High performance building for cold climateDocument Transcript
GREEN ARCHITECTURE A DETAILED REPORT ONHIGH PERFORMANCE BUILDING FOR COLD CLIMATE PRESENTED BY : KRISHNA JHAWAR 09 B B.ARCH 3RD YEAR VASTU KALA ACADEMY
ACKNOWLEDGEMENTSI would like to express my special thanks of gratitude to my guideMs.Ankita Mangalik who gave me the golden opportunity to do thiswonderful project on the topic High Performance Building For ColdClimate, which also helped me in doing a lot of Research and i cameto know about so many new things. I am really thankful to them.Secondly I would also like to thank my parents and friends who helped me alot in finishing this project within the limited time.I am making this project not only for marks but to also increase myknowledge .THANKS AGAIN.
ABSTRACTHigh Performance building design is a practical and climate consciousapproach to building design. Various factors, like geographical location,prevailing climatic conditions, use of locally available and low embodiedenergy materials and design parameters relevant to the type of usage of thebuilding are normally taken into consideration. Such an approach ensuresminimum harm to the environment, while constructing and using thebuilding.A look at traditional building techniques clearly shows that the concept ofsustainable buildings has existed in our country for a long time. Thesebuildings were generally made of locally available materials like wood, mudand stone and dealt with the vagaries of weather without using a largeamount of external energy to keep the inhabitants comfortable.Buildings are among the greatest consumers of energy. Combining cuttingedge energy efficient technologies with adaptation of practices used invernacular architecture which used more of locally available materials andresources is necessary, especially for countries like India where per capitaenergy consumption is rising rapidly due to high economic growth. This willreduce our dependence on the fossil fuels which have to be imported and aredepleting at an alarming rate.A High Performance building uses minimum amount of energy, consumesless water, conserves natural resources, generates less waste and createsspace for healthy and comfortable living.When a number of such buildings are located in proximity, they would createa green zone, providing much healthier environment and minimise heat-island effect. The ultimate aim will then be to create many such areas, whichwould help the towns and cities and therefore the nation in reducing totalenergy requirement and also the overall global carbon footprint.
TABLE OF CONTENTS1. Acknowledgements2. Abstract3. Various Climates Zones Of India4. Building In Cold Climate5. Methodology 5.1 Site 5.2 Orientation And Planform 5.3 Building Envelope 5.4 Techniques6. Conclusion7. References
CLIMATE ZONES OF INDIABased on the climatic conditions of different regions of the country, India hasbeen divided into 5 climatic zones which can be studied through thefollowing map :
BUILDING IN COLD CLIMATERegions that fall under the cold climate experience very cold winters as theyare at a very high altitude. The temperature ranges between 20-30C insummers, while in winters, it can range from-3C to -8C making it quite chilly.As such, trapping the sun’s heat whenever possible is a major designconcern. At the same time, the buildings in such regions need to be properlyinsulated so that the internal heat is retained with minimum loss to theenvironment. Exposure to cold winds should also be minimized.The main objectives of building design in these zones are:(A) Resisting heat lossTo resist heat loss, the following measures may be taken into consideration: (a) Decrease the exposed surface area of the building. (b) Using materials that heat up fast but release heat slowly. (c) Providing buffer spaces between the living area and the outside. (d) Decreasing the rate of ventilation inside the building.(B) Promoting heat gainHeat gain can be promoted by (a) Avoiding excessive shading. (b) Utilising the heat from appliances. (c) Trapping the heat of the sun.
METHODOLOGYArchitects can achieve energy efficiency in the buildings they design bystudying the macro and microclimate of the site, applying bioclimaticarchitectural principles to combat the adverse conditions, and takingadvantage of the desirable conditions. A few common design elements thatdirectly or indirectly affect thermal comfort conditions and thereby theenergy consumption in a building are listed below:1.Site(a) Landform(b) Open Spaces And Built Forms(c) Street Width And Orientation2.Orientation And Planform3.Building Envelope(a) Roof(b) Walls(c) Fenestration(d) Colour And Texture4.Techniques(a) Glazing(b) Trombe Wall(c) Waterwall(d) Roof Based Air Heating System(e) Sunspaces
SITE(a) Landform In cold climates, heat gain is desirable. Hence, buildings should be located on the south slope of a hill or mountain for better access to solar radiation. Exposure to cold winds can be minimised by locating the building onthe leeward side. In case the southern side is the windward side. Thebuilding should be glazed in such a manner that minimum wind enters thebuilding. Parts of the site which offer natural wind barrier can be chosen forconstructing a building.(b) Open Spaces And Built Forms Buildings can be clustered together to minimise exposure to cold winds.
Open spaces between buildings must be such that they allowmaximum solar rays to be incident on the building. They should be treated with a halt and reflective surface so that dayreflect solar radiation onto the building.(c) Street Width And Orientation In cold climates, the street orientation should be east-west to allow formaximum south sun to enter the building. The street should be wide enough to ensure that the buildings on oneside do not shade those on the other side (i.e. solar access should beensured)
ORIENTATION AND PLANFORM Buildings must be compact with small surface to volume ratios toreduce heat loss. Windows should face south to facilitate direct gain. The north side of the building should be well-insulated. Living areas can be located on the southern side while utility areassuch as stores can be on the northern side. Air-lock lobbies at the entrance and exit points of the building reduceheat loss. Heat generated by appliances in rooms such as kitchens may be usedto heat the other parts of the building.
