Sustainable Construction A Life Cycle Approach in Engineering

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Facades form the biggest part of the building‟s outer surface. Therefore enough area is ready on a façade for the use of PV components. If they are used on big and prestigous office buildings (e.g. administration buildings of big companies) they already begin to payback due to the fact that they would be used instead of prestigious and expensive façade claddings and in addition they produce electricity. A facade gives the first impression to the visitors. Architects try to tell their aspects and their clients‟ wishes on the facade with a suitable form and color. Therefore the design of the facade of a building has an important part in the design of the whole building. And it is an aesthetical element for the architect. Therefore PV module use on the building facade needs a special and careful design. At the same time, PV module use on the building facade is an easy way of show of technology use in the construction industry, by being seen from the street easier than its use on the roof. Therefore, PV modules can make buildings more prestigious when used properly. PV modules on facades provide multiple functions. One is the aesthetic as told above. They also produce electricity. They may be used as transparent or semitransparent elements to provide light to the interior. They provide solar control when used as a shading element. But first of all, they separate the interior of the building from the outside. Therefore, the aim of this study is to examine the possibilities of photovoltaic component use on buildings and its energy efficiency. This is going to be done by calculating the energy efficiency of BIPV modules by using both the orientation of the building and the tilt angle of the PV modules. Hence, the energy efficiency tables produced within this study could be used for all of the building skin elements, and especially for the design of the shading elements produced by PV modules. In the end, this study will put forward the possibilities of the PV component use on buildings more efficiently and help produce energy-efficient buildings. 2 SHADING ANALYSIS When “PV - Sun - Radiation - Building” words are thought together, the forming of buildings with the help of passive design system principles according to the sun is recognized. That is due to the fact that climatic comfort conditions could be achieved in the interior by the use of the differences in the angles of the sun-rays. If PV elements are going to be used instead of roof or wall cladding elements, they are going to take the solar radiation instead of them, but in spite, they are going to use most of this solar radiation to produce electricity. The maximum efficiency in Building Integrated PV (BIPV) modules could be achieved while shading a building, because there is an unwanted solar radiation. This unwanted solar radiation will occur in every situation as long as the sun shines. And the building must be protected from this unwanted solar radiation as part of the passive system. Therefore if these shading devices are composed of PV elements, then electricity is going to be produced from this unwanted solar radiation which in turn decreases the electricity demand of the building. Therefore this use is one of the most efficient ways of electricity production by BIPV modules. In order to reach the optimum result in the use of BIPV modules, it is not going to be enough to set the PV elements with the suitable tilt angles. It is necessary to determine the best location in which the radiation is received maximum in the field. Otherwise, the best result could not be achieved. So, the building envelope is going to be formed according to: 1. the tilt angle which the PV panels require for the maximum energy output, and 2. the orientation angle at which solar radiation is received as optimum for providing the comfort conditions. Because of this, how to design a shading element (in horizontal and in vertical) could be reached by the use of the “Shading Analysis” and determining the tilt angle could be done with the use of a simulation program. It could be said that the “skin” of the building helps controlling the comfort conditions in the building. This is important since human beings are not as fortunate as animals against the envi- 122
onmental changes. As architectural means, the buildings‟ skin must protect them from the environmental conditions and keep a mild and comfortable atmosphere inside for the human beings in order to make them feel themselves good. So it must be detailed carefully. In this concept of detailing the skin of the building, the energy coming from the sun plays an important role. Its rays are wanted to enter the building in cold days while they are tried to be escaped from in hot days. The skin of buildings is generally composed of walls and roof . One of the design possibilities in this sense is the shading elements‟ design because walls contain windows within them. Due to the fact that windows let the sunshine get through them, they overheat the interior. For the radiation control, solar radiation should be kept out in summer while it should be let in through the windows as much as possible in winter. “For any given locality the climatic conditions, mainly the temperature, give an index for outlining cool and warm periods which can be designated as