Sustainable Architecture

Certificate G.S.MANDAL’S MARATHAWADA INSTITUTE OF TECHNOLOGY Est.: 1984 AURANGABAD AFFILIATED TO B.A.M.U.

This is to certify that Ms. Banafsha Quadri has successfully completed the submission on Sustainable Architecture as the Elective - a part of academic curriculum of Fifth year Architecture 2008 – 09 of the five-year course of architecture.

H.O.D Ar. Sanjay Mhaske

Subject teacher Ar. Madhura Yadav

Sustainable elective

ACKNOWLEDGEMENT

I would like to take this opportunity to thank all those who have helped me for the completion of this report. Firstly, I would like to thank Ar. Madhura Yadav for guiding and helping me throughout the session for this report. This seminar is dedicated to my family and friends. I would like to thank my father Mr. Imtiaz Quadri, my mother Mrs. Lubna Quadri and my brother Fahad Quadri for helping me for this report. This seminar is dedicated to the dept. of architecture and all my co-mates. This seminar is a part of the academic curriculum for the tenth semester of the five-year degree course of architecture. All the information in this seminar has been compiled from various books and websites and is true to my knowledge.

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Sustainable elective

SOLAR PASSIVE TECHNIQUE TROMBE WALL Contents : • • • • • •

Introduction to passive solar techniques What is Trombe wall? How does it affect ecologically and economically towards sustainability? Constructional detail How it can be used as aesthetic element? Examples

PASSIVE SOLAR TECHNIQUES Also called climatic design, a design approach that uses structural elements of a building to heat and cool a building without the use of mechanical equipment. Passive solar design calls for careful consideration of factors such as local climate and solar energy resources, building orientation, and landscape features. The principal elements of passive solar design include proper building orientation, proper window sizing and placement and design of roof overhangs to reduce summer heat gain and ensure winter heat gain, and proper sizing of thermal energy storage mass (for example, masonry tiles). The heat is distributed primarily by natural convection and radiation, though fans can also be used to circulate room air or ensure proper ventilation.

Every passive solar building includes five distinct design elements: 3 Submitted by:Banafsha Quadri

Sustainable elective 1. An aperture or collector – the large glass area through which sunlight enters the building. 2. An absorber – the dark surface of the storage element that absorbs the solar heat. 3. A thermal mass– the material that stores the absorbed heat. This can be masonry materials such as concrete, stone, and brick; or a water tank. 4. A distribution method – the natural tendency of heat to move from warmer materials to cooler ones (through conduction, convection, and radiation) until there is no longer a temperature difference between the two. In some buildings, this strictly passive distribution method is augmented with fans, ducts, and blowers to circulate the heat. 5. A control mechanism – to regulate the amount of sunlight entering the aperture. This can be as simple as roof overhang designed to allow more sunlight to enter in the winter, less in the summer.

Fig: Elements of passive solar design, shown in a direct gain application There are three basic passive solar designs for heat regulation, each of which incorporates these five elements in different ways : 1. Direct gain This the simplest passive design technique. In direct gain, sunlight enters a building through an opening – usually south-facing windows. It then strikes the building's thermal mass – usually dark-colored masonry floors and/or walls in the interior space that absorb and store the solar heat. At night, as the building cools, heat stored in the floors and walls warms the rooms. 2. Sunspace (isolated gain) This design uses a separate solar room (solarium) to store solar heat. A sunspace can be built as part of a new building or as an addition to an existing one. Sunspaces also require a thermal mass to store heat. This stored heat is distributed throughout the building via ceiling and floor-level vents, windows, and doors, sometimes with the addition of fans. 3. Indirect gain (Trombe wall) In the trombe wall design, a dark-colored wall is placed between a 4 Submitted by:Banafsha Quadri

Sustainable elective building's south-facing windows and its living or working space. The wall absorbs solar heat through radiation, stores it, and then releases it into the building when the indoor temperature falls below that of the wall's surface.

