Thèses : « Usage phase of buildings »

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Borg, Mathias. « Environmental Assessment of Materials, Components and Buildings Building Specific Considerations, Open-loop Recycling, Variations in Assessment Results and the Usage Phase of Buildings ». Doctoral thesis, Stockholm : Tekniska högsk, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3232.

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Paulsen, Jacob. « Life Cycle Assessment for Building Products - The significanse of the usage phase ». Doctoral thesis, KTH, Building Sciences and Engineering, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3159.

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Paulsen, Jacob. « Life cycle assessment for building products : the significance of the usage phase / ». Stockholm : Tekniska högsk, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3159.

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Susman, Gideon. « The application of phase change materials to cool buildings ». Thesis, Brunel University, 2012. http://bura.brunel.ac.uk/handle/2438/7639.

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Five projects improve understanding of how to use PCM to reduce building cooling energy. Firstly, a post-installation energy-audit of an active cooling system with PCM tank revealed an energy cost of 10.6% of total cooling energy, as compared to an identical tankless system, because PCM under%cooling prevented heat rejection at night. Secondly, development of a new taxonomy for PCM cooling systems allowed reclassification of all systems and identified under-exploited types. Novel concept designs were generated that employ movable PCM units and insulation. Thirdly, aspects of the generated designs were tested in a passive PCM sail design, installed in an occupied office. Radiant heat transfer, external heat discharge and narrow phase transition zone all improved performance. Fourthly, passive PCM product tests were conducted in a 4.2 m3 thermal test cell in which two types of ceiling tile, with 50 and 70% microencapsulated PCM content, and paraffin/copolymer composite wallboards yielded peak temperature reductions of 3.8, 4.4 and 5.2 °C, respectively, and peak temperature reductions per unit PCM mass of 0.28, 0.34 and 0.14 °C/kg, respectively. Heat discharge of RACUS tiles was more effective due to their non-integration into the building fabric. Conclusions of preceding chapters informed the design of a new system composed of an array of finned aluminium tubes, containing paraffin (melt temperature 19.79 °C, latent heat 159.75 kJ/kg) located below the ceiling. Passive cooling and heat discharge is prioritised but a chilled water loop ensures temperature control on hotter days (water circulated at 13 °C) and heat discharge on hotter nights (water circulated at 10 °C). Test cell results showed similar passive performance to the ceiling tiles and wallboards, effective active temperature control (constant 24.6˚C air temperature) and successful passive and active heat discharge. A dynamic heat balance model with an IES% generated UK office’s annual cooling load and PCM temperature%enthalpy functions predicted annual energy savings of 34%.

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Ozdenefe, Murat. « Phase change materials and thermal performance of buildings in Cyprus ». Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/phase-change-materials-and-thermal-performance-of-buildings-in-cyprus(a7b37f53-22de-47d4-ad19-2596ee75a558).html.

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This work investigates the thermal performance of buildings in Cyprus and application of a particular passive technology; Phase Change Materials (PCMs) for the ultimate aim of reducing indoor air temperatures and energy supplied for the cooling season.PCMs for passive building applications are emerging technology and have not been tested for the buildings of Cyprus neither by computer simulations nor by practical applications. In this work, particular PCM end product; wallboard, having phase change temperature of 26 oC is employed together with various construction materials and simulated for buildings of Cyprus. Description of the current state in Cyprus has been carried out in terms of low energy building studies, widely used building fabric and building statistics. There is a huge gap in Cyprus in the field of energy performance and thermal comfort of buildings, which creates big room for research. Climatic design of buildings has been abandoned resulting in poor thermal comfort and increased energy consumption. There is still no regulation in place regarding the thermal performance of buildings in North Cyprus.Recent weather data of different Cyprus locations has been investigated and compared with the simulation weather data files that are employed in this work. The author has demonstrated that Finkelstein-Schafer statistics between recent weather data of Cyprus and simulation weather data files are close enough to obtain accurate results.Dynamic thermal simulations has been carried out by using Energy Plus, which is a strong and validated thermal simulation program that can model PCMs. Simulations are done for two different building geometry; “simple building” and “typical building” by employing different construction materials. Simple building is a small size box shaped building and typical building is a real existing building and selected by investigation of the building statistics.Simulation results showed that with this particular PCM product, indoor air temperatures and cooling energies supplied to simple building is reduced up to 1.2 oC and 18.64 % when heavier construction materials are used and up to 1.6 oC and 44.12 % when lighter construction materials are used. These values for typical building are found to be 0.7 oC, 3.24 % when heavier construction materials are used and 1.2 oC, 3.64 % when lighter construction materials are used. It is also found that, if thinner walls and slabs are used in the buildings the effectiveness of the PCM lining increases in significant amount.

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Dyball, Dianne L. « An innovative wall-lining for buildings incorporating phase change materials ». Thesis, University of Brighton, 2013. https://research.brighton.ac.uk/en/studentTheses/efdce4e8-dbb0-407b-9d57-ac45820e6743.

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The use of thermal energy storage in buildings is well understood but contemporary buildings with highly insulated, lightweight construction have low thermal inertia. This causes them to respond rapidly to external temperature changes, which results in significant internal temperature fluctuations and overheating. This research addresses this problem by developing a thermal interactive wall-lining through the inclusion of phase change materials. Phase change materials (PCMs) not only absorb sensible heat but also absorb and release latent heat during phase transition. This research set out to determine if it is possible to locate phase change materials on the surface of a room and if they can effectively improve the thermal performance of a room. Using the scientific method the suitability of different types of PCMs was investigated for inclusion within a vinyl matrix. Experiments evaluated the maximum quantity of PCM loading and thermal analysis identified the largest potential heat storage capacity for the phase change wall-lining. Following successful laboratory experiments a pilot scale prototype phase change wall-lining was manufactured and tested. The test involved an experiment comprising two thermally matched chambers to evaluate the thermal performance of the phase change wall-lining in a controlled environment. The results demonstrated the phase change wall-lining can reduce internal temperatures by more than 2°C and delay the time taken to reach extreme temperatures. The effect of different air flow rates on the ability to charge and discharge the phase change wall-lining have been evaluated to identify the required operating criteria for use in buildings. This research has developed an innovative phase change wall-lining that reduces internal peak temperatures, minimises diurnal temperature fluctuations by storing excess heat and improves the thermal comfort. The outcomes provide a greater understanding of the interaction between air and PCMs when located on the surface of a room, and indicate that such materials have the potential to improve thermal performance of new and existing buildings.

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Javed, Khalid. « Non linear seismic response of asymmetric buildings ». Thesis, University of East London, 1999. http://roar.uel.ac.uk/1260/.

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The study presented in this thesis is an attempt towards a better understanding of the coupled lateral-torsional response of buildings subject to seismic ground motion. Some of the problems identified in the past studies are thoroughly investigated and some new areas of study are explored. Some of these problems encountered in the literature include (a) the existence of several definitions of uncoupled torsional to lateral frequency ratio (b) an arbitrary selection of structural parameters in a parametric analysis resulting in a physically inadmissible structure and (c) the effect of nonlinearity. Because of the simplified models with either eccentricity in one direction or the ground motion applied in only one direction, the effects of a bi-directional loading have not been investigated in detail. These effects may include the relative differences in the amplitude or phase components of the individual accelerograms and their orientation with respect to the building. The phase properties of accelerograms are of particular interest and these have not received much attention in the past. Using analytical methods such as Chasle's[16] and Gerschgorin's[39] theorems, the equation of motion of a bi-eccentric system is derived and all of the existing problems regarding the definition of structural parameters and their bounds are studied in depth. To facilitate nonlinear parametric study, a paraboloid non-linear elastic stiffness model is proposed. Fourier spectral methods are used to study the frequency domain characteristics of the accelerogram pair. The difference in phase and amplitude of the component frequencies in each direction are studied for their effects on the response. For phase difference, cross-correlation function is used as a comparative statistical indicator. USA earthquake records obtained from US National Geophysical Data Centre are grouped into four soil types and the analysis is performed for each group in order to explore the soil-dependency of the aforementioned effects on the response. Computer programs are written in FORTRAN for both parametric and numerical model analyses. The latter can handle any number and orientation of columns with the assumed nonlinear stiffness properties. Newmark's and Runge-Kutta methods of numerical integration with adaptive step size control have been used to calculate parametric and the hysteretic responses of the system. The response to harmonic ground acceleration is used as a preliminary investigation into the response to actual accelerogram frequency components. The study has developed relationships for different definitions of the uncoupled torsional to lateral frequency ratio. Detailed derivation of the Equation of Motion has clarified the confusion that produced different definitions in the past studies. Graphical descriptions of the admissibility bounds on system parameters are produced. The variation in the response quantities is studied for a range of amplitude and phase contents of the applied ground acceleration. The difference in phase and amplitude in x and y ground accelerations have been found to affect the response quite significantly. More generally, the relationship of these differences to the torsional mode amplification has been observed. The effects of structural frequency and eccentricity parameters are also studied. Graphs showing the relationship between, the angle of incidence of the accelerogram with respect to the principal axis of the building, and the phase difference in the accelerogram pair, have been produced. The proposed analysis involving the bi-directional ground acceleration on a bi-eccentric system is an improvement on the current methods employed in design practice. Further work is, however, required before simplified design recommendations can be made and some proposals for future research are given at the end of this thesis.

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Höglund, Philip. « Impact of future usage patterns on the insulation demand for office buildings in Stockholm ». Thesis, KTH, Industriell ekologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-194369.

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The environmental impact from our energy production and use today is a central concern for every major decision maker regardless of interest area. Together with transport and industry, housing and services is a major contributor to our energy consumption. In 2013 housing and services accounted for 38% of the energy consumption in Sweden Therefore, energy consumption in buildings has become an area of great importance with many technological solutions developing to meet the demands from investors and legislation. However, present solutions primarily aim to solve current problems, while ongoing technological and social development is setting new conditions for future buildings. This study investigates the future of office buildings heading towards a more flexible work environment. Advancement of technology accompanied with new emerging economic and social practices is facilitating the flexibility, as well as remote work and more out-of-office time, with possible decrease of the thermal energy produced by humans and equipment. In addition, desktop computers will be replaced by energy efficient thin clients, tablets, and phones while other equipment is also becoming more energy efficient, resulting in reduced secondary heat production and thus lower internal gains. This scenario supposes reduced internal gains, resulting in decreased cooling requirements but also increased heating requirements. However, an alternative scenario with increased internal gains is also likely, due to activity-based workplaces. Activity-based offices dispose of personal desks, instead utilising activity-based areas where employees choose an area or desk where to work, depending on their current task. Disposing of personal desks supports higher occupancy, as employees working elsewhere don’t occupy workplaces at the office. Thus, the amount of desks can be matched to the actual amount of employees working at the office during peak loads. These scenarios are developed, quantified, and used as a basis for the building simulation models. These models are then optimised to meet these new conditions, utilising simulation and multi objective optimisation. The key finding is that office buildings are resilient to changing conditions, and that a state-of-theart office from today meet the demands of tomorrow.
Miljöpåverkan från vår produktion och energianvändning är idag är en central fråga för varje större beslutsfattare oavsett intresse i området. Tillsammans med transport och industri, är bostäder och service en viktig bidragande orsak till vår energiförbrukning. År 2013 bostäder och service stod för 38% av energiförbrukningen i Sverige. Därför har energiförbrukningen i byggnader kommit att få stor betydelse, vilket driver utvecklingen mot nya tekniska lösningar för att möta kraven från investerare och lagstiftning. De nuvarande lösningarna syftar dock främst till att lösa nuvarande problem, samtidigt som teknisk och social utveckling skapar nya förutsättningar för framtida byggnader. Detta projekt undersöker framtiden för kontorsbyggnader, där utvecklingen verkar vara på väg mot distansarbete, outsourcing, och mer arbetstid spenderad utanför kontoret, vilket minskar mängden interna laster som värmer upp kontoret. Samtidigt utvecklas stationära datorer och annan utrustning som ersättas med energieffektiva tunna klienter, tablets, och smarta telefoner, vilket minskar de interna lasterna ytterligare. Ett alternativt scenario är aktivitetsbaserade kontor, där de anställda inte har sin egen arbetsyta, utan istället använder aktivitetsbaserade områden beroende på arbetsuppgift. Detta scenario kan tänkas leda till ökade interna laster då ytan kan användas mer effektivt, som kan kompensera för användning av mer energieffektiv kontorsutrustning. Projektet undersöker tänkbara framtida scenarier och hur framtida kontor kan anpassas för att möta dessa nya förutsättningar med hjälp av klimat- och energisimuleringsmjukvara. Resultaten tyder på flera tydliga trender i användningen av kontorsbyggnader, men effekterna av dessa trender kan resultera i flera scenarier. Därför projektet omfattar flera scenarier för att utvärdera spannet av möjligheter. Simuleringarna tyder på att kontorsbyggnader är motståndskraftiga mot förändrade villkor, och att ett modernt kontor från idag kan möta morgondagens behov.

