climate responsive buildings

7/25/2019 Climate Responsive Buildings

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CLIMATE RESPONSIVE BUILDINGS

Sustainability and Energy E!ien!y

DESIGN CONSIDERATIONS IN

"OT AND DR# CLIMATE$ARM AND "UMID CLIMATE

Presented by: Vishal


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Cli%ate Res&'nsi(e Buildings ) An Intr'du!ti'nBa!*gr'und+ Buildings, as they are designed and used today, contribute to seriousenvironmental problems such as global warming, ozone layer depletion and shortage offossil fuels because of excessive consumption of energy and other natural resources. iththe input of su!cient energy almost everything seems possible and too often climatic

factors are neglected in construction. "he unrestricted demand by the a#uent for morecomfort and living standards, changing life$styles and the unconsidered use of technicalmeans increase these tendencies. %n the other hand, those who cannot a&ord these su&erin unhealthy, overheated or cold shelters.

Cli%ate Res&'nsi(e Design, An IntegratedA&&r'a!- , ' possible alternative is the application of(soft measures) and natural means to reduce energyconsumption by design, construction and materialswhich are adapted to a speci*c climate. +limateesponsive design is based on the way a building-s formand structure moderates the climate for human goodand well being. "he shapeform of buildings and theirorientation, the integration of suitable vegetation andthe arrangement of the externalinternal space re/uirecareful consideration. "he correct use of buildingmaterials, designs of openings and their shading,

natural cooling, passive solar heating and the well$aimed utilization of prevailing winds for ventilation areimportant supporting elements. "his also has its positiveconse/uences in terms of economy, proper use of localresources and reduced energy consumption.

Cli%ate and C'%.'rt+ "he climate of a location is a&ected by its latitude, terrain andaltitude, as well as nearby vegetation, water bodies and their currents. "he mostimportant elements of climate and weather parameters that a&ect human thermal comfortand are relevant to building design are: Solar adiation, 0ong wave adiation,

"emperature, 1umidity, ind, Precipitation.

+limate responsive design can saveenergy, reduce costs, and preserve

natural resources while reducingenvironmental pollution


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Cli%ate Res&'nsi(e Design C'nsiderati'ns in "'tand Dry Regi'nCli%ati! data+ "he climate of

hot$dry zones is in generalcharacterized by high temperatures 234 $ 546+ in summer7,with sharp variations in both diurnal 2day night7 and seasonal2summer$ winter7 temperatures8 precipitation 2rainfall, snow7

which is scarce, irregular and unreliable. +old winds anddustsandstorms prevail in winter. "he solar radiation intensityis high and enhanced by the radiation re9ected from theground. "he air humidity is low and the humidity tends toreduce diurnal variations and moderate temperatures.

Design 'b/e!ti(es +"he main goal of climatic design, on a macro 2settlement7 and micro2building7 level, is to reduce uncomfortable conditions created by extremes of heat anddryness. Buildings must be adapted to extreme summerwinter and daynight conditions.

ot only cooling is needed8 passive heating may also be needed in winter and during coldnights. ;or humans, a good shelter in arid areas is the one that could protect them fromthe intense radiation from the sun, groundsurrounding buildings, from dust, sandstorms8provide them with moisture and ventilation as well.


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21 Narr'3 and s-aded streets+ Plan narrow winding alleysstreets,which are shaded and relatively cool and brea= stormy winds, but allowthrough$ventilation and ade/uate natural lighting. "here are di&erentways of properly designing an urban form ta=ing into account solarradiation and wind.

'rcades $ shading thestreets


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61 Air M'(e%ent and Ventilati'n+ @ain walls and windows should face the prevailing2cool7 wind direction in order to allow maximum cross$ventilation of the rooms. 'ir inta=eopenings should be located so that the coolest and most dust$free air is ta=en. "hus thecool conditions existing at dawn can be maintained inside the building for the longestpossible period. @oderate the e&ects of undesired winds.

ith openings near the topof stac=s, warm air can

escape whereas cooler airenters the building fromopenings near the ground.

ind$catchers are ventilation 9ues carriedabove the roof to catch cool and clean air. >t

creates a pressure gradient which allowsless dense hot air to travel upwards andescape out the top and cold air is suc=ed

"he location of

openings forventilationdetermined byprevalent winddirection

71 T-er%al %ass+ "hermal mass is the ability of amaterial to absorb heat energy, store it, and at alater time, release it in support of maintaininguniform temperature pro*les. "he comfort of peopleinside the buildings depends largely on the thermal

properties of the outer and inner walls and the roof."hermal mass acts as a Athermal batteryA. uringsummer, it absorbs heat, =eeping the houserelatively cool. >n winter, the same thermal mass canstore the heat from the sun to release it at night,helping the home stay warm. 1igher the density ofthe material, higher is the heat storage capability.

