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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.
51

Studies into Thermal Transmittance of Conventional and Alternative Building Materials and Associated with Building Thermal Performance

Balaji, N C January 2016 (has links) (PDF)
The present investigation is focused on the thermal performance of building materials, specifically their thermal transmittance, and consequent impact on building envelope and building thermal performance. Thermal performance of building materials plays a crucial role in regulating indoor thermal comfort when suitably integrated as part of the building envelope. Studies into thermal performance of building materials are few, particularly in the context of designing building blocks to achieve a particular thermal transmittance in buildings. Such studies require both theoretical (numerical) investigations augmented with experimental investigation into material thermal performance. A unique contribution of this study has been assessing the temperature-dependent performance of building material and their influence on thermal conductivity. The thermal performance of conventional and alternative (low energy) building materials have also been investigated to assess their suitability for naturally ventilated building in salient climatic zones in India. The study has also investigated the impact of varying mix proportions in Cement Stabilized Soil Block on thermal performance. There is little evidence of such studies, involving both experimental and theoretical studies, tracing the thermal performance of building materials to building performance. The current study involves three parts: studying thermo-physical properties of building materials, building-envelope performance evaluation and case-study investigation on buildings in various climatic zones. The thermo-physical study involves understanding the role of materials mix-proportion, composition, and microstructure for its influence on building-envelope thermal performance. Studies into building envelope performance for conventional and alternative building materials, includes, steady and dynamic thermal performance parameters. As part of the study, a calibrated hot-box thermal testing facility has been tested to experimentally determine the thermal performance of building envelopes. Case-study investigation involves real-time monitoring and simulation based assessment of naturally ventilated buildings in three climatic zones of India. The study finds noticeable temperature-dependent performance for various building materials tested. However, their impact on overall thermal performance of buildings is limited for the climatic zones tested. Further, the study validates the hitherto unexplored possibility of customizing building materials for specific thermal performances.
52

Experimental and Analytical Methodologies for Predicting Peak Loads on Building Envelopes and Roofing Systems

Asghari Mooneghi, Maryam 09 December 2014 (has links)
The performance of building envelopes and roofing systems significantly depends on accurate knowledge of wind loads and the response of envelope components under realistic wind conditions. Wind tunnel testing is a well-established practice to determine wind loads on structures. For small structures much larger model scales are needed than for large structures, to maintain modeling accuracy and minimize Reynolds number effects. In these circumstances the ability to obtain a large enough turbulence integral scale is usually compromised by the limited dimensions of the wind tunnel meaning that it is not possible to simulate the low frequency end of the turbulence spectrum. Such flows are called flows with Partial Turbulence Simulation. In this dissertation, the test procedure and scaling requirements for tests in partial turbulence simulation are discussed. A theoretical method is proposed for including the effects of low-frequency turbulences in the post-test analysis. In this theory the turbulence spectrum is divided into two distinct statistical processes, one at high frequencies which can be simulated in the wind tunnel, and one at low frequencies which can be treated in a quasi-steady manner. The joint probability of load resulting from the two processes is derived from which full-scale equivalent peak pressure coefficients can be obtained. The efficacy of the method is proved by comparing predicted data derived from tests on large-scale models of the Silsoe Cube and Texas-Tech University buildings in Wall of Wind facility at Florida International University with the available full-scale data. For multi-layer building envelopes such as rain-screen walls, roof pavers, and vented energy efficient walls not only peak wind loads but also their spatial gradients are important. Wind permeable roof claddings like roof pavers are not well dealt with in many existing building codes and standards. Large-scale experiments were carried out to investigate the wind loading on concrete pavers including wind blow-off tests and pressure measurements. Simplified guidelines were developed for design of loose-laid roof pavers against wind uplift. The guidelines are formatted so that use can be made of the existing information in codes and standards such as ASCE 7-10 on pressure coefficients on components and cladding.
53

Zdroje tepla pro vytápění občanské budovy / Heat Source for heating of Civil Building

Trajer, Štěpán January 2016 (has links)
The aim is to design an evaluate options for heating sytem for kindergarden with two floors. The project documention, investment cost and operating cost are included in this project.
54

