957 resultados para Nearly zero energy buildings
Resumo:
Trabalho Final de Mestrado para obteno do grau de Mestre em Engenharia Civil
Resumo:
A reabilitao uma interveno que confere ao edifcio uma qualidade superior que possua aquando da sua construo. Desta forma, e com a entrada em vigor em final de 2013 da nova legislao referente certificao energtica dos edifcios, surge novamente o interesse na temtica de reabilitar energeticamente o parque habitacional. Esta nova legislao aparece na sequencia das novas exigncias da Comisso Europeia e do Parlamento Europeu face s alteraes climticas e consequentemente, em relao eficincia energtica. A reabilitao energtica de edifcios, visa principalmente a melhoria das condies de conforto trmico, a reduo dos consumos energticos com aquecimento, arrefecimento e as guas quentes sanitrias. Tais melhorias so alcanveis com intervenes que se foquem na envolvente dos edifcios, com a aplicao de sistemas de alta eficincia para o aquecimento, arrefecimento, iluminao e guas quentes sanitrias e com a integrao de fontes de energias renovveis. Assim possvel alcanar edifcios com necessidades nulas ou quase nulas de energia, tal como exigem as metas impostas a nvel europeu.
Resumo:
Este trabalho teve como objetivo principal relacionar a aplicao do Regulamento de desempenho energtico dos edifcios de habitao com o conceito de habitao com necessidades quase nulas de energia. O trabalho comea por fazer uma comparao entre a metodologia geral do regulamento que vigora de momento e o seu predecessor de modo a perceber as alteraes tericas que esto subjacentes durante o processo de adaptao. feito um estudo sobre os edifcios com necessidades quase nulas de energia e de vrias estratgias passivas de serem utilizadas em edifcios capazes de conduzir obteno deste ttulo. Por fim, realizou-se a aplicao do regulamento em vigor a um caso real e um estudo sobre efeito do aumento da rea dos envidraados tendo em conta a sua orientao, com o objetivo de aumentar a eficincia energtica.
Resumo:
Segn la normativa Europea relacionada con la eficiencia energtica en edificios, a partir del ao 2020 todos los edificios de nueva planta debern considerarse como Edificios de consumo energtico casi nulo o Near zero energy buildings (nZEB). Aunque an no existe una definicin exacta de los requisitos que tendrn que cumplir este tipo de edificios, resulta evidente que debern tener una demanda energtica reducida. Dado que las ventanas pueden llegar a ser responsables de aproximadamente el 30% del consumo energtico destinado a acondicionar trmicamente un edificio, constituyen uno de los elementos cuya eficiencia debe mejorarse para lograr este tipo de edificios. Frente a este panorama, las ventanas con cmara de agua circulante constituyen un tipo de ventana dinmica poco conocido, pero cuya contribucin a los edificios de consumo de energa casi nulo tanto nuevos como rehabilitados, puede ser muy interesante en climas clidos como Jos del sur de Europa.
