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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.
11

Método para redução de mancha nas vedações externas de edifícios. / Method to reduce soiling deposition on building envelope.

Maranhão, Flávio Leal 11 December 2009 (has links)
O permanente contato das vedações externas dos edifícios com os materiais integrantes das vedações externas dos edifícios (fachadas e telhados) com os agentes de degradação provocam o surgimento de manchas, que normalmente estão associadas à deposição de poluentes e a proliferação de microorganismos. Para inibir o surgimento dessas manchas existem, atualmente, diversos métodos disponíveis, sendo que nenhum tem se mostrado efetivo. Esta tese de doutorado, com base em um extenso programa laboratorial - com o uso de métodos como MEV, FTIR, ângulo de contato, crescimento acelerado de microrganismos, atividade fotocatalítica, entre outros-, criou um novo método, destinado aos materiais de construção silicosos e porosos, que se baseia na modificação de suas propriedades superficiais, por meio da sobreposição de uma camada hidrofóbica por uma hidrofílica. Para se obter essa disposição superficial, utilizou-se um hidrofugante à de octil-silicone, que apresenta elevada repelência à água e maior durabilidade, e um semicondutor à base de dióxido de titânio, que apresenta atividade fotocatalítica quando incidido por radiação ultravioleta. Como resultado, o método proposto (denominado na tese por WR+TiO2-sequencial) apresenta, comprovadamente, os seguintes benefícios: (i) redução de manchas causadas pela adesão de partículas com características apolares, similares às partículas de poluição dos grandes centros urbanos; (ii) limpeza espontânea de certos tipos de manchas, decorrentes dos processos fotocatalíticos que promovem a oxidação/redução de matéria orgânica; (iii) inibição do crescimento de microrganismo em escala laboratorial; (iv) redução da absorção total de água e, principalmente, da cinética do ganho de massa. Por isso, edificações cujas vedações externas venham a ser tratadas com o método aqui proposto são, potencialmente, células ativas para a sustentabilidade do ambiente construído, pois: reduzem o consumo de energia, reduz os custos de manutenção e contribuem para despoluição da atmosfera urbana. / Building roofs and façades usually show blackening surfaces after few years in large cities. On porous and silicious materials those soiling is caused by particles pollution depositions and mould growth, and the available methods available to prevent this phenomenum do not have a good performance along its service life. This thesis, based on an intensive laboratory research with many test technics as SEM, FTIR, contact angle, accelerated mould growth, and photocatalytical activity, create a new method to prevent soiling on porous and silicous building materials. This method modify the materials surface properties, making the outer surface layers with nano-actived titanium dioxide particles, which has photocatalitycal activity under UV radiation, and below it a hydrophobic layer, composed by octyl-silicones. The main results in laboratory scale experiments obtained by this new method (so-called in this thesis by WR+TiO2-sequencial) are: (i) stainings reductions caused by apolar agent, (ii) self-cleaning properties for some stain and after UV radiation exposition, (iii) mould growth resistance, and (iv) water absorption reduction. As a consequences, building envelopes trated with the new method is supposed to contribute to built and environment sustantability, because: can reduce the energy consumption, reduce de maintenance costs e has a de-pollution properties.
12

Simulação energética para análise da arquitetura de edifícios de escritório além da comprovação de conformidade com códigos de desempenho / Building performance simulation for analysis of the architecture of office buildings beyond code compliance checking

Cavalcante, Rodrigo de Castro Dantas 07 April 2010 (has links)
No Brasil e em São Paulo, a ASHRAE Standard 90.1 Energy Standard for Buildings Except Low-Rise Residential Buildings ganhou rápida aceitação nos últimos anos. A norma é referenciada pelo sistema de certificação Leadership in Energy and Environmental Design - LEED para estabelecer padrões mínimos de desempenho energético. Apesar do desenvolvimento de atividade de consultoria para comprovação de conformidade com esse código, a consultoria tem se limitado a intervir no projeto de arquitetura após sua concepção. A fim de investigar a influência da arquitetura no desempenho de edifícios de escritório e justificar a consultoria desde as primeiras etapas do projeto, o desempenho de uma série de modelos é estimado com auxílio da ferramenta de simulação computacional EnergyPlus. As alternativas avaliadas incluem diferentes percentagens de área de fachada envidraçada, propriedades ópticas e térmicas dos fechamentos transparentes, persianas automatizadas, orientação do edifício e proporções do pavimento tipo. Os resultados comprovaram a influência da arquitetura no desempenho energético de edifícios de escritório. Portanto, as decisões tomadas durante a fase de concepção do projeto têm impacto considerável no desempenho final do edifício e, apesar do tempo e dos esforços necessários, devem ser estudadas. / In Brazil and Sao Paulo, ASHRAE Standard 90.1 Energy Standard for Buildings Except Low-Rise Residential Buildings has rapidly gained acceptance in recent years. The standard is referred by the Leadership in Energy and Environmental Design - LEED rating system to set minimum energy performance levels. Although consulting activity was developed to demonstrate compliance to the code, it has been limited to intervene in the architectural design after its conception. With the aim of investigating the influence of architecture on the performance of office buildings and justify the consultancy since early design stages, the performance of a set of models is estimated using EnergyPlus computer simulation tool. The assessed alternatives include different Window-to-Wall Ratios - WWR, optical and thermal properties of glazing systems, automated roller shades, building orientation and proportions of typical floors. The results confirmed the influence of architecture on the energy performance of office buildings. Therefore, decisions taken during early design stages have considerable impact on the final performance of buildings and, despite the time and effort involved, should be studied.
13