Fig: Passive solar design using a Trombe wall Introduction: Since ancient times, people have used thick walls of adobe or stone to trap the sun's heat during the day and release it slowly and evenly at night to heat their buildings. Today's low-energy buildings often improve on this ancient technique by incorporating a thermal storage and delivery system called a Trombe wall. Named after French inventor Felix Trombe in the late 1950s, the Trombe wall continues to serve as an effective feature of passive solar design. Trombe walls have been integrated into the envelope of a recently completed Visitor Center at Zion National Park and a site entrance building (SEB) at the National Renewable Energy Laboratory’s (NREL’s) National Wind Technology Center. The High Performance Building Initiative (HPBi) at NREL helped to design these commercial buildings to minimize energy consumption, using Trombe walls as an integral part of their design. Trombe Wall Design and Construction: A typical unvented Trombe wall consists of a 4- to 16-in (10- to 41-cm)-thick, southfacing masonry wall with a dark, heat-absorbing material on the exterior surface and faced with a single or double layer of glass. The glass is placed from ¾ to 2 in. (2 to 5 cm) from the masonry wall to create a small airspace. Heat from sunlight passing through the glass is absorbed by the dark surface, stored in the wall, and conducted slowly inward through the masonry. High transmission glass maximizes solar gains to the masonry wall. As an architectural detail, patterned glass can limit the exterior visibility of the dark concrete wall without sacrificing transmissivity. Applying a selective surface to a Trombe wall improves its performance by reducing the amount of infrared energy radiated back through the glass. The selective surface consists of a sheet of metal foil glued to the outside surface of the wall. It absorbs almost all the radiation in the visible portion of the solar spectrum and emits very little in the infrared range. High absorbency turns the light into heat at the wall's surface, and low emittance prevents the heat from radiating back towards the glass. For an 8-in-thick (20-cm) Trombe wall, heat will take about 8 to 10 hours to reach the 5 Submitted by:Banafsha Quadri

Sustainable elective interior of the building. This means that rooms receive slow, even heating for many hours after the sun sets, greatly reducing the need for conventional heating. Rooms heated by a Trombe wall often feel more comfortable than those heated by forced air because of the large warm surface providing radiant comfort. Architects can use Trombe walls in conjunction with windows, eaves, and other building design elements to balance solar heat delivery. Strategically placed windows allow the sun's heat and light to enter a building during the day to help heat the building with direct solar gains. At the same time, the Trombe wall absorbs and stores heat for evening use. Properly sized roof overhangs shade the Trombe wall during the summer when the sun is high in the sky. Shading the Trombe wall can prevent the wall from getting hot during the time of the year when the heat is not needed. . Figure 1 shows the Trombe wall locations in the NREL SEB (a), and the Zion Visitor Center (b).

Figure 1. a) NREL SEB,

b) Zion Visitor Center

The National Park Service applied a whole-building design process to create a Visitor Center at Zion National Park that performs more than 70% better than a comparable code-compliant building at no additional construction cost (Torcellini 2004). Trombe walls were one of the many strategies included in that process and design. The Visitor Center Trombe wall design details are shown in the cross section in Figure 2. The 6-ft-high (1.8-m) Trombe wall (740-ft2 total area (68.7-m2) is located on the entire length of south-facing walls of the Visitor Center. The wall is 44% of the total south facing wall area. The Trombe wall is 8-in (20-cm) grout-filled concrete masonry units (CMU) with an R-value of 2.5 hr·ft2·°F/Btu (0.4 K·m2/W). The other walls are 6-in (15-cm) framed walls with an R-value of R-16 hr·ft2·°F/Btu (2.8 K·m2/W). The Trombe During the construction process, the filling of the CMU wall was monitored to ensure the concrete block cores were completely filled, which provides a consistent conductivity through the wall. The placement of the footing insulation was also verified during the construction process to ensure proper installation. The location of this insulation is critical, as Trombe wall performance can be diminished due to three-dimensional heat transfer to the ground. By thermally decoupling the footings from the ground with insulation, unnecessary heat loss is avoided and more heat from the Trombe wall is supplied to the building.