Resumo:
Segn la normativa Europea relacionada con la eficiencia energtica en edificios, a partir del ao 2020 todos los edificios de nueva planta debern considerarse como Edificios de consumo energtico casi nulo o Near zero energy buildings (nZEB). Aunque an no existe una definicin exacta de los requisitos que tendrn que cumplir este tipo de edificios, resulta evidente que debern tener una demanda energtica reducida. Dado que las ventanas pueden llegar a ser responsables de aproximadamente el 30% del consumo energtico destinado a acondicionar trmicamente un edificio, constituyen uno de los elementos cuya eficiencia debe mejorarse para lograr este tipo de edificios. Frente a este panorama, las ventanas con cmara de agua circulante constituyen un tipo de ventana dinmica poco conocido, pero cuya contribucin a los edificios de consumo de energa casi nulo tanto nuevos como rehabilitados, puede ser muy interesante en climas clidos como los del sur de Europa
Resumo:
Hoy en da, el proceso de un proyecto sostenible persigue realizar edificios de elevadas prestaciones que son, energticamente eficientes, saludables y econmicamente viables utilizando sabiamente recursos renovables para minimizar el impacto sobre el medio ambiente reduciendo, en lo posible, la demanda de energa, lo que se ha convertido, en la ltima dcada, en una prioridad. La Directiva 2002/91/CE "Eficiencia Energtica de los Edificios" (y actualizaciones posteriores) ha establecido el marco regulatorio general para el clculo de los requerimientos energticos mnimos. Desde esa fecha, el objetivo de cumplir con las nuevas directivas y protocolos ha conducido las polticas energticas de los distintos pases en la misma direccin, centrndose en la necesidad de aumentar la eficiencia energtica en los edificios, la adopcin de medidas para reducir el consumo, y el fomento de la generacin de energa a travs de fuentes renovables. Los edificios de energa nula o casi nula (ZEB, Zero Energy Buildings NZEB, Net Zero Energy Buildings) debern convertirse en un estndar de la construccin en Europa y con el fin de equilibrar el consumo de energa, adems de reducirlo al mnimo, los edificios necesariamente debern ser autoproductores de energa. Por esta razn, la envolvente del edifico y en particular las fachadas son importantes para el logro de estos objetivos y la tecnologa fotovoltaica puede tener un papel preponderante en este reto. Para promover el uso de la tecnologa fotovoltaica, diferentes programas de investigacin internacionales fomentan y apoyan soluciones para favorecer la integracin completa de stos sistemas como elementos arquitectnicos y constructivos, los sistemas BIPV (Building Integrated Photovoltaic), sobre todo considerando el prximo futuro hacia edificios NZEB. Se ha constatado en este estudio que todava hay una falta de informacin til disponible sobre los sistemas BIPV, a pesar de que el mercado ofrece una interesante gama de soluciones, en algunos aspectos comparables a los sistemas tradicionales de construccin. Pero por el momento, la falta estandarizacin y de una regulacin armonizada, adems de la falta de informacin en las hojas de datos tcnicos (todava no comparables con las mismas que estn disponibles para los materiales de construccin), hacen difcil evaluar adecuadamente la conveniencia y factibilidad de utilizar los componentes BIPV como parte integrante de la envolvente del edificio. Organizaciones internacionales estn trabajando para establecer las normas adecuadas y procedimientos de prueba y ensayo para comprobar la seguridad, viabilidad y fiabilidad estos sistemas. Sin embargo, hoy en da, no hay reglas especficas para la evaluacin y caracterizacin completa de un componente fotovoltaico de integracin arquitectnica de acuerdo con el Reglamento Europeo de Productos de la Construccin, CPR 305/2011. Los productos BIPV, como elementos de construccin, deben cumplir con diferentes aspectos prcticos como resistencia mecnica y la estabilidad; integridad estructural; seguridad de utilizacin; proteccin contra el clima (lluvia, nieve, viento, granizo), el fuego y el ruido, aspectos que se han convertido en requisitos esenciales, en la perspectiva de obtener productos ambientalmente sostenibles, saludables, eficientes energticamente y econmicamente asequibles. Por lo tanto, el mdulo / sistema BIPV se convierte en una parte multifuncional del edificio no slo para ser fsica y tcnicamente "integrado", adems de ser una oportunidad innovadora del diseo. Las normas IEC, de uso comn en Europa para certificar mdulos fotovoltaicos -IEC 61215 e IEC 61646 cualificacin de diseo y homologacin del tipo para mdulos fotovoltaicos de uso terrestre, respectivamente para mdulos fotovoltaicos de silicio cristalino y de lmina delgada- atestan nicamente la potencia del mdulo fotovoltaico y dan fe de su fiabilidad por un perodo de tiempo definido, certificando una disminucin de potencia dentro de unos lmites. Existe tambin un estndar, en parte en desarrollo, el IEC 61853 (Ensayos de rendimiento de mdulos fotovoltaicos y evaluacin energtica") cuyo objetivo es la bsqueda de procedimientos y metodologas de prueba apropiados