Simulação energética para análise da arquitetura de edifícios de escritório além da comprovação de conformidade com códigos de desempenho / Building performance simulation for analysis of the architecture of office buildings beyond code compliance checking

Rodrigo de Castro Dantas Cavalcante 07 April 2010 (has links)
No Brasil e em São Paulo, a ASHRAE Standard 90.1 Energy Standard for Buildings Except Low-Rise Residential Buildings ganhou rápida aceitação nos últimos anos. A norma é referenciada pelo sistema de certificação Leadership in Energy and Environmental Design - LEED para estabelecer padrões mínimos de desempenho energético. Apesar do desenvolvimento de atividade de consultoria para comprovação de conformidade com esse código, a consultoria tem se limitado a intervir no projeto de arquitetura após sua concepção. A fim de investigar a influência da arquitetura no desempenho de edifícios de escritório e justificar a consultoria desde as primeiras etapas do projeto, o desempenho de uma série de modelos é estimado com auxílio da ferramenta de simulação computacional EnergyPlus. As alternativas avaliadas incluem diferentes percentagens de área de fachada envidraçada, propriedades ópticas e térmicas dos fechamentos transparentes, persianas automatizadas, orientação do edifício e proporções do pavimento tipo. Os resultados comprovaram a influência da arquitetura no desempenho energético de edifícios de escritório. Portanto, as decisões tomadas durante a fase de concepção do projeto têm impacto considerável no desempenho final do edifício e, apesar do tempo e dos esforços necessários, devem ser estudadas. / In Brazil and Sao Paulo, ASHRAE Standard 90.1 Energy Standard for Buildings Except Low-Rise Residential Buildings has rapidly gained acceptance in recent years. The standard is referred by the Leadership in Energy and Environmental Design - LEED rating system to set minimum energy performance levels. Although consulting activity was developed to demonstrate compliance to the code, it has been limited to intervene in the architectural design after its conception. With the aim of investigating the influence of architecture on the performance of office buildings and justify the consultancy since early design stages, the performance of a set of models is estimated using EnergyPlus computer simulation tool. The assessed alternatives include different Window-to-Wall Ratios - WWR, optical and thermal properties of glazing systems, automated roller shades, building orientation and proportions of typical floors. The results confirmed the influence of architecture on the energy performance of office buildings. Therefore, decisions taken during early design stages have considerable impact on the final performance of buildings and, despite the time and effort involved, should be studied.
14

Use of Drone and Infrared Camera for a Campus Building Envelope Study

Ariwoola, Raheem Taiwo 01 May 2016 (has links)
Presently, there are concerns that buildings in the USA under-performs in terms of energy efficiency when compared with the original design specifications. A significant percentage of the energy loss in these buildings is associated with the building’s envelope. This study provides a qualitative and analytical understanding of the R-value, which indicates the thermal performance of the elements that make up a building envelope. Infrared thermography is used as a methodology to assess the thermal performance of envelopes of ten buildings on East Tennessee State University Campus. A Fluke Ti25 infrared hand-held camera and a DJI phantom-2 drone mounted with FLIR Vue Pro infrared camera were used for data collection. Data analyses were carried out using ‘Smartview’ and ‘FLIR Reporter Pro’ software. The data analyses revealed energy loss, insulation deficiencies, the associated energy costs of the inefficiencies and the potential savings that could result from correcting these deficiencies in the evaluated building’s envelopes.
15

