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1
SUMMA, SERENA. "Energy efficiency of buildings: Dynamic simulations and experimental analyses." Doctoral thesis, Università Politecnica delle Marche, 2022. http://hdl.handle.net/11566/299081.
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Gli studi riportati in questa tesi aggiungono all'attuale corpus di conoscenze un contributo riguardante sia i nuovi modelli di calcolo dinamico orario, utili per una valutazione affidabile del fabbisogno energetico degli edifici, sia le soluzioni costruttive innovative per migliorare l'efficienza energetica degli edifici e quindi decarbonizzare il settore delle costruzioni attualmente responsabile di circa il 40% delle emissioni globali di gas climalteranti.
Vengono analizzati i nuovi modelli di calcolo contenuti nelle recenti norme pubblicate dal CEN, ovvero la EN ISO 52016-1:2017 "Fabbisogno energetico per il riscaldamento e il raffreddamento, temperature interne e carichi di calore sensibile e latente - Parte 1: Procedure di calcolo" e la relativa EN ISO 52010-1:2017 "Condizioni climatiche esterne - Parte 1: Conversione dei dati climatici per i calcoli energetici". Tali norme offrono la possibilità di valutare il fabbisogno energetico e le temperature operative con un’accuratezza simile a quella dei principali software di simulazione (come Trnsys o Energy Plus), ma in modo meno oneroso. Essendo entrambi gli standard di recente pubblicazione, non esistono in letteratura studi sufficienti ad identificare l'effettiva validità dei metodi e i campi di applicazione. Per questo motivo, utilizzando Tnsys come base, è stata effettuata un'analisi comparativa e di sensibilità, sono state individuate le principali criticità e proposti metodi di calcolo alternativi che, opportunamente integrati nelle norme, ne hanno migliorato l’accuratezza.
A livello sperimentale sono state proposte soluzioni costruttive innovative per migliorare il fabbisogno energetico invernale ed estivo, rispettivamente con lo studio di un edificio iperisolato integrato ad una serra solare dotata di ventilazione meccanica controllata e con lo studio di tre diverse facciate ventilate, anch'esse integrate a ventilazione meccanica controllata, ottimizzate tramite tecniche di machine learning.
Infine, è stato valutato l'impatto del cambiamento climatico sugli attuali NZEB in termini di fabbisogni e comfort, secondo due scenari proposti dall'IPCC (Intergovernmental Panel on Climate Change): RCP4.5, che prevede un'inversione delle emissioni di CO2 entro il 2070 e un aumento massimo della temperatura di 2°C, e RCP8.5, che utilizza un approccio "business-as-usual" e prevede concentrazioni di CO2 quadruple entro il 2100, con un aumento della temperatura di oltre 4°C.The studies reported in this thesis add to the current body of knowledge a contribution concerning both new dynamic hourly calculation models, useful for a reliable assessment of the energy needs of buildings, and innovative construction solutions to improve the energy efficiency of buildings and thus decarbonise the construction sector currently responsible for about 40% of global climate-changing gas emissions. The new calculation models contained in the recent standards published by CEN are analysed, namely EN ISO 52016-1:2017 "Energy demand for heating and cooling, indoor temperatures and sensible and latent heat loads - Part 1: Calculation procedures" and the related EN ISO 52010-1:2017 "Outdoor climatic conditions - Part 1: Conversion of climate data for energy calculations". These standards offer the possibility to estimate energy requirements and operative temperatures with similar accuracy to that of major simulation software (such as Trnsys or Energy Plus), but in a less onerous way. As both standards are recently published, there are not enough studies in the literature to identify the actual validity of the methods and the fields of application. For this reason, using Tnsys as a basis, a comparative and sensitivity analysis was carried out, the main criticalities were identified and alternative calculation methods were proposed which, appropriately integrated into the standards, improved their accuracy. At an experimental level, innovative construction solutions were proposed to improve winter and summer energy requirements, respectively with the study of a hyper-insulated building integrated with a solar greenhouse equipped with controlled mechanical ventilation and with the study of three different ventilated facades, also integrated with controlled mechanical ventilation, optimised using machine learning techniques. Finally, the impact of climate change on current NZEBs in terms of needs and comfort was assessed, according to two scenarios proposed by the IPCC (Intergovernmental Panel on Climate Change): RCP4.5, which foresees a reversal of CO2 emissions by 2070 and a maximum temperature increase of 2°C, and RCP8.5, which uses a "business-as-usual" approach and foresees quadruple CO2 concentrations by 2100, with a temperature increase of more than 4°C.
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Maggiore, Pierpaolo. "Energy retrofit of an office building in Stockholm: energy performance analysis of the cooling system." Thesis, KTH, Installations- och energisystem, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-190960.
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The increasing attention towards energy efficiency issues has triggered an important process involving the renovation of existing buildings and, at the same time, the creation of recognized certifications assuring the quality of the projects. In line with this trend, the Sweco headquarters, an office building characterized by 24700 m2 of floor area and located in Stockholm, was totally retrofitted in 2012 and obtained the Gold rating after being assessed with the Miljöbyggnad certification procedure. The HVAC system was a key element of the retrofit project since one of the final aims was to combine high indoor environment standards with efficient system performances. However, even if the quality of the design is certified, it is possible that, under real operating conditions, complex systems behave differently from the expectations and adjustments are necessary to correct the emerged gap. To achieve this goal, it is essential to identify the points of weakness of the system by carrying out an energy performance analysis, which is the core of this project. In fact, after providing an overview of the building and the retrofit, this work focuses on the analysis of the cooling system installed in the Sweco building and proves the importance of adopting a step-by-step approach to the problem. Therefore, an increasing level of detail characterizes each step of the analysis, whose final aim is to highlight potential aspects to be improved and create a baseline to test possible solutions.SIRen
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Pacillo, Valentina. "Effect of the building zoning on the energy consumption with different dynamic energy simulation tools: ALMABEST versus carnotUIBK." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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In this Thesis a comparison is presented between two software for dynamic energy simulation of buildings coupled to HVAC systems: ALMABEST and carnotUIBK, developed by University of Bologna and University of Innsbruck, respectively. These tools are both developed in MATLAB environment and work using Simulink libraries and Graphical User Interfaces (GUIs).
In the first part of the work, an overview of the main commercially available software for building simulation is given and the description of ALMABEST and carnotUIBK is presented. In particular, it is explained how the user can create the building model by using a series of GUIs, what are the simulation capabilities and limitations of both tools and, finally, a comparison between them in terms of strengths and weaknesses is shown.
In the second part of the Thesis, results obtained from simulations with both tools are presented, focusing on the effects of a different zoning of the same building located in three different European cities, and on how energy demand changes by using an ideal heating system or a floor heating system.
Finally, the effects on the internal temperature and on the heating energy consumption is analysed based on a detailed analysis of the intended use of the building and thus of the behaviour of the occupants within it. In particular, the first floor of the building, divided into four thermal zones and equipped with a floor heating, is considered as a set of offices and the inputs of internal gains and ventilation are considered either constant or with specific hourly profiles according to the working occupation.
Throughout the Thesis, the small percentage deviations of the results obtained with the two tools emphasised that they are valuable and detailed software for the dynamic simulation of buildings and HVAC systems. The comparison highlighted the strengths and weaknesses of the two tools and, in particular, possible future developments.
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Paepcke, Anne. "NANDRAD 1.4 building simulation model." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-230427.
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NANDRAD is a dynamic building energy simulation program. It calulates heating/cooling requirements and electric power consumption with respect to realistic climatic conditions and dynamic room usage. The model includes one-dimensional spatially resolved heat transport through multi-layered walls and thermal storage of solid components (room furniture/building walls). Consequently, massive constructions forms in the European area are very well represented. Further, NANDRAD calculates geometrical long radiation heat exchange inside the room. Heating systems may be modeled with a high level of geometrical detail, i.e. surface heating systems as part of the wall constructions and radiant heaters inside the room. NANDRAD can be applied for passive building simulation, energy optimization and thermal comfort analysis with respect to a very detailed building representation. In this terms, the model supports the simulation of a large number of zones and walls without need for subgrouping or other model reduction strategies.
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Lapioli, Simone. "Energy retrofit of an office building in Stockholm: feasibility analysis of an EWIS." Thesis, KTH, Installations- och energisystem, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-190992.
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The energy retrofit of existing buildings has always been a challenging task to accomplish. The example of the Swecohuset building, proves how an integrated approach design between architectural and energetic aspects as well as the use of well-known and efficient technologies are key aspects to achieve the energy-saving goal. This work, in the first part describes the Swecohuset retrofit process, along with the reasons behind the choices which have led to the current result of a reduction by 2/3 of the energy need for space conditioning purposes. Then, in the second part, after a brief focus on the passive aspects which characterize the current energy performance of the building, it is carried out a feasibility analysis of an EWIS (external wall insulation system) by studying its interaction with a complex system as an optimization problem, with the main purpose of understanding the basis of the BPO and explore further building potentialities.SIRen
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O'Kelly, Matthew E. "Dynamic Simulation of a Superinsulated Residential Structure with a Hybrid Desiccant Cooling System." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1345442100.
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Kos, Cristoffer, and Kristoffer Hermansson. "BUILDING AND SIMULATING DYNAMIC MODELS OF DISTRICT HEATING NETWORKS WITH MODELICA : Using Matlab to process data and automate modelling and simulation." Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-36107.
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District heating systems are common in Nordic countries today and accounts for a great portion of the heat demand. In Sweden, total district heating end use in the last years has been around 50 TWh and district heating accounts for roughly 50 % of the total heat demand. Suppliers of district heating must balance demand and supply, often in large and complex networks. Heat propagation can be in the range of hours and it is not known in detail how the heat will propagate during transient conditions. A dynamic model has been developed in OpenModelica and a method for modeling, handling data, simulating and visualizing the results of a district heating network was developed using Matlab as core. Data from Mälarenergi AB, a district heating producer and grid operator, was used for validation of the model. Validation shows that the model works well in predicting heat propagation and temperature distribution in the network and that the model can be scaled up to a large number of heat exchangers and pipes. The model is robust and can handle bi-directional and reversing flows in complex ring structures. It was concluded that OpenModelica together with Matlab is a good combination for creating models of district heating networks, as a high degree of standardization and automation can be achieved. This, together with visualization of the heat propagation, makes it useful for the understanding of the district heating network during transient conditions.Smarta Flöden
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BELTRAMI, Alberto. "Trnsys integrated modeling support tool for a fast building-plant system design." Doctoral thesis, Università degli studi di Bergamo, 2016. http://hdl.handle.net/10446/52297.
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The present thesis stems from the benefits of the application of energy analysis in any stage of building-plant system design. The research highlights the barriers that prevent this integration and finally proposes the development of a dynamic modeling support tool able to simulate, with a reasonable workload, a very large number of integrated building-plant systems with different scales and resolutions, in order to have a guided design support for architects and HVAC designers/engineers, reducing their modeling effort and errors. The starting point is represented by a flexible and detailed model created with the calculation engine TRNSYS, which allow for the dynamic and integrated simulation of the building envelope, all the heating plant subsystems, and all the plant components related to the production of domestic hot water.
The research explores then strategies and simplifications that can considerably reduce the number of necessary inputs for the simulations, thus minimizing the modeling, implementation and simulation runtime of the model, while still maintaining an acceptable degree of accuracy with respect to the computational results and real energy consumptions. Those results are achieved by defining a methodology, which consists in developing a sizing protocol and a simplification protocol and applying them to real life, complex case studies, first modeling detailed models and progressively enhancing the level of simplification. At each progressive simplification step, the comparison with the detailed model results is given in terms of building energy needs, power curves, efficiencies, modeling and simulation workloads. In particular results show that the accuracy of the most simplified model is always below the 16% with respect to the most detailed model, with a 90% modeling and simulation workload reductions, able to make the tool easy to be adopted at every stage of building-plant system design.
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BELTRAMI, Alberto. "Trnsys integrated modeling support tool for a fast building-plant system design." Doctoral thesis, Università degli studi di Bergamo, 2016. http://hdl.handle.net/10446/222107.
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The present thesis stems from the benefits of the application of energy analysis in any stage of building-plant system design. The research highlights the barriers that prevent this integration and finally proposes the development of a dynamic modeling support tool able to simulate, with a reasonable workload, a very large number of integrated building-plant systems with different scales and resolutions, in order to have a guided design support for architects and HVAC designers/engineers, reducing their modeling effort and errors. The starting point is represented by a flexible and detailed model created with the calculation engine TRNSYS, which allow for the dynamic and integrated simulation of the building envelope, all the heating plant subsystems, and all the plant components related to the production of domestic hot water. The research explores then strategies and simplifications that can considerably reduce the number of necessary inputs for the simulations, thus minimizing the modeling, implementation and simulation runtime of the model, while still maintaining an acceptable degree of accuracy with respect to the computational results and real energy consumptions. Those results are achieved by defining a methodology, which consists in developing a sizing protocol and a simplification protocol and applying them to real life, complex case studies, first modeling detailed models and progressively enhancing the level of simplification. At each progressive simplification step, the comparison with the detailed model results is given in terms of building energy needs, power curves, efficiencies, modeling and simulation workloads. In particular results show that the accuracy of the most simplified model is always below the 16% with respect to the most detailed model, with a 90% modeling and simulation workload reductions, able to make the tool easy to be adopted at every stage of building-plant system design.