Optimalizace nákladů provozní fáze stavebních objektů / Cost optimization of the operational phase of buildings

Kleinerová, Jana January 2016 (has links)
The thesis discusses the operating costs and the possibilities for their optimization. Specifically, it focuses on one of the greatest possible operating costs and it's heating costs. In the first part of the thesis are defined in general expenses, the price and the production, operating costs, optimization of these costs, life cycle of buildings and technological methods to improve the thermal and technical properties of the object. Finally, the theoretical part describes the terms for calculating the energy performance of the building and the payback period, which evaluates the effectiveness of investments. The practical part is assessed according to specific building energy performance, and especially in terms of its demand for heating. The building is designed for six variants of insulation, which is again judged on their energy performance. Subsequently these measures for better thermal insulating properties of the object assessed according to their cost efficiency and return on investment of individual variants.
55

Effective Thermal Resistance of Commercial Buildings Using Data Analysis of Whole-Building Electricity Data

Wang, Tian 04 June 2020 (has links)
No description available.
56

Srovnání nákladů na výstavbu budov z hlediska jejich pláště a způsobu vytápění / Comparison of costs for the construction of buildings in terms of their cladding and method of heating

Szturc, Jakub January 2022 (has links)
The thesis focuses on the cost comparison of the envelope compositions of a passive wood building depending on the type of thermal insulation used and the type of envelope composition. In the practical part, diffusion closed and diffusion open envelope compositions with different types of thermal insulation are proposed. The proposed compositions are priced and compared. The heating method and its costs are also marginally addressed.
57

Sustainable Construction? : A Study on Errors, Damages and Complexity in Construction / Bygger vi hållbart? : En studie av fel, skador och komplexitet i byggandet

