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REDESIGN OF HVAC SYSTEM TO IMPROVE ENERGY EFFICIENCY OF EDUCATIONAL BUILDINGHagene, Brian Matthew 01 May 2012 (has links)
An energy modeling software was used to analyze the current building configuration and simulations were performed in an attempt to redesign the current HVAC system of an educational building to improve the energy efficiency of the building, exceed current building code requirements, and meet the building's cooling and heating load. The different HVAC systems simulated were: Dual Air Duct, Variable-Air Volume (VAV), and Dedicated Outdoor Air Systems (DOAS). Each system was modeled in four operation schedules including: current system operation, fan control, lighting control, and lighting and fan control. These operation schedules are to represent how efficient the building would be in different controlled settings. Results were obtained regarding the energy requirements of the different HVAC systems. For the educational building both VAV and DOAS systems offer 48.8% and 57.9%, respectively, in annual savings in energy use, achieved by adding controls to the lights and fans of both systems reducing energy consumed by ventilation fans. The time of a simple payback period for a new VAV and DOAS system is 10.2 and 9.35 years, respectively, and may remove any considerations to implement a new HVAC system. Based on these findings, educational buildings using Dual Duct should consider using DOAS systems.
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Sistemas de controle solar e ações de retrofittingNuss, Claudio Andre January 2018 (has links)
Os sistemas de controle solar auxiliam no controle da radiação solar incidente no envoltório, e, de acordo com a NBR 15220-3, é recomendável seu uso para a zona bioclimática 3, na cidade de Porto Alegre. Assim, com a ação de retrofitting, é possível utilizar os sistemas de controle solar como modo de adaptar o envoltório das edificações ao clima local e aos padrões de consumo atuais. Dessa forma, o retrofitting do envoltório pode contribuir com a redução do consumo energético e a dependência de sistemas de refrigeração e aquecimento mecânico. Logo, o objetivo da dissertação é qualificar e quantificar energeticamente os sistemas de controle solar com vistas à redução do consumo energético nos ambientes construídos. Um estudo de caso foi realizado na cidade de Porto Alegre, onde um edifício foi selecionado perante um conjunto de edificações existentes. Com o auxílio de um método expedito de cálculo energético, foi realizada a avaliação energética do envoltório da edificação atual e do seu retrofitting proposto. A edificação passou de nível energético E para nível A, comprovando o êxito do estudo de retrofitting aplicado. A pesquisa concluiu que, alinhado com o encontrado na revisão da literatura, as edificações com grandes aberturas orientadas para oeste são um equívoco de projeto no clima de Porto Alegre e que as ações de retrofitting são uma alternativa de adaptação ao clima local, tornando os edifícios eficientes energeticamente. / Shading systems help to control the incident solar radiation on the envelope, and, according to NBR 15220-3, its use is recommended for the bioclimatic zone 3, in the city of Porto Alegre. Hence, with retrofitting, it is possible to use shading systems as a way of adapting the building envelope to the local climate and current consumption patterns. Thus, the retrofitting of the envelope can contribute to the reduction of the energy consumption and of the dependence on systems of refrigeration and mechanical heating. Therefore, the objective of this dissertation is to qualify and quantify the energy of shading systems in order to reduce energy consumption in built environments. Thus, a case study was conducted in the city of Porto Alegre, where a building was selected from a set of existing buildings. We performed an energetic evaluation of current envelope of buildings and its proposed retrofitting by using a facilitated method for energy calculation. The buildings moved from energy level E to level A, proving the success of the study on the applied retrofitting. We conclude that, as also shown in literature review; buildings with large openings oriented to the west in Porto Alegre are a design misconception due to the city’s climate. Thus, retrofitting actions are alternative ways to adapt to the local climate so that buildings are energy efficient.
