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  • 1.
    Allard, Ingrid
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Achieving building energy performance: requirements and evaluation methods for residential buildings in Sweden, Norway, and Finland2015Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Building energy performance has always been important in the cold climate of Sweden, Norway and Finland. To meet the goal that all new buildings should be nearly zero-energy buildings by 2020, set in the EU directive 2010/31/EU [1] on the energy performance of buildings (EPBD recast), the building sector in Europe now faces a transition towards buildings with improved energy performance. In such a transition, a discussion is needed about the objective of the improvement – why, or to what end, the building energy performance should be improved. The objective of improving building energy performance is often a political decision, but scientific research can contribute with knowledge on how the objectives can be achieved.

    This thesis addresses how the indicators used in the requirements used to achieve building energy performance in Sweden, Norway, and Finland, and the methods used to evaluate these requirements, reflect building energy performance. It also addresses difficulties in achieving comparable and verifiable indicators in evaluations of building energy performance. The research objective has two parts: to review, compare, and discuss (i) requirements and (ii) evaluation methods used to achieve energy performance of residential buildings in Sweden, Norway and Finland. The work in this thesis includes reviews of the requirements used in national building codes and passive house criteria to achieve building energy performance, of methods used to evaluate compliance with such requirements, and of methods used specifically to evaluate the indicator Envelope Air Tightness.

    The results show that different sets of indicators are used to achieve building energy performance in the studied building codes and passive house criteria. The methods used to evaluate compliance with requirements used to achieve building energy performance are also different, but calculation methods are generally more often used than measurement methods. The calculation- and measurement methods used are often simple. A methodology to analyze the deviation between predictions- and measurements of building energy performance (the performance gap) was developed, to investigate the effects of different evaluation methods on different indicators used to achieve building energy performance. The methodology was tested in a case-study. This study indicated that the choice of method affects which parts of the performance gap reflected in the indicators Supplied Energy (see Terminology), Net Energy (see Terminology), and Overall U-value. Among the reviewed methods to evaluate air tightness, the Fan/Blower Door Pressurization is well known and preferred by professionals in the field. The results in this thesis may be useful when choosing indicators and evaluation methods to achieve different objectives of improving building energy performance and in the quest towards comparable and verifiable indicators used to achieve building energy performance.

  • 2.
    Allard, Ingrid
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Olofsson, Thomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Östin, Ronny
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    A methodology to investigate the building energy performance gap2015In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118Article in journal (Other academic)
    Abstract [en]

    In order to evaluate compliance with requirements on building energy performance, it is necessary to find strategies to process discrepancies from the results of forward simulations in the design stage and of measurements in the operated stage. The gap between designed performance and measured performance is referred to as the “performance gap”. It can be divided into a procurement gap (between intended design and verified performance) and an operational gap (between verified performance and non-normalized measurements).  

    In this work we introduced a methodology for performance gap analysis, based on separating the procurement- and operational gap. An important component to do this is calibrations of calculations using measured data. The suggested methodology allows for more detailed verifications of building energy performance and can be used to study how indicators reflect the performance gap. The proposed methodology is tested using data from a well-documented and measured operated single family building, in sub-arctic climate in Sweden.

    The indicators studied in the verification were carefully analyzed. The methodology was found reliable based on the obtained results and a sensitivity analysis. An overall observation is that the applicability of the methodology depends on the accuracy of the hybrid method. The accuracy of the performance gap analysis per definition depends on the available information of the operated building, and consequently to access to extensive measured data.

  • 3.
    Bergdahl, Eva
    et al.
    Umeå University, Faculty of Social Sciences, Centre for Regional Science (CERUM).
    Magnus, Rönn
    Umeå University, Faculty of Social Sciences, Centre for Regional Science (CERUM).
    Planering för funktionintegrering - problem och utgångspunkter2001Report (Other academic)
  • 4. Chen, Ailu
    et al.
    Cao, Qingliang
    Zhou, Jin
    Yang, Bin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Chang, Wei-Chung
    Nazaroff, William
    Indoor and outdoor particles in an air-conditioned building during and after the 2013 haze in Singapore2016In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 99, p. 73-81Article in journal (Refereed)
    Abstract [en]

