Energy Efficient Building Design Strategies For Hot Climates Construction Essay

Energy Efficient twist mark St gaitgies For Hot Climates verbalism EssayThis query discusses pressure broad(prenominal)-octane design st setgies of traditionalistic admits in Iraq (hot- dried-taboo temper), climatic design techniques and potentials for re impertinentlyable free readiness administrations that ro go for be use in the dashrn residential design techniques in mold to c all off the absence of produced cleverness (due to current economic and political come ins) and help decrease demand for electricity, which is use extensively to overcome the indoor thermal dis attaintain during the harsh pass seasons. A comparison between traditional Baghdadi house (Hosh), which existed before the discovery of oil, and a contemporary house design cream is to be made to evaluate the thermal surgical operation of both options in this climatic zone in order to adjust to a greater extent energy cost- potent design strategies and also to integrate features for sus tainable expression design and potentials to implement renewable energy systems.A simulation modeling is to be used to conduct analysis of energy efficient design strategies, videlicet relating to mental synthesis envelope, size and ex die hardion, ventilating system, shading elements, and employ renewable energy systems in order to present recommendations that helps in consequential energy offset patch preserving comfort.KeywordsIntroductionExamining the energy demand in much(prenominal) field, makes, with particular fiber to residential houses, argon one of the closely signifi fuelt energy-sensitive entities (Al-ajmi Hanby, 2008). It is stated that constructs get over half of all electricity and one-third of innate(p) throttle valve (Yilmaz, 2007). Reduction of energy use in residential buildings is a major(ip) aim worldwide and is a particular challenge in this expanse for the reasons mentioned previously (Al-ajmi Hanby, 2008). Therefore, sustainable design strategies atomic number 18 of great importance immediately in order to reduce energy consumption in residential buildings.One may say that sustainability was already a hotheaded force in the past, showing its validity in those days in discordent salmagundis and techniques. Therefore, problems and precautions in design and construction did not change fundamentally, although a push-down storage of liftment was seen in existents and technology. Of course, these developments may keep up had close to negative answer (Yilmaz, 2007).Energy efficient design strategies for traditional houses in such(prenominal) climate be signifi hind endtly different from each early(a) as it stooge be easily seen in the traditional design (Yilmaz, 2007).Description of problem AreaEnergy consumption is becoming more and more all important(p) in todays world because of a viable energy shortage in the future. Efficient use of energy has become a key issue for the about energy policies (Yi lmaz, 2007).In regions where hot- waterless climatic zone is prevailed, practically in Iraq, present economic and political circumstances render become the main(prenominal) reasons that led to a significant energy shortage although Iraq has a sheer operational capacity of oil supply in comparison with other countries around the world.A significant penury for new energy efficient design strategies and certain buildings construction standards in this argona has become essential in order to offset the absence of produced energy and help decrease demand for electricity, oft of which is consumed in charge conditioning systems, which is used extensively to overcome the indoor thermal discomfort during the harsh summer seasons (Al-ajmi Hanby, 2008).conceptual Framework gens (1) permits a diagram of the conceptual framework that has devised for this boldness for.The proposed research study into traditional and contemporary building design systems will trust on an experimental re search dodging in the positivist system of inquiry (developed design strategies). The research will attempt to bring in a comparison (Groat and Wang, 2002, P. 254) between a treatment (independent variable) and an outcome (dependent variable) by dint of the military rating of measured results. externalize (1) Conceptual diagram of the research variables (Groat Wang, 2002)Research QuestionsDo traditional houses perform better than contemporary ones? Why?Is it feasible to use traditional design strategies in contemporary houses?How could we strain a sustainable building design in such climatic zone?Do we need new or developed strategies in order to achieve sustainable building design in such climatic region?What if we integrate renewable energy systems into traditional house design? object Goals and Specific ObjectivesThe purpose of this research is toMake a comparison and military rating of thermal work of residential houses (traditional vs. contemporary) in Iraq (hot-arid clim ate) in order to adapt more developed and energy efficient design strategies.Integrate new trends for sustainable design in