"hermal mass storesthe heat from the sun

1eat 9ow indaytime and atnight


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' vaulted roof provides a larger surface area for heat losscompared to a 9at roof.

81 R''.s+ 's the roof is the most criticalpart, high solar re9ectivity and emissivityfor long$wave radiation are essential, aswell as thermal insulation andorade/uate time lag. "he vault, the domeand the 9at roof are the traditional roof

shapes.

91 Lands!a&ing+. Proper landscapingreduces direct sun from stri=ing andheating up of building surfaces. >tprevents re9ected light carrying heat intoa building from the ground or othersurfaces. 0andscaping creates di&erent

air9ow patterns can be used to direct ordivert the wind advantageously bycausing a pressure di&erence.'dditionally, the shade created by treesand the e&ect of grass and shrubs reduceair temperatures adCoining the building.ater ta=es up a large amount of heat in

:1 ;enestrati'ns and S-adingde(i!es+ %f all the elements in thebuilding envelope, windows and otherglazed areas are most vulnerable to heatgain or losses. Proper location, sizing,and detailing of windows and shadingform an important part of bioclimatic

design as they help to =eep the sun andwind out of a building or allow themwhen needed.

"he openings should be protected by the

shading devices

"rees act as barriersagainst hot and dustywinds1

0andscaping for creating coolmicroclimate of a place

+hannelizing breezeover pools


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Cli%ate Res&'nsi(e Design C'nsiderati'ns in $ar%and "u%id Regi'nCli%ati! data+ Places that are close to sea or oceans have a

humid climate as there is large amount of water vapour in theair. >t is characterized by high rainfall and high humidity. "hetemperature range is relatively high at around D4 $ D56+ and is

fairly even during the day and throughout the year. ue tominimal temperature di&erences, winds are light or even non$existent for longer periods. 1owever, heavy precipitation andstorms occur fre/uently.Design 'b/e!ti(es + "he solar radiation is intense and to a great extent di&use due tohaze. "he haze may cause s=y glare which can also be reduced by large shading devices.Vegetation is rich and provides an excellent means of improving the climatic conditions. >tssurface does not heat up and it provides e!cient shading at low cost. 1owever, it has to

be arranged in a way that does not impede air circulation. Since the temperaturedi&erence between day and night is minimal, underta=e measures which avoid heatabsorption and heat storage. "he use of low thermal mass, high re9ective outer surfacesor double$s=in structures are the result. "he indoor temperature can hardly be =ept muchbelow the outdoor temperature. 1owever, by e!cient design the indoor temperature canavoid exceeding the outdoor temperature and inner surfaces can remain relatively cool.

"ogether with proper ventilation, comfortable conditions can be achieved in most cases.Existing air movements should be utilized as much as possible to provide evaporativecooling and to avoid mould growth.

Design C'nsiderati'ns +

01 O&en and S!attered Planning + 'n opensettlement pattern is the appropriate response tothe climate. "o provide su!cient air circulation,buildings should be scattered and have a lowpopulation density. Buildings should be separatedwith large, free spaces between them. "his allowsair9ow which rovides ventilation for coolin and


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21 O&en street Net3'r*+ "he settlement pattern should allowfor a loose open street networ=. S/uares and passages should becovered, but cross$ventilation should not be impeded.


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51 S-a&e and V'lu%e+ ;orms with large surface areas are preferredto compact buildings. "his favors ventilation and heat emission atnighttime.