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Rawls, Sandra K. « Restroom usage in selected public buildings and facilities : a comparison of females and males ». Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/53598.

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Women often experience having to stand in line in order to use public restrooms. The primary purpose of this exploratory study was to determine the number and types of activities performed in the restroom, along with the amount of time spent in the restroom, as these factors might influence the revision of plumbing codes and the design of public restrooms. Data were collected by a self administered questionnaire at four sites--an airport, highway rest area, sports arena, and conference center. The subjects were also timed. The sample consisted of 230 male and 224 female respondents. Males and females were similar in the types of activities performed in the restroom. Urination, washing hands, and checking appearance were the three activities performed most frequently by both genders. Females were more likely to have to stand in line to use the restroom than males, though the wait was usually fewer than five minutes. At two of the sites, airport and sports arena, females, on an average, performed more activities than males. At all four sites, females spent a significantly greater amount of time in the restroom than did males. For female respondents the mean time ranged from 152.5 seconds (sports arena) to 180.6 seconds (rest area). For male respondents the mean time ranged from 83.6 seconds (sports arena) to 112.5 seconds (airport). There was no significant relationship between age and the amount of time spent in the restroom, for either gender at any of the four sites. The results from two sites, however, showed a slight trend toward older people spending more time in the restroom. There was no clear pattern with regard to explaining the relationship between the amount of time spent in the restroom and the number of activities performed. For males only, there were significant differences among the four sites and the amount of time spent in the restroom. For both males and females, there were significant differences between number of activities performed and site. This research indicates that females need a greater number of elimination fixtures than do males, and that revision of plumbing codes, based on further research, is needed.
Ph. D.

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Unéus, Viktor. « Energy efficiency trends in large clusters of residential buildings ». Thesis, Högskolan Dalarna, Energiteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:du-34559.

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The aim of this thesis work is to analyse the trends in heat use among Borlänge Energis district heating customer over the last 20 years. Several reports show that in general the buildings stock get more and more efficient, both in Sweden and other European countries, but will the same trend be seen among Borlänge Energis customer? Data of delivered heat to 324 customers, both single-family houses and multifamily houses, for the period of 1998-2018 is used in this study. The heating that is assumed for domestic hot water is calculated and the heat used for heating is temperature corrected so the heat needed for a normal year could be calculated. The investigated customers are divided into different groups representing various types of buildings with different building years. From this data it’s possible to see trends in heat usage in kWh/building, and year for various types of buildings over the period. Other studies on how trends for heating usage in buildings have report heating usage in kWh/(m2,year). It wasn’t possible in this work to get data of the size of each building, which means that it’s not possible to compare the result from this study with other studies. However, assuming that the building area have been the same and that no extensions of the buildings have been done during the period, the trend in changed heat use should be the same, unless the result is presented in kWh/m2, year and kWh/building, year. The overall results show that there is a reduction in energy use in the buildings in Borlänge during the period 1998-2018. The decrease in heat use are in the order of 0.3 – 0.4 %/year, with larger decrease in multi-family houses. This is considerably less than the decrease of heat use in the buildings stock of 0.9 – 1.2 %/year reported for the entire building stock in Sweden during approximately the same period.

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Amiri, Nasim. « Examination of LEED Certified Building’s Electricity Usage ». TopSCHOLAR®, 2017. https://digitalcommons.wku.edu/theses/2034.

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The number of buildings seeking LEED certification has been growing steadily over the past few years. In this study, three academic buildings which were designed and built to LEED certification standards were targeted in Bowling Green, Kentucky. Their electricity consumption and cost effectiveness were examined and compared with predesigned LEED efficiency models of those three buildings. This research directly examined cost effectiveness of LEED buildings in terms of electricity usage. Three case studies were completed to find the initial and on-going electricity costs of LEED buildings and to verify the LEED standard results. LEED aspects of these buildings were discussed with contractors, architects, project managers, and building maintenance personnel who participated in LEED projects and non-LEED sustainable projects.

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Hossain, Mohammad Akram. « Development of Building Markers and Unsupervised Non-intrusive Disaggregation Model for Commercial Buildings’ Energy Usage ». Case Western Reserve University School of Graduate Studies / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case1517225790921761.

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Jain, Pranjal, et Khaled Alturkmani. « Improving the Efficiency of Thermal Energy Usage in Residential Buildings by Heat Recovery from Wastewater ». Thesis, Högskolan i Halmstad, Akademin för företagande, innovation och hållbarhet, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-44853.

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This study aims to rationalize the consumption of thermal energy in residential buildings by recovering heat from wastewater inside the building before entering the central sewage network outside the building, by conducting an analytical study for a residential tower in Syria to find out the coverage percentage of the heat energy recovered from wastewater for the heating and domestic hot water loads needed for the tower, and calculating the percentage of reduction in carbon dioxide (CO2) gases. It is a simple technology as the thermal recovery system consists of three main components, which are in order: a wastewater tank, heat exchangers, and a heat pump. The research begins with an introduction that consists of the importance of wastewater and the waste heat energy it carries. After that, there are some case studies, research problem, its importance, the aim of the research, and finally the research methodology. In the first chapter, we talked about the concept of heat recovery from wastewater in general, methods of heat recovery, and the most important advantages and disadvantages of this process. It also includes an identification of the main parts used in this technology and how it works, especially the exchangers and the heat pump. This chapter also addresses the problem of forming a layer of biofilms on the surface of heat exchangers from the wastewater side and the most important methods used to treat it. We move on to the second chapter, in which we review the most important facilities for heat recovery from wastewater that have been viewed. Then comes the third chapter in which the heat recovery process was conducted for a nine storey residential tower in Syria, each floor has four apartments, where we first calculated the rate of wastewater flow for the entire tower, and we proposed a heat recovery system (physical model) inside the tower. Then the mathematical equations for heat recovery and the solution of these equations were developed based on some necessary assumptions needed in the solution process to know the most important results desired in this field. It also included the calculation of the coverage ratio of the heat energy recovered from the wastewater for the domestic hot water and heating loads, as well as the calculation of the mass and percentage of the reduction of carbon emitted to the atmosphere. Then simple economic feasibility was also conducted in this chapter to know the daily financial savings as a result of using this technology. The research ends with the most important conclusions and future research that have been reached and the conclusion of the research. The most important results show that the average coverage percentage of heat energy recovered from wastewater for heating load in residential buildings ranges between [30-56%]. It was also found that the average coverage percentage of heat energy recovered from wastewater for domestic hot water load ranges between [65-100%].

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Thorsell, Thomas. « Advances in Thermal Insulation : Vacuum Insulation Panels and Thermal Efficiency to Reduce Energy Usage in Buildings ». Doctoral thesis, KTH, Byggnadsteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-90745.

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We are coming to realize that there is an urgent need to reduce energy usage in buildings and it has to be done in a sustainable way. This thesis focuses on the performance of the building envelope; more precisely thermal performance of walls and super insulation material in the form of vacuum insulation. However, the building envelope is just one part of the whole building system, and super insulators have one major flaw: they are easily adversely affected by other problems in the built environment. Vacuum Insulation Panels are one fresh addition to the arsenal of insulation materials available to the building industry. They are composite material with a core and an enclosure which, as a composite, can reach thermal conductivities as low as 0.004 W/(mK). However, the exceptional performance relies on the barrier material preventing gas permeation, maintaining a near vacuum into the core and a minimized thermal bridge effect from the wrapping of barrier material round the edge of a panel. A serpentine edge is proposed to decrease the heat loss at the edge. Modeling and testing shows a reduction of 60% if a reasonable serpentine edge is used. A diffusion model of permeation through multilayered barrier films with metallization coatings was developed to predict ultimate service life. The model combines numerical calculations with analytical field theory allowing for more precise determination than current models. The results using the proposed model indicate that it is possible to manufacture panels with lifetimes exceeding 50 years with existing manufacturing. Switching from the component scale to the building scale; an approach of integrated testing and modeling is proposed. Four wall types have been tested in a large range of environments with the aim to assess the hygrothermal nature and significance of thermal bridges and air leakages. The test procedure was also examined as a means for a more representative performance indicator than R-value (in USA). The procedure incorporates specific steps exposing the wall to different climate conditions, ranging from cold and dry to hot and humid, with and without a pressure gradient. This study showed that air infiltration alone might decrease the thermal resistance of a residential wall by 15%, more for industrial walls. Results from the research underpin a discussion concerning the importance of a holistic approach to building design if we are to meet the challenge of energy savings and sustainability. Thermal insulation efficiency is a main concept used throughout, and since it measures utilization it is a partial measure of sustainability. It is therefore proposed as a necessary design parameter in addition to a performance indicator when designing building envelopes. The thermal insulation efficiency ranges from below 50% for a wood stud wall poorly designed with incorporated VIP, while an optimized design with VIP placed in an uninterrupted external layer shows an efficiency of 99%, almost perfect. Thermal insulation efficiency reflects the measured wall performance full scale test, thus indicating efficiency under varied environmental loads: heat, moisture and pressure. The building design must be as a system, integrating all the subsystems together to function in concert. New design methodologies must be created along with new, more reliable and comprehensive measuring, testing and integrating procedures. New super insulators are capable of reducing energy usage below zero energy in buildings. It would be a shame to waste them by not taking care of the rest of the system. This thesis details the steps that went into this study and shows how this can be done.
QC 20120228

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de, Bruyn Megan Dawn. « Teachers' perspectives on iPad usage for learners with dyslexia in the intermediate phase ». Diss., University of Pretoria, 2017. http://hdl.handle.net/2263/62913.

