading device to modify the incoming solar radiation.The GSW Headquarters building is a good example of architecture that uses double skin faade to achieve sustainability(Note Plan image north is down) estimate from Flickr Uploaded byrunningforasthmaThe plan demonstrates how the new 515,000 sf connects to the existingbuilding with the new heart and soul leaving a 36 foot clear lease span. This depth with the large glass area results in excellent daylighting characteristics.Building construct GSW HeadquartersArchitect Sauerbruch Hutt onLocation BerlinGSW Headquarters consists of existing tower, three-story street-oriented bar, and new 22-storey, 11-m wide office tower building, which is the most important aspect to present the sustainable concept.In response to urban and functional conditions, the major axis of the building faces east and west, a double skin is provided on the west faade a single-glazed weather screen suspended 1m from the internal double pane windows, which acts a thermal buffer to protect heat loss and a thermal flue drawing air through the building. The second layer of automation is the colourful, perforated aluminium shading panels within the west double skin cavity manage solar heat gain and day lighting. The louvers also can be manually adjustable by the occupants but protects against the direct sunlight in the afternoon.On the east faade, automatically and manually-operated triple-glazed windows withbetween-pane blinds allows fresh air enter into the building to create cross ventilation.F resh air is also admitted independently from the window with the exterior louvered metal panels provided on the east faade. In hot summer season, the operable window of the double skin facade is closed resulting in increasing of temperature inside the cavity. warm air is being channel to central plant via riser for heat recovery.Arupwho engineered the building claims the goal to achieve energy savings of 30-40% in parity to an ordinary building. And because of the cross ventilation created by the flue effect, mechanical ventilation is no longer required 70% the year. http//www.ecorussia.info/en/ecopedia/double-skin-glass-facadesConclusionsDouble Skin Faades are increasing incorporate into high rise building to achieving greater transparency, acceptable indoor environment as well as reducing energy consumption. Double Skin Faades is the by far the only system at present that offers a range of natural ventilation strategies to the occupants.From scotch point of view, Double Skin Faa des does not score well due to its high construction cost and additional maintenance and operational costs. However, Double Skin Faades fair better when we look at social and environmental aspect. Double Skin Faades provide better day lighting, solar control and access to natural ventilation, creating better working environment for the employee and increase the productivity.However Double Skin Facades are not suitable in every part of the world. They are highly depending on the outdoor conditions such as solar radiation, outdoor temperature, etc as the outside conditions have great influence on the indoor environment. Thus, each Double Skin Faade has to be designed according to different constraints such as climate condition (solar radiation, outdoor temperature, etc), site conditions (latitude, local daylight availability, atmospheric conditions, exterior obstructions, ground reflectance, etc), building usage (operating hours, occupants tasks, etc).A thorough investigates and abili ty to control these environmental aspects inevitably leads to increased energy efficiency.