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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

Service life estimations in the design of a PCM based night cooling system

Hed, Göran January 2005 (has links)
The use of Phase Change Material, PCM, to change the thermal inertia of lightweight buildings is investigated in the CRAFT project C-TIDE. It is a joint project with Italian and Swedish partners, representing both industry and research. PCMs are materials where the phase change enthalpy can be used for thermal storage. The Swedish application is a night ventilation system where cold night air is used to solidify the PCM. The PCM is melted in the day with warm indoor air and thereby the indoor air is cooled. The system is intended for light weight buildings with an overproduction of heat during daytime. In the thesis, the results of experiments and numerical simulations of the application are presented. The theoretical background in order design the heat exchanger and applying the installation in thermal simulation software is presented. An extensive program is set up, in order to develop test methods and carry tests to evaluate the performance over time of the PCM. Testing procedures are set up according to ISO standards concerning service life testing. The tests are focused on the change over time of the Thermal Storage Capacity (TSC) in different temperature spans. Measurements are carried out on large samples with a water bath calorimeter. The service life estimation of a material is based on the performance of one or more critical properties over time. When the performances of these properties are below the performance requirements, the material has reached its service life. The critical properties of the PCM are evaluated by simulation of the application. The performance requirements of the material are set up according to general requirements of PCM and requirements according to building legislation. The critical properties of a PCM are the transition temperature, the melting temperature range and the TSC in the operative temperature interval. The critical property of the application is its energy efficiency. The results of the study show that the night cooling system will lower the indoor air temperature during daytime. It also shows that the tested PCM does not have a clear phase change, but an increased specific heat in the operative temperature interval. Increasing the amount of material, used in the application, can compensate this. Finally, the tested PCM is thermally stable and the service life of the product is within the range of the design lives of the building services. It is essential to for all designers to know the performance over time of the properties of PCMs. Therefore it is desirable that standardized testing methods of PCM are established and standardized classification systems of PCMs are developed. / QC 20101020
252

Industrial Construction Methods for Cost-Effective and Sustainable Multi-Storey Buildings

Pourghazian, Hanif January 2008 (has links)
Reduction of the cost of construction is a constant goal for the building industry. One way of reducing the construction cost of buildings is to develop building technologies that will give increased productivity. Reduced construction time at the building-site and waste of materials and resources contribute to furtherreduction of the costs. This is why the sector is developing towards more industrialized construction methods with prefabricated components. The objective of this thesis is development of industrial construction methods forcost-effective and energy-efficient construction of multi-storey buildings. It is important to highlight the difference between cheap or low-cost and cost-effective production. It is possible to produce buildings to a low-cost at the expense of decreased quality and design. Conversely, cost-effective buildings are buildings that are produced to a low cost while maintaining a high standard of design and comfort. While cost reduction efforts are often made based on a, relatively, fixed building process, this research is focused on reducing the costs by changing the building process with the help of innovative building technologies. The construction of a building is a very complex practice with a wide range of interacting processes. The hypothesis is that a holistic approach is advantageous in order to find effective construction methods. To achieve a holistic view, an interdisciplinary approach to the research is required. By approaching the development of construction methods from the point of view of the entire building process, it is possible to achieve optimizations with synergy effects and by that find solutions that are time-efficient, energy-efficient and cost-effective at the same time. The work started by analysing the building process and the construction methods currently used in order to; discover the most common problems, gain understanding of the strengths and weaknesses in the conventional construction methods and identify the fields where the largest potential for improvements existed. Based on this analysis, a new building concept for industrial construction of multi-storey buildings is formulated called The Symphony concept. The concept involves a holistic view of the whole building process and is based on a prefabricated heavy structure that is covered with a prefabricated building envelope consisting of large, light-weight elements with a high degree of prefabrication and finished exterior surfaces. The concept required development of new types of building-elements and assembly methods. The technology was first evaluated while still on the drawing table. Some of these evaluations have been of a more detailed character and are reported in scientific papers. Thereafter an experimental building in full scale was erected in order to test the developed technology during production and assembly, while measurements and tests were performed in order to evaluate the performance of the building in operation. Based on the obtained results suggestions for improvements could be given in order to upgrade the concept further. The economic analysis of the building process showed that the largest cost posts in the construction of dwellings are the climatic shell (24 %), the interior finishing, and the management costs. The construction of the climatic shell is optimized through the use of the Symphony elements while the management costs are reduced through the use of prefabricated elements with a high degree of prefabrication which, substantially, increase the construction speed. Results show that it is possible to reduce the construction costs with about 25 % when constructing according to the Symphony concept compared to conventional construction methods. The construction of the large light-weight Symphony-elements was possible thanks to the CasaBona system. CasaBona is a building system which integrates the thermal insulation with the structural elements in the outer walls by embedding sheet metal profiles into stiff insulation blocks. The results show that the strength of the profile, when embedded in rigid insulation blocks, is increased between 22 % and 33 % when submitted to bending forces, and between 161 % and 210 % when submitted to compressive forces. Simulations of the annual energy use of buildings show that the energy performance of buildings is improved with increased effective thermal mass. Increased mass is also beneficial from the acoustic point of view. However, it is important that the interior space is separated from the exterior climate with constructions that have low U-values. It could be concluded that the most beneficial design strategy is the combination of a heavy core-construction (which has a large mass and thermal inertia) and a light-weight building envelope (which yields low U-value without adding to the thickness of the outer-wall). The construction of the experimental building made it possible to test the technology in an inexpensive yet realistic way. However, it is important to bear in mind that the information which can be gathered from an experimental building can be limited depending on the size of the building and its finishing standard. It could also be noticed that industrial construction benefits from an interdisciplinary design process since this render the increased use of prefabricated components possible. / QC 20100906
253