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Amin, Majdi Talal. "Dynamic Modeling and Verification of an Energy-Efficient Greenhouse With an Aquaponic System Using TRNSYS." University of Dayton / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1450432214.
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Eriksson, Rickard, and Pontus Andersson. "Thermal storage solutions for a building in a 4th generation district heating system : Development of a dynamic building model in Modelica." Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-40114.
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The world is constantly striving towards a more sustainable living, where every part of contribution is greatly appreciated. When it comes to heating of buildings, district heating is often the main source of heat. During specific times, peak demands are created by the tenants who are demanding a lot of heat at the same time. This demand peak puts a high load on the piping system as well as the need for certain peak boilers that run on non-environmental friendly peak fuel. One solution that is presented in this degree project that solves the time difference between production and demand is by utilizing thermal storage solutions. A dynamic district heated building model is developed with proper heat propagation in the pipelines, thermal inertia in the building and heat losses through the walls of the building. This is all done utilizing 4th generation district heating temperatures. Modelica is the tool that was used to simulate different scenarios, where the preheating of indoor temperature is done to mitigate the possibility for demand peaks. Using an already existing model, implementation and adjustments are done to simulate thermal storage and investigate its effectiveness in a 4th generation district heating system. The results show that short-term energy storage is a viable solution in concrete buildings due to high building mass. However, combining both 4th generation district heating with storage in thermal mass is shown not to be suitable due to low temperatures of supply water, which is not able to increase the temperature of the building’s mass enough.
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PICCO, Marco. "Dynamic energy simulation toward integrated design of non-residential buildings. Model description simplifications and their impact on simulation results." Doctoral thesis, Università degli studi di Bergamo, 2014. http://hdl.handle.net/10446/222120.
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The present thesis stems from the benefits of the application of energy analysis in the early-stage building design. The research highlights the barriers that prevent this early integration and finally proposes the development of a simplified modelling methodology tailored around the optimization of energy efficiency during early-stage design. In general, the research aims to identify (a) the accuracy level obtainable through progressive simplifications of the building model, (b) the most significant building parameters with respect to the model accuracy and (c) the maximum level of simplification both able to ensure the respect of time requirements dictated by early-stage building design and to maintain an acceptable level of correctness. Those results are achieved by defining a methodology, which consists in developing a simplification protocol and applying it to a suitable number of case studies featuring large non-residential buildings starting from a detailed model and progressively enhancing the level of simplification. The protocol is based on the use of EnergyPlus software both to develop a detailed model of the building under various system hypothesis, and to simplify the model until a reasonable accuracy is still attained by the energy simulations. At each progressive simplification step, a comparison with the detailed model results is given in terms of building energy needs and power curves of the system. The quantitative differences between detailed and simplified model are analysed to determine the quality of the results of the simplified model. The results of the case studies are then utilized to propose the implementation of a simplified energy simulation tool based on the aforementioned protocol.
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CIRRINCIONE, Laura. "SIMULATION AND EXPERIMENTAL METHODS FOR IMPROVING ENERGY EFFICIENCY, ENVIRONMENTAL PERFORMANCE AND RESILIENCE OF SINGLE AND CLUSTERED GROUPS OF BUILDINGS." Doctoral thesis, Università degli Studi di Palermo, 2021. http://hdl.handle.net/10447/496760.
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Energy consumption in the building sector is responsible for 36% of the energy use worldwide (corresponding to 39% of the total energy-related CO2 emissions), while at the European level the building sector accounts for a share of the total energy consumption comprised between 25% and 40% (corresponding to about 35% of the overall CO2 emissions throughout Europe). Concerning the Italian context, instead, such figures stand at about 40% and 17.5% for the energy consumption and for the CO2 emissions, respectively. In light of this, much attention has been paid, at global, European and single countries (national) levels on the important aspects regarding the reduction of energy consumption and the related decrease of greenhouse gases emissions in order to improve the environmental performance and the resilience of the building sector, both by the political and legislative bodies and by the scientific community.
Despite the effort spent in putting into effect such actions, in recent years, the energy consumption in the building sector has experienced an increase, particularly in Italy. That is why more exertion in advancing the current measures and finding new innovative strategies to improve energy efficiency and resilience of buildings are of paramount importance.
The research work carried out during the PhD course, and presented in this doctoral thesis, arises precisely from this context and from the desire to contribute to the question. To this end, strategies and solutions aimed at improving the energy efficiency, environmental performance and resilience of buildings, were assessed in detail by means of both experimental and modeling approaches. Accordingly, a number of case studies were designed and conducted to estimate how the adoption of some proposed interventions could impact the energy consumption, the indoor thermal comfort and contribute to the reduction of the CO2 emissions of buildings. In doing this, two important aspects influencing the afore-mentioned strategies and solutions were also considered, namely, the effect of the climatic conditions characterizeing the considered sites and the spatial scale at which they are applied, from the single building to a wider group of them, and how such perspective may influence the surrounding areas.
The outcomes of the carried-out work put in evidence how accurate planning, construction and management of buildings, according to the peculiarities of the sites in which they are located, can contribute to reduce the energy and environmental burden of the building sector and at the same time help in the enhancement of urban resilience. Proper solution sets can, in fact, enable the building resilience against the outdoor stresses and simultaneously guarantee a regenerative indoor environment.
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Bouwer, Werner. "Designing a dynamic thermal and energy system simulation scheme for cross industry applications / W. Bouwer." Thesis, North-West University, 2004. http://hdl.handle.net/10394/592.
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The South African economy, which is largely based on heavy industry such as minerals
extraction and processing, is by nature very energy intensive. Based on the abundance of coal
resources, electricity in South Africa remains amongst the cheapest in the world. Whilst the
low electricity price has contributed towards a competitive position, it has also meant that our
existing electricity supply is often taken for granted. The economic and environmental
benefits of energy efficiency have been well documented. Worldwide, nations are beginning
to face up to the challenge of sustainable energy - in other words to alter the way that energy
is utilised so that social, environmental and economic aims of sustainable development are
supported.
South Africa as a developing nation recognises the need for energy efficiency, as it is the most
cost effective way of meeting the demands of sustainable development. South Africa, with its
unique economic, environmental and social challenges, stands to benefit the most from
implementing energy efficiency practices. The Energy Efficiency Strategy for South Africa
takes its mandate from the South African White Paper on Energy Policy. It is the first
consolidated governmental effort geared towards energy efficiency practices throughout
South Africa. The strategy allows for the immediate implementation of low-cost and no-cost
interventions, as well as those higher-cost measures with short payback periods. An initial
target has been set for an across sector energy efficiency improvement of 12% by 2014.
Thermal and energy system simulation is globally recognised as one of the most effective and
powerful tools to improve overall energy efficiency. However, because of the usual extreme
mathematical nature of most simulation algorithms, coupled with the historically academic
environment in which most simulation software is developed, valid perceptions exist that
system simulation is too time consuming and cumbersome. It is also commonly known that
system simulation is only effective in the hands of highly skilled operators, which are
specialists in their prospective fields. Through previous work done in the field, and the design
of a dynamic thermal and energy system simulation scheme for cross industry applications, it
was shown that system simulation has evolved to such an extent that these perceptions are not
valid any more.
The South African mining and commercial building industries are two of the major
consumers of electricity within South Africa. By improving energy efficiency practices within
the building and mining industry, large savings can be realised. An extensive investigation of
the literature showed that no general suitable computer simulation software for cross industry
mining and building thermal and energy system simulation could be found. Because the
heating, ventilation and air conditioning (HVAC) of buildings, closely relate to the ventilation
and cooling systems of mines, valuable knowledge from this field was used to identify the
requirements and specifications for the design of a new single cross industry dynamic
integrated thermal and energy system simulation tool.
VISUALQEC was designed and implemented to comply with the needs and requirements
identified. A new explicit system component model and explicit system simulation engine,
combined with a new improved simulation of mass flow through a system procedure,
suggested a marked improvement on overall simulation stability, efficiency and speed. The
commercial usability of the new simulation tool was verified for building applications by
doing an extensive building energy savings audit. The new simulation tool was further
verified by simulating the ventilation and cooling (VC) and underground pumping system of a
typical South African gold mine. Initial results proved satisfactory but, more case studies to
further verify the accuracy of the implemented cross industry thermal and energy system
simulation tool are needed. Because of the stable nature of the new VISUALQEC simulation
engine, the power of the simulation process can be further extended to the mathematical
optimisation of various system variables.
In conclusion, this study highlighted the need for new simulation procedures and system
designs for the successful implementation and creation of a single dynamic thermal and
energy system simulation tool for cross industry applications. South Africa should take full
advantage of the power of thermal and energy system simulation towards creating a more
energy efficient society.Thesis (Ph.D. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2005.
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Cipriano, Jordi. "Energy characterization and experimental validation of natural ventilated semitransparent double skin PV components." Doctoral thesis, Universitat de Lleida, 2014. http://hdl.handle.net/10803/286038.
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Els sistemes integrats Fotovoltaics (FV) de doble pell, són components de l'edifici que combinen les funcions d'envolvent, amb les d'il·luminació natural, generació d'electricitat i generació d'energia tèrmica. La modelització dels processos de transferència d'energia d'aquests components, especialment en situacions de convecció natural, planteja una alta complexitat i és un dels inconvenients principals per a una disseminació massiva d'aquesta tecnologia. En les últimes dècades s'han dut a terme diferents intents per a superar aquest inconvenient i s'han desenvolupat diferents models de simulació. No obstant això, molt pocs estudis s'han enfrontat a una anàlisi detallat del rang de validesa d'aquestes correlacions i models i tampoc de les limitacions inherents en la seva definició. El segon inconvenient per a una àmplia propagació d'aquests components FV complexos, està relacionat amb la dificultat per a dur a terme campanyes experimentals de mesura del seu comportament energètic en condicions reals. A més dels mencionats inconvenients, s'hi afegeix una gran manca de coneixement per a la cal·libració dels models de simulació de components FV ventilats. Aquesta tesi doctoral aborda aquests inconvenients i introdueix una metodologia general per a la caracterització energètica i la validació experimental dels components FV ventilats. Aquesta investigació també contribueix a augmentar el coneixement sobre mètodes per a integrar el desenvolupament de models de simulació dinàmica, amb enfocaments innovadors per a la seva cal·libració.Los sistemas integrados Fotovoltaicos (FV) de doble piel, son components del edificio que combinan las funciones de envolvente, con las de illuminación natural, generación eléctrica y generación de energía térmica. La modelización de los procesos de transferència de energía de estos components, especialmente en situaciones de convección natural, plantea una alta complejidad y es uno de los inconvenientes principales para una diseminación masiva de esta tecnología. En las últimas décadas, se han llevado a cabo diferentes intentos para a superar este inconveniente y se han desarrollado diferentes modelos de simulación para evaluar la eficiéncia energética global de estos sistemas. Sin embargo, muy pocos estudios se han enfrentado al análisis detallado del rango de validez de estas correlaciones y modelos y tampoco de las limitaciones inherentes en su definición. El segundo inconvenient para una amplia propagación de estos components FV complejos, está relacionado con la dificultad para llevar a cabo campañas experimentales de medida de su comportamento energético en condiciones reales. Además de estos inconvenientes, se constata una carencia significativa de conocimiento sobre métodos para la calibración de los modelos de simulación de componentes FV ventilados . Esta tesis doctoral aborda todos estos inconvenientes mencionados anteriormente e introduce una metodología general para la caracterización energética y la validación experimental de los componentes FV ventilados. Esta investigación también contribuye a aumentar el conocimiento sobre métodos para integrar el desarrollo de modelos de simulación dinámica, con estrategias innovadoras para su calibración.
Double skin semi transparent components with Photovoltaic integrated systems are building components which combine functions of the building envelope with natural lighting, electricity and thermal energy generation. The energy transfer modeling of these components, especially under free convection situations, raises a high complexity and is the first main drawback for a massive dissemination of this technology. Many attempts to fill this gap have been undertaken and some dynamic simulation models of these components have been obtained in the last decades. However, very few studies have faced a detailed analysis of the valid range of these mathematical expressions and simulation models and of the restrictions entailed. The second drawback for a wide spread of these complex PV components is related to the difficulty in setting up monitoring and experimental campaigns to measure their real energy performance with sufficient accuracy and precision. Besides these drawbacks, there is also a lack of knowledge on methods for calibrating building energy simulation models in general, and specifically in the calibration of dynamic models of ventilated PV components. This PhD thesis addresses these existing drawbacks and introduces an overall methodology for the energy characterization and experimental validation of ventilated PV components. This research also contributes in increasing the knowledge on methods for coupling the mathematical development of dynamic simulation models with innovative approaches for its calibration with experimental measures.
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CABONI, OMAR. "La simulazione termoenergetica dinamica del sistema edificio-impianti applicata a un caso studio:l'azienda ospedaliera "G. Brotzu"." Doctoral thesis, Università degli Studi di Cagliari, 2016. http://hdl.handle.net/11584/266777.