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This study contributes to existing research on the perspectives of teachers’ with regards to the use of the iPad for learners with dyslexia. The purpose of this case study was to explore and describe teachers' perspectives on iPad usage for learners with dyslexia in the Intermediate Phase. The primary research question that guided this study was: “What are teachers’ perspectives on iPad usage for learners with dyslexia?” A qualitative research design was used to collect rich data using Intermediate Phase teachers. Eleven teachers from three schools in Johannesburg participated in the study. The data collection tools that were used included focus group discussions, semi-structured interviews and observations. By exploring how these teachers perceived iPad usage, specifically for learners with dyslexia, this study contributed to an existing body of knowledge providing insight into the use of iPads in the classroom and as a learning support tool. The themes that emerged from this study answer the question of what teachers’ perspectives on iPad usage for learners with dyslexia are. Findings indicate that teachers’ perceive the iPad as a useful support tool but that it comes with many challenges that need to be addressed. The findings indicate that the iPad creates interactive learning and increases the confidence of learners with dyslexia. It is recommended that research be conducted with a larger sample size and also for challenges to be addressed so that the iPad can be utilised to its full potential.
Dissertation (MEd)--University of Pretoria, 2017.
Educational Psychology
MEd
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Løtveit, Sjur Vullum. « Cost Optimality of Energy Systems in Zero Emission Buildings in Early Design Phase ». Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for fysikk, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-23249.

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The building sector accounts for a significant proportion of industrial countries total energy use, thus a cut in this sector has been regarded necessary to reach future climate goals. An important measure in this context is the introduction of zero emission buildings, buildings which can be defined as having a net zero annual energy demand. This master thesis is centered around finding cost optimal energy supply systems for zero emission buildings at an early stage of the building process. This thesis is closely linked to the Ådland project, currently the largest pilot project for the Research Center on Zero Emission Buildings. The testing was performed on a four floor building block located in Bergen. The ZEB-definition used was net zero primary energy consumption, where primary energy factors were used as weighting factors for the various energy carriers. Two types of primary energy factors were tested; total primary energy factors and non-renewable primary energy factors. Five different energy supply packages were investigated: Bio+PV, CHP+PV, DH+PV, HP+ST+PV and CHP+ST+PV. The base heating systems were dimensioned to cover the heating demand (space heating and domestic hot water), while PV was dimensioned so that the building reached the ZEB balance. Excess electricity was exported to the grid and sold to the local power company. The simulation tool IDA-ICE was used both for modeling the building and performing the energy simulations. The cost calculations followed the European Cost Optimal Methodology, calculating the net present value of all costs attributed to the implementation of the different packages (investments, annual costs and residual values) over a calculation period of 30 years. Both a pure financial and a macroeconomic calculation were performed for all packages. Sensitivity analyses were performed on the energy price escalation as well as investment costs.When total primary energy factors were used, the package HP+ST+PV proved to be the optimal package in all the different scenarios considered. The macroeconomic and the financial results were almost identical, mainly because of the low CO2-prices. The sensitivity analyses showed that the result is very stable with respect to uncertainties in both investment costs and future energy costs. For non-renewable primary energy factors the results showed that the package HP+ST+PV is best for both normal and high future energy price development, while the package Bio+PV was the best alternative for low energy price developments. The sensitivity analysis on investment cost showed the result for low energy price development was very sensitive for changes in investment costs, while for medium and high energy price development the result were more stable. Overall, for the energy supply packages considered and the primary energy factors used in this thesis, the conclusion is that HP+ST+PV is the cost optimal energy supply solution for the evaluated building.

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Gates, Jonathan Roger. « Solar thermal storage using phase change material for space heating in residential buildings ». Thesis, University of Brighton, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.507199.

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In 2007 the domestic sector was responsible for 27% of all energy consumed by final users in the UK, yet only 1.5% of this energy was met by renewables. The utilisation of renewable energy systems such as active solar water heating with Phase Change Material (PCM) thermal storage, offers vast potential for reducing energy use and CO2 emissions in the domestic energy sector in the UK. Previous research indicated that the incorporation of PCMs in underfloor heating had the potential to make energy savings, but their use in combination with renewable energy had not been explored in the UK. Consequently this was identified as a gap in the current knowledge that the current research would fill. A shortage was also identified in real life performance data on PCM space heating system performance in the UK. The current work successfully addresses this shortfall in data and in doing so provides a significant contribution to knowledge in the area of using solar thermal storage for space heating of residential buildings. An in depth literature review was undertaken as part of the research programme, which identified the key shortcomings in existing PCM based thermal storage systems for space heating. An underfloor space heating system for residential buildings was therefore developed that addresses the weaknesses of the existing systems highlighted in the literature review. The system stores solar thermal energy during the day and then uses this to provide space heating in the evening, thus addressing the problem of matching solar availability to demand. An experimental approach was adopted for the study as numerous researchers (Kauranen et al., 1991, Hasnian, 1998, Kenisarin and Mahkamov, 2007), have demonstrated the unreliability of manufacturer's published thermophysical properties of PCM. Therefore, this research chose to adopt an experimental model approach instead of a mathematical modelling approach. A model consisting of a full size solar collector 4m2 in area and a PCM filled underfloor heating panel was constructed in the laboratory. A methodology was developed to measure the performance of the key modules which allowed the performance of the system to be evaluated. The experimental data indicated that it was possible to use a low flow rate of 2.52 litres per minute, without a detrimental effect on the performance of the PCM panel. The use of a low flow rate minimises parasitic losses and produces significant energy savings in comparison to the use of higher flow rates. The experimental results indicated that the system was able to provide adequate thermal comfort with a maximum floor heat emission of 158 W/m using a flow rate temperature of 50°C. Comparisons of the annual space heating energy of the developed integrated system versus a wet central heating system in the UK revealed a significant reduction of energy use and associated CO2 emissions by as much as 52%.

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Barbado, Baranda Pablo. « Cost Optimality of Energy Systems in Zero Emission Buildings in Early Design Phase ». Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-26088.

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Abstract During the uncontrolled consumption period the building sector has come to account one of the greatest proportions of greenhouse gas emissions and energy use in industrial countries. In this context, European countries have decided to address the environmental challenge by promoting the use of renewable energies and the implementation of low energy consumption requirements. For these reasons, zero emission buildings, which have a net zero annual energy demand, were regarded as a possible solution. And everything points to believe that they will continue to be crucial in a recent future. Consultants and contractors have shown the need towards a better understanding and knowledge regarding the selection of renewable energy supply solution for ZEBs. Accordingly, this Mater Thesis aims to explain how to use the new methodology for a cost-optimal selection of energy systems in early design phase analysis. It consists on a number of guidelines and Excel files that serve as templates for different calculations. The project is part of the development of a decision support method that automates the process of selecting the best system, in this particular case in office buildings. This early design phase study is not only focused on giving a cost-optimal alternative but also on performing a full analysis in terms of energy performance. It also shows the steps for both the energy systems dimension and the selection of office building parameters. A concept office building with four storeys is selected and modelled in connection with the Norwegian ZEB centre’s project report 8. Following the Norwegian NZEB definition, the simulation software IDA-ICE is used as a tool for modelling the building and simulating the energy demand. It analyses six different energy supply combinations which were selected between available renewable technologies in Norway. In comparison to the previous study applied in residential buildings, this project introduces the building’s cooling demand as a new feature of the analysis. Therefore, reversible heat pumps, free-cooling with the ground and chillers are also taken into account. Further, energy systems are economically compared by using global cost calculations, following the European Cost Optimal Methodology. Results are given in a graph where global costs and CO2 emissions produced by the energy balance of the building are shown in each axis. Finally the cost-optimal energy supply, the system with lower global costs, is selected like the most suitable option. In addition, the building energy performance is also discussed as an important parameter to be considered in the decision making process. At the end, the sensitivity analysis shows stable results with regard to changes in energy price development and PV area.

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Grott, Steven, David Lecko, Ryan Parker et Nathan Price. « Telemetry System for Remote Monitoring of Utility Usage in Commercial and Residential Structures ». International Foundation for Telemetering, 2012. http://hdl.handle.net/10150/581677.

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ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California
The system described in this paper can monitor utility usage in commercial and residential structures, and send an alert message over conventional cell phone networks when it detects an anomalous condition. Such a condition could indicate a utility outage, structure failure, HVAC system failure, water leak, etc. The microcontroller-based system can measure electrical current, carbon monoxide, methane, liquid propane, temperature, barometric pressure, and altitude using a wired and wireless sensor network. The microcontroller displays the measurements on local and external graphical user interface, and sends SMS alert messages when necessary. The system may be retrofitted into existing structures.

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Trinh, Hoang T. « Optimisation framework for sustainable design of concrete buildings ». Thesis, Griffith University, 2021. http://hdl.handle.net/10072/409575.

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The building industry is identified as the largest single contributor to climate change, due to extensive consumption of natural resources and the discharge of high volumes of carbon emissions. It is consequently imperative for the whole sector to work towards sustainable design and construction. Although structural engineers have the greatest potential to enhance buildings’ sustainability by means of structural optimisation and/or material efficiency, they often play a restricted role in the sustainable design of a project. While many studies separately investigate the eco-friendly potentials of horizontal frames and vertical systems, most of them have not thoroughly considered all major components together for the whole structure, making it challenging for structural designers to incorporate and apply their findings into design projects. In addition, many design factors that are decided in early design stages have tremendous impacts on a building’s life cycle carbon footprint. Therefore, a comprehensive op imisation methodology that allows for a thorough environmental impact assessment and a quick investigation of the design solutions space is extremely essential. To facilitate sustainable designs of buildings in conceptual and preliminary designs, this research attempts to develop an innovative optimisation framework, combining an advanced deterministic optimisation algorithm and a data-driven surrogate model. Overall, the framework is comprised of two main phases: the design optimisation phase and the surrogate Artificial Neural Networks (ANN) modelling phase. In the design optimisation phase, the carbon-minimised design problems are formulated in accordance with relevant Australian design standards and solved with deterministic Branch-and-Reduce algorithm. Three types of concrete buildings are investigated, namely flat plate, flat slab with drop panels, and beam-slab systems. To verify the effectiveness and reliability of the formulated problems and adopted algorithm, sample building problems are solved and compared with their conventionally designed counterparts. Accordingly, the optimised buildings have shown to be environmentally superior to the conventional designs, with a reduction in EC of 0.8-22.6%, 1.1-32.3%, and 1.8-26.6%, respectively for flat plate, flat slab, and beam-slab buildings. Regardless of the type of buildings, most of the optimised designs were solved within two days, demonstrating significant time efficiency. In the surrogate ANN modelling phase, hundreds of building optimisation problems with different structural heights, spans, and column grids are randomly generated and solved for minimum CO2 emissions. These numerical applications are subsequently used to develop ANNs for the predictions of optimal design solutions. The input variables are the basic information of a building, including the building height, numbers of spans, column spacings, and concrete strengths for slabs and columns. The outputs are the essential design solutions, namely the slab thickness, drop panel depth, beam dimensions, column size, amounts of reinforcement for slabs, beams and columns, and the resultant carbon footprint. Thousands of ANNs with different hyperparameters and configurations are investigated to determine the best performing models. The networks are evaluated based on three statistical metrics: the Root Mean Squared Error (RMSE), Mean Absolute Percentage Error (MAPE), and adjusted Coefficient of Determination (𝑅̅2). Compared to statistical multiple linear regression models, ANNs have shown to possess outstanding prediction capability. Most of the best predicting ANNs produce highly accurate results with small RMSEs, MAPEs of less than 10%, and high goodness of fit (𝑅̅2>0.9). While flat plate and flat slab buildings require only 1-2 days to tune the network, the tuning times of surrogate ANNs for beam slab buildings were 3-4 days, which is still short in comparison with the time frame available at initial design phases. Once the models are properly trained, they can predict the design solutions in seconds. Given the reliability of the dataset generated from the optimisation phase as well as the high efficiency and accuracy of the developed ANNs, this innovative framework can assist structural engineers to deliver the most sustainable designs for entire buildings, especially in the short time frames of early design stages.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Eng & Built Env
Science, Environment, Engineering and Technology
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Pourakbar, Sharifi Naser. « Application of Phase Change Materials to Improve the Thermal Performance of Buildings and Pavements ». Digital WPI, 2017. https://digitalcommons.wpi.edu/etd-dissertations/22.