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Sustainable elective

NREL’s Wind Site, located approximately twelve miles north of Golden, Colorado, constructed a small building at the site entrance. NREL staff designed an energyefficient SEB that would eventually be powered completely by its onboard photovoltaic (PV) array and two wind turbines. Although small, the building is representative of many guard facilities, remote restrooms, and outposts. A Trombe wall was an integral part of the heating system. This Trombe wall has a single piece of high transmittance patterned glass installed on a thermally broken storefront system in front of a 4-in-thick (10-cm) concrete wall with a selective surface. The other walls are 4-in-solid (10-cm) tilt-up concrete walls with an EIFS (exterior insulating finishing system). The 5-in (13-cm) exterior foam has an R-value of 25 hr·ft2·°F/Btu (4.4 K·m2/W). The total area of the Trombe wall is 44 ft2 (4.1 m2), or about 34% of the total south-facing wall. The roof overhang shades the Trombe wall for most of the summer. The interior surface is painted concrete. Trombe Wall Energy Performance The energy performance of the Zion Visitor Center was monitored and analyzed over a two-year period. The analysis consisted of measured electrical end uses, Trombe wall temperature profiles, and thermographic pictures to determine the performance of this Trombe wall (Torcellini, 2004). Similar measurements were taken at the SEB over a one-year period. Figure 3 shows the thermal distribution of the Zion Trombe wall at 8:30 p.m. on December 16, 2000. The interior surface temperature is generally homogeneous, ranging from 90-96ºF (32-36ºC). The wall temperature typically peaks between 8-9 p.m. The reduced wall temperature at the far right section of Trombe wall is due to shading. The building shades a portion of the Trombe wall in the afternoon, resulting in reduced interior temperatures.

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Sustainable elective EXAMPLES: 1. Himachal pradesh state co-operative bank 2. The Blue Ridge Parkway Destination Center, Asheville, N.C Location: Asheville, N.C. Size: Two stories, 12,000 square feet Completed: January 2008 Certification: targeting LEED Gold

EXAMPLE 1: Himachal pradesh state co-operative bank Location : Shimla, Himachal Pradesh Climate : Cold and Cloudy Brief description of building : • This building is a ground and three-storeyed structure with its longer axis facing • the east-west direction. • The smaller northern wall faces the prevailing winter winds from the north-eastern direction. The building shares a common east wall with an adjoining structure. Its west façade overlooks a small street from which the building draws its main requirements of ventilation and daylighting. • A plan and section of the building showingthe various passive techniques incorporated is given.

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Sustainable elective

EXAMPLE 2 • The Blue Ridge Parkway Destination Center blends state-of-the-art computational analysis with state-of-the-shelf passive solar design. • The Center’s mission is to orient visitors to the history, culture and resources of the Parkway and surrounding region, while demonstrating high-performance, ecological design. • Nestled into a hill, the building evokes a “tree-house-like” atmosphere that allows visitors to experience the majestic vistas and surrounding woodlands for which the Parkway is known. • The facility’s optimized passive solar design, along with a mix of other strategies, is projected to reduce energy use by 75 percent.