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This research has developed a first part that involved the validation test of building energy
modeling software, in order to compare calibrate numerical solution to experimental
measures of energy demand and thermo-hygrometric parameters. Once installed in the
Internal Medicine Department (of the AOB Hospital in Cagliari) a building management
system for monitoring that measures, this study has developed the use of a data-driven
modeling, for implement numerical models with the aid of DesignBuilder software.
The management of the input variables, the monitoring data and the building performance
simulation output, allow to create an effective tool for the design and the operation of
buildings. The final aim of this research is to use in current practice that useful and
effective tool in operational support, in order to direct the choice of best energy efficiency
and energy saving solutions.
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Šteffek, Libor. "Simulace energetické náročnosti a reálné užívání budov." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-433629.
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This dissertation thesis primarily focuses on the experimental measurement of energy consumption of a given energy-passive family house as well as theoretical research in the field of energy calculations using computer simulations. The results of quasi-stationary and dynamic simulations, with varying computational and real-time climate data, are compared with experimental measurements. Using the dynamic calculation model, which was validated by actually measured data, the relationship between architectural design and the energy performance of the building was analyzed. The influence of selected different operating modes for heat consumption on heating, cooling, ventilation, and interior overheating is observed. The result of the mutual interaction of several input parameters of variant solutions provides the basis for optimization of the whole design.
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Negrão, Cezar O. R. "Conflation of computational fluid dynamics and building thermal simulation." Thesis, University of Strathclyde, 1995. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21238.
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The present work is a contribution towards the integration of building simulation tools in order to better represent the complexity of the real world. It attempts to overcome certain shortfalls of contemporary simulation applications with respect to indoor air flows. As a result, the evaluation of building energy consumption and indoor air quality is expected to be improved. Advanced fluid flow models (as employed within Building Thermal Simulation - BTS - and Computational Fluid Dynamics - CFD) with different degrees of detail were investigated and their modelling deficiencies identified. The CFD technique which defines the fluid flow on a micro scale was integrated into BTS in which fluid flow is described in a larger scale. The resulting combined approach strengthens the modelling potential of each methodology by overcoming their specific deficiencies. BTS's inability to predict air flow property gradients within a single space was surmounted and the difficult of estimating CFD boundary conditions are now supplied by BTS. The conflation approach is expected to be employed where gradients of indoor air flow properties can be considered crucial to the evaluation of thermal comfort and energy consumption. The BTS environment, ESP-r, was elected to perform the current work and a new CFD program, dfs, was specifically developed for the analysis of three-dimensional, turbulent, transient air flow. Finally, the two approaches were integrated. The integration work focuses on the CFD boundary conditions where the interactions of BTS and CFD take place; these occur at the inside zone surfaces and at the zone openings. Three conflation approaches were devised addressing different degrees of complexity and sophistication. The first one, involving the two types of zone boundaries, corresponds to a simple approach where the BTS and CFD systems exchange information without any direct interaction. The second approach consists of three other schemes to handle the thermal coupling at the internal zone surfaces. The third approach comprises coupling between the nodal network approach as employed by the BTS environment, and the continuity and momentum equations in the CFD technique. A validation methodology consisting of analytical validation, intermodel comparison and empirical validation is described and applied. The technique is shown to be adequate for modelling indoor air flows when compared to existing models. Three situations, covering the different types of air flows encountered within buildings are discussed to demonstrate the combined method's applicability when compared with the nodal network approach. Finally, general conclusions are presented and some possible future work is identified showing that the developed methodology is very promising.
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Figueiredo, António José Pereira de. "Energy efficiency and comfort strategies for Southern European climate : optimization of passive housing and PCM solutions." Doctoral thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/17291.
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Doutoramento em Engenharia CivilPursuing holistic sustainable solutions, towards the target defined by the United Nations Framework Convention on Climate Change (UNFCCC) is a stimulating goal. Exploring and tackling this task leads to a broad number of possible combinations of energy saving strategies than can be bridged by Passive House (PH) concept and the use of advanced materials, such as Phase Change Materials (PCM) in this context. Acknowledging that the PH concept is well established and practiced mainly in cold climate countries of Northern and Central Europe, the present research investigates how the construction technology and energy demand levels can be adapted to Southern Europe, in particular to Portugal mainland climate. For Southern Europe in addition to meeting the heating requirements in a fairly easier manner, it is crucial to provide comfortable conditions during summer, due to a high risk of overheating. The incorporation of PCMs into building solutions making use of solar energy to ensure their phase change process, are a potential solution for overall reduction of energy consumption and overheating rate in buildings. The PH concept and PCM use need to be adapted and optimised to work together with other active and passive systems improving the overall building thermal behaviour and reducing the energy consumption. Thus, a hybrid evolutionary algorithm was used to optimise the application of the PH concept to the Portuguese climate through the study of the combination of several building features as well as constructive solutions incorporating PCMs minimizing multi-objective benchmark functions for attaining the defined goals.
A procura de soluções de sustentabilidade holísticas que conduzam ao cumprimento dos desafios impostos pela Convenção-Quadro das Nações Unidas sobre as Alterações Climáticas é uma meta estimulante. Explorar esta tarefa resulta num amplo número de possíveis combinações de estratégias de poupança energética, sendo estas alcançáveis através do conceito definido pela Passive House (PH) e pela utilização de materiais de mudança de fase que se revelam como materiais inovadores neste contexto. Reconhecendo que este conceito já se encontra estabelecido e disseminado em países de climas frios do centro e norte da Europa, o presente trabalho de investigação foca-se na aplicabilidade e adaptabilidade deste conceito e correspondentes técnicas construtivas, assim como os níveis de energia, para climas do sul da Europa, nomeadamente em Portugal continental. No sudeste da Europa, adicionalmente à necessidade de cumprimento dos requisitos energéticos para aquecimento, é crucial promover e garantir condições de conforto no verão, devido ao elevado risco de sobreaquecimento. A incorporação de materiais de mudança de fase nas soluções construtivas dos edifícios, utilizando a energia solar para assegurar o processo de mudança de fase, conduz a soluções de elevado potencial para a redução global da energia consumida e do risco de sobreaquecimento. A utilização do conceito PH e dos materiais de mudança de fase necessitam de ser adaptados e otimizados para funcionarem integrados com outros sistemas ativos e passivos, melhorando o comportamento térmico dos edifícios e minimizando o consumo energético. Assim, foi utilizado um algoritmo evolutivo para otimizar a aplicabilidade do conceito PH ao clima português através do estudo e combinação de diversos aspetos construtivos, bem como o estudo de possíveis soluções construtivas inovadoras com incorporação de materiais de mudança de fase minimizando as funções objetivo para o cumprimento das metas inicialmente definidas.
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Han, Yilong. "Urban Building Networks' Thermal-Energy Dynamics: Exploring, Mitigating, and Optimizing Inter-Building Effects." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/72956.
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Cities occupy 2% of the earth's surface, and yet consume 75% of the world's resources. As a major contributor to rapidly growing global energy expenditures, urban buildings are often designed and operated inefficiently despite their significant contributions to carbon emissions, triggering environmental deterioration locally and worldwide. Moreover, ongoing industrialization and urbanization pose challenges for achieving a more sustained and resilient built environment. The goal of this PhD research is to advance our understanding of urban building networks' thermal-energy dynamics in order to achieve sustainable energy conservation in the built environment. Considering buildings as networks rather than as stand-alone entities highlights the inextricably linked and interwoven relationship between urban micro-climates and buildings. With this approach, I strive to explore, mitigate, and optimize the mutual influences of the Inter-Building Effect (IBE) in dense urban settings through numerical and empirical analyses. My research also draws inspiration for investigating solutions to complex engineering problems from nature, as I seek to understand synergies between building and biological systems to discover innovative connections and integrate biology to transform buildings through sustainable building network designs. This dissertation contains three interdependent projects to explore, mitigate and optimize the IBE, respectively. I first developed a systematic approach to separately assess the complex interactions that constitute the IBE in dense urban settings and conducted cross-regional analyses in a dynamic simulation environment. Having disaggregated, quantified and understood the effects of mutual shading and mutual reflection within a network of buildings, I then, in the second project, examined different measures to mitigate the negative IBE impact under certain circumstances (e.g. directional reflective optical properties of building facades and thermal storage technologies). These two projects extended prior work that examined the potential for a biological system retroreflective surface to reduce IBE in urban building networks. Therefore, in my third project, I introduced a broad framework that draws parallels between natural and built environment systems through a levels-of-organization perspective leading to the search for an optimal status of the IBE. Inspired from a self-regulating phenomenon of plant density, I presented and discussed an approach to determine optimal urban building network density as an example for how this framework can support cross-level assessment. The findings expand and deepen our understanding of the IBE and provide insights on the strategies to mitigate the negative mutual impact within dense urban building networks. This research contributes a unique and holistic perspective on the interdependencies in the urban building network system. To design density-optimal building networks will become increasingly important to sustainable urban development and smart growth as clusters of dense urban settings continue to grow due to rapid urbanization and population migration in the next few decades.Ph. D.
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Aijazi, Arfa N. (Arfa Nawal). "Machine learning paradigms for building energy performance simulations." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111280.
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Thesis: S.M. in Building Technology, Massachusetts Institute of Technology, Department of Architecture, 2017.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 134-138).
This research seeks to overcome a technical limitation of building energy performance simulations, the computation time, by using surrogate modeling, a class of supervised machine learning techniques where the output is a performance metric. Though early machine learning methods were introduced decades ago, the convergence of computation power, more data collection, and maturation of methods has led to an explosion in the types of problems machine learning can be applied to. A comparison of several common surrogate modeling techniques found that parametric radial basis functions and Kriging are highly accurate regression techniques for predicting building energy consumption. For a single climate, these regression techniques can predict the total energy consumption to within 2% of a detailed energy simulation, but in a fraction of a second, about five orders of magnitude faster. Integrating a Kriging surrogate model with multi-objective optimization, allowed for finding retrofit recommendations in Lisbon that are cost effective and can reduce the present-day energy consumption of an existing apartment by up to 20%. Similarly, integrating surrogate model with multi-objective optimization can find retrofit options in Boston that can reduce the present-day energy consumption and unmet hours in the future. Combined this body of works strives to add value to existing building energy performance simulation tools as more than just an exercise for code compliance but as a real design tool that can guide decision making.
by Arfa Nawal Aijazi.
S.M. in Building Technology
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Vesterberg, Jimmy. "Improved building energy simulations and verifications by regression." Doctoral thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-117248.
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It is common with significant differences between calculated and actual energy use in the building sector. These calculations are often performed with whole building energy simulation (BES) programs. In this process the analyst must make several assumptions about the studied building and its users. These calculations are often verified with measured data through the EUI benchmark indicator which is calculated by normalizing the annual energy use (from the grid) with the floor area. Due to the highly aggregated nature of the EUI indicator it is problematic to use this indicator to deduce erroneous assumptions in the calculations. Consequently, the learning process is often troublesome. Against this background, the main aim of this thesis has been to develop methods that can provide feedback (key building performance parameters) from measured data which can be used to increase simulation accuracy and verify building performance. For the latter, regression models have been widely used in the past for verifying energy use. This thesis has the focus on the use of regression analysis for accurate parameter identification to be used to increase the agreement between BES predictions and actual outcome. For this, a BES calibration method based on input from regressed parameters has been developed which has shown promising features in terms of accurate predictions and user friendliness. The calibration method is based on input from regressed estimations of air-to-air-transmission losses, including air leakage (heat loss factor) and ground heat loss. Since it is known that bias models still can give accurate predictions, these parameters have been evaluated in terms of robustness and agreement with independent calculations. In addition, a method has been developed to suppress the bias introduced in the regression due to solar gain. Finally, the importance of calibrated simulations was investigated. The regressed parameters were found to be robust with yearly variations in the heat loss factor of less than 2%. The regressed estimates of ground heat loss were also in good agreement with independent calculations. The robustness of the heat loss factor based on data from periods of substantial solar gain was also found to be high, with an average absolute deviation of 4.0%. The benefit with calibrated models was mainly found to be increased accuracy in predictions and parameters in absolute terms. With increased access to measured data and the promising results in this thesis it is believed that the presented regression models will have their place in future energy quantification methods for accessing energy performance of buildings.Det är vanligt med betydande skillnader mellan beräknad och verklig energi användning inom byggnadssektorn. Dessa beräkningar utförs ofta med hjälp av byggnads energi simulerings (BES) program där användaren måste göra ett flertal antaganden om den aktuella byggnaden och dess brukare. Det beräknade resultatet kontrolleras ofta i ett senare skede mot byggnadens faktiska behov av energi från nätet. I denna kontroll är det dock svårt att särskilja den energimängd som byggnaden behöver och den del som är kopplad till brukaren. Detta gör att lärdomarna som kan dras i denna verifieringsprocess ofta blir begränsade. Mot denna bakgrund, har det huvudsakliga syftet med denna avhandling varit att utveckla metoder som kan användas för att extrahera information om byggnadens prestanda från mätdata. De extraherade parametrarna skall kunna användas för att öka noggrannheten i prediktioner från BES modeller och för att verifiera byggnaders prestanda. Regression analys har ofta använts i det senare fallet i avseendet att verifiera energi användning. Denna avhandling fokuserar på att utveckla regressionsmodeller som ger en hög noggrannhet i modellens parametrar som möjliggör att de bl.a. kan användas för att kalibrera BES modeller och på så sätt minska den vanligt förekommande diskrepans mellan simulerat och faktiskt utfall. En BES kalibrerings metodik har utvecklats baserat på skattning av transmissions förluster ovan mark, inklusive luftläckage (värmeförlust koefficient) samt värmeförlust till mark (G) med hjälp av regressionsanalys. Denna kalibrerings metodik uppvisar lovande egenskaper i form av noggranna prediktioner och användarvänlighet. Goda prediktioner är dock ingen garanti för att modellens ingående parametrar är fysikaliskt rimliga. Därför har regressionsmodellernas parametrar utvärderats i termer av robusthet och överensstämmelse med oberoende beräkningar. Dessutom har en metod utvecklats för att minimerar solens inverkan på regressionsskattningarna. Slutligen har vikten av kalibrerade simuleringar undersökts. Parametrarna i de framtagna regressionsmodellerna visade sig vara robusta, med årliga variationer i värmeförlust koefficient mindre än 2%. Ytterligare visade sig G var i god överensstämmelse med oberoende beräkningar. Robustheten i värmeförlustfaktorn baserad på data från perioder av betydande solstrålning konstaterades också att vara hög, med en genomsnittlig absolut avvikelse på 4.0%. Fördelen med kalibrerade modeller visade sig främst vara en ökad noggrannhet i prediktioner och modell parametrar i absoluta tal. Med ökad tillgång till mätdata och lovande resultat i denna avhandling är det författarens övertygelse att de presenterade regressionsmodellerna kommer att ha sin plats i framtida bedömnings metoder av byggnaders energiprestanda.