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In recent decades, much research has investigated the efficiency of Phase Change Materials (PCMs) in improving the thermal performance of buildings and pavements. In buildings, increasing the thermal inertia of structural elements by incorporating PCMs decreases the energy required to keep the inside temperature in the comfort range. In concrete pavements, using PCMs decreases the number of freeze/thaw cycles experienced by the pavement and thus increases service life. However, PCMs cannot be added to cementitious binders directly, because they interfere with the hydration reactions between cement and water that produce strength-bearing phases. Therefore different carriers have been proposed to indirectly incorporate PCMs in cementitious materials. Lightweight Aggregate (LWA) is one of the materials that has been proposed as PCM carrier agent. However, it was not studied in depth before. Various experiments were conducted to investigate the problems associated with incorporating LWA presoaked in PCM in cementitious media. The results show that a portion of PCM leaks out of the LWAâ€™s structure and subsequently affects different chemical, physical, and mechanical properties of the binder. In addition, the applicability of Rice Husk Ash (RHA), a common material never before used to encapsulate PCM, as a PCM carrier agent was investigated. The results show that RHA can absorb and contain liquids in its porous structure; and regarding its compatibility with the cementitious media, it can be used as PCM carrier. Different computational simulations using Typical Meteorological Year data were conducted to evaluate the efficiency of PCMs in improving the thermal performance of buildings. Utilizing PCM-incorporated gypsum boards was shown to be a promising strategy to achieve the governmental plans of â€œZero Net Energyâ€� buildings. The results show that using a PCM with a melting point near the occupant comfort zone delays and reduces the inside peak temperature, increases the duration of time during which the inside temperature stays in the comfort zone, and decreases the cost and energy required by HVAC system to keep the inside temperature in this range. However, PCMsâ€™ efficiency is completely dependent on the input temperature profile.

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Malekzadeh, Fatemeh. « Integration of Phase Change Materials in Commercial Buildings for Thermal Regulation and Energy Efficiency ». Thesis, The University of Arizona, 2015. http://hdl.handle.net/10150/603534.

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One of prospective procedures of absorbing thermal energy and releasing it during the required time is the application of phase change materials known as PCMs in building envelopes. High thermal energy storage (TES) materials has been a technology that effects the energy efficiency of a building by contributing in using onsite resources and reducing cooling or heating loads. Currently, many TES systems are emerging and contributing in building assemblies, however using an appropriate type of TES in a specific building and climate requires an in-depth knowledge of their properties. This research aims to provide a thorough review of a broad range of thermal energy storage technologies including their potential application in buildings. Subsequently, a comparative study and simulation between a basecase and an optimized model by PCM is thoroughly considered to understand the effect of high thermal storage building's shell on energy efficiency and indoor thermal comfort. Specifically this study proposes that the incorporation of PCM into glazing system as a high thermal capacity system will improve windows thermal performance and thermal capacity to varying climatic conditions. The generated results by eQUEST energy modeling software demonstrates approximately 25% reduction in cooling loads during the summer and 10% reduction in heating loads during the winter for optimized office building by PCM in hot arid climate of Arizona. Besides, using PCM in glazing system will reduce heat gain through the windows by conduction phenomenon. The hourly results indicates the effect of PCM as a thermal energy storage system in building envelopes for building's energy efficiency and thermal regulation. However, several problems need to be tackled before LHTES can reliably and practically be applied. We conclude with some suggestions for future work.

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Solgi, Ebrahim. « Experimental and numerical investigations of phase change material and night ventilation characteristics in buildings ». Thesis, Griffith University, 2019. http://hdl.handle.net/10072/389083.

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As a key consumer of energy, and producer of greenhouse gas emissions, the building industry can play a pivotal role in reducing the global energy and carbon footprint. Thus, the application of passive techniques in buildings has gained particular attention. These techniques, with minimal auxiliary energy load, can mediate between the external climate and comfortable indoor conditions, while providing an aesthetically pleasing indoor environment. Thermal energy storage is considered an essential component when using passive techniques. The primary aim of energy storage incorporated into buildings using passive strategies is to implement approaches for efficiently controlling the time lag between building energy demand and outdoor energy sources. Examples of passive strategies are advanced thermal energy storage (TES) and night ventilation (NV). Phase change materials (PCMs) as a salient example of advanced TES, have received remarkable attention for their use in energy-efficient buildings. PCMs, which mainly store energy thorough latent heat, can be conveniently integrated into building envelopes as productive lightweight thermal mass. PCMs have also been of paramount interest as compact components, since they can alleviate building energy loads and be easily coupled with other passive/active systems. Given that the role of TES in ameliorating the effectiveness of passive strategies such as NV is critical, recent years have produced a renewed interest in utilizing PCMs as efficient-lightweight thermal mass in preference to traditional sensible heat storage. Passive cooling techniques, such as NV, with an efficiency that is highly conditional upon thermal mass capacity, have been commonly used in conjunction with sensible thermal mass; however, with the proliferation of PCMs, NV can be reconsidered as an effective cooling strategy for lightweight construction. NV, as a well-established passive cooling strategy, uses the cool of night to release the daily stored heat; then during the subsequent warmer daytime the cooled TES can moderate indoor temperature. In countries with a range of climatic zones such as Australia, where the application of lightweight structures is of great importance, and where energy consumption is mainly targeted at the cooling demand, the use of PCMs and NV can be highly productive and applicable in a wide range of environments. However, very little is currently known in regard to the efficacy and requirements of employing PCMs in different Australian climatic zones, either in isolation or in combination with NVs. This research examines the key variables of PCM-enhanced buildings, such as the material properties and coupled thermal insulation, through a parametric study that includes NV efficiency. An optimal PCM-based TES is closely analysed in four major Australian climates, with respect to building and material characteristics and energy consumption. This dissertation follows experimental verifications, using a full-scale calorimeter, with in-depth numerical simulations of the validated model. This dissertation delivers some insights into the aforementioned TES and NV topics, and makes a contribution to building physics by providing building designers and researchers with the basis for practical applications.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Eng & Built Env
Science, Environment, Engineering and Technology
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Jaberansari, M. « The effect of atrium configurations on energy usage in high-rise office buildings in semi-arid climate of Tehran ». Thesis, University of Salford, 2018. http://usir.salford.ac.uk/48371/.

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The building sector is responsible for at least 30% of energy use in most countries worldwide (UN environment, 2017) and around 33% of energy is used by HVAC systems in buildings (Salib & Wood, 2013). As a passive design element, an atrium has the potential to naturally provide heating and cooling, as well as adequate daylight, in arid and temperate climates. Moreover, a naturally ventilated atrium has also proven to be a useful environmental feature in tall building design (Moosavi et al., 2014; Salib & Wood, 2013; Sharples & Bensalem, 2001). This thesis investigated the impact of different configurations of atria on the energy performance of tall office buildings in Tehran. Despite having a rich history of climatic conscious design, the contemporary architecture of the Middle East, and Iran as one of the countries in this region, has witnessed excessive energy use (Holford & Hunt, 2003). The building sector in Iran consumes six times more energy in comparison to that of average European countries (Asgar, 2014a). Moreover, the HVAC sector in Iran uses 61% of the energy in office buildings (IFCO Iranain organization for Fuel Consumption Optimisation in the country, 2010). Providing thermal comfort via passive means is a challenge for tall buildings situated in semi-arid climates and therefore, the atria design for this region is of utmost importance. In this thesis, different types of atria are incorporated into square and rectangular plan tall office buildings and their performances are examined when the buildings are only naturally ventilated throughout the year. The outputs are compared to when HVAC assists the naturally ventilated buildings, and for this, a Dynamic Thermal Simulation (DTS) tool, called Design Builder, has been used. This thesis utilises a Design Science research method. A number of scenarios were simulated with different atria configurations for square and rectangular plan buildings. The outcome of the simulation showed that the atria located on the north and west façades generally perform more efficiently in minimising heat loss. It was also concluded that rectangular plan models generally perform more efficiently than square plan models in terms of lowering energy load and ensuring fewer uncomfortable hours. Amongst the rectangular plan models, the lowest heating and cooling load prototypes had a reduction of 66.65% in energy load. Meanwhile, amongst the square plan models the lowest heating and cooling load prototype had a reduction of 33.71% in energy load.

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Tsang, Wai-man Wyman, et 曾偉文. « A study on the usage and perceptions of office building occupants to green roofs in Hong Kong ». Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/208521.

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As Hong Kong is famous for its image of leading international financial metropolis, many high-rise office buildings are confined inside some developed commercial districts of Hong Kong. A place for provision of greenery in such districts seems impracticable. However, greenery can exist in forms of green roof onto office buildings, it seems a practical way to embellish this concrete city. Academic studies from other countries have proven that having green roof onto buildings is able to bring numerous psychological benefits to the building occupants, but is this fact still true for office building occupants of Hong Kong? Besides, what do office building occupants think about the presence of green roof onto the building they are working inside? In this study we would like to explore the perceptions of office building occupants in Hong Kong toward green roof, as well as their mode of green roof usage in case green roof is present. The opinions on how office building occupants get satisfied with the green roof they have visited during their working time may give us a glance to the direction of green roof development in the future. What they expect on green roof is the best source of evidence in designing an optimal green roof on human-based consideration. Study result features that green roof on office building can provide a decent leisure place to occupants for relaxation, although they seem do not treat green roof as a vital place where they must go. Office building occupants are generally satisfied with green roof having appropriate provisions such as large variety of vegetation, attractive appearance and good management level. Some crucial characteristics of green roof have been identified in the viewpoints of office building occupants such as its aesthetic nature and location for convenient access. In considering the numerous benefits of green roof, every visitor, as office building occupants, agrees that green roof should be present for their needs. It gives positive and supportive evidence as incentive to the industry and developers for future green roof development.
published_or_final_version
Housing Management
Master
Master of Housing Management

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Wagoner, Jared Wesley. « Performance Evaluation of PCM-in-Walls of Residential Buildings for Energy Conservation ». OpenSIUC, 2019. https://opensiuc.lib.siu.edu/theses/2636.