Climatic Response : • Natural ventilation reduces the building’s cooling load in the swing seasons. • The design was developed in direct response to regional climatic conditions. • Climate analysis and preliminary energy modeling were part of the schematic design process. 9 Submitted by:Banafsha Quadri

Sustainable elective • The summer design temperature in Asheville is 87 degrees Fahrenheit (F), and the winter design temperature is 19 F. There are 4,512 heating degree days and 748 cooling degree days, with fairly strong solar radiation in winter. In this heating-dominated climate, the use of passive solar provided an opportunity for significant energy savings. A mild cooling season with low nighttime temperatures allows for natural ventilation and passive nighttime cooling. • Daylighting and energy recovery provided additional opportunities to reduce energy use. • To maximize solar harvesting with this orientation, the south façade was segmented to form a saw-toothed plan, forming a row of south-facing passive solar Trombe walls . • The Trombe walls were integrated into the design of the building, serving as structure, exhibit areas, daylighting elements, air distribution (both for the active HVAC system and the passive Trombe walls), and an intimate space to view the surrounding woods. • The Trombe wall segments are interspersed with east-facing windows that provide instantaneous heat gain on winter mornings. • Each Trombe wall consists of eight-inch concrete providing thermal mass, with a sixinch air-gap and a curtain wall system with insulated glazing. • The sun heats the wall, causing heated air to rise in the air space. • The heated air is directed into the building through vents at the top of the wall, passively drawing cooler air into the vents at the base of the wall to be heated in turn. • At night, dampers close off the walls, preventing reverse thermo-siphoning (i.e., cold air from the cavity falling and entering the building at night), while heat stored in the mass walls is released throughout the night. In summer, the walls are vented at night, allowing for passive cooling

Conclusions: Trombe walls have been integrated into the envelope of a recently completed Visitor Center at Zion National Park and a SEB at NREL’s Wind site. A Trombe wall can enable a building envelope to go from a net-loss feature to a net-gain feature. The Trombe wall provides passive solar heating without introducing light and glare into theses commercial spaces. Overhangs are necessary to minimize the summer gains; however, additional means would be helpful to minimize summer cooling impacts. In both walls, edge effects were minimized with appropriate ground insulation. The Trombe walls in both the Visitor Center and the SEB provide significant heating to the buildings. In the Visitor Center, 20% of the annual heating was supplied by the Trombe wall, and the SEB afternoon and evening heating loads are typically met by the Trombe wall. The annual net effect of the wall has to be considered when designing a Trombe wall, as the additional cooling loads can affect the cooling system performance.

References: 1.Nayak J.K., Hazra R., Prajapati J., Manual on solar passive architecture, Solar Energy Centre, MNES, Govt. of India, New Delhi, 1999. 2.. Lall A. B., Re-development of H. P. state co-operative bank building at mall road - Shimla, MNES Project Report, New Delhi, 1996. 3. Representative designs of energy efficient buildings in India by ‘teri’ 10 Submitted by:Banafsha Quadri

Sustainable elective

MATERIAL STUDY: CELLULAR LIGHT WEIGHT CONCRETE Eco-friendly Materials: Phenomenal growth in the construction industry that depends upon depletable resources. Production of building materials leads to irreversible environmental impacts. Using eco-friendly materials is the best way to build a eco-friendly building.

Cellular Light Weight Concrete (CLC), based on ‘Neopor’ (Germany) technology has been used in over 45 countries of the world over the past 30 years to construct Over a hundred thousand houses, apartments, schools, hospitals, industrial, commercial buildings etc. The introduction in India of a modified version using over 25% fly ash has made it an even more eco-friendly and cost effective version of CLC. The new product is set to revolutionize the manner in which buildings are constructed. In the process, the product brings quality housing closer to the masses at a faster and at a lower cost.

Manufacturing Process: • CLC is a version of lightweight concrete that is produced like normal concrete under ambient conditions. • It is produced by initially making a slurry of Cement +Sand + Fly Ash (constituting 26% - 34 % content) + water, which is further mixed with the addition of pre-formed stable foam in an ordinary concrete mixer under ambient conditions. • The mixture is either poured or pumped into assembled moulds of blocks or form-work of reinforced structural elements or poured onto flat roofs or voids for thermal insulation or filling. The foam imparts free flowing characteristics to this slurry due to ball bearing effect of foam bubbles enabling it to easily flow into all corners and compact by itself in the moulds/forms without requiring any kind of vibration or compaction. • This Cellular Lightweight Concrete (CLC) can be produced in a wide range of densities from 200 kg/m3 to 1,800 kg/m3 to suit different applications