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Gestão energética e ambiental de edificações: avaliação de metodologias para certificaçãoRuzene, Juliana Santos [UNESP] 02 September 2011 (has links) (PDF)
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ruzene_js_me_guara.pdf: 944530 bytes, checksum: 8ee6e0a711627cfaf412e1c2b8e93560 (MD5) / O sistema LEED (Leadership in Energy and Environmental Design) consiste numa metodologia para avaliar o desempenho energético e ambiental de edificações ao longo de seu ciclo de vida, tendo como objetivo direcionar ações para o conceito de edificações sustentáveis (green buildings) e fornecer uma padronização para medir a dimensão ambiental relativa dos projetos. No Brasil, a Eletrobrás, através do Programa Nacional de Conservação de Energia Elétrica (Procel) e em parceria com o Instituto Nacional de Metrologia, Normalização e Qualidade Industrial (Inmetro), lançaram a Etiqueta Nacional de Eficiência Energética em Edificações (ENCE), para edifícios comerciais, de serviços e públicos, reconhecendo edificações que reduzam o consumo de energia elétrica e água. Neste trabalho foi realizado um estudo de certificação energética e ambiental de edificações, bem como a identificação de alternativas técnicas para o enquadramento em níveis mais adequados e correspondente estudo de viabilidade econômica. Como estudo de caso, o edifício da Fundação existente no Campus de Guaratinguetá da UNESP foi analisado de acordo com os preceitos da avaliação de desempenho de ambas as metodologias. Com base nos resultados obtidos, foram realizadas sugestões de tecnologias e modificações possíveis de serem implantadas / The LEED system (Leadership in Energy and Environmental Design) is a methodology for evaluating the energetic and environmental performance of buildings throughout their life cycle, aiming to guide actions for the concept of green building and provide a standard for measuring the size on environmental projects. In Brazil, Eletrobras, through the National Program for Energy Conservation (PROCEL) and in partnership with the National Institute of Metrology, Standardization and Industrial Quality (Inmetro), launched the Label National Energy Efficiency in Buildings (ENCE), for commercial buildings, and public service, recognizing buildings that reduce the consumption of electricity and water. In this research report it was presented an environmental and energetic certification of buildings study, as well as the analysis of technical solutions for the framework in more appropriate levels, and corresponding economic feasibility study. As a case study, the Foundation's existing building on the campus of UNESP at Guaratinguetá was analyzed in accordance with the principles of performance evaluation of both approaches. Based on these results, suggestions were made of possible technologies and changes being implemented
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Energieffektiviseringens påverkan på fastighetsägare och hyresgäster / The impact of energy efficiency on tenants and property ownersFalk, Rikard, Nilsson, Marcus January 2017 (has links)
I detta examensarbete har energieffektiviserande åtgärders påverkan på hyresgäster och fastighetsägare undersökts. Syftet var att sätta sig in i de boendes situation och få en bättre förståelse för deras upplevelse av inomhusklimat och komfort. Därav skulle fastighetsägarens och hyresgästens gemensamma vinning kunna ses. Huvudsakligen utfördes litteraturstudier för teoretisk inhämtning av kunskap. Inledningsvis bedrevs faktamässig påläsning kring vad inomhusklimat är, hur komfort kan mätas samt hur kundnöjdhet fungerar. Detta adderat till en sammanfattning av Rekorderlig renovering, ett gemensamt bostadsprojekt i syfte att minska energianvändningen och förbättra inomhusupplevelsen för hyresgäster, gav en tydligare förståelse för åtgärder, vilka borde studeras. Beräkningsmässigt gjordes kalkyler för att utläsa tendenser som fanns för operativ temperatur och PPD. Dessa behandlade förbättringar av fönster, tilläggsisolering samt lufthastighet. En modell skapades även i VIP-energy för enklare beräkningar vilka simulerades så att energibesparingar kunde erhållas. I övrigt studerades åtgärders påverkan genom teoretiska fakta. Slutligen diskuterades komfortdelar i förhållande till åtgärder och detta visade att största effekt på inomhusklimat och komfort torde vara ventilation och fönster. Fönster kunde enskilt ge den största förändringen i upplevelse för hyresgästen. Det visades på störst skillnad i operativ temperatur av fönster, dock gjordes inga konkreta beräkningar på dess påverkan på exempelvis kallras. Slutsatsen drog således på att fönstret kunde generera påverkan på flest olika faktorer. Dock kunde ventilation möjligen ha en större total positiv verkan på kundnöjdhet, men torde dock ha en svårare genomförbarhet för fastighetsägaren. Rent energibersparingsmässigt visade emellertid LED-belysning och frånluftsvärmepump på störst skillnad. Svårigheten av olika fördelar baserat på olika intressen knöt an till rapportens idé om att kunna ena dessa. / In this project the impact of energy efficiency measures on tenants and property owners was examined. The purpose was to familiarize oneself with the situation of the residents and gain a better understanding of their experience of indoor climate and comfort. Hence, the common profit of the property owner and the tenants could be seen. Mainly, literature studies were conducted for theoretical acquirement of knowledge. Initially, informational reading was conducted about what indoor climate is, how comfort can be measured and how customer satisfaction works. This added to a summary of “Rekorderlig renovering”, a common housing project aimed at reducing energy use and improving the indoor experience of tenants and gave a clearer understanding of what measures, to study. Simple calculations were made in order to see tendencies for operative temperature and the predicted percentage disatisfied. These managed improvements to windows, additional insulation and air velocity. A simpler model was also created in the building simulation program VIP energy for calculations of energy savings. The impact of measures was further studied through theoretical facts. Finally, comfort aspects in relation to measures, were discussed and this showed that the greatest effect on indoor climate and comfort would be ventilation and windows. Windows could individually give the biggest changein experience for the tenant. It was shown that the greatest difference in operative temperature came from windows. However, no concrete calculations were made of its impact on, for example, cold air convection. Thus, the conclusion was made that the windows could generate an impact on most different factors. Ventilation could also have a great overall positive effect on customer satisfaction, but may be a more difficult implement for the property owner. However, in pure energy savings, Led lighting and exhaust air heat pump showed the greatest difference. The difficulty of various benefits based on different interests was in line with the idea of the report of being able to unify these.