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Phase Change Materials have been the subject of increased research in modern times. Phase Change Materials, abbreviated as PCMs, are being used in a variety of applications in the energy conservation world. In this study, the effect of PCMs on a residential building’s energy consumption was evaluated at different locations across the United States and compared to the standard building at the same locations. An average American residential building was designed and modeled in SketchUp software. The building was evaluated for energy consumption at different locations across the United States using weather data for each chosen location. After the baseline results were collected, the building was re-evaluated, under the same conditions, with a Heptadecane embedded in the exterior walls as the chosen PCM for this study. The results of this study show that Phase Change Materials have a wide-ranging effect on the energy consumption of the designed building. Addition of the PCM to the building walls decreased total energy usage, over the course of a year, by 3.02 – 6.72%, depending on the location.

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Giró, Paloma Jessica. « Characterization of polymers and Microencapsulated Phase Change Materials used for Thermal Energy Storage in buildings ». Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/346923.

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The use of renewable heat decreases the consumption of fossil resources, although its usage is intermittent and usually does not match the demand. A proper thermal energy storage system design can eliminate this problem by reducing the consumption of non-renewable resources and improving energy efficiency where used. In buildings, thermal energy storage using phase change materials (PCM) is a useful tool to achieve reduction in energy consumption. These can be incorporated into passive or/and active systems. Thus, a proper selection of materials and extensive characterization for its usage in thermal energy storage is critical for new construction systems and for those already constructed. This Thesis is divided in two blocks and presented as a compendium of published articles in scientific journals indexed in Materials, Engineering, and Energy areas. The emphasis is made in the chemical, physical, thermal, mechanical and environmental characterization of PCM, MPCM (microencapsulated phase change materials), and PCS (phase change slurries). The main purpose is to perform an exhaustive characterization of this kind of materials because several scientific studies have highlighted that PCM mixed with construction materials can suffer leakage. Polymeric encapsulation is an alternative for retaining PCM inside building materials, resulting in a system named MPCM. - Macroscopic samples: the nanoindentation tecnique has been used to characterize thermoplastics that, so far, have had few precedents. As mechanical properties of materials are an important criterion for their selection and nanoindentation allows their evaluation, we have studied the hardness and elastic modulus of different polymeric materials through Loubet and Oliver & Pharr methodologies, to discern which is the most suitable concerning the viscoelastic properties. The obtained values by Oliver & Pharr method are based on the unloading curve analysis; in case of Loubet methodology, these values are a function of the penetration depth of the indentation. Also, we have studied the mechanical changes that occur when a polymer that contains a flame retardant is immersed in PCM. It has been observed that using Mg(OH)2 increases rigidity and mechanical strength while reducing the degradation effect and improving the properties against fire. This block contains two scientific published papers. - Microscopic samples: This block is based on MPCM studies. A review of publications related to PCM, MPCM and slurries (PCS) (same shell and different PCM; different shell and same PCM; same shell and same PCM, but different encapsulation ratios) was prepared. Then, the evaluation of the chemical, physical, thermal, mechanical, and environmental properties of different MPCM and PCS samples was performed, concluding that AFM is a useful tool to characterize the stiffness and Young's modulus of MPCM. Because temperature is a key parameter in PCM systems, AFM experiments were carried out at different temperatures, in order to simulate the PCM in solid and/or liquid state. PCS samples were observed using SEM device coupled to a cryogenic system. Besides, environmental properties of PCS have been studied by gas chromatography (VOC’s). In addition, PCS were cycled for the evaluation of the polymeric shell durability after pumping the sample several cycles. Also, the chemical and thermophysical properties before and after pumping the sample were compared. Finally, due to the thermal behavior results of PCS in some performed studies, and depending on the liquid or dried PCS sample, the optimum conditions by means thermogravimetric analysis were evaluated. The second block contains five scientific published articles, one article under review after its first revision, one article finished without being submitted to a journal, and one unfinished research. Finally, the contribution in the state of the art of this PhD Thesis related with thermal energy storage in buildings using PCM, MPCM, and PCS is presented.
Un correcto diseño del sistema de almacenamiento de energía térmica (TES) puede eliminar un uso discontinuo y que habitualmente no coincide con la demanda. El TES mediante materiales de cambio de fase (PCM) en climatización pasiva y activa en edificios es un instrumento útil para alcanzar un descenso del consumo de energía. La Tesis se divide en dos bloques y se presenta como compendio de artículos publicados en revistas científicas indexadas en las áreas de Materiales, Ingeniería, y Energía, haciendo émfasis en la caracterización química, fisica, térmica, mecánica y ambiental de PCM, MPCM (materiales de cambio de fase microencapsulados) y PCS (pulpas con cambio de fase). - Caracterización de diferentes termoplásticos mediante nanoindentación. a través de los métodos de Loubet y Oliver & Pharr. También se han estudiado los cambios mecánicos que se producen cuando un polímero que contiene carga ignifugante en su formulación se sumerge en PCM. Este bloque contiene dos artículos científicos. - Estudio de MPCM. Se ha llevado a cabo una revisión de publicaciones por otros autores. Se han caracterizado con AFM diferentes MPCM y PCS, a diferentes temperaturas. Se han observado muestras de PCS mediante el uso de SEM acoplado a un sistema de crionizado, y se han estudiado las propiedades medioambientales por cromatogyafía de gases. Además, se han ciclado PCS para ver la durabilidad de la pared polimérica después de ciertos ciclos de bombeo. Se han investigado las condiciones óptimas mediante análisis termogravimétrico en PCS. Este segundo bloque contiene cinco artículos científicos publicados, un artículo aceptado en primera revisión, un artículo finalizado sin enviar a revista, y un estudio en investigación. Finalmente, se presentan las conclusiones principales de la contribución de esta Tesis Doctoral en el estado del arte de los PCM, MPCM, y PCS para almacenaje de energía en edificios.

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Navarro, Farré Lidia. « Thermal energy storage in buildings through phase change materials (PCM) incorporation for heating and cooling purposes ». Doctoral thesis, Universitat de Lleida, 2016. http://hdl.handle.net/10803/398840.

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La reducció del consum energètic dels sistemes de calefacció i refrigeració dels edificis és un repte fonamental per assolir els objectius marcats per l’Horitzó 2020. Noves aplicacions d'emmagatzematge d'energia tèrmica en edificis es mostren prometedores per reduir aquest elevat consum energètic. Un dels objectius d'aquesta tesi doctoral és revisar les aplicacions passives i actives d'emmagatzematge d'energia que es troben en la literatura, especialment aquelles que utilitzen materials de canvi de fase (PCM). En aplicacions passives els requeriments de confort i les condicions climàtiques són els principals paràmetres que s’han tingut en compte fins ara. Per això s'estudia la influència de càrregues internes en el aplicacions passives de PCM. D'altra banda, es presenta un sistema innovador que actua com una unitat d'emmagatzematge tèrmic i alhora com un sistema de calefacció i refrigeració. El rendiment tèrmic d'aquest sistema es testeja sota condicions reals i s'avalua el seu potencial de reducció del consum d'energia.
La reducción del consumo energético de calefacción y refrigeración de los edificios es un reto para lograr los objetivos marcados por el Horizonte 2020. Nuevas aplicaciones de almacenamiento de energía térmica en edificios se muestran prometedoras para reducir este elevado consumo energético. Uno de los objetivos de esta tesis doctoral es revisar aplicaciones pasivas y activas de almacenamiento de energía que se encuentran en la literatura, especialmente aquellas con materiales de cambio de fase (PCM). En aplicaciones pasivas los requerimientos de confort y las condiciones climáticas son los principales parámetros que se han tenido en cuenta hasta ahora. Se estudia la influencia de cargas internas en aplicaciones pasivas de PCM. También, se presenta un sistema innovador que actúa como una unidad de almacenamiento térmico y como calefacción y refrigeración. El rendimiento térmico de este sistema se testea bajo condiciones reales y evalúa su potencial de reducción del consumo energético.
Reducing the energy consumption of heating and cooling systems of buildings is a key challenge to achieve the targets set for the Horizon 2020. New applications of thermal energy storage in buildings are promising to reduce the high energy consumption. One of the objectives of this PhD is to review passive and active applications of thermal energy storage in buildings found in the literature, especially those that use phase change materials (PCM). In passive applications comfort requirements and climatic conditions are the main parameters that have been considered so far. For this study, the influence of internal loads has been taken into account in passive PCM applications. Moreover, an innovative system which acts as a storage unit and a heating and cooling supply is presented. The thermal performance of this system is studied and the potential in reducing the energy consumption of heating and cooling is evaluated.

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Politi, Stefano <1988&gt. « Buildings Embodied Impacts over the Life Cycle : an Essential Assessment Framework for the Early Design Phase ». Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amsdottorato.unibo.it/9055/1/Politi_Stefano_tesi.pdf.

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The present thesis project revolves around recognition of the critical environmental footprint generated by constructions, from their conception to their disposal. The first part of the research therefore centered on the study of the environmental consequences arising from the construction industry through the analysis of the sustainability assessment protocols or green buildings rating systems (GBRSs), identifying a “set core” of representative categories and indicators of buildings’ sustainability. As a consequence of a number of evidences emerged from the analysis upon the “embodied impacts” (not related to buildings operation) this research centered on the Life Cycle Assessment (LCA) methodology, which emerged as an appropriate tool to measure such impacts. A second analysis of GBRS frameworks was conducted in order to identify the most distinctive aspects, providing a shared buildings LCA framework and underlining several discrepancies in how the method is applied within a wide context and regarding the interpretation of the results. The last part of the thesis, therefore, dealt with the development of a simplified approach capable of overcoming the drawbacks that emerged in order to facilitate the environmental evaluation, from both a methodological and operational point of view, during the early phases of the process which turned out to be particularly significant stages for describing the environmental profiles of buildings. With respect to the complexity of the LCA assessment for non-expert practitioners, implementation of the proposed framework within the Building Information Modelling (BIM) environment was investigated resulting in the development of a customizable and convenient LCA-BIM integration approach. The research concluded with an illustrative application to a case study in order to test the proposed LCA-BIM integration, intending to demonstrate the process and, at the same time, identify and discuss the potential advantages and disadvantages of such a method with a view of future developments.
Il progetto di ricerca presentato in questa tesi di dottorato è incentrato sul tema della determinazione e della valutazione del profilo ambientale degli edifici durante il loro ciclo di vita. Inizialmente la ricerca si è concentrata sullo studio degli effetti ambientali ascrivibili agli edifici attraverso i protocolli di valutazione della sostenibilità (Rating Systems) identificando un "nucleo" di categorie e indicatori rappresentativi della sostenibilità degli edifici. A seguito di alcune considerazioni emerse dall’analisi sugli “impatti inglobati” (non ascrivibili alle fasi operative), la ricerca si è orientata sulla metodologia Life Cycle Assessment (LCA), individuata come uno strumento appropriato per la misura di questo tipo di impatti. Una seconda analisi dei protocolli di sostenibilità è stata condotta al fine di individuare gli aspetti più distintivi dell’LCA in riferimento alle applicazioni sull’ambiente costruito, delineando una serie di requisiti condivisi ed evidenziando alcune discrepanze nell’applicazione del metodo in contesti eterogeni e nell'interpretazione dei risultati. L'ultima parte della tesi, quindi, affronta lo sviluppo di un approccio condiviso e semplificato volto a superare i limiti emersi e facilitare le valutazioni ambientali, sia da un punto di vista metodologico che operativo. In particolare, l’approccio è stato ideato per essere applicato durante le prime fasi del processo costruttivo (progettazione), considerate determinanti nella configurazione dei profili ambientali degli edifici. In merito alla complessità dello svolgimento delle analisi per gli utenti meno esperti, è stata studiata l’integrazione del framework proposto con gli strumenti Building Information Modeling (BIM), attraverso lo sviluppo di un flusso di lavoro personalizzabile e conveniente. La ricerca si è conclusa con l'applicazione sperimentale del metodo su un caso studio al fine di testare il flusso di lavoro proposto per l'integrazione tra LCA e BIM, mostrandone il processo operativo, individuandone e discutendone i potenziali vantaggi e svantaggi in vista di successivi approfondimenti e sviluppi.