Simulations of Design Modifications in Military Health Facilities

Kiss, Christopher William 2011 May 1900 (has links)
The Military Health System (MHS) is a worldwide network of healthcare facilities and personnel. The healthcare facility inventory is aging and requires extensive facility management, renovations and replacement construction to maintain the environment of a high quality of care. Recent developments in sustainability and evidence-based design (EBD) have created additional requirements for the design and construction of facilities. These areas of design emphasis, sustainability and EBD, are developing best practices according to the respective theory. Existing facilities in the MHS have been directed to undergo restoration and modernization by Department of Defense (DoD) civilian leadership. Governmental directives have mandated that these restorations and new construction complies with current building codes and that EBD design features be included in healthcare facility planning. The hospital building type has changed over history due to innovations in building technology, such as HVAC and steel frame construction, as well as healthcare initiatives, such as treatment of tuberculosis and the mentally ill. The design concepts of environmental sustainability and EBD are currently altering the hospital typology. Building professionals have found significant differences in facilities that are categorized as evidence-based and those noted as sustainable. The future of successful healthcare designs relies on a balance of these concepts. The hospital building type has one of the highest energy intensities out of all commercial building types. Hospitals have become more energy intense due to the evolution of the deep-plan hospital. The design of the building envelope is the most lasting feature affecting the energy use of a hospital, due to its service-life typically equaling the life of the facility. The building envelope design consists of the shape of the building, material selection, as well as its orientation. This research demonstrates the relationship between incorporating positive building occupant features, such as increased day lighting and views of nature, and efficient energy design choices. The use of energy simulation software and early design collaboration between multiple professional disciplines is recognized as critical to optimal design solutions.
16

An Analysis Of The Thermal Performance Of Metu Staff Housing Units And Calibration Of Their Simulated Model

Bagci, Mediha Ozlem 01 June 2008 (has links) (PDF)
The aim of this study was to investigate the thermal performance of residential units in the Middle East Technical University (METU) Campus, Ankara. The study was conducted on the unoccupied residential units to eliminate the occupant interventions. There were only three unoccupied residential units in the study period, hence sample was considered as randomly selected. Case study units were triplex row houses and all physical characteristics were identical apart from their orientations. The thermal performance of these three residential units was assessed by compiling data on temperature and relative humidity from a number of their rooms on certain days in January and February. The study was conducted in winter months, because heating loads are more significant than cooling loads for energy consumption in Ankara / the measurement period was determined according to the coldest days of the year. In this context, the temperature and humidity charts were evaluated and one of the units was simulated using the software tool Ecotect v.5.20. The simulation temperature charts demonstrate similar behavior and trends as the measured temperature / although, it was approximately 4 0C lower than the measured temperature. The possible reason for such a difference may be the precision of the material properties. Six different calibrations were tested by changing the thermal properties of the envelope materials to obtain comparable results with the measured temperature readings. Based on the calibrated model, it was found that an increase in the U-value of the envelope materials did not have a significant effect on the simulated temperature charts.
17

Tätskikt i klimatskal : En studie av byggentreprenörers arbetssätt

Nilsson, Tim January 2013 (has links)
As energy prices skyrocket and the environmental issues become more frequently debated, interest in energy-efficient buildings has increased sharply in the past decade. Because of this, the interest to achieve high air tightness in building envelopes have once again awakened, due to a good air tightness contributes to lower energy consumption in several ways and to a healthier indoor environment. As the regulations for energy consumption and controls of achieved air tightness has tightened considerably in recent years, the work regarding sheets for air tightness changed significantly for construction contractors. This thesis includes a study that aims to detect what kind of manuals, recommendations or instructions contractors working according, and how a number of randomly selected construction companies in Halland, Sweden, are dealing with the matter of high air tightness of the building envelopes. The study also includes a knowledge inventory of supervisors, site managers and skilled workers, and what their opinions and attitudes are like towards work regarding the sheets of air tightness. The results have been compared with a similar survey dated to 2004, conducted by the SP Technical Research Institute of Sweden in collaboration with Chalmers University of Technology. The thesis provides a picture of the industry situation, but shouldn’t be seen as a statistical result due to its limited extent.
18

Assessing Thermal Performance Of Office Building Envelopes / A Case Study On Energy Efficiency