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Zhai, Zhiqiang 1971. "Developing an integrated building design tool by coupling building energy simulation and computational fluid dynamics programs." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/17617.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Architecture, 2003.Includes bibliographical references (p. 237-246).
Building energy simulation (ES) and computational fluid dynamics (CFD) can play important roles in building design by providing essential information to help design energy-efficient, thermally comfortable and healthy buildings. However, separate applications of ES and CFD usually cannot give an accurate prediction of building thermal and airflow behaviors due to the partial modeling of the problem. An integration of ES and CFD can eliminate many of the assumptions used in ES and CFD because of the complementary nature of ES and CFD results. This thesis studies the fundamentals, implementation and application of ES and CFD coupling, significantly advancing the knowledge and experience in this area. The study has been focused on the iterative coupling of individual ES and CFD programs, which shows good potential of providing reasonable results with acceptable computing costs. The research first analyzes the principles and challenges of ES and CFD program coupling. To bridge three major discontinuities in time-scale, spatial resolution and computing speed between ES and CFD programs, special coupling strategies have been developed. Particularly, the staged coupling strategies proposed can effectively reduce computing time while preserving the accuracy and details of the computed results. The study discusses the solution characteristics of iterative coupling simulation. Through theoretical analysis and numerical experiments, the research verifies the solution existence and uniqueness of a coupled simulation. The investigation concludes that a converged and stable simulation can be achieved with four different data coupling methods. The study has further developed an improved iteration and control algorithm for the coupled simulation. An integrated program, E+MIT-CFD, has been developed by coupling a new- generation ES program (E+) with a newly-developed ready-to-plug-in CFD solver (MIT- CFD). All the coupling methods and strategies proposed have been implemented in this program. The program has been well validated with various experimental facilities. The comparison of numerical solutions with experimental data reveals the advantages of the integrated simulation over the separate ES and CFD applications. The study further demonstrates the performance and capabilities of the coupled program through practical
(cont.) through practical design projects. Finally, sensitivity analysis of the coupling simulation to building characteristics and coupling strategies has been performed, based on which general guidelines are established for appropriate usage of the coupling simulation.
by Zhiqiang Zhai.
Ph.D.
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Colella, Vanessa Stevens. "Participatory simulations : building collaborative understanding through immersive dynamic modeling." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/61099.
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Castilho, Gabriela Mouriño. "Energy behaviour and consumption reduction in service buildings." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/23298.
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Mestrado em Sistemas Energéticos SustentáveisIn view of the current global scenery, in which several nations are striving against global warming, energy efficiency rises as a cost-effective prospect. As the building sector accounts for over one-fifth of the total delivered energy consumed worldwide, it has great potential for implementing rationalization and energy efficiency measures. Service buildings are expected to have the highest growth in energy consumption when compared to residential buildings and are therefore the focus of this thesis. Energy reduction efforts for service buildings are vast; however, they are concentrated mostly on technological opportunities. Behaviour changes represent a great potential for reducing energy consumption without significant financial costs, but still, they are commonly disregarded. Hence, the present dissertation aims to propose a quantitative methodology to analyze occupants’ behaviours and their impact on energy consumption in service buildings. Results are acquired through the use of dynamic simulation, namely DesignBuilder software. Energy consumption due to behaviour is determined by simulating the occupant interactions with equipment, lighting and HVAC systems. To that end, three occupancy profiles were fixed: standard occupants’ interactions are defined by Decree-Law nº 79/2006; efficient occupants have extreme efficient behaviours leading to energy savings; inefficient ones lead to extreme energy waste. Dynamic simulation results give evidence of the occupancy impact on energy consumption. Efficient behaviours were able to reduce energy consumption by over 34%. However, regardless of the rigorousness of efficient behaviours, waste potential by inefficient occupants was always higher than saving potential. This result highlights the importance of understanding occupant behaviours and its accurate consideration of dynamic simulation tools.
No atual cenário mundial, no qual diversas nações lutam contra o aquecimento global, a eficiência energética se destaca como uma opção viável. O setor de edifícios é responsável pelo consumo de mais de um quinto da energia total gerada, e por isso possui grande potencial para a implementação de medidas de racionalização e eficiência energética. Espera-se que os edifícios de serviços tenham o maior crescimento no consumo de energia quando comparados aos edifícios residenciais, e, portanto, são o foco desta tese. As possibilidades de redução de energia para os edifícios de serviços são vastas; no entanto, estas se concentram principalmente em oportunidades tecnológicas. As mudanças de comportamento representam um grande potencial para reduzir o consumo de energia sem custos financeiros significativos, no entanto ainda são geralmente desconsiderados. Dessa forma, a presente dissertação visa propor uma metodologia quantitativa para análise dos comportamentos dos ocupantes e seu impacto no consumo de energia em edifícios de serviços. Os resultados foram adquiridos através do uso da simulação dinâmica de edifícios, pelo software DesignBuilder. O consumo de energia devido ao comportamento foi determinado pela simulação das interações entre os ocupantes e os equipamentos, sistema de iluminação e de aquecimento, ar condicionado e ventilação. Para este fim, foram considerados três perfis de ocupação: o ocupante de referência teve por base as definições do Decreto-Lei nº 79/2006; os ocupantes eficientes possuem comportamentos extremos e eficientes que levam a economias de energia; ocupantes ineficientes causam um desperdício extremo de energia. Resultados da simulação dinâmica evidenciam o impacto da ocupação no consumo de energia. Comportamentos eficientes . foram capazes de reduzir o consumo em mais de 34%. No entanto, independentemente do rigor dos comportamentos eficientes, o potencial de desperdício de energia pelos ocupantes ineficientes foi, em todos os casos, superior ao potencial de economia energética pelos ocupantes eficientes.Este resultado destaca a importância de compreender os comportamentos dos ocupantes e assegurar sua análise de forma precisa sobre as ferramentas de simulação dinâmica.
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Lindgren-Mönestam, Björn. "Evaluation of energy performance in single family houses." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-80227.
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In order to improve people’s living situation and decrease the use of fossil energy in the world, researchers’ attention has been focused on the energy side of the building sector. Especially single family houses in the Nordic countries Norway, Sweden and Finland have been given attention in the Increasing Energy Efficiency in Buildings (IEEB) project, with the purpose of increasing energy efficiency in buildings. In the project presented in this report, this has been studied by simulating a low energy single family house at different locations in Scandinavia, and applying the various national building codes to the house to see how it would match the energy requirements. The simulated locations included the different climates in Helsinki, Oulu (Finland), Oslo, Narvik (Norway), Piteå, Umeå, Karlstad, Borlänge, Stockholm and Kalmar (Sweden). The house fulfilled almost all the national energy requirements with more or less margin because of its low energy use. A comparison with actual measurements of the house did not match as good, because of uncertainty in measurement methods and climate aspects. The national building codes and climate in the Nordic countries turned out to be similar enough for a coordination of the building codes to be possible in the future.
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Pesic, Nikola. "Geo-climatic potential for advanced natural ventilation comfort cooling approach in mid-rise office buildings in the north-western Mediterranean." Doctoral thesis, Universitat Politècnica de Catalunya, 2020. http://hdl.handle.net/10803/670793.
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The objective of this investigation is to evaluate the geo-climatic potential for comfort cooling energy savings in mid-rise office buildings applying advanced natural ventilation (ANV) approach based on the stack-effect. The region of interest is the Mediterranean coastline of Catalonia with selected reference geographical locations—the cities of Barcelona, Terrassa and Tarragona. In the first part of this research is evaluated the climatic potential for natural ventilation (CPNV) for each location, as a theoretical level of availability of natural ventilation (NV) based on the model of adaptive thermal comfort. For a comparison of geo-climatic potentials in a wider regional context, additional reference locations are chosen along the Northern Mediterranean: Valencia, Marseille, Rome, Koper, Split, Athens and Nicosia. Generated results confirm that NV is feasible mainly from April to October while in July and August is considerably limited due to unfavourable climate conditions. The second part of the work examines cooling energy savings of the hypothetical mid-rise office-type building model “A”. Applied building performance simulations (BPS) demonstrates achieved total yearly cooling energy savings in the region of Catalonia between 22% and 51%. The same model positioned along the Northern Mediterranean displays cutting in yearly cooling energy loads in a wider range—from 6% to 51%.The following section evaluates levels of climate change vulnerability applying climate scenarios for the selected time-slices—the years 2050 and 2080. It is indicated that the potential of ANV will be reduced close to zero in July and August in 2080. However, the introduction of selected assisted cooling techniques demonstrates that this impact can be absorbed approximately back to the previously evaluated scale in the horizon of 2050. In the last part of the investigation, the new defined building model “B” displays an improvement of comfort cooling energy efficiency: selected NV techniques are merged in order to take advantage of lower nocturnal outdoor temperatures by passive means, whose potential is reflected on the decrease of active day-time cooling loads. For this purpose, the positioned model in Barcelona achieves the yearly reduction of cooling energy loads by 65% in present-time weather conditions. At the conclusion, under projected climate configurations for 2050 and 2080, in Barcelona Terrassa and Tarragona, the series of BPS displays a higher level of climate resilience and the overall reduction of cooling energy loads within 53% and 59%.
The key-contribution and the novelty of this research is in the performed series of experimental BPS of the building model “A” where are detected ANV system’s weaknesses as a result of estimated unfavourable climate effects. Relative to observed limited cooling performances, ANV is shifted from an autonomous comfort cooling concept to being a part of a complex ventilative system with specific day- and night-time cycles. Such a new established design approach based on dynamic heat storage is associated with an introduction of lower nocturnal and early morning outdoor air temperatures, as being less affected with future regional climate change. An achieved advantageous momentum in energy performances is categorized through strengths and opportunities. Thereby, the building model “B”, the outcome of this investigation, represents the climate responsive building form with an integrated climate sensitive comfort cooling system, which delivers a higher level of energy efficiency—seen as an acquired factor of resilience towards estimated climate change threats. Such a conceptualised hypothetical building prototype may prove to be a beneficial contributor in the current process of rapid deployment of renewable energy sources in the regional building sector, observed as well from the perspective of the ongoing European Union’s energy transition.El objetivo de esta investigación es evaluar el potencial geo-climático para el ahorro de energía de enfriamiento de confort en los edificios de oficinas de mediana altura aplicando el concepto de ventilación natural avanzada (ANV). El enfoque es en la costa Mediterránea de Cataluña y las ubicaciones geográficas seleccionadas: Barcelona, Terrassa y Tarragona. La primera parte de investigación evalúa el potencial climático de ventilación natural (CPNV), un nivel teórico de disponibilidad de ventilación natural (NV) aplicando el modelo de confort térmico adaptativo. Para una comparación de los potenciales geo-climáticos en un contexto regional más amplio, están elegidas las ubicaciones a lo largo del Mediterráneo Norte: Valencia, Marsella, Roma, Koper, Split, Atenas y Nicosia. Los resultados confirman que NV es factible principalmente desde abril hasta octubre, mientras que en julio y agosto es considerablemente limitada. La segunda parte del trabajo examina los ahorros de energía de enfriamiento de un hipotético modelo “A” del edificio de oficinas de media altura. Las simulaciones de rendimiento de edificios (BPS) en la región de Cataluña demuestran una reducción anual de cargas de enfriamiento entre 22% y 51%. El mismo modelo posicionado a lo largo del Mediterráneo Norte muestra la reducción de las cargas anuales en un rango más amplio, entre 6% y 51%. La siguiente sección evalúa los niveles de vulnerabilidad al cambio climático aplicando escenarios climáticos para los años 2050 y 2080. Se indica que el potencial de ANV se reducirá cerca de cero en julio y agosto de 2080. Sin embargo, la introducción de unas técnicas de enfriamiento asistidas demuestra que ese impacto puede ser absorbido aproximadamente a la escala previamente evaluada en el horizonte de 2050. La última parte de investigación exhibe que el modelo “B” tiene un mejor nivel de la eficiencia energética del enfriamiento de confort: se fusionan técnicas de NV seleccionadas para aprovechar las temperaturas exteriores nocturnas más bajas por medios pasivos, cuyo potencial se refleja sobre la disminución de las cargas de enfriamiento activo diurno. Para este propósito, el modelo posicionado en Barcelona consigue la reducción anual de las cargas de enfriamiento en un 65% en las condiciones meteorológicas actuales. En conclusión, bajo las configuraciones climáticas proyectadas para 2050 y 2080, en Barcelona, Terrassa y Tarragona, la serie de BPS muestra un mayor nivel de resiliencia climática con la reducción de las cargas de enfriamiento entre 53% y 59%. El aporte clave de la investigación se encuentra en BPS experimentales del modelo “A” donde se detectan las debilidades del sistema ANV como consecuencia del cambio climático estimado. En relación con los rendimientos de enfriamiento limitados, ANV se cambia de un concepto autónomo a ser parte de un sistema de ventilación más complejo con los ciclos específicos diurnos y nocturnos. Este nuevo enfoque de diseño establecido basado en el almacenamiento dinámico de calor se asocia con una introducción del aire exterior con temperaturas más bajas durante la noche y las primeras horas de la mañana, como menos afectado por el futuro cambio climático regional. Un impulso ventajoso logrado en el desempeño energético se categoriza a través de las fortalezas y oportunidades. Por lo tanto, el modelo "B" representa la forma del edificio receptivo al clima con un sistema de enfriamiento de confort integrado sensible, lo que ofrece un mayor nivel de eficiencia energética, visto también como un factor adquirido de resiliencia frente a las amenazas estimadas del cambio climático. Tal prototipo de edificio hipotético puede resultar como un contribuyente beneficioso en el proceso actual de despliegue rápido de fuentes de energía renovables en el sector de la construcción regional, observado también desde la perspectiva de la transición energética en curso de la Unión Europea
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Sommerfeldt, Nelson. "Demonstrating the significance of microclimate on annual building energy simulations using RadTherm." Thesis, KTH, Uthålliga byggnadssystem, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-102850.