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With, Christoffer. « Train-Induced Vibrations on Embankments and in Buildings : Prediction and Validation of Some Models ». Doctoral thesis, Stockholm : Division of Soil and Rock Mechanics, Royal Institute of Technology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4810.

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Wang, Xichun. « Application of MPCM slurry with cooled ceiling to realize a low energy building design ». online access from Digital Dissertation Consortium, 2008. http://libweb.cityu.edu.hk/cgi-bin/er/db/ddcdiss.pl?3341125.

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Erdurmus, Salih Bugra. « Benefit-cost Analysis For Retrofitting Of Selected Residential Buildings In Istanbul ». Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606817/index.pdf.

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During the evaluation of the seismic retrofitting option for risk reduction/mitigation measures to be applied over buildings, Benefit Cost Analysis is an often-used method. During this study of Benefit Cost Analysis, the condition that the earthquake can happen just after or sometime after retrofitting will be taken into consideration rather than some approaches that focus on the benefits and costs regarding the annual probability of the occurrence for possible earthquakes. The analysis will use conditional probability such that the earthquake will be assumed to occur at different periods of time (5, 10, 20 years etc.) after the mitigation measures are taken so that benefit-cost ratios and net social benefits can be observed over time using the results at these periods. Also during this study the indirect effects of earthquake such as business disruption, social disturbance will also be taken into consideration. As a final step, it is aimed to conclude with convincing financial results regarding the direct and indirect effects of the earthquake in terms of benefits and costs to encourage people and the public officials to reduce the potential vulnerability of the housing units people live by taking the necessary precautions against the earthquake.

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Decroix, Anne-Amandine. « Stabilité physique et désordre orientationnel dans un cristal à usage thérapeutique : la caféine ». Thesis, Lille 1, 2009. http://www.theses.fr/2009LIL10084/document.

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Ce travail porte sur l'étude des états physiques de la cafëine solide, composé bien connu des industries pharmaceutique et agroalimentaire. afin de comprendre la nature de son polymorphisme original et des instabilités associées. Les caractérisations expérimentales ont été menées par DSC, DRX, RMN et relaxation diélectrique. La caractérisation de la mobilité moléculaire des phases anhydres a mis en évidence la présence d'une dynamique complexe extrêmement lente à température ambiante. Deux processus dynamiques analogues sont observés dans les phases 1 et II. notés AI et AII, et un processus plus lent dans la phase l, noté BI. Les transformations entre les phases 1 et II ont été étudiées afin de rechercher les origines des capacités extraordinaires de la caféine à pouvoir être maintenue dans des situations de métastabilité très prononcées. Cette investigation a révélé des processus de transformation inhabituellement lents, influencés par la dynamique moléculaire lente. Les résultats obtenus suggèrent que la cinétique de transformation 1?II est du 1er ordre, qu'elle est contrôlée par la vitesse de germination et que la dynamique par l'intermédiaire du processus BI en est un facteur déterminant. Un modèle cohérent a également été construit pour la transition II?I, il suggère une transformation à partir de la surface. avec une influence particulièrement importante de la microstructure de l'échantillon. Des opérations de broyage ont permis de confirmer l'influence microstructurale de la transition II ?1 et ont révélé que le broyage induit mécaniquement une transformation de la phase 1 vers la phase II, mais aussi de la phase II vers la phase 1 selon l'intensité du broyage
We present the study of the physical state of solid caffeine, a well-known pharmaceutieal and food-industry compound, ln order to understand its original polymorphism and the associatcd instabilities. Experimental characterisations have been obtaincd by DSC. XRD. NMR and dielcctric relaxation. The study of lhe moleeular mobility of anhydrous phases shows a very slow complex dynamic at room temperature. Two similar dynamical processes are observed in phases 1 and II. called AI, and AII. and a process slower in phase I callcd BI. The phases transformations (from I to II and II to I) have been studied to determine the origin of the extraordinary property of caffeine to be maintained in situation of high metastability. This investigation reveals anomalous slow transformation processes, influenced by the slow molecular mobility. The results suggest a first order I?II transformation kinetic, controlled by the nucleation rate, and directly governed by the BI dynamical process. A coherent model has also been proposed for the II?I transition, suggesting a transformation f'rom the surface, with a high influence of the microstructure. Milling operations confirm the microstructural influence for the II?I transition. It has also been shown that milling induees I?II transformation but also II?I transformation according to the milling intensity

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Mer'eb, Muhammad Musa. « Greenometer-7 a tool to assess the sustainability of a building's life cylce at the conceptual design phase / ». Cleveland, Ohio : Cleveland State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=csu1209184917.

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Thesis (D.Eng.)--Cleveland State University, 2008.
Abstract. Title from PDF t.p. (viewed on May 8, 2008). Includes bibliographical references (p. 321-343). Available online via the OhioLINK ETD Center. Also available in in print.

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Karimi, Asli Kaveh. « Strategies for promoting sustainable behavior regarding electricity consumption in student residential buildings in the city of Linköping ». Thesis, Linköpings universitet, Industriell miljöteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-73567.

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Achieving sustainable consumption of energy is an important issue due to the increasing demand for energy and its environmental impact. One of the biggest consumers of the global energy production is the residential sector. Factors determining pattern of energy consumption in this sector are firstly, characteristics of the buildings and equipment and appliances which are used inside them and secondly, people who are using the buildings. The former could be approached by using efficiency strategies; i.e. designing and using materials and utilities which are low energy demanding or reducing consumption of energy. The latter could be reached by adoption of demand side management strategies which could improve pattern of energy consumption by the end users. Combining these strategies bring out energy-smart buildings with energy-smart people as the users. This project aims at introducing potential approaches to strategies of promoting sustainable behavior regarding energy consumption in individuals, with the focus on the students of Linköping University living in the properties of housing company of the city, Studentbostäder. For fulfilling this purpose, literature review has been done for finding influencing factors on and strategies for shaping of pro-environmental behavior. In the next step, two projects with focus on demand side management for changing energy consumption of individuals have been studied. Afterward, a questionnaire based on the results of the literature review was prepared and used to gain an understanding of first: attitude, values, knowledge, and awareness of students of Linköping University regarding environmental issues, and second: point of view of the students toward the strategies for shaping pro-environmental behavior. Results of the above mentioned methods were used for identifying characteristics of a demand side management project based on provision of feedback on energy consumption for the users. It has been proposed that designing and implementing such project has the potential of affecting pattern of energy consumption by people and lead to its reduction, especially among students accommodating at housing company of city of Linköping, Studentbostäder. More studies are needed for finding feasibility of implementing such project.

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Barreneche, Güerisoli Camila. « Development and characterization of new materials incorporating phase change materials (PCM) for thermal energy storage (TES) applications in buildings ». Doctoral thesis, Universitat de Lleida, 2013. http://hdl.handle.net/10803/123749.

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Actualment, la demanda d'energia per satisfer el confort tèrmic en edificació és un dels majors reptes per a les administracions. Per tant, l'eficiència dels diferents sistemes d'emmagatzematge d'energia s està investigant intensament per la comunitat científica. Una alternativa viable és l'ús de materials de canvi de fase (PCM). Les parafines han estat molt utilitzades com PCM per la seva alta capacitat d'emmagatzematge de calor (al voltant de 100-130 kJ·kg-1) i la seva baixa temperatura de fusió la qual és molt estable. A més, el consum d'energia i les oscil·lacions de la temperatura internes d'edificis es poden reduir quan un PCM s'incorpora en evolvents. L'objectiu principal d'aquesta tesi és el desenvolupament de nous materials que continguin PCM basant-se en l'estudi del procés per obtenir la correcta introducció del PCM dins el material. A més, les propietats termofísiques d'aquests nous materials s'han de conèixer i per tant caracteritzar a nivell de laboratori. Aquesta tesi doctoral se centra en els treballs publicats en revistes científiques amb alt factor d'impacte indexats al camp de l Energia els quals reflecteixen treball realitzat. D'altra banda, aquesta tesi conté una revisió de l'estat de l'art destacant els requisits per a un PCM i llista tots els tipus de PCM disponibles al mercat i utilitzats en investigació. D'altra banda, un nou concepte de material compost que incorpora PCM ha estat desenvolupat en aquesta tesi. Aquest compost té la matriu polimèrica, i inclou un residu del procés de reciclatge de l acer. D'aquesta manera s'obtenen làmines denses que es poden modelar. La fabricació d'aquest material podria considerar-se un mètode per a la reutilització d'aquest residu. D'altra banda, aquest tipus de residus conté òxids de metalls pesants que augmenten les propietats d'aïllant acústic de la làmina aconseguint millorar el resultat final de la solució constructiva. A més, el comportament termofísico dels materials compostos utilitzats en edificis és difícil de caracteritzar i l'anàlisi tèrmica dels PCM és un pas necessari per al disseny dels mateixos. Les dues primeres caracteritzacions termofísiques estudiades en aquesta tesi es van realitzar mitjançant corbes calorimètriques que és una de les tècniques més potents disponibles actualment. tres estudis més van ser van realitzar amb dispositius desenvolupats per diferents grups d'investigació a Espanya per tal de mesurar les propietats termofísiques dels materials compostos o materials multicapa que incorporen PCM.
Hoy en día, la demanda de energía para satisfacer el confort térmico en edificación es uno de los mayores desafíos para las administraciones. Por lo tanto, la eficiencia de los diferentes sistemas de almacenamiento de energía está siendo intensamente investigado por la comunidad científica. Una alternativa viable es el uso de materiales de cambio de fase (PCM). La parafina ha sido muy usada como PCM debido a su alta capacidad de almacenamiento de calor (alrededor de 100-130 kJ·kg-1) y a su baja temperatura de fusión la cual es muy estable. Además, el consumo de energía y las oscilaciones de la temperatura internas se pueden reducir cuando un PCM se incorpora en envolventes de edificios. El objetivo principal de esta tesis es el desarrollo de nuevos materiales que contengan PCM basándose en el estudio del proceso para obtener la correcta introducción del PCM. Además, las propiedades termofísicas de estos nuevos materiales se debe conocer y por tanto caracterizar a nivel de laboratorio. Esta tesis doctoral se centra en los trabajos publicados en revistas científicas con alto factor de impacto indexados en el campo de Energía los cuales reflejan el trabajo realizado. Por otra parte, esta tesis contiene una revisión del estado del arte destacando los requisitos para un PCM y lista todos los tipos de PCM comercializados y utilizados en investigación. Por otra parte, un nuevo concepto de material compuesto que incorpora PCM ha sido desarrollado en esta tesis. Este compuesto tiene la matriz polimérica, e incluye un residuo del proceso de reciclaje de acero. De este modo se obtienen láminas densas moldeables. La fabricación de este material podría considerarse un método para la reutilización de este residuo. Por otra parte, este tipo de residuos contiene óxidos de metales pesados que aumentan las propiedades de aislante acústico de la lámina consiguiendo mejorar el resultado final de la solución constructiva. Además, el comportamiento termofísico de los materiales compuestos utilizados en edificios es difícil de caracterizar y el análisis térmico de los PCM es un paso necesario para el diseño de los mismos. Las dos primeras caracterizaciones termofísicas estudiadas en esta tesis se realizaron mediante calorimetría diferencial de barrido que es una de las técnicas más potentes disponibles actualmente. tres estudios más fueron realizaron con dispositivos desarrollados por diferentes grupos de investigación en España con el fin de medir las propiedades termofísicas de los materiales compuestos o materiales multicapa que incorporan PCM.
Nowadays, energy demand to satisfy thermal comfort in buildings is one of the major challenges for governments and administrations. Therefore, energy storage system efficiency is being studied by the international scientific community. A feasible alternative is the use of phase change materials (PCM). Paraffin waxes have been used as PCM because of their high heat storage capacity (around 100-130 kJ·kg"1) and their low and stable melting temperature. Furthermore, the energy consumption and indoor oscillations temperature may be reduced when PCM is incorporated in building envelopes and the thermal inertia increment when PCM is combined with thermal insulation was widely studied. The main objective of this thesis is the development of new materials containing PCM based on the study of process to get the correct PCM introduction. In addition, thermophysical properties of these new materials must be characterized. In order to perform the characterization, it was used several developed devices. This PhD thesis is based on papers published in scientific journals with high impact factor in the Energy field and one patent that reflect the work performed. This thesis contains a review of the state of the art highlighting the requirements order to a certain PCM and lists and sorts all PCM available in the market and used in research. On the other hand, a new concept of composite material incorporating PCM is developed in this thesis. This composite has polymeric matrix and includes one waste from the steel recycling process obtaining mouldable dense sheets. The manufacture of this material is considered a way to reuse the waste. Furthermore, this waste contains heavy metals oxides which add acoustic insulation properties to the final constructive system. One patent and two papers are the main result. Moreover, thermophysical behaviour of composite materials used in buildings envelopes is difficult to characterize. In addition, PCM thermal analysis is a necessary step of building design as well as it will be a key point in the final thermal results of the envelope. The first two thermophysical characterizations studied in this thesis were performed using differential scanning calorimetry which is one of the most powerful techniques. Three more studies were performed using devices developed by different research groups in Spain in order to measure thermophysical properties of composite materials or multilayered materials incorporating PCM.