para calcular el rendimiento energtico de los mdulos fotovoltaicos en diferentes condiciones climticas. Sin embargo, no existen ensayos normalizados en las condiciones especficas de la instalacin (p. ej. sistemas BIPV de fachada). Eso significa que es imposible conocer las efectivas prestaciones de estos sistemas y las condiciones ambientales que se generan en el interior del edificio. La potencia nominal de pico Wp, de un mdulo fotovoltaico identifica la mxima potencia elctrica que ste puede generar bajo condiciones estndares de medida (STC: irradicin 1000 W/m2, 25 C de temperatura del mdulo y distribucin espectral, AM 1,5) caracterizando elctricamente el mdulo PV en condiciones especficas con el fin de poder comparar los diferentes mdulos y tecnologas. El vatio pico (Wp por su abreviatura en ingls) es la medida de la potencia nominal del mdulo PV y no es suficiente para evaluar el comportamiento y produccin del panel en trminos de vatios hora en las diferentes condiciones de operacin, y tampoco permite predecir con conviccin la eficiencia y el comportamiento energtico de un determinado mdulo en condiciones ambientales y de instalacin reales. Un adecuado elemento de integracin arquitectnica de fachada, por ejemplo, debera tener en cuenta propiedades trmicas y de aislamiento, factores como la transparencia para permitir ganancias solares o un buen control solar si es necesario, aspectos vinculados y dependientes en gran medida de las condiciones climticas y del nivel de confort requerido en el edificio, lo que implica una necesidad de adaptacin a cada contexto especfico para obtener el mejor resultado. Sin embargo, la influencia en condiciones reales de operacin de las diferentes soluciones fotovoltaicas de integracin, en el consumo de energa del edificio no es fcil de evaluar. Los aspectos trmicos del interior del ambiente o de iluminacin, al utilizar mdulos BIPV semitransparentes por ejemplo, son an desconocidos. Como se dijo antes, la utilizacin de componentes de integracin arquitectnica fotovoltaicos y el uso de energa renovable ya es un hecho para producir energa limpia, pero tambin sera importante conocer su posible contribucin para mejorar el confort y la salud de los ocupantes del edificio. Aspectos como el confort, la proteccin o transmisin de luz natural, el aislamiento trmico, el consumo energtico o la generacin de energa son aspectos que suelen considerarse independientemente, mientras que todos juntos contribuyen, sin embargo, al balance energtico global del edificio. Adems, la necesidad de dar prioridad a una orientacin determinada del edificio, para alcanzar el mayor beneficio de la produccin de energa elctrica o trmica, en el caso de sistemas activos y pasivos, respectivamente, podra hacer estos ltimos incompatibles, pero no necesariamente. Se necesita un enfoque holstico que permita arquitectos e ingenieros implementar sistemas tecnolgicos que trabajen en sinergia. Se ha planteado por ello un nuevo concepto: "C-BIPV, elemento fotovoltaico consciente integrado", esto significa necesariamente conocer los efectos positivos o negativos (en trminos de confort y de energa) en condiciones reales de funcionamiento e instalacin. Propsito de la tesis, mtodo y resultados Los sistemas fotovoltaicos integrados en fachada son a menudo soluciones de vidrio fcilmente integrables, ya que por lo general estn hechos a medida. Estos componentes BIPV semitransparentes, integrados en el cerramiento proporcionan iluminacin natural y tambin sombra, lo que evita el sobrecalentamiento en los momentos de excesivo calor, aunque como componente esttico, asimismo evitan las posibles contribuciones pasivas de ganancias solares en los meses fros. Adems, la temperatura del mdulo vara considerablemente en ciertas circunstancias influenciada por la tecnologa fotovoltaica instalada, la radiacin solar, el sistema de montaje, la tipologa de instalacin, falta de ventilacin, etc. Este factor, puede suponer un aumento adicional de la carga trmica en el edificio, altamente variable y difcil de cuantificar. Se necesitan, en relacin con esto, ms conocimientos sobre el confort ambiental interior en los edificios que utilizan tecnologas fotovoltaicas integradas, para abrir de ese modo, una nueva perspectiva de la investigacin. Con este fin, se ha diseado, proyectado y construido una instalacin de pruebas al aire libre, el BIPV Env-lab "BIPV Test Laboratory", para la caracterizacin integral de los diferentes mdulos semitransparentes BIPV. Se han definido tambin el mtodo y el protocolo de ensayos de caracterizacin en el contexto de un edificio y en condiciones climticas y de funcionamiento reales. Esto ha sido posible una vez evaluado el estado de la tcnica y la investigacin, los aspectos que influyen en la integracin arquitectnica y los diferentes tipos de integracin, despus de haber examinado los mtodos de ensayo para los componentes de construccin y fotovoltaicos, en condiciones de operacin utilizadas hasta ahora. El laboratorio de pruebas experimentales, que consiste en dos habitaciones idnticas a escala real, 1:1, ha sido equipado con sensores y todos los sistemas de