Modelling and predictive control techniques for building heating systems

Model predictive control (MPC) has often been referred to in literature as a potential method for more efficient control of building heating systems. Though a significant performance improvement can be achieved with an MPC strategy, the complexity introduced to the commissioning of the system is often prohibitive. Models are required which can capture the thermodynamic properties of the building with sufficient accuracy for meaningful predictions to be made. Furthermore, a large number of tuning weights may need to be determined to achieve a desired performance. For MPC to become a practicable alternative, these issues must be addressed. Acknowledging the impact of the external environment as well as the interaction of occupants on the thermal behaviour of the building, in this work, techniques have been developed for deriving building models from data in which large, unmeasured disturbances are present. A spatio-temporal filtering process was introduced to determine estimates of the disturbances from measured data, which were then incorporated with metaheuristic search techniques to derive high-order simulation models, capable of replicating the thermal dynamics of a building. While a high-order simulation model allowed for control strategies to be analysed and compared, low-order models were required for use within the MPC strategy itself. The disturbance estimation techniques were adapted for use with system-identification methods to derive such models. MPC formulations were then derived to enable a more straightforward commissioning process and implemented in a validated simulation platform. A prioritised-objective strategy was developed which allowed for the tuning parameters typically associated with an MPC cost function to be omitted from the formulation by separation of the conflicting requirements of comfort satisfaction and energy reduction within a lexicographic framework. The improved ability of the formulation to be set-up and reconfigured in faulted conditions was shown.

Ympäristöluokitusjärjestelmät talotekniikan suunnitteluprosessissa

Vihreä rakentaminen on voimakkaasti kasvava rakennusliiketoiminnan osa-alue, johon useat toimijat ovat alkaneet herätä. Suomessakin on otettu käyttöön erilaisia ympäristösuorituskyvyn mittarointijärjestelmiä, joilla pyritään varmentamaan laadukas lopputulos vihreille rakennuksille. Tutkimuksen tavoitteena on selvittää vihreän rakentamisen kannattavuutta. Työn teoriaosassa käydään läpi ympäristöluokitusjärjestelmien ominaisuuksia ja eroavaisuuksia sekä LEED-ympäristöluokitusjärjestelmän sisältö ja suhde Suomen rakentamismääräyksiin. Työn empiirisessä osassa tutkitaan LEED:n talotekniselle suunnittelulle aiheuttamia vaikutuksia sekä niihin liittyvien valintojen elinkaarikustannuksia. Vaikutuksia tutkitaan suunnitteluohjeiden ja -vaatimusten tasolta, suunnittelijoiden ja haastattelujen pohjalta sekä tutkimalla case-kohdetta, jossa tavoitteena on korkeimman LEED-luokituksen saavuttaminen.

Performance Energética no contexto do sistema LEED

Com o aumento constante de procura de recursos naturais por parte dos vários setores da sociedade é urgente encontrar soluções para reduzir o seu consumo sem se travar a expansão demográfica que se tem vindo a sentir nos grandes centros urbanos. É através da implementação de medidas de sustentabilidade e pelo aumento da eficiência de utilização desses recursos que se tem vindo a combater esta tendência cada vez maior de consumismo global, sendo isto apenas possível com a implementação de ferramentas tecnológicas avançadas que permitem estabelecer limites ao considerado eficiente e premiando, em termos financeiros e de imagem de marketing, as entidades que o alcancem. O LEED é um sistema de certificação de sustentabilidade voluntário de edifícios residenciais e comerciais que estabelece métricas de comparação de parâmetros indicadores de consumos energéticos, hídricos e de materiais em todo o ciclo de vida do edifício e que tem vindo a ganhar destaque em crescendo a nível mundial. Esta dissertação teve como objetivo comparar a performance de consumo energético no âmbito do sistema LEED com a do sistema de certificação energética de edifícios nacional (SCE) de um grande edifício de serviços, estabelecendo um paralelismo de semelhanças e diferenças entre os dois e de avaliar os efeitos de potenciais medidas de eficiência energética e seus efeitos nas classificações de mérito obtidas em cada sistema. Os resultados obtidos na simulação que permitiu avaliar a performance foi muito satisfatório, tendo sido aproveitado pela empresa para efeitos de certificação LEED do edifício em estudo.