Larsson, Per January 2020 (has links)
Topics on the environment and sustainability attracts ever more attention today, especially in the construction sector. In Sweden, the building- and housing industry answers for a significant share of the total energy consumption, waste production and greenhouse gas emissions. The construction sector is often depicted as conservative with a low rate of productivity and innovation. Sweden’s National Board of Housing, Building and Planning suggests that errors and damages in construction causes expenses corresponding to tens of thousands new housing units each year in Sweden. In a time of climate action and pursuit of more circularity in resource use this issue becomes a burning question. There is no doubt that the industry has adopted the increasing awareness on sustainability issues. Carbon emission levels and renewable energy is being measured as any other key performance indicator. The strive for increased sustainability in construction becomes relevant for any actor who wants to remain relevant on the market. Considering recent studies emphasizing errors, damages, and inadequacies in construction a relevant question to ask would be if the reality lives up to the ambitions of a sustainable building industry. This study investigates underlying factors causing errors and damages in construction. Development on sustainability matters is plotted in relation to how it has affected the industry. Chosen literature covers sustainability development, building errors and damages as well as complexity matters unique for the construction industry. The study’s literature review is balanced by multiple interviews and a survey conducted with industry working professionals. The results suggest that the development of errors and damages in construction has been stable in recent years. However, data collection thru interviews and surveys declares that most participants has experienced an increase in errors and damages. The distribution of information and knowledge regarding errors and damages in construction has increased, which may have caused a perceived increase of errors and damages. Whether increased focus on sustainability matters has affected the occurrence of errors and damages depends on which time span is being considered. Sustainability related adaptions of work methods and materials may give rise to errors and damages in the short term. Hence, the heightened sustainability focus together with a rapid development pace calls for caution when designing buildings. The study’s data collection suggests an increasing lack of competence regarding the design of buildings and contract documents. Ambiguous and more demanding requirements together with lack of general liability and competence supply is described as the most urgent issues affecting errors, damages, and deficiencies in construction. / Frågor som berör miljö- och hållbarhet får allt mer uppmärksamhet i samhället, inte minst inom byggsektorn. I Sverige står bygg- och fastighetssektorn för en betydande andel av landets totala energianvändning, avfallsproduktion och utsläpp av växthusgaser. Byggsektorn beskrivs traditionellt som konservativ och beskylls ofta för att ha en låg produktivitetsutveckling och innovationsgrad. Boverket hävdar att fel, skador och brister i byggandet orsakar kostnader motsvarande ett produktionsbortfall på tiotusentals bostäder i Sverige varje år. I en tid av klimatomställningar och strävan mot ett mer cirkulärt användande av naturresurser blir denna fråga ytterst relevant. Att branschens aktörer tagit till sig det ökande hålbarhetsfokuset råder det inga tvivel om. Företags koldioxidutsläpp och andel förnybar energi är nyckeltal som deklareras i allt högre utsträckning. Att bygga hållbart är en självklarhet för vilken aktör som helst som vill behålla sin position på marknaden. Med bakgrund i de studier som lyfter fram fel, skador och brister inom byggandet är det relevant att fråga sig ifall verkligheten lever upp till ambitionen om det hållbara byggandet. Denna studie undersöker bakomliggande orsaker till att det uppstår fel och skador i byggandet. Branschens utveckling kopplat till hållbarhetsfrågan kartläggs i syfte att identifiera hur den påverkat byggandet. Den litteratur som studerats berör hållbarhetsutveckling, byggfel och byggskadorsamt den komplexitet som ofta är unik för byggbranschen. Genom intervjuer med tjänstemän samt en enkätstudie med yrkesarbetare ges en verklighetsanknytning och avstämning mot aktuell litteratur. Studiens resultat påvisar att utvecklingen av byggfel och byggskador varit oförändrad i närtid. Inom ramen för studiens datainsamling uppger majoriteten av de tillfrågade att de upplevt en ökning av fel och skador. Samtidigt har information och spridning av upptäckta fel och skador i byggandet ökat, vilket i sig kan ha föranlett en upplevd ökning. Huruvida det ökade hållbarhetsfokuset inom byggsektorn har påverkat förekomsten av byggfel och byggskador beror på vilken tidshorisont som beaktas. Hållbarhetsrelaterade omställningar av arbetsmetoder och material riskerar att ge upphov till fel och skador på kort sikt. Med ökat fokus på hållbarhetsfrågor och snabb utveckling ökar behovet av att kunna se den långsiktiga hållbarheten vid valet av byggtekniska lösningar. Studiens datainsamling pekar på ökande kompetensbrist i fråga om byggnaders och byggbeskrivningars utformning. Tvetydiga och mer omfattande kravställningar i kombination med bristande helhetsansvar och kompetensförsörjning beskrivs som de största riskfaktorerna i fråga om fel, skador och brister i byggandet.
58

Lastbilsanläggning 2.0 : En hållbarhetsstudie inom energi av en specialiserad industribyggnad / Truck building 2.0 : A sustainability study within energy of a specialized industrial building

Hygerth, Karolina January 2018 (has links)
Industribyggnader är en del av den växande konsumtionen av energi enligt energimyndigheten i Sverige, vilket innebär att det sätts krav på energianvändningen. Därför finns det ett behov av att sänka energibehov och bygga med fokus på hållbarhet. Syftet med denna studie var att undersöka energianpassningar som främjar en ekonomisk hållbarhet. Undersökningen genomfördes som en fallstudie av en befintlig lastbilsanläggning, där möjliga energianpassningar efterforskades för att förbättra hållbarheten för byggnadens energibehov. De metoderna som användes var flera energi och miljöfokuserade multikriterieanalyser och energiberäkningar. Multikriterieanalyserna gav både ett förbättrat klimatskal och värmekälla, vilket bidrog till ett lägre energikrav för lastbilsanläggningen. Utöver energidirekta lösningar gjordes ytterligare ändringar för att utöka hållbarheten för byggnadens framtid i miljöfrågan, till exempel etablering av grönytefaktor. Slutsatsen för studien var att det är möjligt att bygga en energianpassad lastbilsanläggning, på ett ekonomiskt hållbart sätt. Genom att etablera ett bergvärmesystem och byta till miljömässigt hållbara material i klimatskalet, finns det en återbetalningstid för lastbilsanläggningen som visar på en ekonomisk hållbarhet efter ca 18 år. / Industrial buildings are a part of the growing consumption of energy, according to the Swedish Energy Agency, which imposes demands on energy use. Therefore, there is a demand to reduce energy requirements and build with a focus on sustainability. The purpose of this study was to investigate energy adaptations that promote economic sustainability. The study was conducted as a case study of an existing truck building, where possible energy adjustments were investigated to improve the sustainability of the building's energy demands.The methods used were several energy and environmental-focused multicriteria analyzes and energy calculations. Multicriteria analyzes gave both an improved building envelope and heat source, which contributed to a lower energy requirement for the building. In addition to energy-based solutions, further changes were made to extend the sustainability of the building's future in the environmental issue, such as the establishment of a greenfactor.The conclusion of the study was that it is possible to build an energy-efficient truck building in a economically sustainable way. By establishing a geothermal heating system and switching to environmentally sustainable materials in the building envelope, there is a pay-back time for the truck building which shows an economic sustainability after about 18 years.
59