Uniqueness of CLC in relation to other Light-weight Concretes: Extensive research to develop lightweight concrete has been going-on all over the world for many years. The versions, that have been introduced by companies like ‘Siporex’, ‘Hebel’, Yutong or “H+H” are Aerated Autoclaved Concretes, requiring a large Factory set-up, with heavy Capital Investment (~$ 10 million) in plant and equipment 11 Submitted by:Banafsha Quadri

Sustainable elective and involvenelaborate processing.This autoclaved products have naturally to be very expensive. The Neopor based CLC, is the first of its kind with a very simple method of production, which can easily be adopted in pre-cast plants or even at the project-site itself under ambient conditions. It requires only a nominal investment (<0.5% of AAC plant). The CLC version with fly ash as one of its major constituents, is still cheaper and more environment friendly. It is produced using Cement, Sand, fly-ash (optional), Water and foaming compound with the help of normal Concrete/ Transit mixers, simple foaming equipment, ordinary moulds, unskilled labour and is water mist/spray cured under ambient conditions, just as for ordinary concrete. The foam creates millions of tiny voids or cells in the material, hence the name cellular concrete. Other unique features of CLC are that: It can be produced in a wide range of density from 400 – 1,800 kg/cubic meter. The material of density up-to 600 kg/m3 is normally used for providing thermal insulation. The density of 800 - 1,000kg/m3 is used for non-structural masonry, while the density above 1,200 kg/m3 is used for structural applications, including reinforced elements. It may be cast in-situ into a complete structure or the walling and /or roofing elements of a structure or It can be made into pre-cast elements - whether reinforced or un-reinforced.

Cellular Light-weight Concrete - A superior substitute to Bricks:Brick is the most extensively used building material all over the World. To most of the people, brick symbolizes the basic unit of construction – one, which seems to have been present since time immemorial. But in spite of its long history the bricks suffer from many shortcomings. ⇒ Top soil erosion: Bricks are produced with the use of good quality agricultural topsoil. Use of CLC in preference to bricks, will therefore prevent ruining of arable land for establishing brick kilns and help in increasing food production for the growing millions in the World. ⇒ Power & Fuel Hungry: Manufacturing of 0ne lakh bricks requires 25.77 Mt. of coal, while the energy required for producing CLC is negligible. Added to this is the considerable fuel saving in transportation of CLC as it lighter and can also be produced at the project site itself. ⇒ Smallness of size: Smaller size of brick warrants higher mortar and labour inputs for masonry and plastering work. A CLC block substitutes 14 bricks for an external/party wall and 7bricks in case of partition walls. Alternatively, the whole wall could be poured in-situ like ordinary reinforced concrete, thus dispensing with the masonry operation altogether. ⇒ Inadequate & Seasonal Supply: Supply of bricks is mostly not able to keep pace with the demand. Moreover production is restricted to six months in a year, while a project can continuously produce CLC all through the year at a regular pace to match their requirements. ⇒ One size, Different Quality: 12 Submitted by:Banafsha Quadri

Sustainable elective To top it all, even the bricks produced are not of a uniformly good quality. The quality of CLC production can be controlled accurately at the project site, just like Concrete. The need for an alternative building material was, therefore, being keenly felt in the construction industry. The materials promoted so far are not cost effective. The introduction of CLC has not only over-come shortfalls of bricks, but it is also more versatile, apart from being eco-friendly and economical.

Advantages of CLC: •

Reduction of dead load : Unstable ground conditions or desire to add extra floors on to existing structures, often limits application of normal dense concrete. Under utilization of available FAR is one consequence or, the other possibility being the introduction of lightweight concrete. Lightest possible dead load is also highly appreciated for economy in structural design in high earthquake prone areas.