monitorizacin gracias a los cuales es posible obtener datos fiables para evaluar las prestaciones trmicas, de iluminacin y el rendimiento elctrico de los mdulos fotovoltaicos. Este laboratorio permite el estudio de tres diferentes aspectos que influencian el confort y consumo de energa del edificio: el confort trmico, lumnico, y el rendimiento energtico global (demanda/produccin de energa) de los mdulos BIPV. Conociendo el balance de energa para cada tecnologa solar fotovoltaica experimentada, es posible determinar cul funciona mejor en cada caso especfico. Se ha propuesto una metodologa terica para la evaluacin de estos parmetros, definidos en esta tesis como ndices o indicadores que consideran cuestiones relacionados con el bienestar, la energa y el rendimiento energtico global de los componentes BIPV. Esta metodologa considera y tiene en cuenta las normas reglamentarias y estndares existentes para cada aspecto, relacionndolos entre s. Diferentes mdulos BIPV de doble vidrio aislante, semitransparentes, representativos de diferentes tecnologas fotovoltaicas (tecnologa de silicio monocristalino, m-Si; de capa fina en silicio amorfo unin simple, a-Si y de capa fina en diseleniuro de cobre e indio, CIS) fueron seleccionados para llevar a cabo una serie de pruebas experimentales al objeto de demostrar la validez del mtodo de caracterizacin propuesto. Como resultado final, se ha desarrollado y generado el Diagrama Caracterizacin Integral DCI, un sistema grfico y visual para representar los resultados y gestionar la informacin, una herramienta operativa til para la toma de decisiones con respecto a las instalaciones fotovoltaicas. Este diagrama muestra todos los conceptos y parmetros estudiados en relacin con los dems y ofrece visualmente toda la informacin cualitativa y cuantitativa sobre la eficiencia energtica de los componentes BIPV, por caracterizarlos de manera integral. ABSTRACT A sustainable design process today is intended to produce high-performance buildings that are energy-efficient, healthy and economically feasible, by wisely using renewable resources to minimize the impact on the environment and to reduce, as much as possible, the energy demand. In the last decade, the reduction of energy needs in buildings has become a top priority. The Directive 2002/91/EC Energy Performance of Buildings (and its subsequent updates) established a general regulatory frameworks methodology for calculation of minimum energy requirements. Since then, the aim of fulfilling new directives and protocols has led the energy policies in several countries in a similar direction that is, focusing on the need of increasing energy efficiency in buildings, taking measures to reduce energy consumption, and fostering the use of renewable sources. Zero Energy Buildings or Net Zero Energy Buildings will become a standard in the European building industry and in order to balance energy consumption, buildings, in addition to reduce the end-use consumption should necessarily become selfenergy producers. For this reason, the faade system plays an important role for achieving these energy and environmental goals and Photovoltaic can play a leading role in this challenge. To promote the use of photovoltaic technology in buildings, international research programs encourage and support solutions, which favors the complete integration of photovoltaic devices as an architectural element, the so-called BIPV (Building Integrated Photovoltaic), furthermore facing to next future towards net-zero energy buildings. Therefore, the BIPV module/system becomes a multifunctional building layer, not only physically and functionally integrated in the building, but also used as an innovative chance for the building envelope design. It has been found in this study that there is still a lack of useful information about BIPV for architects and designers even though the market is providing more and more interesting solutions, sometimes comparable to the existing traditional building systems. However at the moment, the lack of an harmonized regulation and standardization besides to the non-accuracy in the technical BIPV datasheets (not yet comparable with the same ones available for building materials), makes difficult for a designer to properly evaluate the fesibility of this BIPV components when used as a technological system of the building skin. International organizations are working to establish the most suitable standards and test procedures to check the safety, feasibility and reliability of BIPV systems. Anyway, nowadays, there are no specific rules for a complete characterization and evaluation of a BIPV component according to the European Construction Product Regulation, CPR 305/2011. BIPV products, as building components, must comply with different practical aspects such as mechanical resistance and stability; structural integrity; safety in use; protection against weather (rain, snow, wind, hail); fire and noise: aspects that have become essential requirements in the perspective of more and more environmentally sustainable, healthy, energy efficient and economically affordable products. IEC