Modélisation Bond Graphs en vue de l'Efficacité Énergétique du Bâtiment / Bond Graphs modeling in order to improve the energy efficiency in buildings

Merabtine, Abdelatif 19 November 2012 (has links)
L'objectif des travaux présentés dans ce mémoire concerne le développement d'un modèle global représentant le couplage de l'enveloppe du bâtiment avec les équipements énergétiques. Une approche systémique appelée les Bond Graphs, peu employée jusqu'ici dans la modélisation des systèmes thermiques, est utilisée. Le modèle global du bâtiment, regroupant sous le même environnement de simulation, les modèles de l'enveloppe du bâtiment, les apports solaires, les émetteurs de chauffage et de rafraîchissement et le système de ventilation, est développé pour reconstituer l'ensemble des articulations énergétiques entre l'enveloppe et les environnements intérieur et extérieur. A travers la modélisation d'un bâtiment multizone, le couplage systémique des modèles de l'enveloppe et des apports solaires est présenté. Par ailleurs, un système combinant un plancher chauffant et un plafond rafraîchissant est étudié à l'aide des modèles des émetteurs de chauffage et de rafraîchissement. Le renouvèlement d'air dans le bâtiment est également concerné par la modélisation Bond Graph. Enfin, des éléments de validation expérimentale sont présentés. Pour cela, la plateforme de tri-génération d'énergie ENERBAT est exploitée. L'objectif est d'étudier le couplage optimal enveloppe du bâtiment - équipements énergétiques pour lequel les modèles BG sont développés. Une étude paramétrique tenant compte des interactions entre les paramètres étudiés est menée sur un projet réel de rénovation. Finalement, une combinaison appropriée des paramètres étudiés a été retenue afin de réduire la consommation énergétique selon la réglementation thermique française (RT2012) / Our works focus on the setting of reliable tools able to analyze the interaction between the building envelope and HVAC systems. The developed approach is based on Bond Graphs methodology, a graphical modeling language which is particularly suitable for energy exchanges. A numerical model gathering, under the same simulation environment, sub-models representing the building envelope, the solar gains, the floor heating, the chilled ceiling and the ventilation system, is developed in order to predict the energy interactions between these sub-systems. The multi-zone building model is developed in order to simulate and analyze the overall building thermal behavior. Then, the solar gains model is also included to predict the solar radiation exchanges in a way close to reality. The model of the heating and cooling system, combining the floor heating and the chilled ceiling, is developed in order to improve the thermal comfort of the building. Afterwards, the ventilation system is modeled in order to represent the air exchange inside the building. The experimental validation is carried out on the tri-generation unit integrated with a thermal solar system (platform ENERBAT). Furthermore, the parametrical study was realized in order to gain a better understanding according to the impact of some factors in the energy performance of the single-family building located in Meurthe-et-Moselle region (France). Optimization of several measures, such as insulation of the building envelope, type of glazing, building orientation and ventilation system, is performed to respond to the requirements of the French thermal standard (RT2012)
60

Sistema de fixação e juntas em vedações verticais constituídas por placas cimentícias: estado da arte, desenvolvimento de um sistema e avaliação experimental. / Fixing system and joints in vertical enclosures consisting of fiber cement boards: state of the art, development of a system and experimental evaluation.