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Material Savings: CLC uses no gravel - only sand, cement, water, fly ash and foam. The use of cellular concrete yields substantial savings in locations where gravel is not readily available or hard to obtain or is very costly. In multi-story constructions, partitions, floor screeds and other non-load bearing building elements are recommended to be made in cellular concrete, there by substantially reducing the dead-load of the structure (and consequently saving reinforcing steel required for foundations and the main structural elements).

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Saving in Transportation costs: Reduced weight of materials and zero transportation of CLC produced at project site imply lesser transportation expenses.

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Ease of Handling Building elements of CLC can be handled manually in largerdimensions (double sized) in comparison with those of dense concrete. Hilly Area Construction in hilly areas will become easier with CLC as the problematic transportation of bricks from the plains is dispensed with.

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Eco-friendly CLC is remarkably eco-friendly. It saves depletion of the top-soil, while at the same time it can actually use fly-ash - an industrial waste- as one of its major constituents. The production process of CLC or it’s use does not release any harmful effluents to ground, water or air (unlike smoke of brick kilns and ruining of top soil in production of bricks).CLC, due to its low weight is ideal for making partitions. The use of CLC for thispurpose will reduce the need for plywood partitions. This consequently will result in reduction in deforestation and will benefit environment.

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Sustainable elective • •

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Thermal Insulation Air is known to be the best insulation material available. Air voids, if smaller than 2mm each, consequently increase thermal insulation substantially. Normal aggregate concrete has a specific thermal conductivity (Lambda) of 2.1 W/mK, compared to 0.405 only for 1200kg/m3 cellular concrete. To offer identical thermal insulation as a 100 mm thick CLC wall, the equivalent thickness of dense concrete wall would have to be more than 5 times thicker (i.e. 500 mm) and ten times heavier. Fire Protection: Fire rating of cellular concrete is far superior to that of brickwork or dense concrete. Just a 100 mm thick wall of 1200 kg/m3 CLC, offers a fire endurance (heat transmission) of 3 hours. Moreover, there are no dangerous fumes or spread of fire as experienced with plywood partitions having rigid (styropore, urethane) insulation material - often the reason for loss of life of entrapped individuals due to toxic fumes during fires. Speedier Constructions: The absence of gravel coupled with the ball-bearing effect of the foam lends cellular concrete much higher consistency. No vibration is necessary when pouring cellular concrete into moulds/forms. It distributes evenly and fills all voids completely ensuring uniform density all over the material. This way full-height walls of a complete building (all internal and external walls) can be poured in-situ in one step, thus speeding-up the construction considerably. Moreover, freedom from dependence on suppliers of walling masonry materials like bricks or hollow blocks and ability to self regulate output of CLC material at site to suit one’s pace of progress, can help in achieving speedier outputs.

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Universal applicability The wide range in densities and consequently their different thermal and structural properties, make CLC equally suitable for use: As reinforced load-bearing in-situ walls and roofs in Low Rise Buildings. Even block-work (made from pre-cast blocks produced at the project site or obtained from a pre-casting plant) can also be used for load-bearing low rise constructions. Non load-bearing internal or external walls in High Rise Buildings. Thermal Insulation of building roofs and walls & roofs of cold storage. Filling of depressions in Toilets, floors etc.

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Superior to other alternative materials

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CLC is superior in performance, more eco-friendly and cost effective in comparison to other available alternative materials like Autoclaved Aerated Concrete, Ordinary Burnt Clay bricks or Dense concrete Hollow blocks.

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Sustainable elective

Examples:

References: • Eco-Friendly Building MaterialsScience and Technology Park, University of PunePresentation byProf.R.K.Ambegaonkar, Former Chairman of B.O.S.Metallurgy & Dean , Faculty of Engineering, University of Pune. • www.greenhomebuildings.com • www.bccssystems.com • www.bmtpc.com

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