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Buildings account for over 35% of the energy demand in OECD countries, making them a prime target for improvement. (EIA 2011) To help building owners reduce energy usage, ratings systems such as LEED have been developed. A prerequisite for certification is the demonstration of energy efficiency through computer modeling; however, the complex nature of building energy simulations too often leads to errors of up to 30% (Turner and Frankel 2008). One source of significant error can be the assumptions made of environmental conditions, which are often simplified to speed up simulations. To demonstrate the significance of active microclimate modeling, a building energy model combined with a microclimate model has been created in RadTherm, a commercial CAE thermal solver. Simulations are run using Passive House construction in three types of environments, and demonstrate an increase in energy demand over an annual time scale when microclimatic components are included. The increase in demand is less than 1%, however the decrease in radiant heat losses are up to 30%. Using the same methodology with revisions to the building construction and urban geometry, a larger increase in energy demand is expected.
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Ahmad, Mushtaq. "Systematic time-based study for quantifying the uncertainty of uncalibrated models in building energy simulations." Texas A&M University, 2003. http://hdl.handle.net/1969.1/1191.
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This thesis documents the usefulness and accuracy of uncalibrated simulations to determine for what end-uses these simulations should be used. The study was divided into three segments 1)comparison of the accuracy of two simulation models, massless and advanced, against measured data 2) comparison of the results from two simulations models, simplistic and massless, to determine the sensitivity of envelope shape and details for two weather conditions 3) identification of the parameters that have a significant impact on the simulation output.
Five buildings were selected as the test sample. Four of the buildings were multi story commercial buildings. The fifth was a single-family residential house. For the first segment of the study two simulation models were created for all the buildings; the massless model with emphasis on the envelope using massless construction and typical values for system parameters and the advanced model with the inclusion of thermal mass and extensive as-built details of the systems. For the second part of the research the simplistic model was created having a single floor one-zone with glazing and conditioned areas equivalent to the massless model. The sensitivity analysis was done using the massless model and selected variables from the loads and systems as sensitivity parameters.
By following the procedure mentioned, it was found that uncalibrated simulation models do not depict the real operating conditions of a building. For some cases the simulated values are higher than the measured data while for others they are significantly lower. The CV (RMSE) between the measured and simulated values ranges from 30 to 150%. From the comparison of the simplistic and massless model, it was concluded that the outer envelope shape and details have an impact on the heating and cooling energy use irrespective of the weather conditions. For internally load dominated buildings this impact is more on the heating loads than on the cooling loads. The conclusions from the sensitivity analysis were that outside air fraction and the total supply air have the most significant impact on the simulation output while thermal mass has a small impact.
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Coonick, Alun Howard. "Dynamic aspects of a wind/diesel system with flywheel energy storage." Thesis, Imperial College London, 1991. http://hdl.handle.net/10044/1/46726.
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Wisniewski, Daniel. "Simulations of Dynamic Nuclear Polarization pathways in large spin ensembles." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/39045/.
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Dynamic Nuclear Polarization (DNP) is a method for signal enhancement in NMR, with numerous applications ranging from medicine to spectroscopy. Despite the success of applications of DNP, the understanding of the underlying theory is still limited. Much of the work on the theory of DNP has been carried out on small spin systems; this is a restriction due to the exponential growth of the Liouville space in quantum simulations. In the work described in this thesis, a methodology is presented by which this exponential scaling can be circumvented. This is done by mathematically projecting the DNP dynamics at resonance onto the Zeeman subspace of the density operator. This has successfully been carried out for the solid effect, cross effect and recently for the Overhauser effect in the solid state (see appendix A.4). The results are incoherent state-dependent dynamics, resembling classical behaviour. Such form of effective dynamics allows the use of kinetic Monte Carlo algorithms to simulate polarization dynamics of very large spin systems; orders of magnitude larger than has previously been possible. We verify the accuracy of the mathematical treatment of SE-DNP and CE-DNP, and illustrate the insight large spin-system simulations provide into the mechanism of DNP. For SE-DNP the mechanism of polarization to the bulk of spin systems is determined to be spin diffusion, and we carried out studies into the efficiency and performance of radicals, with an outlook on radical design. We also show that the Zeeman projection can be applied to heteronuclear spin systems if the nuclear species are close in frequency, and we present a formalism for simulating C-13 nuclear spin systems based on a linear rate approach, enabling simulations of thousands of spins in a matter of minutes. A study into the scaling of the kinetic Monte Carlo algorithm error, and the simulation run time, with respect to an increasing number of spins is also presented. For CE-DNP the error analysis led to establishing a parameter regime in which the effective dynamics are accurate. We show that spin diffusion is the mechanism of transfer of polarization to bulk nuclei. We also show how the effective rates for CE-DNP can be used to understand the efficiency of bi-radicals, point to optimisation possibilities, and hold a potential to aid in bi-radical design. We finally show large scale simulations for CE-DNP bi-radical systems with improved parameters; leading to very rapid build-up of nuclear polarization.
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Høseggen, Rasmus Z. "Dynamic use of the building structure - energy performance and thermal environment." Doctoral thesis, Norwegian University of Science and Technology, Department of Energy and Process Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1998.
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The main objectives of this thesis have been to evaluate how, under which premises, and to what extent building thermal mass can contribute to reduce the net energy demand in office buildings. The thesis also assesses the potential thermal environmental benefits of utilizing thermal mass in office buildings, i.e. reduction of temperature peaks, reduction of temperature swings, and the reduction in the number of hours with excessive operative temperatures. This has been done by literature searches, and experimental and analytical assessments. This thesis mainly concerns office buildings in the Norwegian climate. However, the methods used and the results obtained from this work are transferable to other countries with similar climates and building codes.
Within the limitations of this thesis and based on the findings from all parts and papers this thesis comprises, it is shown that utilization of thermal mass in office buildings reduces the daytime peak temperature, reduces the diurnal temperature swing, decreases the number of hours with excessive temperatures, and increases the ability of a space to handle daytime heat loads. Exposed thermal mass also contributes to decrease the net cooling demand in buildings. However, thermal mass is found to have only a minor influence on the heating demand in office buildings.
The quantity of the achievements is dependent on the amount of exposed thermal mass, night ventilation strategy, and airflow rates. In addition, parameters such as set point temperatures, control ranges, occupancy patterns, daytime ventilation airflow rates, and prevailing convection regimes are influential for the achieved result. The importance of these parameters are quantified and discussed.
Hovedmålene med denne avhandlingen har vært å evaluere hvordan, under hvilke forutsetninger og i hvilken utstrekning termisk masse kan bidra til å redusere netto energibehov i kontorbygninger. Avhandlingen vurderer også hvilke potensielle fordeler termisk masse har for det termiske inneklimaet, dvs. reduksjon av maksimumstemperatur, temperatursvingninger og antall timer med overtemperaturer. Disse undersøkelsene er gjort gjennom søk i litteraturen, feltstudier og analytiske metoder. Avhandlingen omfatter i hovedsak kontorbygninger under norske forhold, men metodene og resultatene er overførbare til andre land med sammenlignbare klimatiske forhold og byggeskikk.
Innenfor avgrensningene gjort i avhandlingen og basert funnene i de ulike delene og artiklene avhandlingen består av, er det vist at utnyttelse av termisk masse i kontorbygg bidrar til å redusere netto energibehov. Termisk masse reduserer også maksimumstemperaturen dagtid, demper temperaturvariasjonene over døgnet og reduserer antall timer med overtemperaturer. Utnyttelse av termisk masse bidrar også til at rom kan tåle en høyere intern varmelast enn lette rom uten at dette går ut over den termiske komforten. Termisk masse har imidlertid liten betydning for energibehovet for oppvarming i kontorbygg.
Gevinsten med å utnytte termisk masse avhenger av tilgjengeligheten av eksponerte tunge materialer, strategi for nattventilasjon og ventilasjonsluftmengder. I tillegg innvirker parametere som settpunkttemperaturer, dødbånd og kontrollintervaller for ventilasjonen og bruksmønster. Innvirkningen av disse parametrene er diskutert og kvantifisert.
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Bemis, Jamie (Jamie L. ). "Urban building energy modeling as a dynamic tool for sustainability planning." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105072.
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Thesis: M.C.P., Massachusetts Institute of Technology, Department of Urban Studies and Planning, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 33-34).
Cities around the world are actively aiming to reduce greenhouse gas emissions in an effort to combat the negative consequences associated with anthropogenic climate change. The City of Boston is no exception-in 2011, then-mayor Tom Menino established the rigorous goals of reducing city-wide greenhouse gas emissions by 25% by 2020 and by 80% below 2005 levels by 2050. Given the realities of finite time and resources, it's critical to identify the most effective strategies to achieving energy efficiency in order to meet these objectives. This thesis explores how urban building energy modeling (UBEM) can be utilized to develop high-impact community-led energy efficiency programs. UBEM is a recently developed type of bottom-up energy modeling that presents a number of advantages over past urban energy modeling methods- namely, the ability for comparing complex scenarios, and the ability to generate hourly load profiles for individuals buildings. In addition, literature suggests that community-based energy efficiency programs achieve higher participation rates than traditional information-based programs. This thesis combines the technical benefits of UBEM with the practical advantages of community-led energy efficiency programs to develop a context-specific and community-based energy efficiency program for the Dudley Triangle neighborhood of Boston. It then explores how this type of a program can achieve the triple bottom line objectives of creating high quality local jobs, reducing environmental impacts, and supporting a local economy.
by Jamie Bemis.
M.C.P.
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Liu, Jingyuan. "Diversity and templating in hydrazone dynamic combinatorial libraries : new building blocks, recognition and simulations." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613097.
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Garcia, Kerdan I. "Optimisation of building energy retrofit strategies using dynamic exergy analysis and exergoeconomics." Thesis, University College London (University of London), 2017. http://discovery.ucl.ac.uk/1546154/.
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Existing buildings represent one of the most energy intensive sectors in today’s society, where comprehensive building energy retrofit (BER) strategies play a major role in achieving national reduction targets. Despite the efforts made in recent decades through policies and programmes to improve building energy efficiency, the building sector (which proportionally has the highest demand for heat) has the lowest thermodynamic efficiency among all UK economic sectors. As other sectors have shown, exergy and exergoeconomic analyses can be indispensable tools for the design and optimisation of energy systems. Therefore, there is a need for modification of existing BER methods in order to include thermodynamic analysis with the aim improve true efficiency of buildings and minimise its environmental impact. However, a paradigm shift represents a big challenge to common building practice as traditional methods have prioritised typical energy and economic objectives. The aim of this thesis is to develop a methodological framework for the evaluation of BER strategies under exergy analysis and exergoeconomic accounting supported with the integration of the calculation framework into a typical dynamic building simulation tool. There are two original contributions to the knowledge of this research. First, the techno-economic appraisal of BER strategies, based on the typical energy-efficient and cost-benefit method, is enhanced by adding a whole-building exergy analysis combined with an exergoeconomic method (SPECO). Second, ExRET-Opt, a retrofit-oriented simulation tool based on dynamic exergy calculations and exergoeconomic analysis combined with a comprehensive and robust retrofit database, is developed and implemented for this research. In addition, a multi-objective optimisation module based on genetic algorithms is included within the simulation framework in order to improve BER design under different thermodynamic and non-thermodynamic conflicting cost objective functions. Three UK non-domestic case studies implementing a wide range of active and passive retrofit strategies are presented. Results suggest that under identical economic and technical constraints, the inclusion of exergy/exergoeconomic indicators as objective functions into the optimisation procedure has resulted in buildings with similar energy and thermal comfort performance as traditional First Law methods; while providing solutions with better thermodynamic performance and less environmental impact. The approach also demonstrates to provide BER designs with an appropriate balance between active and passive measures, while consistently accounting of irreversibilities and its costs along every subsystem in the building energy system. The developed framework/tool seems like a promising approach to introduce the Second Law into typical building energy practice and for the development of policies, incentives, and taxes based on exergy destruction footprints. Such policies could help highly thermodynamically-efficient or low exergy BER designs to become widely available.