standards, commonly used in Europe to certify PV modules (IEC 61215 and IEC 61646 respectively crystalline and thin-film Terrestrial PV Modules-Design Qualification and Type Approval), attest the feasibility and reliability of PV modules for a defined period of time with a limited power decrease. There is also a standard (IEC 61853, Performance Testing and Energy Rating of Terrestrial PV Modules) still under preparation, whose aim is finding appropriate test procedures and methodologies to calculate the energy yield of PV modules under different climate conditions. Furthermore, the lack of tests in specific conditions of installation (e.g. faade BIPV devices) means that it is difficult knowing the exact effective performance of these systems and the environmental conditions in which the building will operate. The nominal PV power at Standard Test Conditions, STC (1.000 W/m2, 25 C temperature and AM 1.5) is usually measured in indoor laboratories, and it characterizes the PV module at specific conditions in order to be able to compare different modules and technologies on a first step. The Watt-peak is not enough to evaluate the panel performance in terms of Watt-hours of various modules under different operating conditions, and it gives no assurance of being able to predict the energy performance of a certain module at given environmental conditions. A proper BIPV element for faade should take into account thermal and insulation properties, factors as transparency to allow solar gains if possible or a good solar control if necessary, aspects that are linked and high dependent on climate conditions and on the level of comfort to be reached. However, the influence of different faade integrated photovoltaic solutions on the building energy consumption is not easy to assess under real operating conditions. Thermal aspects, indoor temperatures or luminance level that can be expected using building integrated PV (BIPV) modules are not well known. As said before, integrated photovoltaic BIPV components and the use of renewable energy is already a standard for green energy production, but would also be important to know the possible contribution to improve the comfort and health of building occupants. Comfort, light transmission or protection, thermal insulation or thermal/electricity power production are aspects that are usually considered alone, while all together contribute to the building global energy balance. Besides, the need to prioritize a particular building envelope orientation to harvest the most benefit from the electrical or thermal energy production, in the case of active and passive systems respectively might be not compatible, but also not necessary. A holistic approach is needed to enable architects and engineers implementing technological systems working in synergy. A new concept have been suggested: C-BIPV, conscious integrated BIPV. BIPV systems have to be consciously integrated which means that it is essential to know the positive and negative effects in terms of comfort and energy under real operating conditions. Purpose of the work, method and results The faade-integrated photovoltaic systems are often glass solutions easily integrable, as they usually are custommade. These BIPV semi-transparent components integrated as a window element provides natural lighting and shade that prevents overheating at times of excessive heat, but as static component, likewise avoid the possible solar gains contributions in the cold months. In addition, the temperature of the module varies considerably in certain circumstances influenced by the PV technology installed, solar radiation, mounting system, lack of ventilation, etc. This factor may result in additional heat input in the building highly variable and difficult to quantify. In addition, further insights into the indoor environmental comfort in buildings using integrated photovoltaic technologies are needed to open up thereby, a new research perspective. This research aims to study their behaviour through a series of experiments in order to define the real influence on comfort aspects and on global energy building consumption, as well as, electrical and thermal characteristics of these devices. The final objective was to analyze a whole set of issues that influence the global energy consumption/production in a building using BIPV modules by quantifying the global energy balance and the BIPV system real performances. Other qualitative issues to be studied were comfort aspect (thermal and lighting aspects) and the electrical behaviour of different BIPV technologies for vertical integration, aspects that influence both energy consumption and electricity production. Thus, it will be possible to obtain a comprehensive global characterization of BIPV systems. A specific design of an outdoor test facility, the BIPV Env-lab BIPV Test Laboratory, for the integral characterization of different BIPV semi-transparent modules was developed and built. The method and test protocol for the BIPV characterization was also defined in a real building context and weather conditions. This has been possible