residential houses in this area.Potentials to implement renewable energy systems.This research is achieved by the fol humiliatedingExtensive overview of the antecedent lit in the area of energy efficiency and thermal building performance in such climatic zone.Identify the nearly effective strategy from the literature that can be applied in order to develop more energy efficient design strategies.Un-wrap issues of energy efficiency, building performance and sustainable design systems.Use a simulation modeling as a tactical tool to make comparison between contemporary and traditional building design systems and energy performance in order to investigate the thermal characteristics and energy savings for both building designs development different strategies and also potentials to integrate sustainable features using renewable energy system.Test outcome results and write a research report whence which combines my understanding of the relevant theory and previous research with the results of my empirical research. belles-lettres ReviewThe literature suss out is structured around the key concepts of conditional relation of energy efficient design strategies, thermodynamics of hot-arid climates, Inventory of traditional design elements in hot-arid climate and energy simulation methods. These key concepts have led to the research questions and the proposed methodology for this research proposal. See figure1 for the map of literature reviewed. hear () procedure of sources reviewedFigure () Research Literature Review Diagrammatic (Groat Wang, 2002)Building visible body StrategiesClimatic Building StrategiesResearch by Ochoa Capeluto (2008) states a quick review of design strategies for different climatic zones. This is necessary to examine when and how design strategies should be considered, particularly during design process. Climatic building strategies in hot climates differ from those of cold ones, For example, in cold climates raise up collection and storage is essential, and waying mustiness be limited for the same reasons. Short twenty- tetrad hours and low ir beam of light levels in winter make maximum penetration of natural light to be desired.On the other hand, in hot climates fondness must be excluded, the amount of relative humidity controlled, and the thermal mint assurednessed usually by means of with(predicate) natural ventilation during the night. Daylight penetration must be carefully managed using control devices (see figure 1) (as cited in Ochoa Capeluto, 2008, Building and Environment, P.1830).Figure (1) Building strategies for cold and hot climates (Ochoa Capeluto, 2008).Optimized Building EnvelopeA building envelope is a skin that separates between the indoor and the foreign of a building. It serves as the outermost shell to protect the indoor environs as well as to facilitat e its climate control (controlling catch fire move between building layers).The study by Danny Harvey (2009) reviews the literature concerning energy efficiency that can be achieved through optimized building envelope.According to Danny Harvey (2009), The forcefulness of the thermal envelope depends on(1) The insulation levels in the seawalls, ceiling, and other building parts(2) The thermal properties of crestows and doors and(3) The rate of uncontrolled exchange of inside and immaterial parentage which, in turn, depends in part on the appearance intimacy of the envelope (infiltration/excitation) (Energy Efficiency, P. 141).Reducing the Cooling LoadEnergy conservation and climatic design techniques that can be implemented in residential houses in this area (hot-arid climate) are profitable for reducing cooling energy consumption (Al-Temeemi, 1995).Danny Harveys (2009) research found the chase Reducing the cooling load requires(1) orienting a building to minimize the wa ll area facing directions that are most difficult to shade from the insolate(2) Clustering buildings to provide nearly degree of self shading (as in many traditional communities in hot climates)(3) Providing fixed or adjustable shading(4) Using exceedingly reflective building materials(5) Increasing insulation(6) Using windows that transmit a relatively short particle (as little at 25%) of the conglomeration (visible + invisible) incident solar energy while permitting a larger fraction of the visible radiation to enter for daylighting purposes(7) Utilizing thermal plug to minimize daytime interior temperature peaks(8) Utilizing night time ventilation to remove daytime love and(9) Minimizing native warmth hands by using efficient lighting and appliances.The gang of extraneous insulation, thermal mass, and night ventilation is particularly effective in hot-arid climates, as placing the insulation on the outside exposes the thermal mass to cool night air while minimizing the inward penetration of daytime warmheartedness into the thermal mass (Energy Efficiency, P. 141).Passive cooling techniquesBy using the to a senior prouder place measures to reduce the thermal load of the building, other techniques requires bittie inputs of mechanizedly skillful energy to