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Investigation of a novel multifunctional roof panel for hybrid photovoltaic/thermal/daylight application in atrium and large green houseYu, Xu January 2015 (has links)
Daylight is an energy efficient solution for illumination and visual comfort in buildings. However, successful daylight design requires effective daylight control technology to eliminate the negative impact such as overheating, unbalanced indoor daylight distribution and glare. With this mind, the current thesis presents a novel multifunctional roof panel which might be applied in atrium and large green house. The working principle of the panel is based on the non-imaging low-concentration solar collector: dielectric Compound Parabolic Concentrator (CPC). Detailed study on the dielectric CPC has found that there would be some light escaping from side wall of CPC when the incident light is beyond CPC acceptance angle, which could actually be used for indoor daylight provision; while the incident light concentrated on the base of CPC could be used for concentrating PV application. Thus a dielectric CPC panel which consists of several trough dielectric CPC rods is designed and manufactured, its function of hybrid PV/Daylight is investigated through PHOTOPIA simulation and outdoor testing, both simulated and measured results showed that under sunny condition, only 10-15% of light could be transmitted through the panel in cooling season, and the rest of the light is used for concentrating PV application; while light transmittance of about 40-60% is achievable in winter period, when daylight is desired. Additionally, constant light transmittance of about 40% is achievable under overcast sky. The above figures could verify the seasonal daylight control ability of the panel. On the other hand, for the designed panel, the rejected heat on PV could still flow into the building. As a result, a PV/Thermal system is designed to remove the rejected heat on PV cell and reutilize it for thermal application such as food drying. The design parameter such as approach velocity, pitch distance, and perforation porosity are numerically investigated by CFD simulation. The prototype of the system is built and measured under solar simulator and real sky. Both simulated and measurement results showed that the heat recovery efficiency could be 40-80% depending on different geometries and approach velocities; and little amount of rejected heat could transfer from the PV cell to the building interior. The hybrid PV/Thermal application seems to be achievable. Lastly, the energy and economic performance for the EW-orientated dielectric CPC panel is investigated using new proposed concept of “inner south projection angle” and its correlation with the CPC optical performance, the building energy simulation software EnergyPlus and its weather data are also employed. An example case on an educational building with a central atrium in Nottingham shows that: compared to the conventional double glazing window, there is 55% increase in useful daylight illuminance (500-2000lux) percentage; 81.5% reduction in window solar heat gain in cooling season and only 10.78% reduction in window solar heat gain in heating season; there is also a power generation of 290.65W/m2 from PV cells; and the estimated payback period is less than 5 years. Therefore, the proposed multifunctional roof panel for PV/Thermal/Daylight application could comprehensively utilise the solar energy and provide comfort thermal and visual indoor environment.
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An investigation into curriculum alignment in building construction curriculaBennett, Sandra 05 September 2005 (has links)
The nature of objectives of vocational education and training (VET) in Botswana identifies it as a national strategy aimed at augmenting economic growth and development. This assigns importance to investments on VET as a form of investment in human capital targeted at the economy and specifically to meet labour market needs. Thus, educational accountability, prompted by economic, technological and structural changes is of great importance to the major stakeholders of VET. This research examines a VET curriculum, specifically the Botswana Technical Education Programme-building construction curriculum, in regard to the degree of alignment between the curricula and the training needs of the building construction curricula. At the core of the research is the need to investigate the fitness for purpose of the curricula designed to provide skilled manpower to the building and construction industry. The research results indicates that: <ul> <li>-- there is a sharp contrast between the broad occupational needs of the industry and the focus of the written curriculum. The written curriculum is skewed towards the provision of training at the unskilled occupation levels while the human resource needs of the industry are within the technical and professional skilled occupational areas;</li> <li>-- vocational educators have developed the written curriculum at the micro level of the building construction industry, while the industry requires programmes to address macro level goals of the industry;</li> <li>-- the BTEP validation model presented responds to concerns of internal quality control processes in curriculum development (performing various vetting functions on the document). It does not provide overall guidance for alignment strategies to be used to ensure alignment of the curriculum and the training needs of the industry;</li> <li>-- the tension between employers from the industry on the one hand, and vocational educators on the other, stems from criticisms that vocational programmes are out¨Cof-touch with the realities of the industry;</li> <li>-- VET educators are not acting as brokers of government policy. Government has a very clear policy on the role and purpose of VET and has provided a direction for the role of VET in this regard.</li> </ul> Further research needs to be concerned with the wider economic implications of having a supply driven VET sector as opposed to, at minimum, striving to create a balance between the supply and demand side of vocational training. The VET sector in Botswana also needs to be concerned with building industry/education partnerships to address issues of workforce development. Future research needs to identify ways in which VET educators can maintain currency of knowledge and thus keep VET curriculum relevant. Copyright 2005, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Bennett, S 2005, An investigation into curriculum alignment in building construction curricula, MEd dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-09052005-100444 / > / Dissertation (MEd (Curriculum and Instructional Design and Development))--University of Pretoria, 2006. / Curriculum Studies / unrestricted