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Persson, Johannes. "Low-energy buildings : energy use, indoor climate and market diffusion." Doctoral thesis, KTH, Energiprocesser, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-143480.
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Low-energy buildings have, in recent years, gained attention and moved towards a large-scale introduction in the residential sector. During this process, national and international criteria for energy use in buildings have become stricter and the European Union has through the Energy Performance of Buildings Directive imposed on member states to adapt their building regulations for ‘Nearly Zero Energy Buildings’, which by 2021 should be standard for new buildings. With a primary focus on new terraced and detached houses, this thesis analyses how the concept of low-energy buildings may be further developed to reduce the energy use in the residential sector. The main attention is on the technical performance in terms of indoor climate and heat consumption as well as on the market diffusion of low-energy buildings into the housing market. A multidisciplinary approach is applied, which here means that the concept of low-energy buildings is investigated from different perspectives as well as on different system levels. The thesis thus encompasses methods from both engineering and social sciences and approaches the studied areas through literature surveys, interviews, assessments and simulations. The thesis reveals how an increased process integration of the building’s energy system can improve the thermal comfort in low-energy buildings. Moreover, it makes use of learning algorithms – in this case artificial neural networks – to study how the heat consumption can be predicted in a low-energy building in the Swedish climate. The thesis further focuses on the low-energy building as an element in our society and it provides a market diffusion analysis to gain understanding of the contextualisation process. In addition, it suggests possible approaches to increase the market share of low-energy buildings.QC 20140321
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Anastasopoulou, Kyriaki. "Creation of a Low Energy Building with the help of Energy Simulation." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-25325.
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In this Thesis Project, the creation of a Low Energy building was examined in order to investigate how complex was to select the suitable parameters and systems of the dwelling, aiming to achieve the lowest possible energy consumption in one year period. All the technologies implemented into the system intended to be as energy efficient and profitable as possible. Another objective of this study was also to present the potential of the system to produce a part of the consumed energy, through renewable energy sources, approaching by this way also the standards of a Zero Energy Building. Firstly, the floor plan of the 150 m2 detached house, was drawn in the designing program AutoCAD. In continuation, this 2D floor plan was imported into the simulation program as well as all the initial input data so as for the Base model of the building to be created For the analysis of the building, the Simulation Program IDA ICE 4.7 was used. Gradually, alternations and adjustments were made into the Base model. Different models were created planning to analyze their results and conclude to the proper solution. All the simulations run for one year time period in order to present the total energy usage, system’s losses and demands in each case. In addition, as for the current study, the location of the construction was Athens, all building’s characteristics were chosen to comply with the Greek Regulation for Low Energy Buildings. Finally, through the procedure followed after having accomplished a series of simulations, the final annually energy demands managed to be within the required limits.Online Presentation
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Karami, Peyman. "Robust and Durable Vacuum Insulation Technology for Buildings." Doctoral thesis, KTH, Byggnadsteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176494.
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Today’s buildings are responsible for 40% of the world’s energy use and also a substantial share of the Global Warming Potential (GWP). In Sweden, about 21% of the energy use can be related to the heat losses through the climatic envelope. The “Million Program” (Swedish: Miljonprogrammet) is a common name for about one million housing units, erected between 1965 and 1974 and many of these buildings suffer from poor energy performance. An important aim of this study was to access the possibilities of using Vacuum Insulation Panels (VIPs) in buildings with emphasis on the use of VIPs for improving the thermal efficiency of the “Million Program” buildings. The VIPs have a thermal resistance of about 8-10 times better than conventional insulations and offer unique opportunities to reduce the thickness of the thermal insulation. This thesis is divided into three main subjects. The first subject aims to investigate new alternative VIP cores that may reduce the market price of VIPs. Three newly developed nanoporous silica were tested using different steady-state and transient methods. A new self-designed device, connected to a Transient Plane Source (TPS) instrument was used to determine the thermal conductivity of granular powders at different gaseous pressure combined with different mechanical loads. The conclusion was that the TPS technique is less suitable for conducting thermal conductivity measurements on low-density nanoporous silica powders. However, deviations in the results are minimal for densities above a limit at which the pure conduction becomes dominant compared to heat transfer by radiation. The second subject of this work was to propose a new and robust VIP mounting system, with minimized thermal bridges, for improving the thermal efficiency of the “Million Program” buildings. On the basis of the parametric analysis and dynamic simulations, a new VIP mounting system was proposed and evaluated through full scale measurements in a climatic chamber. The in situ measurements showed that the suggested new VIP technical solution, consisting of 20mm thick VIPs, can improve the thermal transmittance of the wall, up to a level of 56%. An improved thermal transmittance of the wall at centre-of-panel coordinate of 0.118 to 0.132 W m-2K-1 and a measured centre-of-panel thermal conductivity (λcentre-of-panel) of 7 mW m-1K-1 were reached. Furthermore, this thesis includes a new approach to measure the thermal bridge impacts due to the VIP joints and laminates, through conducting infrared thermography investigations. An effective thermal conductivity of 10.9 mW m-1K-1 was measured. The higher measured centre-of-panel and effective thermal conductivities than the published centre-of-panel thermal conductivity of 4.2 mW m-1K-1 from the VIP manufacturer, suggest that the real thermal performance of VIPs, when are mounted in construction, is comparatively worse than of the measured performance in the laboratory. An effective thermal conductivity of 10.9 mW m-1K-1 will, however, provide an excellent thermal performance to the construction. The third subject of this thesis aims to assess the environmental impacts of production and operation of VIP-insulated buildings, since there is a lack of life cycle analysis of whole buildings with vacuum panels. It was concluded that VIPs have a greater environmental impact than conventional insulation, in all categories except Ozone Depilation Potential. The VIPs have a measurable influence on the total Global Warming Potential and Primary Energy use of the buildings when both production and operation are taken into account. However, the environmental effect of using VIPs is positive when compared to the GWP of a standard building (a reduction of 6%) while the PE is increased by 20%. It was concluded that further promotion of VIPs will benefit from reduced energy use or alternative energy sources in the production of VIP cores while the use of alternative cores and recycling of VIP cores may also help reduce the environmental impact. Also, a sensitivity analysis of this study showed that the choice of VIPs has a significant effect on the environmental impacts, allowing for a reduction of the total PE of a building by 12% and the GWP can be reduced as much as 11% when considering both production and operation of 50 yes. Finally, it’s possible to conclude that the VIPs are very competitive alternative for insulating buildings from the Swedish “Million Program”. Nevertheless, further investigations require for minimizing the measurable environmental impacts that acquired in this LCA study for the VIP-insulated buildings.Dagens byggnader ansvarar för omkring 40% av världens energianvändning och står också för en väsentlig del av utsläppen av växthusgaser. I Sverige kan ca 21 % av energianvändningen relateras till förluster genom klimatskalet. Miljonprogrammet är ett namn för omkring en miljon bostäder som byggdes mellan 1965 och 1974, och många av dessa byggnader har en dålig energiprestanda efter dagens mått. Huvudsyftet med denna studie har varit att utforska möjligheterna att använda vakuumisoleringspaneler (VIP:ar) i byggnader med viss fokus på tillämpning i Miljonprogrammets byggnader. Med en värmeledningsförmåga som är ca 8 - 10 gånger bättre än för traditionell isolering erbjuder VIP:arna unika möjligheter till förbättrad termisk prestanda med minimal isolerings tjocklek. Denna avhandling hade tre huvudsyften. Det första var att undersöka nya alternativ för kärnmaterial som bland annat kan reducera kostnaden vid produktion av VIP:ar. Tre nyutvecklade nanoporösa kiselpulver har testats med olika stationära och transienta metoder. En inom projektet utvecklad testbädd som kan anslutas till TPS instrument (Transient Plane Source sensor), har använts för att mäta värmeledningsförmågan hos kärnmaterial för VIP:ar, vid varierande gastryck och olika mekaniska laster. Slutsatsen blev att transienta metoder är mindre lämpliga för utföra mätningar av värmeledningsförmåga för nanoporösa kiselpulver låg densitet. Avvikelsen i resultaten är dock minimal för densiteter ovan en gräns då värmeledningen genom fasta material blir dominerande jämfört med värmeöverföring genom strålning. Det andra syftet har varit att föreslå ett nytt monteringssystem för VIP:ar som kan användas för att förbättra energieffektiviteten i byggnader som är typiska för Miljonprogrammet. Genom parametrisk analys och dynamiska simuleringar har vi kommit fram till ett förslag på ett nytt monteringssystem för VIP:ar som har utvärderats genom fullskaleförsök i klimatkammare. Resultaten från fullskaleförsöken visar att den nya tekniska lösningen förbättrar väggens U-värde med upp till 56 %. En förbättrad värmegenomgångskoefficienten för väggen i mitten av en VIP blev mellan 0.118 till 0,132 W m-2K-1 och värmeledningstalet centre-av-panel 7 mW m-1K-1 uppnåddes. Detta arbete innehåller dessutom en ny metod för att mäta köldbryggor i anslutningar med hjälp av infraröd termografi. En effektiv värmeledningsförmåga för 10.9 mW m-1K-1 uppnåddes. Resultaten tyder även på att den verkliga termiska prestandan av VIP:ar i konstruktioner är något sämre än mätvärden för paneler i laboratorium. En effektiv värmeledningsförmåga av 10.9 mW m-1K-1 ger dock väggkonstruktionen en utmärkt termisk prestanda. Det tredje syftet har varit att bedöma miljöpåverkan av en VIP-isolerad byggnad, från produktion till drift, eftersom en livscykelanalys av hela byggnader som är isolerade med vakuumisoleringspaneler inte har gjorts tidigare. Slutsatsen var att VIP:ar har en större miljöpåverkan än traditionell isolering, i alla kategorier förutom ozonnedbrytande potential. VIP:ar har en mätbar påverkan på de totala utsläppen av växthusgaser och primärenergianvändningen i byggnader när både produktion och drift beaktas. Miljöpåverkan av de använda VIP:arna är dock positiv jämfört med GWP av en standardbyggnad (en minskning med 6 %) medan primärenergianvändningen ökade med 20 %. Slutsatsen var att ytterligare användning av VIP:ar gynnas av reducerad energiförbrukning och alternativa energikällor i produktionen av nanoporösa kiselpulver medan användningen av alternativa kärnmaterial och återvinning av VIP kärnor kan hjälpa till att minska miljöpåverkan. En känslighetsanalys visade att valet av VIP:ar har en betydande inverkan på miljöpåverkan, vilket ger möjlighet att reducera den totala användningen av primärenergi i en byggnad med 12 % och utsläppen av växthusgaser kan vara minska, så mycket som 11 % när det gäller både produktion och drift under 50 år. Avslutningsvis är det möjligt att dra slutsatsen att VIP:ar är ett mycket konkurrenskraftigt alternativ för att isolera byggnader som är typiska för Miljonprogrammet. Dock krävs ytterligare undersökningar för att minimera de mätbara miljöeffekter som förvärvats i denna LCA-studie för VIP-isolerade byggnader.
QC 20151109
Simulations of heat and moisture conditions in a retrofit wall construction with Vacuum Insulation Panels
Textural and thermal conductivity properties of a low density mesoporous silica material
A study of the thermal conductivity of granular silica materials for VIPs at different levels of gaseous pressure and external loads
Evaluation of the thermal conductivity of a new nanoporous silica material for VIPs – trends of thermal conductivity versus density
A comparative study of the environmental impact of Swedish residential buildings with vacuum insulation panels
ETICS with VIPs for improving buildings from the Swedish million unit program “Miljonprogrammet”
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Doban, Nicolae. "Building predictive models for dynamic line rating using data science techniques." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187812.