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Tlili, Inès. « Développement analytique et suivi dans l’environnement des traces des antibiotiques à usage humain et vétérinaire ». Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10208.

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En raison de leur utilisation répandue dans les soins de santé humaine et animale, les antibiotiques et autres résidus de médicaments sont omniprésents dans l’environnement en général et le milieu aquatique particulièrement. Compte tenu de leurs impacts potentiels sur le fonctionnement de l'écosystème et la santé publique, la quantification des résidus de médicaments sur l'environnement est devenue une nécessité. Diverses techniques d'analyse se sont avérées être appropriées pour la détection fiable de tels composés. Cependant, la quantification peut être difficile car ces contaminants émergents sont présents à l’état de traces ou d'ultra-traces. Par conséquent, l'exactitude des analyses environnementales dépend à la fois de l'efficacité et de la robustesse de la méthode d'extraction et de quantification. Des procédures d’analyse de traces de ces contaminants émergents, ont été donc mise au point et des méthodes basées sur des analyses LC-MS/MS ont été développées. Pour les échantillons aqueux, l’extraction est menée sur phase solide (SPE, OASIS HLB). Les MLOQ sont comprises entre 0.2 et 3 ng/L. Pour la matrice solide, la procédure d’extraction à haute température et pression a été utilisée suivie d’une purification SPE. Afin d’évaluer le contexte de la pollution totale, la méthodologique analytique validée a été appliquée à des échantillons d’eaux potables et usées provenant de la France et de la Tunisie. Les résidus de médicament associés à la matière solide en suspension (MES) ont également été quantifiés pour compléter l’évaluation du degré de pollution environnementale
Due to their widespread use in human and animal health care, antibiotics and other drug residues are ubiquitous in the environment in general and the aquatic environment in particular. Given their potential impacts on the functioning of the ecosystem and public health, the quantification of drug residues on the environment has become a necessity. Various assay techniques have been found to be suitable for the reliable detection of such compounds. However, quantification can be difficult because these emerging contaminants are present in the trace or ultra-trace state. Therefore, the accuracy of environmental analyzes depends on both the effectiveness and the robustness of the extraction and quantification method. Trace analysis procedures for these emerging contaminants were therefore developed and methods based on LC-MS / MS analyzes were also developed. For aqueous samples, extraction is carried out on solid phase (SPE, OASIS HLB). MLOQs range from 0.2 to 3 ng / L. For the solid matrix, the extraction procedure at high temperature and pressure was used followed by SPE purification. To assess the context of total pollution, the validated analytical methodology was applied to drinking and wastewater samples from France and Tunisia. Drug residues associated with suspended solid matter (SSM) were also quantified to complete the assessment of the degree of environmental pollution

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Traylor, Caleb. « Investigation on the Effects of Indoor Temperature Modulations on Building Energy Usage and Human Thermal Comfort ». Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc984201/.

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Energy efficiency in the operation of buildings is becoming increasingly important with a growing emphasis on sustainability and reducing environmental impacts of irresponsible energy usage. Improvements have been made both on the technology side of energy efficiency and on the human behavior side. However, when changing human behavior, it is critical to find energy conservation measures that will maintain comfort for occupants. This paper analyzes how this can be done by implementing a modulating temperature schedule based on the concept of alliesthesia, which states that pleasure is observed in transient states. EnergyPlus simulations were used to show that in cooling applications, this type of scheduling can produce significant energy savings. However, energy savings are not predicted for the same type of scheduling for heating applications. Thermal comfort was examined with a cooling experiment and a separate heating experiment, each lasting 45 minutes and taking place during the corresponding season. The experiments showed that modulating temperatures can cause occupants to experience more pleasure than if the temperature remained constant in a cooled space, whereas modulating temperatures had a negative impact on comfort relative to the constant temperature in the heated space. This presents evidence for an ideal opportunity for cooling applications by implementing modulating temperature schedules: an increase in thermal pleasure accompanied by a decrease in cooling energy.

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Faheem, Ahmed. « Behaviour of ventilated hollow core slabs for improving the energy efficiency of office buildings ». Thesis, The University of Sydney, 2016. http://hdl.handle.net/2123/15284.

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Ventilated hollow core slabs (VHCSs) have shown to reduce energy requirements in building heating and cooling applications, as they enhance the use of building thermal mass by increasing the contact between the ventilation air and the structure. This thesis aims to contribute towards the accurate modelling of VHCSs for evaluating their thermal performance for building cooling applications under hot climatic conditions. For this purpose, a numerical procedure is developed for the prediction of the thermal performance of VHCS units. A turbulence model suitable for this purpose is identified first by assessing the ability of five different turbulence models to predict the dimensionless velocity and temperature profiles as well as the Nusselt numbers in a horizontal pipe subjected to turbulent mixed convection conditions typical of VHCSs. The Standard k-ε model showed the best performance, and as such, it is adopted to model the thermal performance of a VHCS geometry for which experimental thermal responses are reported in the literature. The numerical predictions of local temperatures within the VHCS agreed well with the experimental measurements, and hence the Standard k-ε model is adopted here for the modelling of VHCSs. The validated numerical approach is firstly applied to evaluate the impact integrating various types of micro-encapsulated phase change materials in VHCSs on their daily thermal performance in terms of the slab’s cooling potential when ventilated at night using naturally cold air under two ideal room temperature conditions. Analysis is also carried out towards quantifying how the ‘inter-interconnections’ of the hollow cores contribute to the thermal behaviour of VHCSs. The geometry is then simplified to represent a segment of a standard VHCS to evaluate the ability of the slab’s geometric parameters and the inclusion of thin metal sheeting on its hollow core and bottom surfaces to improve the slab’s cooling potential in office building applications.

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Soibelman, Lucio 1961. « The exploration of an integrated representation for the conceptual phase of structural design for tall buildings through distributed multi-reasoning algorithms ». Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/10134.

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Darle, Maria, Saga Lindqvist et Bezawit Tsegai. « The climate impact of different building systems : A study regarding materials in residential buildings and their environmental impact ». Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-390024.

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This report was done on behalf of Uppsala municipality with the aim to investigate how much the CO2-equivalent emissions differ between different building systems during the construction phase, considering the different choice of material used in the frames. Several multi-family houses with different building systems were therefore studied and compared by using previous LCA from collected climate reports regarding each construction project. Different scenarios of the residential development in Uppsala until year 2050, including multi- and single-family houses, were further on brought forward. The impact that the choice of material had on the climate was then studied by comparing the scenarios with the climate goals set up by Uppsala municipality regarding the construction sector. This was discussed in order to investigate whether Uppsala municipality would reach the climate goals or not. The conclusion of the study is that the building systems with wooden frames in general release less CO2-equivalent emissions than the ones with concrete frames. One of the reasons for this is that the production of the materials has different amounts of waste and the fact that concrete consists of cement, which causes a lot of emissions during the production of the material. Another part of the report was to investigate if climate improved concrete could decrease the CO2-equivalent emissions from building systems with concrete frames. This was done by doing a case-study, where parts of the concrete frame for one of the building systems were replaced, which resulted in a small decrease of the emissions. It is however, in a larger perspective, important to reduce the emissions as much as possible and there is still room to continue the improvement of concrete.

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Di, Palma Debora. « Progressive collapse of concrete structures during construction phase : analysis and measures for risk reduction ». Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.

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Shoring systems are used as temporary support for structures under construction and their primary function is to support and transmit various types of loads. To optimize this phase it has been developed a technique known as Clearing or partial Striking; it consists in removing a percentage of shores few days after the casting such that the load is redistributed between the slab and the remaining shores. In this way the shores removed in one floor can be used to start building the upper one. It is thus really important to conceive the process in a proper way assuring that the whole system is able to support the loads acting on it. This is the reason for which there is a prudent need to understand which conditions lead to the collapse of shoring systems and what measures can impounded in the design process to mitigate the risk of failure. The aim of this thesis is to perform a progressive collapse analysis, during the construction phase of the building, by instantly removing one or several primary load bearing elements and analyzing the structure’s remaining capability to absorb the damage. The analysis have been performed varying load conditions and slab thicknesses and, once the results from standard shores cases have been obtained, calculations with load limiters have been performed. The entire study has been developed with finite elements by means of ANSYS APDL starting from a FE model developed by Alvarado (2010). The important aspect of this investigation has been the risk reduction of progressive collapse, in particular it has been analyzed the behavior performed by the structure when enhanced support systems are used. Along with the finite element study it has been taken part in a experimental study aimed at analyze the load transmission in enhanced shoring system.