the “underheated” and “overheated” periods. The “overheated” period is the one when shading is needed.” (Olgyay & Olgyay, 1973, p.16) And the one when solar radiation is necessary in the interior is the “underheated” period. As Olgyay & Olgyay stated (1973), “the effect of climatic elements on the human physiology can be graphically charted” (p.20). In Figure 1, the bioclimatic chart is given. The x-axis is the relative humidity while the y-axis is the temperature. Also shading, radiation, air movement, moisture are shown. At higher temperatures, wind is required and the velocity of the required wind is stated on the chart. If the humidity is high, required wind velocity is also shown on the chart. In the comfort zone, people feel themselves comfortable. Below this zone there is the shading line (at around 21,1 ºC). Above this line, wind and shading is required while below the line, solar radiation is necessary to feel comfortable. This shading line is important since it determines the “Underheated zone” and the “Overheated zone”. Underheated zone is under the shading line and overheated zone is above it. Shading is necessary above the shading line at overheated zone. With the use of the meteorological data, the average values are found for the city in question. These average values are converted into curves in a coordinate system whose x-axis shows the days of the year and y-axis shows the hours of a day. When the graphics which show the average temperature curves and average relative humidity percentage curves are collided with keeping the shading line in mind, a shading line that is dependent on time is achieved. Therefore two areas are defined, one is between the shading lines (this gives the overheated period), and the other gives the underheated period. The times in these periods are then converted into solar time and they are placed in the sun-path diagram. The sun-path-diagram of Izmir is achieved as shown in Figure 2. (Zeren, 1967, pp.23-31) The overheated period and the underheated period are transferred to the sun-path-diagram as in Figure 2. The dark area is the overheated period where shading is necessary but it has two tones: the darker and the lighter area. The curved lines indicate two days of a year where the sun is at the same altitude in the sky. The darker area of the overheated period means that shading is required at both of the corresponding days. The lighter area shows the days when only one of these two days (usually the autumn days) needs shading. The non-shaded areas of the diagram show the days when no shading but radiation is required. The sun-path-diagram changes according to the latitude. Therefore a special sun-path-diagram is prepared for each latitude. In order to determine where shading must be done and where mustn‟t, sun-path-diagram and mask are used together. This process is called as “Shading Analysis”. Sun-path diagram: The path which the sun follows is projected onto a horizontal plane in the sun-path diagram as seen in Figure 2. In this diagram, the outer circle is the horizon, and the observer stands at the center. “The curved lines indicated by days and months of the year represent the sun-paths on the dates shown. Lines „radiating‟ from the North Pole indicate the hours. Between the hour lines are lighter lines indicating twenty-minute intervals” (Olgyag & Olgyay, 1973, p.40). Mask: The mask which is seen in Figure 3 is placed on the sun-path-diagram which is seen in Figure 2, according to the orientation of the facade in question. Their centers should intersect. The 90-90º line of the mask represents the facade of the building in question. The mask is 123
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Sustainable Construction A Life Cyc
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COST- the acronym for European COop
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Foreword The COST Action C25 "Susta
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Contents Sustainability of Construc
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Sustainability of Constructions Int
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1.4 Raising the level of Sustainabl
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Sustainability of Construction Stru
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WP9 WP10 ‣ Verification methods f
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In the context of the Action a comp
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ia. (“Politehnica” University o
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- Introduction to the aims and obje
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The Role of Environmental Assessmen
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2 ENVIRONMENTAL ASSESSMENT OF BUILD
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process is used to facilitate the e
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With assistance of information tech
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Building Sustainability Assessment:
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• To improved reliability through
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Table 2. Parameters declared in the
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From the outputs of this building s
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Green Building Design Guideline İ.