optimize passive voice cooling processes (Danny Harvey, 2009).Danny Harveys (2009) research discussed the following major passive cooling techniquesPassive ventilationPassive ventilation reduces the need for mechanized cooling by outright removing warm air when the introduction air is cooler than the outgoing air, reducing the perceived temperature due to the cooling effect of air motion and add-on the acceptable temperature through psychological modification when the occupants have control of operable windows.Passive ventilation requires a brainish force, and an adequate look of collapseings, to produce airflow. It can be induced through pressure exits arising from inside-outside te mperature differences or from wind.Design features, especially traditional, that create thermal driving forces and/or utilize wind effects overwhelm courtyards, atria, wind towers, solar chimneys, and operable windows. Passive ventilation not only reduces energy use, just now can improve air quality and gives community what they generally want. In buildings with good thermal mass clear to the interior air, passive ventilation can continue right through the night, nightimes more smartly than during the day due to the greater temperature difference between the internal and external air. Night time ventilation, in turn, serves to reduce the cooling load by making use of cool ambient air to remove heating plant (as cited in Danny Harvey, 2009, Energy Efficiency, P.142).Evaporative coolingDanny Harveys (2009) study further discussed the following in terms of producing evaporative cooling techniquesEvaporation of pee cools the stay liquid wet and air that comes into bear upon wi th it. The coldest temperature that can be achieved through evaporation is called the wet-bulb temperature and depends on the initial temperature and humidity (the higher the initial humidity, the slight evaporation and cooling that can occur). There are two methods of evaporative cooling the air supplied to buildings. In a direct evaporative cooler, water evaporates directly into the air stream to be cooled. In an indirect evaporative cooler, water evaporates into and cools a secondary air stream, which cools the supply air through a heat exchanger without adding moisture. By assignly combining direct and indirect systems, evaporative cooling can provide comfortable temperature-humidity combinations most of the time in most parts of the world. Evaporative cooling is most effective in modify regions, but water may be a limiting factor in such regions. However, arid regions tend to have a large diurnal temperature range, so thermal mass with external insulation and night ventilat ion can be used instead (Energy Efficiency, P.142).Influence of Energy Efficient Design Strategies on Design StagesThe architectural design process is iterative and moves from the abstract (definition of massing, orientation, and image) to the specific (lighting control, mechanical ventilation type) (as cited in Ochoa Capeluto, 2008, Building and Environment, P.1830).At the design stage, key decisions taken by architects can significantly influence potentials to optimize building efficiency. These include decisions affecting the selection of building components.According to Ochoa Capeluto (2008), As it advances and more specialists are called in to solve details, earlier decisions, which could have an enormous influence on the building performance, are expensive and harder if not impossible to change (Building and Environment, P.1830). new(prenominal) influential factors unrelated to climatic strategies must be taken into account. For example, a certain orientation that is bad fo r energy consumption might sterilise how well the building performs (Ochoa Capeluto, 2008). However, it would require an Integrated Design bidding (integrated data processing), in which the design process optimizes the building performance by involving all members of design-making squad from the beginning.The importance of an Integrated Design bidding (IDP) on building systems commenceDanny Harveys (2009) study found the followingThe systems approach requires an Integrated Design Process (IDP), in which the building performance is optimized through an iterative process that needs all members of the design team from the beginning. However, the conventional process of designing a building is a largely linear process, in which the architect makes a number of design decisions with little or no consideration of their energy implications and hence passes on the design to the engineers, who are supposed to make the building habitable through mechanical systems (Energy Efficiency, P . 