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A performance evaluation of mainstream timber framed and traditional masonry housing in the UKBailey, David January 2016 (has links)
Within the UK traditional masonry construction techniques are struggling to deliver the quantity and ecological quality of housing required by an ever increasing UK population. This research employs a case study review of a mainstream mixed timber frame and masonry housing development - Green Street, in order to explore the ecological viability of timber prefabrication as an alternative to the established masonry construction methods currently employed in the majority of British housing. Four houses of each construction type in the Green Street development were outfitted with a number of environmental monitoring sensors for continuous monitoring. In addition the study incorporates fabric testing in the form of air permeability testing, Co-heating analysis, thermography, and a life cycle analysis. Building Use Survey, project management and design team interviews and an industry questionnaire form the final part of the evaluation protocol. The study revealed that heating the timber dwellings ultimately required less energy per degree difference between inside and outside temperatures. During the summer the timber housing displays a greater diurnal temperature swing, while on average the temperature remains consistently lower than the masonry housing. The masonry housing was found to be both more air tight and exhibiting a lower heat loss coefficient, despite that, the performance gap between design and reality for space heating is less in the timber prefabricated housing. The life cycle analysis revealed that the timber walls have a lower impact on climate change. BUS methodology results found that construction type had little to no impact on occupants. The design team review highlighted the need for a greater level of prefabrication in timber housing to increase precision and work around a serious skills shortage. An industry questionnaire suggested that timber construction in the UK can often suffer from poor construction practice, predicated by a gap in specialized knowledge. The research concludes that in this instance, the timber prefabrication technique produced dwellings that perform ecologically on par with their masonry counterparts. In answering the research question, the evidence suggests that at this stage the technique would be better employed on a case by case basis and supported by specialists in timber fabrication, rather than implemented as a blanket alternative for existing masonry construction. Already a number of insights from this research have filtered into industry practice and will continue to better inform both industrial and academic partners in their decisions regarding the use of timber prefabrication in mainstream UK housing.
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CornerSchnödt, Heinrich 31 July 2007 (has links)
The premise of this thesis is that architecture indeed superseded the act of ordinary building. Beyond the idea of shelter or utilitarian accommodation, architecture is the art of embedding or encoding substantial humanist values which result in the form of the man-made architectural object. / Master of Architecture
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Generalizable surrogate models for the improved early-stage exploration of structural design alternatives in building constructionNourbakhsh, Mehdi 27 May 2016 (has links)
The optimization of complex structures is extremely time consuming. To obtain their optimization results, researchers often wait for several hours and even days. Then, if they have to make a slight change in their input parameters, they must run their optimization problem again. This iterative process of defining a problem and finding a set of optimized solutions may take several days and sometimes several weeks. Therefore, to reduce optimization time, researchers have developed various approximation-based models that predict the results of time-consuming analysis. These simple analytical models, known as “meta- or surrogate models,” are based on data available from limited analysis runs. These “models of the model” seek to approximate computation-intensive functions within a considerably shorter time than expensive simulation codes that require significant computing power. One of the limitations of metamodels (or interchangeably surrogate models) developed for the structural approximation of trusses and space frames is lack of generalizability. Since such metamodels are exclusively designed for a specific structure, they can predict the performance of only the structures for which they are designed. For instance, if a metamodel is designed for a ten-bar truss, it cannot predict the analysis results of another ten-bar truss with different boundary conditions. In addition, they cannot be re-used if the topology of a structure changes (e.g., from a ten-bar truss to a 12-bar truss). If designers change the topology, they must generate new sample data and re-train their model. Therefore, the predictability of these exclusive models is limited. From a combination of the analysis of data from structures with various geometries, the objective of this study is to create, test, and validate generalizable metamodels that predict the results of finite element analysis. Developing these models requires two main steps: feature generation and model creation. In the first step, involving the use of 11 features for nodes and three for members, the physical representation of four types of domes, slabs, and walls were transformed into numerical values. Then, by randomly varying the cross-sectional area, the stress value of each member was recorded. In the second step, these feature vectors were used to create, test, and verify various metamodels in an examination of four hypotheses. The results of the hypotheses show that with generalizable metamodels, the analysis of data from various structures can be combined and used for predicting the performance of the members of structures or new structures within the same class of geometry. For instance, given the same radius for all domes, a metamodel generated from the analysis of data from a 700-, 980-, and 1,525-member dome can predict the structural performance of the members of these domes or a new dome with 250 members. In addition, the results show that generalizable metamodels are able to more closely predict the results of a finite element analysis than metamodels exclusively created for a specific structure.