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The traditional power systems are statically rated and sometimes renewable energy sources (RES) are curtailed in order not to exceed this static rating. The RES are curtailed because of their intermittent character and therefore, it is difficult to predict their output at specific time periods throughout the day. Dynamic Line Rating (DLR) technology can overcome this constraint by leveraging the available weather data and technical parameters of the transmission line. The main goal of the thesis is to present prediction models of Dynamic Line Rating (DLR) capacity on two days ahead and on one day ahead. The models are evaluated based on their error rate profiles. DLR provides the capability to up-rate the line(s) according to the environmental conditions and has always a much higher profile than the static rating. By implementing DLR a power utility can increase the efficiency of the power system, decrease RES curtailment and optimize their integration within the grid. DLR is mainly dependent on the weather parameters and specifically, in large wind speeds and low ambient temperature, the DLR can register the highest profile. Additionally, this is especially profitable for the wind energy producers that can both, produce more (until pitch control) and transmit more in high wind speeds periods with the same given line(s), thus increasing the energy efficiency. The DLR was calculated by employing modern Data Science and Machine Learning tools and techniques and leveraged historical weather and transmission line data provided by SMHI and Vattenfall respectively. An initial phase of Exploratory Data Analysis (EDA) was developed to understand data patterns and relationships between different variables, as well as to determine the most predictive variables for DLR. All the predictive models and data processing routines were built in open source R and are available on GitHub. There were three types of models built: for historical data, for one day-ahead and for two days-ahead time-horizons. The models built for both time-horizons registered a low error rate profile of 9% (for day-ahead) and 11% (for two days-ahead). As expected, the predictive models built on historical data were more accurate with an error as low as 2%-3%. In conclusion, the implemented models met the requirements set by Vattenfall of maximum error of 20% and they can be applied in the control room for that specific line. Moreover, predictive models can also be built for other lines if the required data is available. Therefore, this Master Thesis project’s findings and outcomes can be reproduced in other power lines and geographic locations in order to achieve a more efficient power system and an increased share of RES in the energy mix
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Bontemps, Stéphanie. "Validation expérimentale de modèles : application aux bâtiments basse consommation." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0337/document.
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Avec la généralisation de la construction des bâtiments basse consommation, passifs et à énergie positive, mais aussi la rénovation du parc existant, il est indispensable d’avoir recours à la simulation pour évaluer, entre autres, les performances énergétique et environnementale atteintes par ces nouveaux bâtiments. Les attentes en termes de garantie de performance énergétique étant de plus en plus importantes, il est primordial de s’assurer de la fiabilité des outils de simulation utilisés. En effet, les codes de simulation doivent être capables de représenter le comportement de ces nouveaux types de bâtiments de la façon la plus juste et fidèle possible. De plus, les incertitudes liées aussi bien aux paramètres de conception qu’aux différentes sollicitations ainsi qu’aux usages des bâtiments doivent être prises en compte pour pouvoir garantir la performance du bâtiment sur sa durée de vie.Cette thèse s’est intéressée à la validation expérimentale de modèles appliquée à un bâtiment de type cellule test. Cette méthodologie de validation se déroule en plusieurs étapes au cours desquelles on évalue la qualité du modèle en termes de justesse et de fidélité. Plusieurs cas d’études ont été menés sur lesquels nous avons pu identifier les paramètres les plus influents sur la sortie du modèle, examiner l’influence du pas de temps sur le processus de validation expérimentale, analyser l’influence de l’initialisation et confirmer l’aptitude de la méthodologie à tester le modèleConstruction of low, passive and positive energy buildings is generalizing and existing buildings are being renovated. For this reason, it is essential to use simulation in order to estimate, among other things, energy and environmental performances reached by these new buildings. Expectations regarding guarantee of energy performance being more and more important, it is crucial to ensure the reliability of simulation tools being used. Indeed, simulation codes should reflect the behavior of these new kinds of buildings in the most consistent and accurate manner. Moreover, the uncertainty related to design parameters, as well as solicitations and building uses have to be taken into account in order to guarantee building energy performance during its lifetime.This thesis investigates the empirical validation of models applied to a test cell building. This validation process is divided into several steps, during which the quality of the model is evaluated as far as consistency and accuracy are concerned. Several study cases were carried out, from which we were able to identify the most influential parameters on model output, inspect the influence of time step on the empirical validation process, analyze the influence of initialization and confirm methodology’s ability to test the model
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Caleiro, Luis Carlos Ferreira. "Dynamic simulation of strategies for thermal comfort using phase change materials." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14382.
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Mestrado em Engenharia CivilNowadays, as global warming becomes one of the most urgent problems in the world, there is a need to find better ways to utilize energy: not only in the field of energy production, transmission, distribution, and consumption, but also in the area of energy storage. With energy storage technologies, it is possible to overcome the contradiction between the energy production and consumption, alleviate the tense production load of power plants at peak hours, and reduce consumers’ electricity costs by avoiding higher peak hour tariffs. Thermal energy storage, or heat and cold storage, allows the storage of heat or cold to be used later. This method needs to be reversible so it allows for multiple cycles. The technology that was studied for this effect was Phase Change Materials or PCMs. With that in mind, and with the help of dynamic building simulation software, EnergyPlus, several scenarios of an existing build that has PCM incorporated were studied in order to ascertain the real effect the technology is having on the case study, including thermal comfort.
Hoje em dia, com o aquecimento global a tornar-se um dos problemas mais urgentes da Terra, há necessidade de encontrar melhores maneiras de utilizar energia: não apenas no campo da produção de energia, transmissão, distribuição e consumo, mas também na área de armazenamento de energia. Com tecnologias de armazenamento de energia, é possível de ultrapassar a contradição entre a produção e consumo, aliviar a tensão que existe na produção nas estações de energia nas horas de pico e reduzir o custo de electricidade aos utentes ao evitar as tarifas nas horas de pico. A armazenagem de energia calorífica, do calor e frio, permite o armazenamento de calor ou frio para ser usado mais tarde. Este método precisa de ser reversível para permitir vários ciclos deste processo. A tecnologia estudada para este efeito foi os materiais que mudam de fase, ou PCMs (Phase Change Materials). Com isto em mente, e com a ajuda de software de simulação dinâmica, EnergyPlus, vários cenários de um edifício existente que tem PCM incorporado foram estudados em ordem de poder concluir o verdadeiro efeito que a tecnologia está a ter no caso estudo, incluindo o conforto térmico.
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Hamm, Marc. "Dynamic mean field simulations of liquid crystalline and amorphous (co)polymers : building a model for polymer joining." Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619528.
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Norbert, Harmati. "Energy performance optimization of administrative buildings in the function of occupant comfort." Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2015. http://www.cris.uns.ac.rs/record.jsf?recordId=94816&source=NDLTD&language=en.
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The research is aimed in order to increase the efficiency and improve theenergy performance of multi-level administrative buildings in temperateclimate conditions. Special emphasis is on achieving and maintainingacceptable indoor environmental standards and thermal comfort ofoccupants. The investigation is based on a complex multi-criteria optimizationutilizing the most contemporary technology of dynamic energy simulations.The developed methodology for energy performance evaluation andimprovement in the function of occupant comfort will have the possibility ofapplication on similar and newly designed buildings. The formulated modelalso possesses flexibility and adaptability for further improvement andapplication in different climatic conditions.Истраживање је усмерено на повећање ефикасности и унапређење енергетских перформанси вишеспратних административних зграда у умереним климатским условима. Посебан нагласак је на постизању и одржавању прихватљивих унутрашњих микроклиматских стандарда и термичког комфора корисника. Истраживања су заснована на комплексној вишекритеријумској оптимизацији уз примену најсавременије технологије динамичке енергетске симулације. Развијена је методологија, флексибилна и прилагодљива, за вредновање и унапређење енергетских перформанси у функцији корисничког комфора, за примене и на друге сличне и новопројектоване објекте. Формулисан модел је подобан за даља унапређења и примену у различитим климатским условима.
Istraživanje je usmereno na povećanje efikasnosti i unapređenje energetskih performansi višespratnih administrativnih zgrada u umerenim klimatskim uslovima. Poseban naglasak je na postizanju i održavanju prihvatljivih unutrašnjih mikroklimatskih standarda i termičkog komfora korisnika. Istraživanja su zasnovana na kompleksnoj višekriterijumskoj optimizaciji uz primenu najsavremenije tehnologije dinamičke energetske simulacije. Razvijena je metodologija, fleksibilna i prilagodljiva, za vrednovanje i unapređenje energetskih performansi u funkciji korisničkog komfora, za primene i na druge slične i novoprojektovane objekte. Formulisan model je podoban za dalja unapređenja i primenu u različitim klimatskim uslovima.
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Rodríguez-Urdaneta, Alejandro. "Geographical Mapping of the Building Envelope Surface Optimal Optical Properties Minimizing the Energy used to Maintain Indoor Conditions." Thesis, Högskolan Dalarna, Energiteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:du-35491.
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Several studies have shown that the buildings envelope optical properties are important in terms of energy use and thermal comfort level. However, no study has been found in regard of the optimal optical properties for the building envelope. Moreover, developments in the coil-coating industry have made possible to design cost effective optical selective surfaces for the construction sector. Based on the above mentioned, this study pretends to map the envelope optimal optical properties minimizing the energy use for large-open-volume buildings locates in Stockholm, Copenhagen, Liverpool, Amsterdam, Berlin, Vienna, Bern, Rome, and Madrid.A building could be seen as a very complex solar energy conversion system, which is very difficult to describe accurately. Nonetheless, it is possible to use Building Energy Simulation (BES) tools to model, to some extent, its thermal performance under many simplistic assumptions. The simulation tool TRNSYS 17 and the optimization tool GenOpt were selected for this study. Additionally, detailed small-open-volume building thermal performance data, obtained during passive measurements from the steel manufacturer SSAB, in Borlänge-Sweden, were used to assess the methodology for the creation of the large-open-volume simulation models. The variations in large-open-volume building design around Europe are not well documented, which constitutes one of the major impediments for this research. However, detailed European historical building U-value data from the European Union project called iNSPiRe made it possible to achieve the objective of this study.The simulation work showed, that the building envelope optimal optical properties are related to the magnitude of the heating and cooling loads. Consequently, GenOpt was used to plot the sensitivity of the building envelope optimal optical properties to the ratio between the heating demand and the total energy demand (Qheat/Qtotal). In regard to the large-open-volume building optimal optical properties in the selected locations, it was found that the allocation of optimal optical properties does not lead to significant energy savings in locations with relatively low solar availability and high thermal insulation levels. Nonetheless, a final envelope optical properties study for a small-open-volume building model based on three existing buildings differing only on their optical properties was made for 243 world-capital cities. The simulations reinforced the results for the large-open-volume building in the European locations, and additionally showed huge energy savings potential for most of the world capital cities. This investigation restates the results obtained by Joudi (2015), “Possible energy savings by the smart choice of optical properties on the interior and exterior surfaces of the building.”Varios estudios han demostrado que las propiedades ópticas de las envolturas delos edificios son importantes en términos de consumo energético y de nivel deconfort térmico. Sin embargo, no se ha encontrado estudio alguno con respecto alas propiedades ópticas óptimas para las envolturas de los edificios.Conjuntamente, los desarrollos en la industria de bobinas metálicas revestidas hanhecho posible diseñar superficies selectivas rentables para el sector de laconstrucción. Basándose en lo anteriormente expuesto, este estudio pretendemapear las propiedades ópticas óptimas de la envoltura que minimizan el uso deenergía para edificios de gran volumen abierto localizados en Estocolmo,Copenhague, Liverpool, Ámsterdam, Berlín, Viena, Berna, Roma y Madrid.Un edificio podría ser visto como un sistema de conversión de energía solar muycomplejo, que es muy difícil de describir con precisión. No obstante, es posibleutilizar las herramientas de Simulación de Energía de Edificios (BES) para modelar,hasta cierto punto, su rendimiento térmico bajo una considerable cantidad desuposiciones simplistas. El programa de simulación TRNSYS 17 y el programa deoptimización GenOpt fueron seleccionadas para este estudio. Adicionalmente, conel fin de evaluar la metodología utilizada para la creación de los modelos desimulación para edificios de gran volumen abierto, se utilizaron datos detallados derendimiento térmico de edificios de pequeño volumen abierto, obtenidos durantemediciones pasivas del fabricante de acero SSAB, en Borlänge-Suecia. Lasvariaciones en el diseño de edificios de gran volumen abierto en toda Europa noestán bien documentadas, lo que constituye uno de los principales impedimentospara esta investigación. Sin embargo, los datos detallados y en orden cronológicode los niveles de aislamiento térmico (U-value) en la construcción europea,recopilados por el proyecto de la Unión Europea llamado iNSPiRe, permitieronalcanzar el objetivo de este estudio.El trabajo de simulación demostró que las propiedades ópticas óptimas de laenvoltura del edificio están relacionadas con la magnitud de las cargas decalefacción y refrigeración. En consecuencia, GenOpt fue utilizado para graficar lasensibilidad de las propiedades ópticas óptimas de la envolvente del edificio conrespecto a la proporción entre la demanda de calefacción y la demanda total deenergía (Qheat/Qtotal). En cuanto a las propiedades ópticas óptimas del edificio degran volumen abierto en las ubicaciones seleccionadas, se encontró que laasignación de propiedades ópticas óptimas no conduce a ahorros de energíasignificativos en ubicaciones con disponibilidad solar relativamente baja y altosniveles de aislamiento térmico. Sin embargo, un último estudio de propiedadesópticas de envolvente para un modelo de construcción de pequeño volumen abiertobasado en tres edificios existentes que difieren sólo en sus propiedades ópticas serealizó para 243 capitales mundiales. Las simulaciones reforzaron los resultadospara el edificio de gran volumen abierto en las localidades europeas, y ademásmostraron un enorme potencial de ahorro de energía para la mayoría de lascapitales mundiales. Esta investigación reitera los resultados obtenidos por Joudi (2015), "Posibles ahorros de energía por la elección inteligente de propiedadesópticas en las superficies interiores y exteriores del edificio".