BUILDING ENVELOPE(a) Roof False ceilings with internal insulation such as polyurethane foam (PUF),thermocol, wood wool, etc. are feasible for houses in cold climates. Aluminium foil is generally used between the insulation layer and theroof to reduce heat loss to the exterior. A sufficiently sloping roof enables quick drainage of rain water andsnow. A solar air collector can be incorporated on the south facing slope ofthe roof and hot air from it can be used for space heating purposes. Skylights on the roofs admit heat as well as light in winters. Skylights can be provided with shutters to avoid over heating in summers.(b) Walls Walls should be made of materials that lose heat slowly. The south-facing walls (exposed to solar radiation) could be of highthermal capacity (such as Trombe wall) to store day time heat for laterused. The walls should also be insulated. The insulation should have sufficient vapour barrier (such as two coatsof bitumen, 300 to 600 gauge polyethylene sheet or aluminium foil) on thewarm side to avoid condensation.
Hollow and lightweight concrete blocks are also quite suitable. Skylights can be provided with shutters to avoid over heating insummers. On the windward or north side, a cavity wall type of construction maybe adopted.(c) Fenestration It is advisable to have the maximum window area on the southern sideof the building to facilitate direct heat gain. They should be sealed and preferably double glazed to avoid heatlosses during winter nights. Condensation in the air space between the panes should be prevented, Movable shades should be provided to prevent overheating insummers.(d) Colour And Texture The external surfaces of the walls should be dark in colour so that day absorb heat from the sun.
TECHNIQUES(a) GlazingSouth facing glazing is ideal for cool temperate climates. It allows maximumsolar access in winter and can be easily shaded in summer.In cool temperate climates:• Maximize South facing glazing with solar exposure (especially in livingareas). [See: Passive Solar Heating]• Minimize east & west facing glazing.• Use adjustable shading. Insulating glass unit with low-e• Use insulating glass and frames and/or snug fitting insulating drapes withsealed pelmets.
(b)Trombe Wall• A Trombe wall is a thermally massive wall with vents provided at the topand bottom. It may be made of concrete, masonry, adobe, and is usuallylocated on the southern side (in the northern hemisphere) of a building inorder to maximize solar gains.• The outer surface of the wall is usually painted black for maximizingabsorption and the wall is directly placed behind glazing with an air gap inbetween.• Solar radiation is absorbed by the wall during the day and stored assensible heat. The air in the space between the glazing and the wall getsheated up and enters the living spaces by convection through the vents.• Cool air from the rooms replaces this air, thus setting up a convectioncurrent. The vents are closed during night, and heat stored in the wallduring the day heats up the living space by conduction and radiation.• Trombewalls have been extensively used in the cold regions of Leh.• It is noteworthy that in buildings with thermal storage walls, indoortemperature can be maintained at about 15 oCwhen the outside temperatureis as low as -11 oC.• Generally, thickness of the storage wall is between 200 mm and 450 mm,the air gap between the wall and glazing is 50-150mm, and the total area ofeach row of vent is about 1% of the storage wall area.• The trombewall should be adequately shaded for reducing summer gains.
(c)Water Wall• Water walls are based on the same principle as that for trombe walls,except that they employ water as the thermal storage material.• A water wall is a thermal storage wall made up of drums of water stackedup behind glazing. It is usually painted black to increase heat absorption.• It is more effective in reducing temperature swings, but the time lag isless.•Heat transfer through water walls is much faster than that for trombewalls.• Therefore, distribution of heat needs to be controlled if it is notimmediately required for heating the building. Buildings that work during thedaytime, such as schools and offices, benefit from the rapid heat transfer inthe water wall.• Overheating during summer may be prevented by using suitable shadingdevices.
(d)Roof-Based Air Heating System• In this technique, incident solar radiation is trapped by the roof and is usedfor heating interior spaces.• In the Northern Hemisphere, the system usually consists of an inclinedsouth-facing glazing and a north-sloping insulated surface on the roof.Between the roof and the insulation, an air pocket is formed, which is heatedby solar radiation.• A moveable insulation can be used to reduce heat loss through glazedpanes during nights.• There can be variations in the detailing of the roof air heating systems.Climate Roof base air heating system for winter heating in HimachalPradesh State Cooperative Building.• In the Himachal Pradesh State Cooperative Bank building, the southglazing is in the form of solar collectors warming the air and a blower fancirculating the air to the interior spaces.
(e)Sunspace• A sun space or solarium is the combination of direct and indirect gainsystems.• The solar radiation heats up the sun space directly, which in turn heatsup the living space(separated from the sun space by a mass wall)byconvection and conduction through the mass wall.In the northern hemisphere, the basic requirements of buildings heated bysunspace are :(a) a glazed south facing collector space attached yet separated from thebuilding(b) Living space separated from the sun space by a thermal storage wall.Sunspaces may be used as winter gardens adjacent to the living space.The Himurja building in Shimla has well designed solarium as integral part ofsouth wall to maximize solar gain.
CONCLUSIONWhile achieving extra value from sustainable attributes may involve moreinnovative approaches to asset management, the use of advancedsustainable approaches is not necessarily complex. As governments move toincrease price messaging (taxes and credits) to encourage sustainability, thiswill increasingly affect net value of existing assets and improve investmentperformance for buildings adapted or adaptable to these goals. It will alsoincreasingly encourage owners to consider less traditional solutions toenhancing asset performance and value.
REFERENCES- www.ncict.net/green buildings- Nayak J K, Hazra R. Development of design guidelines by laws.- Bansal N K, Hauser G, Minke G. Passive building design: A handbook of Natural climatic control.