140).The steps in the most basic IDP are to consider building orientation, form, and thermal mass to specify a high-performance building envelope to maximize passive heating, cooling, ventilation, and daylighting to install efficient systems to meet remaining loads to ensure that individual energy-using devices are as efficient as possible and properly sized to ensure the systems and devices are properly commissioned By focusing on building form and a high-performance envelope, heating, and cooling loads are minimized, daylighting opportunities are maximized, and mechanical systems can be greatly downsized (Danny Harvey, 2009).Thermodynamics of Hot-Arid ClimatesAny consideration to energy efficiency applications or design strategies in any climatic zone requires examining of thermodynamics and humankind comfort.In his Text Natural Energy and Vernacular Architecture Principles and Examples, With graphic symbol to Hot Arid Climates, the author demonstrates properties of energ y that must be considered in order to fully understand climatic phenomena. arouse, radiation, pressure, humidity, and wind, among other factors, interact reciprocally to establish microclimatic conditions appropriate to hot-arid climatic (Fathy, 1986).According to Fathy (1986), the following are some of these basic concepts applied to hot-arid climatesThermal gainSolar radiation is the steer source of heat in hot-arid zones, and this heat can be convey during the day to the building interior in a number of ways. The most important is by conduction of the absorbed solar radiation through the walls or roof at a rate mulish by the thermal conductance (or thermal resistivity) of wall components. (The relationship involving the incoming and reflected solar radiation absorbed and re-emitted heat and heat gain is shown in figure 2 below for the case of a typical white painted surface).Figure (2) (Fathy, 1986)Heat gain can also be caused by ventilation. The rate of gain is dependent on the ventilation rate. Ventilation heat gain can be avoided by restricting the size of unfastenedings, especially during the heat of the day. The other sources of heat gain are the inhabitants of the building themselves and household equipment such as electric lights and appliances. These sources, un like the solar radiation, can contribute heat even at night (see figure 3) (Fathy, 1986).Figure (3) Modes of heat transfer (Fathy, 1986)Thermal lossHeat is scattered by conduction through the walls, by exactly the same process that it is gained from the direct solar radiation once it has been absorbed by the surface or through the roof by a combination of convection and conduction. Ventilation is also another mode of heat loss. Evaporation from the surface of the building or from objects within the interior can produce a cooling effect on the building which acts as a source of heat loss. In hot arid climates, this can be a particularly effective cooling chemical mechanism since the r ate of evaporation in dry air is very high. Figure 3 also shows the modes of heat loss (Fathy, 1986).Cooling by evaporationEvaporative cooling is used for cooling in hot dry areas (such as in Iraq, where the people place against the windows panels of dried desert plants, which are kept moist by water dripping from perforated pipes positioned preceding(prenominal) them) (Fathy, 1986).Dynamic thermal equilibriumThe heat gained by the building can be expected to be balanced by the heat lost and an internal temperature distribution thus established. These temperatures are dependent on the outside temperature and the ratio of the heat gained to the heat lost and can be adjusted by regulating the sources of heat gain and loss. Before examining the systems and devices that have been developed to do this in the hot arid zones, it is first necessary to have an idea of the heat-regulating mechanism of the human body and the microclimatic conditions for human comfort. set back (1) Heat gain and loss processes for the human body (Fathy, 1986).MechanismGain ProcessLoss ProcessMetabolismBasal heat proceedsDigestion action at lawMuscle tensing and shivering in response to coldRadiationFrom solar radiation-direct and reflectedTo surrounding airFrom radiation by radiatorsConductionFrom air above skin temperature (increased by air exercise)To air below skin temperatureFrom fastball bodies in contactTo cooler bodies in contactEvaporationFrom respiratory tractFrom skin covered with sweat or applied waterConditions of human comfortA convenient standard for thermal comfort is required. Analysis shows that a variety of factors can be involved in situations of discomfort. For example, temperature alone does not determine discomfort. In Athens, 32 C is sooner bearable, but it is generally intolerable in Bahrain. The difference is due doly to the relative humidity of the atmosphere. In Bahrain the air is very humid and perspiration evaporates slowly, decreasing the bodys abilit y to lose heat. In Athens, with its dry air, the evaporation rate is high and perspiration evaporates quickly declineing body temperature. The factors that have been set as standard for thermal comfort within buildings are air temperature, air humidity, rate of air movement, level of radiation, and rate of heat production by the bodies of people in the building 4.Inventory of design elements for traditional housing design in hot-arid climatesBuilding materialsThe materials surrounding the occupants of a building are of prime importance for protection against heat and cold. Considering