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Zhang, Rongpeng. "Dynamic Optimization of Integrated Active - Passive Strategies for Building Enthalpy Control." Research Showcase @ CMU, 2014. http://repository.cmu.edu/dissertations/404.
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The building sector has become the largest consumer of end use energy in the world, exceeding both the industry and the transportation sectors. Extensive types of energy saving techniques have been developed in the past two decades to mitigate the impact of buildings on the environment. Instead of the conventional active building environmental control approaches that solely rely on the mechanical air conditioning systems, increasing attention is given to the passive and mixed-mode approaches in buildings. This thesis aims to explore the integration of passive cooling approaches and active air conditioning approaches with different dehumidification features, by making effective use of the information on: 1) various dynamic response properties of the building system and mechanical plants, 2) diverse variations of the building boundary conditions over the whole operation process, 3) coupling effect and synergistic influence of the key operational parameters, and 4) numerous parameter conflicts in the integrated active-passive operation. These issues make the proposed integration a complex multifaceted process operation problem. In order to deal with these challenges, a systematic approach is developed by integrating a number of advanced building/system physical models and implementing well established advanced dynamic optimization algorithms. Firstly, a reduced-order model development and calibration framework is presented to generate differential-algebraic equations (DAE) based physical building models, by coupling with the high-order building energy simulations (i.e., EnergyPlus) and implementing MLE+ co-simulation programs in the Matlab platform. The reduced-order building model can describe the dynamic building thermal behaviors and address substantial time delay effects intrinsic in the building heat transfer and moisture migration. A calibration procedure is developed to balance the modelling complexity and the simulation accuracy. By making use of the advanced modeling and simulation features of EnergyPlus, the developed computational platform is able to handle real buildings with various geometric configurations, and offers the potential to cooperate with the dominant commercial building modeling software existing in the current AEC industry. Secondly, the physical model for the active air conditioning systems is developed, which is the other critical part for the dynamic optimization. By introducing and integrating a number of sub-models developed for specific building components, the model is able to specify the dynamic hygrothermal behavior and energy performance of the system under various operating conditions. Two representative air conditioning systems are investigated as the study cases: variable air volume systems (VAV) with mechanical dehumidification, and the desiccant wheel system (DW) with chemical dehumidification. The control variables and constraints representing the system operational characteristics are specified for the dynamic optimization. Thirdly, the integrated active-passive operations are formulated as dynamic optimization problems based on the above building and system physical models. The simultaneous collocation method is used in the solution algorithm to discretize the state and control variables, translating the optimization formulation into a nonlinear program (NLP). After collocation, the translated NLP problems for the daily integrated VAV/DW operation for a case zone have 1605/2181 variables, 1485/2037 equality constraints and 280/248 inequality constraints, respectively. It is found that IPOPT is able to provide the optimal solution within minutes using an 8-core 64-bit desktop, which illustrates the efficiency of the problem formulation. The case study results indicate that the approach can effectively improve the energy performance of the integrated active-passive operations, while maintaining acceptable indoor thermal comfort. Compared to the conventional local control strategies, the optimized strategies lead to remarkable energy saving percentages in different climate conditions: 29.77~48.76% for VAV and 27.85~41.33% for DW. The energy saving is contributed by the improvement of both the passive strategies (around 33%) and active strategies (around 67%). It is found that the thermal comfort constraint defined in the optimization also affects the energy saving. The total optimal energy consumption drops by around 3% if the value of the predicted percentage dissatisfied (PPD) limit is increased by one unit between 5~15%. It is also found that the fitted periodic weather data can lead to similar operation strategies in the dynamic optimization as the realistic data, and therefore can be a reasonable alternative when the more detailed realistic weather data is not available. The method described in the thesis can be generalized to supervise the operation design of building systems with different configurations.
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Gallardo, Carla. "Residential building stocks and flows as dynamic systems : Chilean dwelling stock and energy modeling, including earthquakes." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for vann- og miljøteknikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18786.
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The building sector comprises a very important part of each country’s economy, playing an important role in the consumption of resources and energy. In practice there is little knowledge on how the building stock develops. It is useful then to understand the dynamics and the metabolism of the built environment. Research on building stocks, predominantly on the residential sector, has been performed mainly for developed countries. There is little or none research on building stock for developing countries, so given that there is still a big gap regarding service levels (floor area per capita) between developed and developing countries, it is of importance to understand the dynamics of developing countries as well.Given that earthquakes occur in populated areas, it is important to assess the dynamics of such systems. The Chilean dwelling stock is subjected to earthquakes, so this focused on including earthquake activity to the dynamic MFA model of the dwelling stock. A leaching approach was used, basing the analysis on the typology distribution of different vulnerability classes. Different scenarios were defined in order to analyze the effect of policies on building codes and practices on the typology distribution of the stock, and hence on the demolition and renovation rate due to earthquakes. Policies for strengthening and renovating the building stock have a large positive impact on overall demolition rates. Patching types of policies have little effect when it comes to making the stock less vulnerable in the long term.An energy analysis was carried out for the overall stock, based on the mass balance yielded by the building stock dynamic MFA model. Effects of policies on energy and renovation standards are observed through the analysis of scenarios as well. The energy consumption of the stock has not reached saturation yet, and the timing for this will be strongly influenced by the energy intensity development of the stock. The combined effect of policies for decreasing the vulnerability of the dwelling stock and energy efficiency policies could be further explored if each vulnerability class could be described by an energy intensity factor. Further data gathering or modeling on this would be of importance to further understand the system.Even if there is data uncertainty and the model present weaknesses, the approach used for modeling the Chilean dwelling stock allows for a systematic view of the effects earthquakes on the system. The building sector is an important contributor of CO2 emissions. A detailed carbon analysis for the future development of the building stock is then relevant to this study. However, considering the time constraints, this research has focused on the modeling of the building stock including earthquake activity and an overall energy assessment of it. A simplified carbon analysis was left out due to the fact that by considering a constant emission factor the analysis of the trends of CO2 emissions would be equivalent to the analysis of the energy model.
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REALI, MAURO. "Development of innovative materials for building envelopes in dynamic behavior for energy saving and environmental sustainability." Doctoral thesis, Università Politecnica delle Marche, 2018. http://hdl.handle.net/11566/253016.
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Il risparmio energetico, lo sfruttamento delle energie rinnovabili, il rispetto dell'ambiente, e il comfort abitativo, rappresentano gli obiettivi della ricerca condotta, afferente il tema della Protezione Civile ed Ambientale, in 'ambito edilizio. Nello specifico sono stati sviluppati vetri innovativi capaci di conciliare aspetti contrastanti quali: garantire l'introspezione di luce naturale e nello stesso tempo gestire gli apporti termici esterni. I prototipi studiati riescono ad adattarsi agli stimoli esterni, grazie ad elementi fotocromatici organici che, sotto la radiazione solare, si oscurano gradualmente aumentando l'energia riflessa e garantendo il contenimento delle temperature interne.
Al calare della radiazione solare, tornano trasparenti lasciando filtrare la luce solare. La ratio dei vetri è la schermatura dell'energia termica grazie all'assemblaggio di vetri Low-E, riflettenti le radiazioni dell'infrarosso, con elementi fotocromatici in grado di riflettere, attivandosi, la banda ultravioletta e gran parte della radiazione visibile. Nelle campagne sperimentali, è stato possibile apprezzare le prestazioni dei vetri sperimentali, confrontandole con quelle di un modulo bassoemissivo campione (uno dei prodotti più performanti e diffusi sul mercato). I vantaggi dei vetri sperimentali sono stati quantificati, secondo le procedure tecniche dalle Norme UNI EN 410/2000 e UNI EN 673/2011, attraverso la valutazione dei parametri caratterizzanti delle vetrate, primi tra tutti il fattore solare G che è l'energia termica totale trasmessa dai vetri e il fattore di trasmissione luminosa v che rappresenta la luce naturale introiettata. I test hanno confermato la validità dei moduli sperimentali che, al massimo oscuramento, sono riusciti a schermare il 25% in più di energia termica, rispetto al campione di riferimento e garantire 8÷10 gradi K in meno di temperatura all'interno dei box; mentre, allo stato trasparente hanno garantito l'introspezione di luce naturale.The energy saving, the exploitation of renewable energy, respect for the environment, and living comfort, represent the objectives of the research conducted, relating to the theme of Civil and Environmental Protection, in the building sector. Specifically, innovative glasses have been developed capable of reconciling contrasting aspects such as: guaranteeing the introspection of natural light and at the same time managing the external thermal contributions. The studied prototypes are able to adapt to external stimuli, thanks to organic photochromatic elements that, under the solar radiation, gradually darken by increasing the reflected energy and ensuring the containment of internal temperatures. When the solar radiation drops, they return transparent, letting the sunlight filter through. The ratio of the glasses is the shielding of the thermal energy thanks to the assembly of Low-E glasses, reflecting the infrared radiation, with photochromatic elements able to reflect, activating, the ultraviolet band and a large part of the visible radiation. In experimental campaigns, it was possible to appreciate the performance of experimental glasses, comparing them with those of a low-emission sample module (one of the most performing and widespread products on the market). The advantages of the experimental glasses were quantified, according to the technical procedures of the Standards UNI EN 410/2000 and UNI EN 673/2011, through the evaluation of the characteristic parameters of the windows, first of all the solar factor G which is the total thermal energy transmitted by glass and the light transmission factor v representing introjected natural light. The tests have confirmed the validity of the experimental modules that, at the most obscuring, have managed to screen 25% more thermal energy, compared to the reference sample and guarantee 8 ÷ 10 degrees K less temperature inside the boxes; while, in the transparent state, they guaranteed the introspection of natural light.
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Huang, Puxi. "Hygrothermal performance of Moso bamboo-based building material." Thesis, University of Bath, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.715306.
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This study focuses on the hygrothermal performance of Moso bamboo. The knowledge in this aspect is remarkable important for the research of building energy saving and the low carbon building design. However, the detailed hygrothermal properties of Moso bamboo are fairly rare. To obtain these data, a series of experimental works have been done for measurement of density, porosity, thermal conductivity, specific heat capacity, water vapour permeability, hygrothermal expansion and sorption isotherm of Moso bamboo. To obtain further understanding on the hygrothermal performance of Moso bamboo, a number of dynamic heat and moisture transfer experiments were conducted. These experiments simulated two extreme outdoor environments and one indoor environment. The temperature and RH responses of Moso bamboo panels were monitored. Then a coupled transient heat and moisture transfer numerical simulation at the material level was conducted to predict and validate the hygrothermal performance of Moso bamboo. A sensitivity study of the hygrothermal properties of bamboo was also presented to indentify the influence of each hygrothermal property of Moso bamboo. Major findings include the following aspects. Both experiment and simulation results appear to be consistent with the results of measurements of the basic hygrothermal parameters. The parametric study found that density can be regarded as the most sensible parameter to influence the temperature simulation results at the transient state, while the thermal conductivity dominated the temperature variation at the steady state. The water vapour diffusion resistance factor can be regarded as the most critical parameter to influence the RH simulation results. The influence of liquid water diffusivity is negligible in this study. The parametric study results indicated that the simulation with moisture is more accurate than the simulation without moisture in both equilibrium and transient state. The results also imply that the existence of moisture could increase the heat capacity and reduce the thermal conductivity. The results of this study recommend that the external part of the bamboo culm wall can be utilised to minimise the RH variation of the panel while the internal part of the bamboo culm wall is suitable to increase the thermal insulation performance of the panel. To avoid hygroexpansion, the implementation of external part of bamboo culm wall needs to be minimised.
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Lam, King-hang, and 林勁恆. "Techniques for dynamic modelling of BIPV in supporting system design and BEMS." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39558460.
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Samant, Gajanan Balkrishna. "Verification of the "Energy Accumulation in Waves Travelling through a Checkerboard Dielectric Material Structure in Space-time" Using Spice Simulations." Digital WPI, 2009. https://digitalcommons.wpi.edu/etd-theses/1210.
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"Recently, there has been some good interest in the field of Dynamic Materials, also referred to as Spatio-Temporal Composites. These materials have been theoretically attributed to show ability to switch their electromagnetic properties in time, as contrast to the spatial variations shown by regular materials of non-dynamic nature, existing naturally. Though there is no exhibition of dynamic material in nature yet, there are suggestions for its synthesis. This paper follows the idea of using standard lossless transmission line model approximating a material substance. Such a material though not truly homogeneous, could be made to vary its properties in time. The aim of this work is to test this idea for its functional efficiency in comparison to analytical results obtained from earlier works on the subject. We make use of Spice simulation for this. An important aspect of this work is to facilitate the dynamic operations in a static environment. Almost all the simulators available today like Spice, ADS, etc intrinsically provide no ability for parameter variations in time. Nonetheless, we make use of certain popular tricks to implement circuits imitating the dynamic circuit components we need. Such implementations are separately tested to demonstrate their success in providing us with the dynamic environment we desire. Finally, within the limitations of the computing capabilities, we could successfully show an agreement between the results obtained and the existing theory. "