0ow building with wideoverhanging roof

71 R''% Arrange%ents+ "he arrangement of rooms depends ontheir function. Since the thermal load is related to the orientation,rooms on the east side are warm in the morning and, if not built withmuch thermal mass, cool down in the afternoon. ooms on the westside are cooler in the morning and heat up in the afternoon. oomsfacing north and south remain relatively cool if provided withade/uate shading.

oom arrangementaccording to climatic

preferences

81 "eat st'rage and ti%e lag+ +onstructions with a high thermalstorage capacity and a long time lag are to be avoided. ue to therelatively narrow diurnal temperature 9uctuation it is not possible toachieve much cooling by utilization of the thermodynamic propertiesof building components. "he main goal is, on the one hand to storeas little heat as possible in the structure in order to obtain the

maximum bene*t of the cooler night temperatures. ' relatively shorttime lag of some 5 hours may be ade/uate..:1 T-er%al insulati'n+ "hermal insulation has very little e&ectiveness. ue to the free9ow of air, the ambient air temperatures inside and outside the building are very much thesame. >nsulation may be Custi*ed only in places where sun radiation is received, e.g. forroofs and sun$exposed walls.1igh re9ectivity and high emissivity are re/uired propertiesfor =eeping the indoor temperature and the inner surface temperature low. "he same e&ectcan be achieved with properly ventilated double s=in constructions.

61 S-a&e and V'lu%e+"he main goal is the reduction of direct heatgain by radiation through openings and of the internal surfacetemperature. "he building should therefore be designed not only with

protected openings, but also with protected walls. "his tas= will bemuch easier if the building is =ept low. >n addition, the roof shouldextend far beyond the line of walls, with broad overhanging eavesand other means of shading.


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+onstruction details showingenhanced ventilation of theroof space

0f,however, exposed to the sun, they should be built inthe form of a ventilated double leaf construction, theinner leaf having a re9ective surface on its outer sideand perhaps with thermal insulation.

001 R''.s , >n warm$humid areas the roof ispreferably pitched to allow heavy rains to run o&.0arge overhangs protect the walls and openings fromradiation and precipitation. "he roof should be madeof lightweight materials with a low thermal capacity

91 Cr'ss,(entilati'n+ "he high humidity and warmtemperatures re/uire maximum ventilation, whichleads to very open buildings. ;ree passage of air forcross$ventilation through the interior is important.

"his can be achieved by large openings, not only inthe outer walls but also in the internal partitions. 'n

even more e!cient solution is that of single$ban=edrooms with access from open verandahs or galleries.

"he 9oor is preferably elevated above the ground toallow for a better ventilation. 1ouses are best builton stilts or at least on raised platforms.

"he main elements: Shading trees, wideoverhanging roof, raised 9oor, free 9ow of

air through the building


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021 $ind'3s and O&enings+ >n warm humid areas openings areimportant elements for the regulation of the indoor climate. "heyshould be large and fully openable, with inlets of a similar size onboth sides of the room allowing a proper cross$ventilation. indowsare preferably e/uipped with 9exible louvres allowing a regulation ofventilation. "o avoid direct solar radiation and glare, openings

should be shaded by an overhanging roof, screens, lattices, grillsetc. 'll these measures have to be designed to give minimalresistance to the air9ow. %penings should be placed according tothe prevailing breezes, so as to permit a natural air9ow through theinternal space. "his air9ow is most e&ective if concentrated at bodylevel.

041 Lands!a&ing+ 1igh trees with wide, shading crowns providesigni*cant protection from solar radiation and should beincorporated as much as possible into any landscape planning.. 'nunshaded pavement exposed to the sun heats up, hence a vegetalcover of the ground, =eeps it comparatively cool and contributesmuch to a cooler outdoor microclimate. 'nother e!cient solution isto grow a green cover over roofs and walls. "his cover functions as a

second s=in which provides protection against solar radiant heat,reduction of glare, noise, dust, protection of the wall and roofsurfaces from wind and a regulating e&ect on humidity

0arge openings and

screened$in porches.

indow with glasslouvres

(+annopy e&ect) by trees "he proper arrangement of vegetation, mainly of shade$providing trees, withinthe surrounding space is an important aspect for the improvement of the indoor

climate


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Re.eren!es

http:www.slideshare.netdeepthithangaraCclimate$responsive$architecture

http:collections.infocollections.orgu=eduendGs=4HceD.3.html

http:sustainability.about.comod

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