A case study was selected to examine the application of generalizable metamodels for the early-stage exploration of structural design alternatives in a construction project. The results illustrates that the optimization with generalizable metamodels reduces the time and cost of the project, fostering more efficient planning and more rapid decision-making by architects, contractors, and engineers at the early stage of construction projects.
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Domestic sustainable and low energy design in hot climatic regionsAldossary, Naief January 2015 (has links)
Low energy building methods, and the corresponding economic and environmental aspects, are an important area of consideration in many developed countries. Saudi Arabia characterized by its hot climates and geographical location in a global region renowned for its high energy consumption and carbon emission rates. Consequently, this research aims to foster the development of low energy housing in Saudi Arabia and establish a low carbon domestic design framework for Saudi Arabia that takes into account the local climatic conditions, context and socio-cultural challenges. In order to fulfil the above stated aims, this research establishes a definition system for low energy consumption in kWh/m² for the Saudi Arabian climate. To achieve the aims stated above, a comprehensive, four stage study has been performed. This investigation has attempted to: (a) identify factors resulting in high energy consumption in domestic buildings in Saudi Arabia; (b) identify the weaknesses of housing design in terms of architectural layouts and mass, house envelope design and construction materials used, and on-site renewable energy strategies; (c) establish and develop a low carbon domestic design framework that supports architects, civil engineers and building professionals in the design of sustainable homes for the Saudi Arabian climate, context and cultural requirements; and (d) propose three different, viable housing prototypes employing the established framework, thereby validating that framework through the identification of their energy consumption levels. Each stage of this research utilizes a specific methodology: public survey analysis; site visits and modeling analysis; expert consultation, using the Delphi technique approach; and the validation analysis approach. This study contributes to the body of knowledge within this field by offering a low carbon domestic framework for the design of low energy homes in Saudi Arabia. These findings are broadly applicable to other regions with similar climatic conditions and cultural requirements, such as those in the Middle East and GCC countries. The findings suggest that an energy reduction of up to 71.6 % is possible. Therefore, the system for low energy consumption level standards is suggested as a range between 77 kWh/m² and 98 kWh/m². The comprehensive economic and environmental benefits of these reductions have been analysed and benchmarked against the current situation in selected developed countries.
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Concrete crack width under combined reinforcement corrosion and applied loadYang, Shangtong January 2010 (has links)
For reinforced concrete structures subjected to chlorides, carbon dioxide laden and other aggressive environments, corrosion of the reinforcing steel is seen as a global problem. Maintenance and repairs resulting primarily from premature concrete cracking and spalling have an estimated cost running to $100 billion per annum world-wide. The continual demands for greater load carrying capacity of existing infrastructure only exacerbate the problem. In practice, concrete crack width propagation is seen as one of the most important criteria for design and assessment of the long term serviceability of concrete structures. It is therefore economically beneficial to have a fundamental understanding of the growth of the crack width over time so that better informed decisions can be made regarding the carrying out of any repairs. This research attempts to examine the process of concrete cracking and determine the surface crack width of concrete structures under the combined effects of reinforcement corrosion and applied load in both an analytical and numerical manner. In the analytical method, a model for stiffness reduction of cracked concrete has been derived based on the concept of fracture energy and an analytical solution has been obtained. In the numerical method, an interfacial element has been developed to predict concrete crack width under combined effects based on a cohesive crack model in conjunction with finite element codes. To help accurate prediction of crack width in the numerical method, a realistic constitutive relationship for concrete under direct tension has been obtained from the laboratory experiments. It is concluded in this thesis that both the analytical and numerical methods are one of very few available theoretical methods that can predict with reasonable accuracy concrete crack width of reinforced concrete structures under the combined effects of reinforcement corrosion and applied load. This research focuses on concrete cracking caused by reinforcement corrosion and applied load without considering other factors, e.g., weathering, freeze-thaw and chemical attack. Both methods can be used as a tool to assess the serviceability of corrosion affected concrete infrastructure if reinforcement corrosion and applied load are the main causal factors of concrete cracking. For this type of concrete structures, therefore, scientific information can be provided for asset managers in decision making regarding possible interventions. Timely interventions have the potential to prolong the service life of reinforced concrete structures.