    Particles released from biomass burning can contribute to severe air pollution. We monitored indoor and outdoor particles in a mechanically ventilated and air-conditioned building during and after the 2013 haze event in Singapore. Continuous monitoring of time-and size-resolved particles in the diameter range 0.01–10 μm was conducted for two weeks in each sampling campaign. During the haze event, the averaged size-resolved outdoor particle volume concentrations (dV/d(logDp)) for diameters larger than 0.3 μm were considerably higher than those during the post-haze days (9–185 μm3 cm−3versus 1–35 μm3 cm−3). However, the average number concentration of particles with diameters in the range 10–200 nm was substantially lower on the hazy days than on the post-haze days (11,400 to 14,300 particles cm−3 for hazy days, versus an average of 23,700 particles cm−3 on post-haze days). The building mechanical ventilation system, equipped with MERV 7 filters, attenuated the penetration and persistence of outdoor particles into the monitored building. Indoor particle concentrations, in the diameter ranges 0.3–1.0 μm and 1.0–2.5 μm, closely tracked the corresponding patterns of outdoor particle concentrations. For particles in the size range 0.01–1.0 μm, the size-resolved mean indoor/outdoor (I/O) ratios were in the range 0.12–0.65 with the highest mean I/O ratio at 0.3 μm (0.59 in AC on mode and 0.64 in AC off mode). The air conditioning and mechanical ventilation system with MERV 7 filters provided low single-pass removal efficiency (less than ∼ 30%) for particles with diameters of 0.01–1.0 μm. During the haze, for particles larger than ∼0.2 μm, lower I/O ratios and higher removal efficiencies occurred with the air conditioning operating as compared to with mechanical ventilation only. This observation suggests the possibility of particle loss to air conditioning system surfaces, possibly enhanced by thermophoretic or diffusiophoretic effects.

  • 5. Engstrom, Emma
    et al.
    Forsberg, Bertil
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Sustainable Health.
    Health impacts of active commuters' exposure to traffic-related air pollution in Stockholm, Sweden2019In: Journal of Transport and Health, ISSN 2214-1405, E-ISSN 2214-1405, Vol. 14, article id 100601Article in journal (Refereed)
    Abstract [en]

    Introduction: Addressing walking and cycling commuters, this study aimed to measure personal exposure to traffic-related air pollution and analyze the associated health risks. Method: Diffusive NO2-samplers were worn by 19 participants as they commuted to work in rush-hour traffic in May 2018 in Stockholm, Sweden (in total 336 trips, 197 h). The average NO2-concentration per route was measured, and the health impacts were calculated based on previous epidemiological studies of the association between annual NO2-exposure and premature death. Result: The measured average concentration per route ranged from 48 to 105 mu gNO(2)/m(3), and the average 67 mu gNO(2)/m(3) was more than five times higher than the urban background. This corresponded to an annual mean exposure of 16.4 mu gNO(2)/m(3), 40% higher than the average exposure at other times. Thus, the increased risk for premature death was 3.3%, with a range of 1.9%-4.8%, as related to assumptions regarding breathing rates and risk relationships between NO2-exposure and premature death. For active commuters in Stockholm in general, this indicated that one-fourth (23%) of the annual inhaled dose of NO2 could be attributed to commuting, and that the risk for premature death increased by 2.5% (1.4%-3.7%) due to air pollution. Note that these results were indicative rather than precise. These relationships may be applicable to active commuters in other cities. Conclusion: The results indicated that active commuting in Stockholm is associated with significant exposure to traffic-related air pollution and that this increases the risk of premature death. It is recommended that future studies consider longer time periods to assess active commuters' personal exposure with higher precision. Policy implications include greater separation between active commuters and motor traffic, and promotion of behavioral changes in favor of emissions free vehicles and active modes of transport.