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2.2.1. Solar shading Solar shading
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Use state-of-the-art irrigation con
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REFERENCES: Ayaz ,E. Mimarist perio
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Structural, economic and environmen
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Figure 1. Types and sources of data
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espiratory inorganic substances and
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Table 3. CML results, exact values
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nario. That means, flows of the rec
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1900 1910 1920 1930 1940 1950 1960
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Alt. A Alt. B Figure 8. Alternative
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ACKNOWLEDGMENT Authors from Technic
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Load, kN The aim of this comparativ
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On the basis of previous conclusion
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Table 6. Inventory table per FU (1p
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As the experiments have shown, comp
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1) covered with patterned stainless
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• Energy: the operational energy
Page 84 and 85: 4 LIFE CYCLE INVENTORY 4.1 Methodol
Page 86 and 87: 6 ACKNOWLEDGEMENT B. Rossi is suppo
Page 89 and 90: The potential use of Waste Tyre Fib
Page 91 and 92: Table 2: Geometric properties of th
Page 93 and 94: Table 3: Tensile Strength of shredd
Page 95 and 96: Figure 8: Compressive strength 28 d
Page 97 and 98: IFCC-2.0 IFCC-1.0 IFCC-1.5 Figure 1
Page 99 and 100: Figure 17: Toughness Index - Effect
Page 101: Laws of Malta. 2001. CAP 435 Enviro
Page 104 and 105: the future, the model will most lik
Page 106 and 107: for each of the potential solutions
Page 108 and 109: stavb. Magistrsko delo. Ljubljana,
Page 110 and 111: 1.2 UK Roadmap to Carbon Zero The U
Page 112 and 113: 1.5 Design Team Cabe, the governmen
Page 114 and 115: • Perceptions of End Users: Discu
Page 116 and 117: REFERENCES BAILEY L, TOLMIE-THOMSON
Page 118 and 119: to the production of the specific u
Page 120 and 121: Figure 1. Proposals of different de
Page 122 and 123: The sustainable development of tran
Page 124 and 125: 3.2 Bed Zed, UK Bed zed is a commun
Page 126 and 127: GWL these uses are separated while
Page 128 and 129: Energy consumption for heating, kWh
Page 130 and 131: Heat losses, MWh Heat losses, MWh t
Page 132 and 133: REFERENCES: Juodis, E. 2000. Energy
Page 136 and 137: placed over the sun-path-diagram wi
Page 138 and 139: In the table, when the simulation p
Page 140 and 141: estimate the output of the panels i
Page 142 and 143: plan. The aim of this kind of chang
Page 144 and 145: First (front) group (zone) Second (
Page 146 and 147: predicted, illustrated and listened
Page 148 and 149: Figure 13 Evaluation of receiver po
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Page 154 and 155: 2 POSITIONING STRUCTURAL FLEXIBILIT
Page 156 and 157: Table 1: Building layers Envelope F
Page 158 and 159: Figure 5: The results of the survey
Page 160 and 161: 1 INTRODUCTION Bridges are importan
Page 162 and 163: 3 CONCLUSION This paper reviewed st
Page 164 and 165: tween this bridge and a reinforced
Page 166 and 167: The construction sequence assumed f
Page 168 and 169: Agency life cycle costs (present va
Page 170 and 171: Figure 3a: User’s life cycle cost
Page 172 and 173: Figure 5: system boundaries for the
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Page 176 and 177: the construction of these bridges.
Page 178 and 179: Figure 2a „Flat-Pack‟ arch syst
Page 180 and 181: As far as analysis of the „FlexiA
Page 182 and 183: Figure 5 Initial/whole life cycle c
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FLIR Systems 13.9 °C FLIR Systems
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Figure 2: NPV of costs in 60 year b
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REFERENCES 1. ATTMA - The Air Tight
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2 MULTI-CRITERIA DECISION MAKING ME
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The results of pairwise comparisons
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with C i* =1 if A i =A * . 3 APPLIC
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Figure 4. Criteria taken into accou
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As far as the problem of the constr
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timber connection with appropriate
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Numerical simulations of ash pegs t
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192
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a building this gives a prime excus
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Lack of past investment in the main
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2.3 Methodology The research will b
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