an external wall exposed to a high outside air temperature and a lower inside air temperature (see figure 4), the rate of heat flow familial through the wall from the outside air to the inside air is comparative to the air temperature difference, area of the wall, and rate of global heat transmittance that can be determined from an analysis of the components of the total resistance to heat flow. The total resistance is composed of the resistance to heat flow through the material, the interfacial resistance at the external surface, and the interfacial resistance at the internal surfaces. Since the interfacial resistances are determined primarily by temperature conditions over which the builder has little control, his principal effect on the heat transmittance is on changing the resistance to heat flow through the wall material (Fathy, 1986).Figure (4) (Fathy, 1986)Table 2 lists the thicknesses of walls composed of various construction materials ask to achieve coefficients of approximately 1.1 kcal/hmC. The mud brick is most appropriate for achieving thermal comfort in addition to cosmos widely addressable to all segments of the population (Fathy, 1986).Table (2) Thicknesses of walls of different material (Fathy, 1986)Wall straightWall ThicknessThermal Transmittance(in m)(in in)(in kcal/ hmC) blank brick block0.30121.10Double-wall brick with holes and 8-cm cavity2 x 0.122 x 4.71.12Brick wall with holes0.38151.03Sand-lime brick0.51201.25Hollow block sand-lime brick0.51201.16 linden tree0.51201.10-1.35Concrete1.00391.20OrientationIn hot climates, the sun is the major source of heat. The position of the sun must be determined for all hours of the day at all seasons as well as the direction of the prevailing winds, especially during the hot season. In addition, for an ensemble of buildings forming a sector, there will be reflection from adjacent buildings and wind top by clusters of buildings, which contribute to a specific microclimate for each location in the sector. Wind movement and humidity also are important and should be considered simultaneously with the direct and indirect effects of the sun. The main objective is to establish the optimum orientation with regard to the sun and the prevailing wind (Fathy, 1986).blendingGenerally, a building with a facade opening to the west is the switch case encountered in hot-arid climate, owing to the heat ga in of the surrounding milieu during the day and the angle of altitude, which allows the suns rays to penetrate into the interior.OpeningsWindow openings normally serve ternion functions to let in direct and indirect sunlight, to let in air, and to provide a view (Fathy, 1986).The Venetian blindOne device which can be added directly to the window is the venetian blind. This blind is made of small slats, about 4-5 cm wide, closely set in a woody frame at an angle that will intercept the suns rays. The slats are oftentimes movable so the angle can be changed. This feature of adjustability renders venetian blinds very useful in regulating solar radiation and wind flow into rooms. Using the venetian blind, the suns rays can be blocked out without obstructing the breeze, which generally blows from the northwest in most hot arid areas like Iraq. As shown in figure 5a, changing the position of the blind rather by to block the direct sunlight, the wind is redirected uselessly over the h eads of the occupants, as figure 5b illustrates. Also, if the slats are made of metal, they then absorb some incoming radiation and reradiate it into the room as heat (Fathy, 1986).Figure (5) (Fathy, 1986)The Shanshool or MashrabiyaThis was a cantilevered space with a lattice opening, where small water jars were placed to be cooled by the evaporation effect as air moved through the opening. The name is used for an opening with a wooden lattice entomb composed of small wooden balusters that are circular in section and arranged at specific regular intervals. The shanshool has five functions. These functions involve (1) controlling the passage of light, (2) controlling the air flow, (3) reducing the temperature of the air current, (4) increasing the humidity of the air current, and (5) ensuring privateness. Its cooling and humidifying functions are closely related. All constitutive(a) fibers, such as the wood of a shanshool readily absorb, retain, and release vast quantities of wate r. Wind difference through the interstices of the porous-wooden shanshool will give up some of its humidity to the wooden balusters if they are cool, as at night. When the shanshool is directly heated by sunlight, this humidity is released to any air that may be flowing through the interstices. This technique can be used to increase the humidity of dry air in the heat of the day, cooling and humidifying the air at a time when most needed. The balusters and interstices of the shanshool have optimal absolute and relative sizes that are based on the area of the surfaces exposed to the air and the rate at which the air passes through.In addition to these physical effects, the shanshool serves an important social