Energiutredning av Kv. Salladen nr 9

Ek, Caroline January 2009 (has links)
No description available.
254

Viking Future Centre : Vision om en identitetsbyggnad i Göteborg / Viking Future Centre : Vision of an identity building in Gothenburg

Larsson, Jimmy January 2008 (has links)
This thesis project is a vision of an identity building in Gothenburg, situated on the pier called Bananpiren. The purpose of the project is to create interest and stimulate discussions around the place and the building.In order to gain inspiration of what such a place can contain and express, a number of similar projects have been analysed, for example the Sydney Opera and the Yokohama International Port Terminal.A number of suggestions was then created and analysed, all of which are presented in chronological order in order to show the rejections and the developed designs that resulted in the final formation to proceed with.The result was finalised in a number of presentation images of the project that can be used by Cullbergs Arkitektkontor AB when presenting the project. / Examensarbetet är en vision till en identitetsbyggnad i Göteborg belägen på Bananpiren. Idén med projektet är att väcka intresse och skapa diskussion över platsen och byggnaden.För att få inspiration över vad en sådan här plats kan innehålla och förmedla har liknade projekt analyserats, till exempel Sydneyoperan och Yokohama international port terminal.Under genomförandet har en mängd förslag testats och analyserats, här redovisas i kronologisk ordning hur de olika förslagen har utvecklats eller förkastats innan vi kom fram till en slutlig utformning att jobba vidare på.Resultatet ledde till att Cullbergs Arkitektkontor AB fick en mängd presentationsbilder över projektet som de kan använda sig av i presentationer av projektet.
255

Examensarbete: Prefabricerad produktion med betongelement : En kostnadsutvärdering mellan prefabricerad och platsbyggd produktion / Prefabricated Production

Danielsson, Erik, Robertsson, Hans January 2008 (has links)
No description available.
256

Do Muslims make the difference: explaining variation on mosque building policies in Western Europe

Stark, Lisa Michelle 05 1900 (has links)
The research question this thesis asks is what accounts for the intra state variation of mosque building projects in Western Europe, using as case studies Britain, France, Germany and the Netherlands. Two mosque projects are considered in each case study state and two theories are proposed and tested: resources mobilization theory and opportunity structure theory.
257

Den teoretiska energiåtgången : Två energiberäkningar av Blåsbälgen / The theoretical energy consumption : Two energy calculations of Blåsbälgen

Sällström, David, Persson, André January 2013 (has links)
Arbetet är utfört åt VVS-Byrån i Växjö AB för att visa hur en mer noggrann energiberäkning påverkar den teoretiska energianvändningen jämfört med en tidigare gjord energiberäkning. Genom att samla ihop olika arkitekt- och konstruktionsritningar har vi med hjälp av programmet VIP-Energy konstruerat ett så sanningsenligt klimatskal som möjligt. Programmet har även bearbetat rekommenderad indata från Svebyprogrammet, Boverkets byggregler och SMHI, samt indata av olika byggnadsinstallationer. Resultatet visar att skillnader i verksamhetsenergi till rumsluft, externfastighetsenergi och tappvarmvatten har störst inverkan på energiåtgången. Beräkningarna visar också att det fall där köldbryggor är modellerade i 2D ger en teoretisk energiåtgång som liknar de uppmätta värdena mer än det fall då köldbryggorna läggs in som ett 20 % påslag gentemot ett första Um-värde.
258