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Batagar, Amina. « Assessing the thermal performance of phase change materials in composite hot humid/hot dry climates : an examination of office buildings in Abuja-Nigeria ». Thesis, University of Newcastle upon Tyne, 2013. http://hdl.handle.net/10443/2146.

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The aim of this study is to investigate the possibility of using Phase Change Materials (PCM) in improving indoor thermal comfort while conserving electricity in office buildings in the composite Hot Humid/Hot Dry climate of Abuja, Nigeria. The first stage is a quantitative investigation of electricity consumption in 15 Nigerian office Buildings. Purpose-built mechanically cooled office buildings are selectively chosen across major Nigerian cities and climates. The surveyed data is analysed and used to construct a hypothetical office building as a base case. Scientifically validated software DesignBuilder v3 and EnergyPlus V6 and V7 are used for the parametric analysis of simulation results. The building simulations are used in two stages, firstly to test passive and climatically responsive scenarios to reduce electricity consumption then secondly to study the potential benefit of incorporating PCM in the building fabric and its effect on thermal comfort and electricity conservation. Results show that cooling, lighting, and appliance loads account for approximately 40%, 12% and 48% respectively of electricity consumption in the buildings audited. Power outages are frequently experienced necessitating alternative power usage. A data collection method is presented for energy auditors in locations where alternative back-up power is essential. Simulation results indicate that the magnitude of energy saving can be achieved by optimizing the passive and climate sensitive design aspects of the building and an electricity saving of 26% is predicted. Analysis indicates that it is difficult to achieve thermal comfort in office buildings in Abuja without mechanical cooling. Adding such a PCM to the building fabric of a cyclically cooled mechanical building may alleviate indoor discomfort for about 2 hours in case of power outage and is predicted to save 7% of cooling load. Cyclic cooling is the cooling of the interiors long enough to maintain comfort for a maximum duration within the working hours. The use of lightweight partitions instead of the heavyweight ones common in Nigeria is shown to a 2-fold improvement in consumption. Adding a PCM to light-weight partition walls with transition temperature of 24°C, conductivity of 0.5W/m K, and a thickness of 10mm gives the best predicted energy savings.

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Boozula, Aravind Reddy. « Use of Bio-Product/Phase Change Material Composites in the Building Envelope for Building Thermal Control and Energy Savings ». Thesis, University of North Texas, 2008. https://digital.library.unt.edu/ark:/67531/metadc1248391/.

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This research investigates the bio-products/phase change material (PCM) composites for the building envelope application. Bio-products, such as wood and herb, are porous medium, which can be applied in the building envelope for thermal insulation purpose. PCM is infiltrated into the bio-product (porous medium) to form a composite material. The PCM can absorb/release large amount of latent heat of fusion from/to the building environment during the melting/solidification process. Hence, the PCM-based composite material in the building envelope can efficiently adjust the building interior temperature by utilizing the phase change process, which improves the thermal insulation, and therefore, reduces the load on the HVAC system. Paraffin wax was considered as the PCM in the current studies. The building energy savings were investigated by comparing the composite building envelope material with the conventional material in a unique Zero-Energy (ZØE) Research Lab building at University of North Texas (UNT) through building energy simulation programs (i.e., eQUEST and EnergyPlus). The exact climatic conditions of the local area (Denton, Texas) were used as the input values in the simulations. It was found that the EnergyPlus building simulation program was more suitable for the PCM based building envelope using the latent heat property. Therefore, based on the EnergyPlus simulations, when the conventional structure insulated panel (SIP) in the roof and wall structures were replaced by the herb panel or herb/PCM composite, it was found that around 16.0% of energy savings in heating load and 11.0% in cooling load were obtained by using PCM in the bio-product porous medium.

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45

Boozula, Aravind Reddy. « Use of Bio-Product/Phase Change Material Composite in the Building Envelope for Building Thermal Control and Energy Savings ». Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1248391/.

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This research investigates the bio-products/phase change material (PCM) composites for the building envelope application. Bio-products, such as wood and herb, are porous medium, which can be applied in the building envelope for thermal insulation purpose. PCM is infiltrated into the bio-product (porous medium) to form a composite material. The PCM can absorb/release large amount of latent heat of fusion from/to the building environment during the melting/solidification process. Hence, the PCM-based composite material in the building envelope can efficiently adjust the building interior temperature by utilizing the phase change process, which improves the thermal insulation, and therefore, reduces the load on the HVAC system. Paraffin wax was considered as the PCM in the current studies. The building energy savings were investigated by comparing the composite building envelope material with the conventional material in a unique Zero-Energy (ZØE) Research Lab building at University of North Texas (UNT) through building energy simulation programs (i.e., eQUEST and EnergyPlus). The exact climatic conditions of the local area (Denton, Texas) were used as the input values in the simulations. It was found that the EnergyPlus building simulation program was more suitable for the PCM based building envelope using the latent heat property. Therefore, based on the EnergyPlus simulations, when the conventional structure insulated panel (SIP) in the roof and wall structures were replaced by the herb panel or herb/PCM composite, it was found that around 16.0% of energy savings in heating load and 11.0% in cooling load were obtained by using PCM in the bio-product porous medium.

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Panayiotou, Gregoris. « Thermal performance of dwellings in Cyprus and approaches for energy conservation ». Thesis, Brunel University, 2014. http://bura.brunel.ac.uk/handle/2438/9204.

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Energy has always been the dominant driving force for the socio-economic development of mankind. Nowadays, the global energy system is highly depended on fossil fuels. A great share of the final energy consumption, over 40%, in the EU-27 is consumed by the existing building stock whereas dwellings account for 66.62% of this. Thus, the need to increase the energy performance of dwellings is an important instrument in the efforts to lessen Europe’s energy dependency. In order to define measures to increase the energy performance of dwellings a deeper understanding of their characteristics should be gained. Unfortunately, in Cyprus there is a gap in knowledge on this aspect. In this thesis the characteristics of the dwellings in Cyprus are defined through a sample of 500 dwellings. The results revealed that more than 80% of dwellings in Cyprus do not have thermal insulation installed on their envelope. From this it is clear that the definition of the optimum thermal insulation material to be applied in dwellings is very important. Thus, the commercially available thermal insulation materials and topologies used in Cyprus were reviewed and defined through a market survey and the typical dwelling was modelled. The effect of the application of thermal insulation to its energy behaviour was simulated using TRNSYS. This resulted in the definition of the optimum thermal insulation materials and topologies to be applied in both new and existing dwellings. Accordingly, the application of advanced commercially available materials such as Phase Change Materials (PCM) to the envelope of the typical dwelling was investigated. The energy savings achieved by the addition of a PCM layer on the envelope of the typical dwelling was found to be 28.6%. The optimum PCM case was also combined with the optimum thermal insulation combination and an energy saving of 68% was predicted. The incorporation of Renewable Energy Sources (RES) to the typical dwelling was also simulated and studied. Specifically, two types of standalone RES systems were initially evaluated; a solely photovoltaic (PV) system and a hybrid PV-Wind system. The results showed that the solely PV system is a much better option due to the very high solar potential of Cyprus in comparison to the poor wind profile of the island. Subsequently, a grid-connected PV system was also evaluated and the results showed that when a RES system is grid-connected the cost of the system is reduced to half of that of the standalone cases. This research has revealed that the optimum topology combinations to be applied in both new and existing dwellings in Cyprus is thermal insulation plaster or thermal insulation bricks (only for new dwellings) on the external walls combined with expanded polystyrene on the roof. These results will provide valuable information that will assist both engineers and architects in the efficient design of dwellings in Cyprus. The investigation of the application of macroencapsulated PCM showed that these materials are not yet an economically viable solution for application in Cyprus The findings also show that a solely PV system is the optimum RES system to be applied in Cyprus especially when it is grid-connected. The findings of this project are useful for individuals, house builders and designers as well as policy makers for the design of energy saving subsidy schemes.

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Campbell, Kevin Ryan. « Phase Change Materials as a Thermal Storage Device for Passive Houses ». PDXScholar, 2011. http://pdxscholar.library.pdx.edu/open_access_etds/201.

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This study describes a simulation-based approach for informing the incorporation of Phase Change Materials (PCMs) in buildings designed to the "Passive House" standard. PCMs provide a minimally invasive method of adding thermal mass to a building, thus mitigating overheating events. Phase change transition temperature, quantity, and location of PCM were all considered while incrementally adding PCM to Passive House simulation models in multiple climate zones across the United States. Whole building energy simulations were performed using EnergyPlus from the US Department of Energy. A prototypical Passive House with a 1500 Watt electric heater and no mechanical cooling was modeled. The effectiveness of the PCM was determined by comparing the zone-hours and zone-degree-hours outside the ASHRAE defined comfort zone for all PCM cases against a control simulation without PCM. Results show that adding PCM to Passive Houses can significantly increase thermal comfort so long as the house is in a dry or marine climate. The addition of PCM in moist climates will not significantly increase occupant comfort because the majority of discomfort in these climates arises due to latent load. For dry or marine climates, PCM has the most significant impact in climates with lower cooling degree-days, reducing by 93% the number of zone-hours outside of thermal comfort and by 98% the number of zone-degree-hours uncomfortable in Portland, Oregon. However, the application of PCM is not as well suited for very hot climates because the PCM becomes overcharged. Only single digit reductions in discomfort were realized when modeling PCM in a Passive House in Phoenix, Arizona. It was found that regardless of the climate PCM should be placed in the top floor, focusing on zones with large southern glazing areas. Also, selecting PCM with a melt temperature of 25°C resulted in the most significant increases in thermal comfort for the majority of climates studied.

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Huang, Ming Jun. « The application of computational fluid dynamics (CFD) to predict the thermal performance of phase change materials for the control of photovoltaic cell temperatures in buildings ». Thesis, Ulster University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248684.

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Avigès, Perle. « Usage des opiacés dans les conduites toxicomaniaques et intérêt du dosage simultané par chromatographie en phase liquide de la morphine, de la codéine et de la buprénorphine ». Paris 5, 1996. http://www.theses.fr/1996PA05P134.

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Houl, Yassine. « Increasing Effective Thermal Resistance of Building Envelope's Insulation Using Polyurethane Foam Incorporated with Phase Change Material ». Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1505159/.

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Incorporating insulation material with phase change materials (PCMs) could help enhance the insulation capability for further building energy savings by reducing the HVAC loadings. During the phase change process between the solid and liquid states, heat is being absorbed or released by PCMs depending on the surrounding temperature. This research explores the benefits of a polyurethane (PU)-PCM composite insulation material through infiltrating paraffin wax as PCM into PU open cell foam. The new PU-PCM composite provides extra shielding from the exterior hot temperatures for buildings. Through this study, it was demonstrated that PU-PCM composite insulation could potentially help building energy savings through reducing the loads on the HVAC systems based on the building energy modeling using EnergyPlus. The Zero Energy Lab (ZØE) at the University of North Texas was modeled and studied in the EnergyPlus. It is a detached building with all wall facades exposed to the ambient. It was determined that the new PU-PCM insulation material could provide 14% total energy saving per year and reduce the electricity use due to cooling only by around 30%.

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