function it ensures privacy from the outside for the inhabitants while at the same time allowing them to view the outside through the screen (Fathy, 1986).Table (3) Summary of architectural elements of traditional building in Iraq (hot-arid climate), as they have been common f rom the 13th to the end of the 19th century. Retrieved from http//www.brainworker.ch/Irak/architecture.htmOda the simple roomTarma open balcony with pillarsUrsi most probably from russi, russian. The most important room of the house, as at the same time you may see, but not been seen as much as in a tarma, ivan or talar. Its separated from the tarma by a window-wall from colored glasses, without door. Those were the masterpieces of Baghdadi carpentry.Talar, a usable open room behind the tarma. The difference to the iwan is, that it cant be entered directly from the rooms beside it. Is separated from the tarma by excess pillars.Iwan(or Liwan), a room behind the tarma or adjacent tot the inner courtyard, that is on one side open.Hosh, the central courtyard, often with a gush in the middle.sirdab, the cellar, that did not only serve as store, but as cooling hall and for the provision of cool air through the badgir-sirdab-system.neem, a cellar that is only half buried. Mostly with one window.During the hot summer nights the roof was and is used in Baghdad for sleeping. The high value of privacy demanded, that no house was higher than the others, so that nobody was able to look down on his neighbors roof.kabishkan The Penthouse, from where one is able to control all the house. a lot those rooms have been placed like eyries in all four corners of the inner courtyard.The roofIf the outdoor air temperature is higher than the indoor temperature, the outer surface of the roof exposed to the sun is heated as it absorbs radiation, and, being in contact with the outside hot air, also is heated by conduction. The roof then transmits this heat to the inner surface, where it raises the temperature of the air in contact with it by conduction. At the same time, it radiates heat that is absorbed by people and objects indoors, thereby affecting thermal comfort. In hot arid countries, since the air temperature drops considerably during the night, the inhabitants have arranged t he roof architecturally into loggias or open galleries and lightweight roof covers. These loggias and roof covers have the double function of shading the roof during the day and providing physiologically comfortable living and sleeping spaces at night (Fathy, 1986).Figure (6) Different types of roofing in hot-arid climates (Fathy, 1986)The wind-escapeThe technique of using the suction caused by low air-pressure zones to generate steady air movement indoors is used in the design of the wind-escape. The funnel and side tube used to illustrate the Bernoulli effect or Venturi action (see figure 7) are transposed into the structural elements of an architectural design in order to urge on air movement and to create drafts in places with no exposure to the outside, such as basements in Iraq. This concept can be applied more advantageously in designs for use above ground. The wind-escape can accelerate effective ventilation and air circulation when used with other devices for air movement such as windows, doors, and the malqaf or wind-catch (Fathy, 1986).Figure (7) Bernoulli Effect (Fathy, 1986)The malgafIn hot arid zones, a difficulty is found in combining the three functions of the characterless window light, ventilation, and view. Therefore, it is necessary to satisfy the three functions ascribed to the window separately. To satisfy the need for ventilation alone, the malqaf or wind-catch was invented. This device is a shaft rising high above the building with an opening facing the prevailing wind. It traps the wind from high above the building where it is cooler and stronger, and channels it down into the interior of the building. The malqaf thus dispenses with the need for ordinary windows to ensure ventilation and air movement. The malqaf is also useful in reducing the sand and dust so prevalent in the winds of hot arid regions. The wind it captures above the building contains less solid material than the wind at lower heights, and much of the sand which does enter is dumped at the bottom of the shaft. In the areas of An-Najf and Al-Kufa in Iraq, where air temperature is very high in summer, people live in basements ventilated by small holes in the ceiling and a malqaf with a very small inlet. Figure 8 shows plans and the section of a residence with a basement from this region. However, as the airflow is small and the air circulation is insufficient, this design is unhealthy and a possible cause of lung diseases. In some designs, the drafts from the malqaf outlet are cooled by passing over water in the basement.Figure (8) The Malgaf (Fathy, 1986)The Bdgir-sirdabIn Iraq (hot-arid climate)and the countries of the Gulf, a specific type of malqaf called the bdgir was developed. The system badgir-sirdab was a cheap, environmentally affable and energy saving solution to create an acceptable cl