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The integrated design of new build multi vector energy supply schemesRees, Marc January 2012 (has links)
Future energy supply infrastructure schemes for the built environment are set to consist of a diverse mix of distributed generation technologies, increasingly stringent local emissions reduction targets, and potentially complex ownership structures. This thesis presents a new modelling method that integrates technical design, green house gas emissions analysis and financial analysis models for new build multi energy vector systems. The model was used to compare and characterise several alternative heating technology options for the carbon constrained design of a generic UK market town residential development. Of the options examined, natural gas combined heat and power based district heating was shown to provide the least cost solution for projects built before 2020. Beyond 2025, electric heat pumps provided the cheapest option in response to the decarbonisation of the grid supplied electricity. The integrated model was used as the basis of an optimised infrastructure design tool. This was applied to determine the least cost energy supply technology mix for a new build community redevelopment scheme at Ebbw Vale, South Wales. It was shown that both the optimal design and corresponding optimal cost is dependent upon the year of build completion for the project and the
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BIM-based smart compliance checking to enhance environmental sustainabilityKasim, Tala January 2015 (has links)
The construction industry has been facing immense challenges to move towards more- sustainable buildings with minimum harm to the environment. The building design and construction process is conditioned by numerous sustainability regulations and assessment measures, to promote sustainable construction. These regulations are continuously expanding in their requirements, and incorporating a huge amount of data that needs to be rigorously dealt with, in order to check compliance and asses the performance Building Information Modelling (BIM) promotes the effective information and process integration across the building life-cycle and supply chain. This integration should comply with an increasingly-complex regulatory environment and statutory requirements. The aim of this thesis is to improve and facilitate the sustainability compliance checking process, by focusing on inter-operability between existing methods of compliance checking and building information modelling. This thesis presents a generic approach for BIM based compliance checking against standards and regulations, with a particular focus on sustainable design and procurement. To achieve this, a methodology has been developed to enable automated sustainability compliance checking. This involves (a) extracting regulatory requirements from sustainability-related regulations available in textual format; (b) converting these into BIM- compatible rules; (c) processing these rules through a dedicated rule-based service; and (d) performing regulatory compliance analysis underpinned by the concept of BIM. A semantic extension of the IFC (Industrial Foundation Classes) for sustainability compliance checking has been developed. The outcome of the research was implemented in the RegBIM project and is in the process of being exploited as an online service by industrial organization, the Building Research Establishment (BRE) in the UK.
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Diretrizes para a elaboração de um modelo de gestão dos fluxos de informações como suporte à logística em empresas construtoras de edifícios. / Guidelines for elaborating an information flow model as a support to the logistics in building construction firms.Villagarcia Zegarra, Sofia Lilianne 19 December 2000 (has links)
Este trabalho objetiva propor diretrizes para a elaboração de um modelo de gestão de fluxo de informações como suporte à logística em empresas construtoras de edifícios. O foco da pesquisa limita-se especificamente à gestão de materiais, apesar da logística também abranger mão-de-obra, serviços e equipamentos. O objetivo da gestão de materiais é o de assegurar um fluxo continuo e sem interferências de materiais e componentes à obra, na quantidade requerida, com a qualidade especificada, no tempo e lugar certo, ao menor custo total. Estas diretrizes foram identificadas visando a uma integração funcional dentro da empresa construtora. Com base em um estudo de caso realizado em três empresas construtoras e em um levantamento e estudo bibliográfico, foram estudados os fluxos de informações ligados à gestão de materiais que ocorrem dentro das empresas construtoras. Desta maneira, identificaram-se os principais fatores que facilitam e que dificultam os fluxos de informações entre agentes relacionados com a gestão de materiais. Uma vez analisados estes fatores, foram identificadas as diretrizes objeto desta pesquisa e foi proposto um fluxo de informações modelo baseado exclusivamente nos casos estudados. Adicionalmente, foram discutidos alguns parâmetros a se levar em conta para avaliar o modelo proposto e conseguir uma melhoria continua dentro do processo. Também, foi brevemente discutida a forma como as parcerias com os fornecedores, o uso de produtos normalizados, a Internet e os códigos de barras poderiam inovar estes fluxos de informações e conseguir a integração tão almejada na cadeia de suprimentos. / This research aims to identify guidelines for developing an information flow management model to support materials management in building construction firms. The main purpose of building materials management is to have the required materials at the right place, at the right time, in the right quantity without prejudicing cost and quality. These guidelines were identified considering a functional integration within the construction firm. Based on three case studies developed in construction firms and a literature review, the materials management information flows inside the construction firm were studied. In this way, the principal factors that affect or enhance these information flows were analyzed. Once analyzed these factors, we were able to determine the best arrange for these flows and identify the guidelines and propose an information flow model based exclusively in the three cases studied. Besides this, we discussed the parameters that should be taken into account to guarantee a continuous improvement in the model proposed. Finally, we briefly discuss how partnering with suppliers, the use of normalized products, the Internet and the use of code bars could innovate traditional information flows and integrate the supply chain.
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