Reliability in the whole life cycle of building systems

Purpose – The purpose of this research is to show that reliability analysis and its implementation will lead to an improved whole life performance of the building systems, and hence their life cycle costs (LCC). Design/methodology/approach – This paper analyses reliability impacts on the whole life cycle of building systems, and reviews the up-to-date approaches adopted in UK construction, based on questionnaires designed to investigate the use of reliability within the industry. Findings – Approaches to reliability design and maintainability design have been introduced from the operating environment level, system structural level and component level, and a scheduled maintenance logic tree is modified based on the model developed by Pride. Different stages of the whole life cycle of building services systems, reliability-associated factors should be considered to ensure the system's whole life performance. It is suggested that data analysis should be applied in reliability design, maintainability design, and maintenance policy development. Originality/value – The paper presents important factors in different stages of the whole life cycle of the systems, and reliability and maintainability design approaches which can be helpful for building services system designers. The survey from the questionnaires provides the designers with understanding of key impacting factors.

Green building: análise das dificuldades (ainda) enfrentadas durante o processo de certificação LEED no Brasil

A preocupação com o esgotamento dos recursos naturais e a conscientização sobre as questões ligadas à sustentabilidade provocaram o estudo em um setor que tem sido apontado como de grande importância para a transformação do meio ambiente: a construção civil. Com isso percebemos o surgimento de um conjunto de práticas e procedimentos visando as chamadas "construções sustentáveis", que introduziram uma nova realidade comercial no segmento da construção civil. Para avaliar se uma construção é ou não sustentável surgiram os eco-labellings, que através de sistema de pontuação ou conceitos permitem avaliar qualitativamente em que grau de sustentabilidade uma edificação encontra-se. Em especial, o mercado brasileiro vem, desde 2004, buscando a certificação ambiental LEED; sendo assim, a presente dissertação tem como objetivo identificar, após quase uma década desde a primeira submissão de projeto brasileiro ao USGBC, quais ainda são as dificuldades enfrentadas no processo de certificação LEED. O referencial teórico reforçou que o segmento da construção civil contribui de duas formas para a degradação do meio ambiente: no consumo de recursos naturais e energéticos, e na geração de grande quantidade de resíduos. Por esse motivo, estudos nessa área são extremamente importantes para a transformação do meio ambiente, que, através da adoção de práticas construtivas sustentáveis poderá minimizar os impactos gerados. Neste trabalho, optou-se pela utilização de pesquisa exploratória quanto aos fins, uma vez que existe pouco conhecimento acumulado sobre a avaliação do processo de certificação LEED, e bibliográfica, complementada com pesquisa de campo, quanto ao meio, pois fundamenta-se em estudo desenvolvido com base em material publicado, complementado por entrevistas no campo. Este trabalho caracteriza-se por se um estudo introdutório à compreensão do tema e convida a estudos complementares mais abrangentes, dada a relevância do assunto nas três esferas de sustentabilidade: social, ambiental e econômica.