Life-cycle Cost Evaluation of Building Envelope Energy Retrofits

Maleki, Afarin 17 January 2012 (has links)
Improving the energy efficiency of our existing building stock is attainable by upgrading the building envelope through carrying out various retrofit measures. The objective of this thesis is to evaluate the life-cycle cost implications of energy retrofits for existing buildings. Measures examined include improving insulation and air-tightness with overcladding strategies. The life-cycle costs of the upgrades are determined for an existing building and compared with model energy performance. A life-cycle cost evaluation for the building envelope upgrades is provided, together with the payback period and the projected return on investment (ROI) for two energy escalation rate scenarios. A costbenefit matrix for various over-cladding strategies is provided to facilitate the evaluation of each option. Further, this thesis presents a simplified ROI algorithm to enable owners, architects and engineers to evaluate the cost-benefit of their building envelope retrofit options.
259

Life-cycle Cost Evaluation of Building Envelope Energy Retrofits

Maleki, Afarin 17 January 2012 (has links)
Improving the energy efficiency of our existing building stock is attainable by upgrading the building envelope through carrying out various retrofit measures. The objective of this thesis is to evaluate the life-cycle cost implications of energy retrofits for existing buildings. Measures examined include improving insulation and air-tightness with overcladding strategies. The life-cycle costs of the upgrades are determined for an existing building and compared with model energy performance. A life-cycle cost evaluation for the building envelope upgrades is provided, together with the payback period and the projected return on investment (ROI) for two energy escalation rate scenarios. A costbenefit matrix for various over-cladding strategies is provided to facilitate the evaluation of each option. Further, this thesis presents a simplified ROI algorithm to enable owners, architects and engineers to evaluate the cost-benefit of their building envelope retrofit options.
260

Problematik och lösningar vid våtrumsstambyten

Andersson, Magnus January 2008 (has links)
Litteraturstudier visar att det mellan år 1961 och 1970 byggdes 600 000 flerbostadshus i Sverige, tiden är nu inne för en renovering av dessa byggnaders våtrumsstammar. De tekniker som konkurrerar om de stora renoveringsarbetena är den klassiska stambytesrenoveringen, Relining och Prefab-badrum. Huvuddelen av denna uppsats utgörs av en undersökning av de tre teknikerna men rapporten beskriver också problem som kan uppstå vid renoveringar av våtrumsstammar och den ger en allmän redovisning för Sveriges byggnadsbestånd. Den klassiska stamrenoveringsmetoden, då det gamla badrummet rivs ut och ett nytt badrum byggs upp utifrån den gamla stommen, är ett omfattande och tidskrävande projekt. För att minimera bland annat kostnader, byggtid och byggavfall har man tagit fram nya, mindre tidskrävande tekniker. Så sent som år 1990 gjordes den första Relining renoveringen i Sverige. Denna är idag intakt vilket tyder på att livslängden för denna typ av renovering är minst 18 år. Tack vare att rören gjuts får de nya rören varken fogar eller skarvar, vilket minskar risken för fuktskador. Efter ett stambyte då man använt sig av Relining kan dock en mindre kunnig konsument tro att badrummet är intakt och kommer att så vara en lång tid framöver, men eftersom endast ledningarna renoveras, skulle detta kunna leda till att ett tätskikt kan fortsätta att läcka utan något ingrepp görs. Prefab-badrummen, vars teknik också är ny, bygger på att ett nytt badrum byggs i det gamla, vilket minimerar rivningsarbetet. När Rum i Rum AB renoverar badrummen använder de sig utav en ventilationsspalt för att eventuell framtida fukt ska kunna ventileras ut genom öppningen vid tröskeln in till badrummet. Detta är en prisvärd renovering som innefattar ett framtidstänkande, då eventuella läckor kan upptäckas direkt så några skador inte hinner bildas. Det finns dock en risk för en ”prefab” känsla ges, det vill säga mindre valmöjligheter när det gäller utformningen. Nu när miljonprogrammet kommer att behöva en stamrenovering anser jag att Prefab-badrummen är det bästa alternativet. De flesta av dessa badrum har liknande eller till och med samma utformning, vilket skulle gynna den utvecklade logistiken som finns inom Prefab-badrummen för att då hinna med all renovering som behövs.

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