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Ultra low power cooperative branch predictionBielby, Matthew Iain January 2015 (has links)
Branch Prediction is a key task in the operation of a high performance processor. An inaccurate branch predictor results in increased program run-time and a rise in energy consumption. The drive towards processors with limited die-space and tighter energy requirements will continue to intensify over the coming years, as will the shift towards increasingly multicore processors. Both trends make it increasingly important and increasingly difficult to find effective and efficient branch predictor designs. This thesis presents savings in energy and die-space through the use of more efficient cooperative branch predictors achieved through novel branch prediction designs. The first contribution is a new take on the problem of a hybrid dynamic-static branch predictor allocating branches to be predicted by one of its sub-predictors. A new bias parameter is introduced as a mechanism for trading off a small amount of performance for savings in die-space and energy. This is achieved by predicting more branches with the static predictor, ensuring that only the branches that will most benefit from the dynamic predictor’s resources are predicted dynamically. This reduces pressure on the dynamic predictor’s resources allowing for a smaller predictor to achieve very high accuracy. An improvement in run-time of 7-8% over the baseline BTFN predictor is observed at a cost of a branch predictor bits budget of much less than 1KB. Next, a novel approach to branch prediction for multicore data-parallel applications is presented. The Peloton branch prediction scheme uses a pack of cyclists as an illustration of how a group of processors running similar tasks can share branch predictions to improve accuracy and reduce runtime. The results show that sharing updates for conditional branches across the existing interconnect for I-cache and D-cache updates results in a reduction of mispredictions of up to 25% and a reduction in run-time of up to 6%. McPAT is used to present an energy model that suggests the savings are achieved at little to no increase in energy required. The technique is then extended to architectures where the size of the branch predictors may differ between cores. The results show that such heterogeneity can dramatically reduce the die-space required for an accurate branch predictor while having little impact on performance and up to 9% energy savings. The approach can be combined with the Peloton branch prediction scheme for reduction in branch mispredictions of up to 5%.
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FULL-VIEW COVERAGE PROBLEMS IN CAMERA SENSOR NETWORKSLi, Chaoyang 08 August 2017 (has links)
Camera Sensor Networks (CSNs) have emerged as an information-rich sensing modality with many potential applications and have received much research attention over the past few years. One of the major challenges in research for CSNs is that camera sensors are different from traditional scalar sensors, as different cameras from different positions can form distinct views of the object in question. As a result, simply combining the sensing range of the cameras across the field does not necessarily form an effective camera coverage, since the face image (or the targeted aspect) of the object may be missed. The angle between the object's facing direction and the camera's viewing direction is used to measure the quality of sensing in CSNs instead. This distinction makes the coverage verification and deployment methodology dedicated to conventional sensor networks unsuitable.
A new coverage model called full-view coverage can precisely characterize the features of coverage in CSNs. An object is full-view covered if there is always a camera to cover it no matter which direction it faces and the camera's viewing direction is sufficiently close to the object's facing direction. In this dissertation, we consider three areas of research for CSNS: 1. an analytical theory for full-view coverage; 2. energy efficiency issues in full-view coverage CSNs; 3. Multi-dimension full-view coverage theory. For the first topic, we propose a novel analytical full-view coverage theory, where the set of full-view covered points is produced by numerical methodology. Based on this theory, we solve the following problems. First, we address the full-view coverage holes detection problem and provide the healing solutions. Second, we propose $k$-Full-View-Coverage algorithms in camera sensor networks. Finally, we address the camera sensor density minimization problem for triangular lattice based deployment in full-view covered camera sensor networks, where we argue that there is a flaw in the previous literature, and present our corresponding solution. For the second topic, we discuss lifetime and full-view coverage guarantees through distributed algorithms in camera sensor networks. Another energy issue we discuss is about object tracking problems in full-view coverage camera sensor networks. Next, the third topic addresses multi-dimension full-view coverage problem where we propose a novel 3D full-view coverage model, and we tackle the full-view coverage optimization problem in order to minimize the number of camera sensors and demonstrate a valid solution.