Gestão de projectos no âmbito da construção sustentável

A indústria da construção, nomeadamente no sector da edificação, baseia-se essencialmente em métodos de construção tradicional. Esta indústria é caracterizada pelo consumo excessivo de matérias-primas, de recursos energéticos não renováveis e pela elevada produção de resíduos. Esta realidade é de todo incompatível com os desígnios do desenvolvimento sustentável, nos quais se procura a conveniência harmoniosa entre as dimensões ambiental, social e económica. O desafio da sustentabilidade, colocado à actividade da construção, tem motivado abordagens distintas, não só por parte das várias especialidades da engenharia, como também da arquitectura. É nesta perspectiva, que o presente modelo pretende ser um contributo para uma abordagem inovadora, introduzindo linhas de intervenção e de orientação, para apoiar e estimular o desenvolvimento de soluções sustentáveis em edifícios habitacionais, em qualquer fase do ciclo de evolução de um projecto e das várias especialidades do mesmo. Assim, no sentido de optimizar os recursos envolvidos no projecto são expostas estratégias de intervenção, com os seguintes objectivos: optimização do potencial do local, preservação da identidade regional e cultural, minimização do consumo de energia, utilização de materiais e produtos de baixo impacto ambiental, redução do consumo de água, redução da produção de emissões, resíduos e outros poluentes, adequada qualidade do ambiente interior e optimização das fases de operação e manutenção. A ferramenta apresentada surge como um instrumento facilitador para a equipa de projectistas, e que se esta adaptada para o desenvolvimento de projectos de edifícios de habitação, dada a génese dos métodos utilizados. As soluções de sustentabilidade apresentadas neste manual emanam dos sistemas de certificação LíderA, LEED, BREEAM e SBToolpt. O modelo encontra-se estruturado, no que às fases de projecto diz respeito, de acordo com os requisitos expressos na Portaria 701-H/2008 de 29 de Julho, tendo sido igualmente seguido o descrito para os respectivos intervenientes.

Uso eficiente da água num edifício de habitação

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Civil

Eficiência energética e energias renováveis em edifícios

As preocupações com a escassez dos recursos fósseis, o aumento gradual e acentuado dos seus preços e problemas ambientais, cada vez mais há uma preocupação em relação à eficiência energética e as energias renováveis, sendo estes os dois pilares para se encaminhar para uma política energética sustentável. Sobretudo nos edifícios que são responsáveis por grande parte do consumo de energia mundial. Cabo Verde tem um elevado grau de desperdício energético e de consumo de energia elétrica, torna-se imprescindível ressaltar a importância da análise de Eficiência Energética nas Edificações. Contudo, em Cabo Verde, relativamente à vertente da eficiência energética nos edifícios, não existe ainda uma legislação que de alguma forma condicione o consumo de energia e os impactos ambientais associados aos edifícios. De igual forma, as construções com características bioclimáticas ou incorporando sistemas passivos ainda não são prática corrente, pois não existe nenhuma regulamentação que garante que o projetista aquando a conceção de um edifício aplique estratégias de construção bioclimática ou integração das energias renováveis, fazendo o uso do potencial dos recursos renováveis existente no país. Assim, o conforto dos ocupantes dos edifícios e a diminuição das necessidades de consumo não estão presentes de uma forma satisfatória na construção de edifícios em Cabo Verde. Neste contexto, a presente dissertação tem como intuito, recolher e estruturar informação relativa a temática da eficiência energética e energias renováveis nos edifícios de forma a promover a eficiência energética nos edifícios e apoiar o desenvolvimento das energias renováveis em Cabo Verde, contribuindo para a mudança de mentalidade. Assim este estudo pretende refletir sobre a importância da construção sustentável, a Certificação Energética, sistemas e procedimentos para garantir, no mínimo, igual conforto dos ocupantes e simultaneamente a redução do consumo de energia nos edifícios, mudança de comportamentos e escolhas com menor consumo energético. São ainda apresentados as possibilidades de integração das energias renováveis nos edifícios. Assim decidiu-se analisar a implementação de um sistema de microgeração fotovoltaico, para aumentar a eficiência energética de edifícios de acordo com a legislação vigente em Cabo Verde. Nestes termos, é dimensionado um sistema para atender cerca de 70% do consumo anual de energia elétrica do edifício, com consumo de 3869 kWh/ano. Com a realização deste estudo, pretende-se incentivar a implementação de unidades de microprodução fotovoltaica para a produção de energia elétrica em edifícios, bem como aproximar o cidadão comum das soluções técnicas/económicas no campo do aproveitamento das energias renováveis para a produção de energia elétrica.