Fontenelle, João Heitzmann 23 May 2012 (has links)
A construção civil é o maior consumidor de recursos naturais do planeta, apropriando-se atualmente de mais da metade da massa total dos materiais extraídos. Neste contexto, o desenvolvimento de sistemas construtivos que proporcionem uma redução do consumo de materiais, conhecida como o princípio da desmaterialização dos edifícios, pode ser uma estratégia para a redução do impacto que a construção civil exerce sobre o ambiente, e um passo em direção a uma economia mais sustentável. A utilização de placas cimentícias para a produção de vedações vem crescendo em várias partes do mundo, seja para a produção de vedações verticais externas, seja como revestimento não aderido sobre vedos existentes, destinados tanto a melhoria estética quanto o desempenho destas fachadas. Uma vedação com placas cimentícias possui em torno de 25% da massa de uma alvenaria tradicional constituída por blocos de concreto para a execução de uma mesma área de vedação vertical, o que pode contribuir ainda para uma redução dos materiais empregados nas estruturas e fundações de um edifício. Apesar da utilização destas placas cimentícias estar coerente com a estratégia da desmaterialização, algumas experiências de vedações executadas com estes componentes manifestaram problemas de manutenção de suas características ao longo do tempo, apresentando fissuras geralmente nas juntas entre placas. Verificando-se as propriedades dos materiais que constituem esta placa cimentícia, principalmente a variação dimensional em relação à temperatura e umidade, constatou-se uma incompatibilidade entre a amplitude das variações dimensionais resultantes e os sistemas de fixação e juntas empregados para a sustentação das mesmas. A avaliação experimental de choque térmico comprovou a influência destas variações para a deterioração das juntas entre as placas. Com base nesta constatação, e em análises dos processos de fixação de placas cimentícias adotados por fornecedores em diversas partes do mundo, foi desenvolvido neste trabalho um novo sistema de fixação para placas cimentícias e de juntas entre estas com capacidade de atender a esta variação dimensional. Realizaram-se protótipos destes componentes os quais foram submetidos a uma avaliação experimental de choque térmico, resultando em nenhuma alteração visível nas juntas e nas superfícies destas placas. Como resultado concluiu-se que a criação de mecanismos que possibilitem acomodação às variações dimensionais, tanto nos dispositivos de fixação destas à estrutura, quanto nos acabamentos das juntas, podem contribuir significativamente para a durabilidade do sistema de vedações constituída por placas cimentícias. / The construction industry is the largest consumer of natural resources in the planet, currently appropriating more than half of mass of the total material extracted. In this context, the development of building systems that provide their dematerialization can be considered as a strategy to reduce the environmental construction impact, and a step toward a more sustainable economy. The use of fiber cement boards for the building production is growing in many parts of the world, to produce external vertical building enclosure or building envelopes, to improving the aesthetics and performance of these facades. A fiber cement board walls weigh around 25% of the traditional masonry mass made of concrete blocks for the same area of vertical building enclosure which can further contribute to a reduction of the materials used in building structures and foundations. Although the use of fiber cement boards complies with the dematerialization strategy, some experiments carried out with these cladding showed maintenance problems over time, usually cracks in the joints between panels. Checking the properties of materials constituting fiber cement boards, especially the dimensional variation due to changing temperature and humidity, there was an incompatibility between these dimensional variations amplitude and fixing systems and joints used to support them. The thermal shock experimental evaluation proved the influence of these variations on joints deterioration. Based on this observation, and on analyzes of the fiber cement suppliers recommendations over the world, a new system for fixing fiber cement board and joints between them was developed in this work with capacity to adapt to this dimensional variation. Prototypes of these components were made and submitted the thermal shock evaluation, resulting in no visible changes in the joints and on the surfaces of these panels. As a result, it was concluded that the creation of mechanisms that allow accommodating the dimensional variations, both in fixing these panels to the structure, and in the joints finishing can significantly contribute to the vertical building enclosure system durability.

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