Surmeli, Ayse Nesen 01 June 2004 (has links) (PDF)
In this study, the energy conservation potential of selected retrofitting interventions on an office building were investigated, on the basis of which some rational strategies for the improvement of building envelopes in terms of energy, environment and comfort design were proposed. Examined were various measures on envelope constructions that can be retrofitted to existing buildings. By using simulation techniques, the effectiveness of such measures in reducing energy consumption and environmental threat were also assessed. Effects of glazing types, effect of insulation and thermal mass were analyzed as energy efficient retrofit measures to the Engineering Building (MM building) situated on Middle East Technical University Campus, Ankara. The Energy-10 computer program was used for the modeling and simulation of the energy flows through the envelope to examine measures for reducing thermal load. Within this framework, the energy conservation potential of single and combined retrofitting actions was investigated. Based on results from the evaluation model, it was found that a saving of 161.20 MWh in the annual heating load could result, depending on the glazing type. The evaluation showed that thermal insulation is the most effective factor in thermal performance when placed as an exterior layer on walls. The study showed thermal mass has significant impact on increasing the duration, where highest temperatures were achieved, under passive mode. The study also revealed that applying a combination of retrofitting measures which responded to the challenges and opportunities presented by different fa&ccedil / ade orientations, a saving of 52.41% can be achieved in annual heating energy use in case study building.
19

Modélisation des transferts d’air et leur impact sur le comportement hygrothermique de l'enveloppe des bâtiments / Air flow modelling and coupling with hygrothermal transfer in building envelopes

Belleudy, Clément 23 February 2016 (has links)
Dans un contexte de durcissement des règlementations thermiques, la maîtrise de l'étanchéité à l'air des bâtiments est essentielle pour atteindre les objectifs de consommation énergétique. Les fuites d'air parasites à travers l'enveloppe, dues aux défauts de conception ou à une mauvaise mise en oeuvre, mènent à une surconsommation énergétique, mais aussi à des pathologies liées à l'humidité, mettant en péril la durabilité du bâti et la santé des occupants. Le risque lié à l'humidité est particulièrement présent dans les cas des enveloppes légères à ossature bois, sensibles aux transferts d'air.Il est donc nécessaire de mieux comprendre et de quantifier l'impact de ces transferts d'air sur le champ hygrothermique et sur le flux de chaleur au niveau d'un défaut d'étanchéité. Dans ce but, deux modèles numériques traitant les transferts couplés 'air-chaleur' et couplés 'air-chaleur-humidité' sont développés. Le second modèle est d'abord validé en 1D à l'aide de benchmarks numériques. Ensuite, des mesures de température dans un isolant en ouate de cellulose traversé par un flux d'air humide sont comparées avec les sorties des modèles. Une bonne concordance mesures-modèles est obtenue. Le modèle 'air-chaleur-humidité' s'avère plus précis pour prédire le champ de température que le modèle 'air-chaleur'.Suite à cette validation 2D du modèle couplé 'air-chaleur-humidité', celui-ci est appliqué à une géométrie de défaut complexe, mettant en jeu des isolants poreux perméables à l'air en contact avec des fines lames d'air. Ce défaut se veut réaliste, puisqu'il est issu de campagnes de mesures nationales qui ont permis d'identifier les points sensibles des enveloppes à ossature bois vis à vis des fuites d'air parasites. Des simulations sont réalisées avec des conditions aux limites variables en température et humidité sur des temps longs (quatre ans), en exfiltration et en infiltration d'air. Ces études permettent de dégager certaines tendances vis-à-vis des risques liés à l'humidité. Ainsi, l'exfiltration provoque une humidification significative de l'assemblage tandis que l'infiltration mène à un séchage. Une méthodologie pour évaluer les flux thermiques à l'échelle du défaut est également proposée.Dans une dernière partie, une approche simplifiée est proposée pour prendre en compte l'impact des défauts d'étanchéité à l'air sur la déperdition thermique à l'échelle bâtiment. La perte thermique supplémentaire générée par un défaut d'étanchéité peut être caractérisée par un coefficient de perte thermique propre au défaut, et le couplage du flux d'air avec l'enveloppe a une influence significative sur l'évaluation du flux déperditif total. Enfin, l'influence des transferts d'humidité sur les tendances observées est discutée. / Within the context of more stringent buildings codes, mastering airtightness is of importance to achieve energy efficient buildings. Unintended air leakage through the building envelope, which is due to bad design and poor workmanship, not only increases energy consumption, but also leads to moisture disorders, affecting building durability and occupants health. This moisture risk is present in particular for lightweight structures such as timber frame buildings, which are sensitive to air leakage.It is therefore necessary to better understand and to assess the impact of unintented air transfers on the hygrothermal field and the heat flux in the vicinity of an airtightness defect. To this end, two numerical models are developped, dealing with Heat-Air (HA) and Heat-Air-Moisture (HAM) transfer respectively. The HAM model is firstly validated in 1D using numerical benchmarks from literature. Then, temperature measurements in a cellulose insulation layer subjected to moist air flow are compared with the models outputs, and good agreement is obtained. The HAM model provides a better prediction of the temperature field compared to the HA model.Following this 2D experimental validation of the HAM model, it is applied to a complex defect geometry, including porous insulation materials and thin air gaps. This defect is meant to be realistic, as it is drawn from a measurement campaign aiming to identify typical envelope leakage points encountered in timber frame buildings.Long term simulations are performed under transient temperature and humidity conditions, in case of air exfiltration and air infiltration. This study helps identifying tendencies towards moisture risk: infiltrating air flow dries the assembly whereas exfiltrating air flow humidifies it. A methodology to assess heat fluxes through the defect is presented.Finally, a simplified approach is derived from the detailed HAM-model, to take into account the contribution of airtightness defects on the total heat loss on the building scale. It is shown that the additional heat loss induced by an airtightness defect may be described by a specific heat loss coefficient. In addition, the coupling between air flow and envelope has a significant impact on total heat flux calculations. The influence of moisture transfers on observed tendencies is also discussed.
20