once assessed the state of the art and research, the aspects that influence the architectural integration and the different possibilities and types of integration for PV and after having examined the test methods for building and photovoltaic components, under operation conditions heretofore used. The test laboratory that consists in two equivalent test rooms (1:1) has a monitoring system in which reliable data of thermal, daylighting and electrical performances can be obtained for the evaluation of PV modules. The experimental set-up facility (testing room) allows studying three different aspects that affect building energy consumption and comfort issues: the thermal indoor comfort, the lighting comfort and the energy performance of BIPV modules tested under real environmental conditions. Knowing the energy balance for each experimented solar technology, it is possible to determine which one performs best. A theoretical methodology has been proposed for evaluating these parameters, as defined in this thesis as indices or indicators, which regard comfort issues, energy and the overall performance of BIPV components. This methodology considers the existing regulatory standards for each aspect, relating them to one another. A set of insulated glass BIPV modules see-through and light-through, representative of different PV technologies (mono-crystalline silicon technology, mc-Si, amorphous silicon thin film single junction, a-Si and copper indium selenide thin film technology CIS) were selected for a series of experimental tests in order to demonstrate the validity of the proposed characterization method. As result, it has been developed and generated the ICD Integral Characterization Diagram, a graphic and visual system to represent the results and manage information, a useful operational tool for decision-making regarding to photovoltaic installations. This diagram shows all concepts and parameters studied in relation to each other and visually provides access to all the results obtained during the experimental phase to make available all the qualitative and quantitative information on the energy performance of the BIPV components by characterizing them in a comprehensive way.
Resumo:
Os edifcios de balano energtico nulo (NZEB - Net-Zero Energy Building) e/ou quase nulo (nZEB), tm vindo a ganhar crescente ateno desde a publicao da diretiva europeia 2010/31/EU [15]. Em Portugal, com a introduo do Decreto-Lei n.118/2013, d o primeiro passo para os edifcios com necessidades quase nulas de energia. Os novos edifcios licenciados aps 31 dezembro de 2020, ou aps 31 de dezembro de 2018 no caso de edifcios pblicos, sero edifcios com necessidades quase nulas de energia. O objetivo do trabalho descrito neste artigo consiste na aplicao do conceito Net Zero Energy Building, ao edifcio existente do Instituto Superior Politcnico Gaya (ISPGaya), em Vila Nova de Gaia, com o intuito de analisar a viabilidade de otimizao de energia e a metodologia deste conceito ao edifcio, com recurso a ferramentas de simulao. Neste trabalho efetumos uma simulao energtica do edifcio, atravs do DesignBuilder, que servir como termo de comparao para outras simulaes. Sero delineadas as especificaes a implementar no edifcio por forma a ser considerado Net Zero Energy Building, com alteraes na simulao do mesmo de acordo com as novas especificaes. Por ltimo, ser feita a comparao tcnica, financeira e ambiental da soluo NZEB encontrada. Atravs das vrias simulaes energticas ao edifcio, conclui-se que possvel baixar as necessidades energticas do edifcio atravs de medidas de eficincia energtica, em especial na iluminao e que os resultados obtidos, apesar de ser vivel a implementao do conceito Net Zero Energy Building, traduzem um esforo financeiro e algumas condicionantes para a sua concretizao.
Resumo:
A zero-energy home (ZEH) is a residential dwelling that generates as much energy annually from onsite renewable sources, as it consumes in its operation. A positive energy home (PEH) generates more energy than it consumes. The key design and construction elements, and costs and benefits of such buildings, are the subject of increasing research globally. Approaching this topic from the perspective of the role of such homes in the planning and development supply chain, this paper presents the measured outcomes of a PEH and discusses urban design implications. Using twelve months of detailed performance data of an occupied sub-tropical home, the paper analyses the design approach and performance outcomes that enable it to be classified as positive energy. Second, it analyses both the urban design strategies that assisted the house in achieving its positive energy status, and the impacts of such housing on urban design and infrastructure. Third, the triple bottom line implications are discussed from the viewpoint of both the individual household and the broader community. The paper concludes with recommendations for research areas required to further underpin and quantify the role of ZEHs and PEHs in enabling and supporting the economic, social and ecological sustainability of urban developments.