This research is important due to the numerous applications for CSNs. Especially some deployment can be in remote locations, it is critical to efficiently obtain accurate meaningful data.
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Cross-Layer Design for Energy Efficiency on Data Center NetworkCheocherngngarn, Tosmate 27 September 2012 (has links)
Energy efficient infrastructures or green IT (Information Technology) has recently become a hot button issue for most corporations as they strive to eliminate every inefficiency from their enterprise IT systems and save capital and operational costs. Vendors of IT equipment now compete on the power efficiency of their devices, and as a result, many of the new equipment models are indeed more energy efficient. Various studies have estimated the annual electricity consumed by networking devices in the U.S. in the range of 6 - 20 Terra Watt hours.
Our research has the potential to make promising solutions solve those overuses of electricity. An energy-efficient data center network architecture which can lower the energy consumption is highly desirable. First of all, we propose a fair bandwidth allocation algorithm which adopts the max-min fairness principle to decrease power consumption on packet switch fabric interconnects. Specifically, we include power aware computing factor as high power dissipation in switches which is fast turning into a key problem, owing to increasing line speeds and decreasing chip sizes. This efficient algorithm could not only reduce the convergence iterations but also lower processing power utilization on switch fabric interconnects. Secondly, we study the deployment strategy of multicast switches in hybrid mode in energy-aware data center network: a case of famous Fat-tree topology. The objective is to find the best location to deploy multicast switch not only to achieve optimal bandwidth utilization but also minimize power consumption. We show that it is possible to easily achieve nearly 50% of energy consumption after applying our proposed algorithm. Finally, although there exists a number of energy optimization solutions for DCNs, they consider only either the hosts or network, but not both. We propose a joint optimization scheme that simultaneously optimizes virtual machine (VM) placement and network flow routing to maximize energy savings. The simulation results fully demonstrate that our design outperforms existing host- or network-only optimization solutions, and well approximates the ideal but NP-complete linear program. To sum up, this study could be crucial for guiding future eco-friendly data center network that deploy our algorithm on four major layers (with reference to OSI seven layers) which are physical, data link, network and application layer to benefit power consumption in green data center.
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Analysis of Dowlink Macro-Femto Cells Environment Based on Per-Energy CapacityLeón, Jaime 05 1900 (has links)
Placing smaller cells in a heterogeneous cellular network can be beneficial in
terms of energy because better capacities can be obtained for a given energy
constraint. These type of deployments not only highlight the need for appropriate
metrics to evaluate how well energy is being spent, but also raise important issues
that need to be taken into account when analysing the overall use of energy. In this
work, handoff strategies, bandwidth allocation, and path loss models in different
scenarios, illustrate how energy can be consumed in a more efficient way when
cell size is decreased. A handoff strategy based on per-energy capacity is studied
in order to give priority to a more energy efficient handoff option. Energy can
also be spent more adequately if the transmit power is adjusted as a function of
interference. As a result, users can experience higher capacities while spending less
energy, depending whether they handoff or not, increasing the overall performance
of the network in terms of energy efficiency.
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"Study of a direct combustion into steam"Stefano, Marco, Meglio, Rosamaria January 2013 (has links)
No description available.
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Improving Commercial Broiler Attic Inlet Ventilation Through Data Acquisition Coupled with CFD AnalysisOlsen, Jonathan William Wiley 15 December 2012 (has links)
The use of solar heated attic air is an area of increasing interest in commercial poultry production. Attic inlets satisfy the demand for alternative heating while being simple to implement in an existing poultry house. However, little attention has been given to the configuration of the attic space and its influence on thermal energy extraction. This issue was approached in a threefold manner: i.) test case experimental data for the operation of attic inlets in an east-west oriented commercial broiler house was recorded, ii.) a two-dimensional computational fluid dynamics (CFD) attic inlet ventilation model (AIVM) was developed and verified using the experimental data, and iii.) the simulation was used to investigate the efficiency of attic inlet system improvements. The simulation demonstrated that the strategic placement of a simple diverter and an inlet riser may increase thermal energy extraction by 40% over the measured attic inlet system.
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