Método para redução de mancha nas vedações externas de edifícios. / Method to reduce soiling deposition on building envelope.

Flávio Leal Maranhão 11 December 2009 (has links)
O permanente contato das vedações externas dos edifícios com os materiais integrantes das vedações externas dos edifícios (fachadas e telhados) com os agentes de degradação provocam o surgimento de manchas, que normalmente estão associadas à deposição de poluentes e a proliferação de microorganismos. Para inibir o surgimento dessas manchas existem, atualmente, diversos métodos disponíveis, sendo que nenhum tem se mostrado efetivo. Esta tese de doutorado, com base em um extenso programa laboratorial - com o uso de métodos como MEV, FTIR, ângulo de contato, crescimento acelerado de microrganismos, atividade fotocatalítica, entre outros-, criou um novo método, destinado aos materiais de construção silicosos e porosos, que se baseia na modificação de suas propriedades superficiais, por meio da sobreposição de uma camada hidrofóbica por uma hidrofílica. Para se obter essa disposição superficial, utilizou-se um hidrofugante à de octil-silicone, que apresenta elevada repelência à água e maior durabilidade, e um semicondutor à base de dióxido de titânio, que apresenta atividade fotocatalítica quando incidido por radiação ultravioleta. Como resultado, o método proposto (denominado na tese por WR+TiO2-sequencial) apresenta, comprovadamente, os seguintes benefícios: (i) redução de manchas causadas pela adesão de partículas com características apolares, similares às partículas de poluição dos grandes centros urbanos; (ii) limpeza espontânea de certos tipos de manchas, decorrentes dos processos fotocatalíticos que promovem a oxidação/redução de matéria orgânica; (iii) inibição do crescimento de microrganismo em escala laboratorial; (iv) redução da absorção total de água e, principalmente, da cinética do ganho de massa. Por isso, edificações cujas vedações externas venham a ser tratadas com o método aqui proposto são, potencialmente, células ativas para a sustentabilidade do ambiente construído, pois: reduzem o consumo de energia, reduz os custos de manutenção e contribuem para despoluição da atmosfera urbana. / Building roofs and façades usually show blackening surfaces after few years in large cities. On porous and silicious materials those soiling is caused by particles pollution depositions and mould growth, and the available methods available to prevent this phenomenum do not have a good performance along its service life. This thesis, based on an intensive laboratory research with many test technics as SEM, FTIR, contact angle, accelerated mould growth, and photocatalytical activity, create a new method to prevent soiling on porous and silicous building materials. This method modify the materials surface properties, making the outer surface layers with nano-actived titanium dioxide particles, which has photocatalitycal activity under UV radiation, and below it a hydrophobic layer, composed by octyl-silicones. The main results in laboratory scale experiments obtained by this new method (so-called in this thesis by WR+TiO2-sequencial) are: (i) stainings reductions caused by apolar agent, (ii) self-cleaning properties for some stain and after UV radiation exposition, (iii) mould growth resistance, and (iv) water absorption reduction. As a consequences, building envelopes trated with the new method is supposed to contribute to built and environment sustantability, because: can reduce the energy consumption, reduce de maintenance costs e has a de-pollution properties.

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