A Legendre spectral element model for sloshing and acoustic analysis in nearly incompressible fluids
Resumo:
A new spectral finite element formulation is presented for modeling the sloshing and the acoustic waves in nearly incompressible fluids. The formulation makes use of the Legendre polynomials in deriving the finite element interpolation shape functions in the Lagrangian frame of reference. The formulated element uses Gauss-Lobatto-Legendre quadrature scheme for integrating the volumetric stiffness and the mass matrices while the conventional Gauss-Legendre quadrature scheme is used on the rotational stiffness matrix to completely eliminate the zero energy modes, which are normally associated with the Lagrangian FE formulation. The numerical performance of the spectral element formulated here is examined by doing the inf-sup test oil a standard rectangular rigid tank partially filled with liquid The eigenvalues obtained from the formulated spectral element are compared with the conventional equally spaced node locations of the h-type Lagrangian finite element and the predicted results show that these spectral elements are more accurate and give superior convergence The efficiency and robustness of the formulated elements are demonstrated by solving few standard problems involving free vibration and dynamic response analysis with undistorted and distorted spectral elements. and the obtained results are compared with available results in the published literature (C) 2009 Elsevier Inc All rights reserved
Resumo:
This paper presents a review undertaken to understand the concept of 'future-proofing' the energy performance of buildings. The long lifecycles of the building stock, the impacts of climate change and the requirements for low carbon development underline the need for long-term thinking from the early design stages. 'Future-proofing' is an emerging research agenda with currently no widely accepted definition amongst scholars and building professionals. In this paper, it refers to design processes that accommodate explicitly full lifecycle perspectives and energy trends and drivers by at least 2050, when selecting energy efficient measures and low carbon technologies. A knowledge map is introduced, which explores the key axes (or attributes) for achieving a 'future-proofed' energy design; namely, coverage of sustainability issues, lifecycle thinking, and accommodating risks and uncertainties that affect the energy consumption. It is concluded that further research is needed so that established building energy assessment methods are refined to better incorporate future-proofing. The study follows an interdisciplinary approach and is targeted at design teams with aspirations to achieve resilient and flexible low-energy buildings over the long-term. 2012 Elsevier Ltd.
Resumo:
Este trabalho surgiu do mbito da Tese de Dissertao do Mestrado em Energias Sustentveis do Instituto Superior de Engenharia do Porto, tendo o acompanhamento dos orientadores da empresa Laboratrio Ecotermolab do Instituto de Soldadura e Qualidade e do Instituto Superior de Engenharia do Porto, de forma a garantir a linha traada indo de acordo aos objectivos propostos. A presente tese abordou o estudo do impacto da influncia do ar novo na climatizao de edifcios, tendo como base de apoio anlise a simulao dinmica do edifcio em condies reais num programa adequado, acreditado pela norma ASHRAE 140-2004. Este trabalho pretendeu evidenciar qual o impacto da influncia do ar novo na climatizao de um edifcio com a conjugao de vrios factores, tais como, ocupao, actividades e padres de utilizao (horrios), iluminao e equipamentos, estudando ainda a possibilidade do sistema funcionar em regime de Free-Cooling. O princpio partiu fundamentalmente por determinar at que ponto se pode climatizar recorrendo nico e exclusivamente introduo de ar novo em regime de Free-Cooling, atravs de um sistema tudo-ar de Volume de Ar Varivel - VAV, sem o apoio de qualquer outro sistema de climatizao auxiliar localizado no espao, respeitando os caudais mnimos impostos pelo RSECE (Decreto-Lei 79/2006). Numa primeira fase foram identificados todos os dados relativos determinao das cargas trmicas do edifcio, tendo em conta todos os factores e contributos alusivos ao valor da carga trmica, tais como a transmisso de calor e seus constituintes, a iluminao, a ventilao, o uso de equipamentos e os nveis de ocupao. Consequentemente foram elaboradas diversas simulaes dinmicas com o recurso ao programa EnergyPlus integrado no DesignBuilder, conjugando variveis desde as envolventes prpria arquitectura, perfis de utilizao ocupacional, equipamentos e taxas de renovao de ar nos diferentes espaos do edifcio em estudo. Obtiveram-se vrios modelos