Ecolabeling and Green Certification for Effective Fisheries Management – An Analysis

Nowadays there is a growing environmental concern and the business communities have slowly started recognising environmental protection and sustainable utilization of natural resources into their marketing strategies. This paper discusses the various Ecolabeling and Certification Systems developed world over to regulate and introduce Fair Trade in Ornamental Fish Industry. Ecolabeling and green certification are considered as part of these strategies implemented partly out of compulsion from the National and International Regulatory Bodies and Environmental Movements. All the major markets of ornamental fishes like European Union, USA and Japan have started putting restrictions on the trade to impose ecolabeling as a non tariff barrier like the one imposed on seafood and aqua cultured products. A review was done on the available Ecolabeling and Green Certification Schemes available at local, national and international levels for fisheries including aquaculture and ornamental fish trade and to examine the success and constraints faced by these schemes during its implementation. The primary downside of certification is the multiplicity of ecolabels and cost incurred by applicants for certification, costs which may in turn be passed on to consumers. The studies reveal serious inadequacies in a number of ecolabels and cast doubt on their overall contribution to effective fisheries management and sustainability. The paper also discusses the inititive taken in India to develop guidelines for Green Certification of Fresh water ornamental fishes.

Contextual prerequisites for the application of ILS principles to the building services industry

Purpose – This paper proposes assessing the context within which integrated logistic support (ILS) can be implemented for whole life performance of building services systems. Design/methodology/approach – The use of ILS within a through-life business model (TLBM) is a better framework to achieve a well-designed, constructed and managed product. However, for ILS to be implemented in a TLBM for building services systems, the practices, tools and techniques need certain contextual prerequisites tailored to suit the construction industry. These contextual prerequisites are discussed. Findings – The case studies conducted reinforced the contextual importance of prime contracting, partnering and team collaboration for the application of ILS techniques. The lack of data was a major hindrance to the full realisation of ILS techniques within the case studies. Originality/value – The paper concludes with the recognition of the value of these contextual prerequisites for the use of ILS techniques within the building industry.

Integration of chaos theory and mathematical models in building simulation: Part I: Literature review

Current mathematical models in building research have been limited in most studies to linear dynamics systems. A literature review of past studies investigating chaos theory approaches in building simulation models suggests that as a basis chaos model is valid and can handle the increasingly complexity of building systems that have dynamic interactions among all the distributed and hierarchical systems on the one hand, and the environment and occupants on the other. The review also identifies the paucity of literature and the need for a suitable methodology of linking chaos theory to mathematical models in building design and management studies. This study is broadly divided into two parts and presented in two companion papers. Part (I) reviews the current state of the chaos theory models as a starting point for establishing theories that can be effectively applied to building simulation models. Part (II) develops conceptual frameworks that approach current model methodologies from the theoretical perspective provided by chaos theory, with a focus on the key concepts and their potential to help to better understand the nonlinear dynamic nature of built environment systems. Case studies are also presented which demonstrate the potential usefulness of chaos theory driven models in a wide variety of leading areas of building research. This study distills the fundamental properties and the most relevant characteristics of chaos theory essential to building simulation scientists, initiates a dialogue and builds bridges between scientists and engineers, and stimulates future research about a wide range of issues on building environmental systems.

Integration of chaos theory and mathematical models in building simulation: Part II: Conceptual frameworks

Current mathematical models in building research have been limited in most studies to linear dynamics systems. A literature review of past studies investigating chaos theory approaches in building simulation models suggests that as a basis chaos model is valid and can handle the increasing complexity of building systems that have dynamic interactions among all the distributed and hierarchical systems on the one hand, and the environment and occupants on the other. The review also identifies the paucity of literature and the need for a suitable methodology of linking chaos theory to mathematical models in building design and management studies. This study is broadly divided into two parts and presented in two companion papers. Part (I), published in the previous issue, reviews the current state of the chaos theory models as a starting point for establishing theories that can be effectively applied to building simulation models. Part (II) develop conceptual frameworks that approach current model methodologies from the theoretical perspective provided by chaos theory, with a focus on the key concepts and their potential to help to better understand the nonlinear dynamic nature of built environment systems. Case studies are also presented which demonstrate the potential usefulness of chaos theory driven models in a wide variety of leading areas of building research. This study distills the fundamental properties and the most relevant characteristics of chaos theory essential to (1) building simulation scientists and designers (2) initiating a dialogue between scientists and engineers, and (3) stimulating future research on a wide range of issues involved in designing and managing building environmental systems.