de forma a promover um estudo comparativo e aprofundado que permitisse determinar o impacto do ar novo na climatizao do edifcio, perspectivando a capacidade funcional do sistema funcionar em regime de Free-Cooling. Deste modo, a anlise e comparao dos dados obtidos permitiram chegar s seguintes concluses: Tendo em considerao que para necessidades de arrefecimento bastante elevadas, o Free-Cooling diurno revelou-se pouco eficaz ou quase nulo, para o tipo de clima verificado em Portugal, pois o diferencial de temperatura existente entre o exterior e o interior no suficiente de modo a tornar possvel a remoo das cargas de forma a baixar a temperatura interior para o intervalo de conforto. Em relao ao Free-Cooling em horrio nocturno ou ps-laboral, este revelou-se bem mais eficiente. Obtiveram-se prestaes muito interessantes sobretudo durante as estaes de aquecimento e meia-estao, tendo em considerao o facto de existir necessidades de arrefecimento mesmo durante a estao de aquecimento. Referente ventilao nocturna, isto , em perodos de madrugada e fecho do edifcio, concluiu-se que tal contribui para um abaixamento do calor acumulado durante o dia nos materiais construtivos do edifcio e que libertado ou restitudo posteriormente para os espaos em perodos mais tardios. De entre as seguintes variveis, aumento de caudal de ar novo insuflado e o diferencial de temperatura existente entre o ar exterior e interior, ficou demonstrado que este ltimo teria maior peso contributivo na remoo do calor. Por fim, ponto assente que de um modo geral, um sistema de climatizao ser sempre indispensvel devido a cargas internas elevadas, requisitos interiores de temperatura e humidade, sendo no entanto aconselhado o Free- Cooling como um opo vivel a incorporar na soluo de climatizao, de forma a promover o arrefecimento natural, a reduo do consumo energtico e a introduo activa de ar novo.
Resumo:
Dissertao para obteno do grau de Mestre em Engenharia Civil na rea de Especializao de Edificaes
Resumo:
Conselho Nacional de Desenvolvimento Cientfico e Tecnolgico (CNPq)
Resumo:
This research was commissioned by Metecno Pty Ltd, trading as Bondor. The InsulLiving house was designed and constructed by Bondor. The house instrumentation (electricity circuits, indoor environment, weather station) was provided by Bondor and supplied and installed by independent contractors. This report contains analysis of data collected from the InsulLiving house at Burpengary during 1 year of occupancy by a family of four for the period 1 April 2012 31 March 2013. The data shows a daily average electricity consumption 48% less than the regional average. The analysis confirms that the 9 star house performed thermally slightly better than the simulated performance. The home was 'near zero energy', with its modest 2.1kW solar power system meeting all of the needs for space heating and cooling, lighting and most water heating.
Resumo:
One could argue that the nature of our housing stock is a key determining factor in the ability of our citizens to manage risk, be resilient to various natural and human events, and to recover from these events. Recent research has been examining current challenges posed by our housing stock and exploring potential solutions from a range of perspectives. The aim of this paper is to discuss key findings from recent built environment research in Australia to initiate cross-sectorial discussion and debate about the implications and opportunities for other sectors such as emergency management and insurance. Three recent building research projects are discussed: - Heat waves The impact of heat waves on houses and occupants, and proposed changes to building regulations, air conditioning standards and building design, to reduce risks associated with heat waves. - Net zero energy homes Exploration of the potential benefits of a strategic optimization of building quality, energy and water efficiency, and household or community level distributed energy and water services for disaster management and recovery. - Building information Mapping of the flow of information about residential buildings, and the potential for national or regional building files (in a similar manner to personal medical records) to assist all parties to make more informed decisions that impact on housing sustainability and community resilience. The paper discusses how sustainability, environmental performance and resilience are inter-related, and can be supported by building files. It concludes with a call for increased cross-sectorial collaboration to explore opportunities for a whole-of-systems approach to our built environment that addresses a range of economic and environmental challenges as well as disaster and emergency management.