A normative approach to multi-agent systems for intelligent buildings

Building Management Systems (BMS) are widely adopted in modern buildings around the world in order to provide high-quality building services, and reduce the running cost of the building. However, most BMS are functionality-oriented and do not consider user personalization. The aim of this research is to capture and represent building management rules using organizational semiotics methods. We implement Semantic Analysis, which determines semantic units in building management and their relationship patterns of behaviour, and Norm Analysis, which extracts and specifies the norms that establish how and when these management actions occur. Finally, we propose a multi-agent framework for norm based building management. This framework contributes to the design domain of intelligent building management system by defining a set of behaviour patterns, and the norms that govern the real-time behaviour in a building.

Avaliação do potencial de microgeração em despacho econômico para atendimento aos requisitos de etiquetagem de edifícios

The discussions about the energy rationalization are gaining more and more space on the everyday of engineers and other professionals in the field of energy. A greater focus is being tied to commercial buildings, because they are one of the biggest responsible for the high energetic expenditure according to the National Energetic Balance, especially by the use of air conditioners for the people’s thermal comfort. Such finding made INMETRO to develop a building labeling procedure through th National Program of Electric Energy Conservation in Buildings; by means of this systematic, the built areas are classified by levels that go from A(the best) to E(the worst), taking into account envelopment, illumination system and air conditioning. A bonus process based on water rationalization, use of renewable energy sources, cogeneration systems or technical innovations, allows the classification to be changed up to one level. A study made exactly on a commercial building, the building of Foundation for Technological and Scientific Development located inside of the College of Engineering of Guaratinguetá, sought to identify technical/economic alternatives for the building certification and appealed to the bonus based on water rationalization. The present study is based on analysis of deploying a cogeneration system formed by internal combustion engine and an absorption refrigeration system as bonus alternative, so that the costs are analyzed regarding energy consumption and use of the motor. With the calculations and results, the viability of the building to receive a bonus from INMETRO through its National Program for Energy Conservation in Buildings is studied and concluded from this study whether or not you can get a better level of energy efficiency for the building in question... (Complete abstract click electronic access below)

Methodology of CO2 emission evaluation in the life cycle of office building facades

The construction industry is one of the greatest sources of pollution because of the high level of energy consumption during its life cycle. In addition to using energy while constructing a building, several systems also use power while the building is operating, especially the air-conditioning system. Energy consumption for this system is related, among other issues, to external air temperature and the required internal temperature of the building. The facades are elements which present the highest level of ambient heat transfer from the outside to the inside of tall buildings. Thus, the type of facade has an influence on energy consumption during the building life cycle and, consequently, contributes to buildings' CO2 emissions, because these emissions are directly connected to energy consumption. Therefore, the aim is to help develop a methodology for evaluating CO2 emissions generated during the life cycle of office building facades. The results, based on the parameters used in this study, show that facades using structural glazing and uncolored glass emit the most CO2 throughout their life cycle, followed by brick facades covered with compound aluminum panels or ACM (Aluminum Composite Material), facades using structural glazing and reflective glass and brick facades with plaster coating. On the other hand, the typology of facade that emits less CO2 is brickwork and mortar because its thermal barrier is better than structural glazing facade and materials used to produce this facade are better than brickwork and ACM. Finally, an uncertainty analysis was conducted to verify the accuracy of the results attained. (C) 2011 Elsevier Inc. All rights reserved.