  • 6.
    Gradin, Gustav
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Hantering- och belastningsproblematik för byggnadsarbetare2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the construction industry isheavy lifting and handlingof rough machinesa daily exposure to the workers. Damage and accidents occur due poor ergonomic conditions. It’s difficult to remedy the injuries because they don’t happen overnight but after a long time of bad ergonomics. Assistive aidthat are available to ease the workload or decrease the vibrations aretime consuming and difficult to useI most cases. In an industry where the ways of workinghave been the same for a long time, it is difficult to change.In my project I have made research at two workplaces in Umeå, both at the company NCC. There I have asked carpenters, electricians, plumbers and othersabout how they seehandling and load problems. I also checkif the workers have knowledge about their tools and working methods. To have a good working environment is a key factor at NCC and they’re working hard at achieving that. Information from the group regarding safe useof machines and safe methodsfor the worker are availableto share. The information is conveyed to the craftsmen in the form of work preparation, daily security review, education, etc. but the damage is still to a large extent.The thesis work was conducted using literature studies, questionnaire surveys and dialogues to collect information on charged work. Finally, the theory was compared with actual work methods at the construction sites I visited to see what couldbe addressed.The result that emerged during the time I was working washow many of the workers knew that they were working the wrong way and could in the long run could be harmful. It was something they were aware of but were not so keen to do anything about it. One thing I found outwas that the assistive aidisnot used to the extent that they should and there is a certain degree of laziness among the professionals. When I was reviewing the answers, I’ve saw thatmany responded that they only used tools sometimes or only if they were nearby.I learned a lot of the work and partly that it is not easy to think anything in theory and expect it to work.I also learned that the construction industry is a special industry when it comes to change. For NCC, which has eighteen thousand employees, it takesa lot to change work-thinking and approaches.

  • 7.
    Grind, Ludvig
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energieffektivisering vid platta på mark för lättare byggnader vid ändring av grundläggningsmaterialet2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Energy efficiency of buildings is becoming increasingly more relevant in an industry where energy requirements are getting higher and higher. The different options for achieving a more energy-efficient building are few and generally aimed at increasing the insulation thickness ofa specific building component. This may prove to be a challenge in urbancities where plot areas are limited, and the possibility of increasing wall and roof thickness’s is not a viable option.This report examines the possibility of replacing the architectural concrete in the foundation to a lighter, more insulation concrete called LWAC, or lightweight aggregate concrete. This would in turn reduce the building’s heating demand by increasing the foundations insulation capacity and reduce the buildings overall heat loss. This replacement takes place in the energy simulation program IDA-ICE. In IDA-ICEsix simulations are performed in six different cities around the world. Allthe simulations are performed for a building model that has the same structure, material layers, installations and characteristic material values as an existing building, Backen 6:1, located in Umeå, Sweden. In the simulations, the heat demand for the model are compared while using architectural concrete in the foundation vs using lightweight aggregate concrete. The results from these six simulations showsan overall decrease forthe buildings U-valuebut an increase in the building’soverallheat demand. This result is later linked to the lightweight aggregate concretes lower density and inferior heat storage capacity compared to the architectural concretes higher density and superior heat storage capacity.

  • 8.
    Gustafsson, Lovisa
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Uppregling av väggar som stöd för mängdning2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The development of the construction industry is in constant motion forward thanks to BIM. In theory, it seems like many of the solutions that come with the implementation of BIM are simple to understand and work with, but in practice, the technical solutions are far from being completely implemented in the industry. In the work with quantifying within a project the development has become stagnant and the majority compile quantities manually.  This is a time-consuming method that is advantageously replaced with a technical solution from for example a Revit-environment.

     

    This report aims to recommend a method for managing quantifying in an easier way. By performing two technical methods of quantifying on a reference object, the approaches have been analyzed in terms of possibilities and problems. The long process of Revit is discussed and compared with the complicated settings of the application MWF. In summary, MWF is recommended because of the overall documents with rewarding data and drawings. The suggested usage for the data strengthens the conclusion.

  • 9.
    Holmquist, Martin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Vidareutveckling av parameterstyrd broprojektering2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this report is to illustrate the approach and the ability to develop a parametric slab frame bridge using visual programming. Parametric controlling is enabled by the created link between Grasshopper, Rhinoceros3D and Tekla structures. A profound presentation is presented to demonstrate how you can meet a more detailed bridge model, comprising more adjustable options than previously performed studies. This is done in order to create a pre-programmed script that can be used in practice and to streamline the design of future projects.

     

    The result is presented in the form of solutions to achieve the project goals. Since the results builds on previous work, no approach to the basic bridge design will be presented. The result demonstrates how to combine the components in order to create the conditions and designs for the slab frame bridge using Grasshopper, as requested by the further development. Together with previous work, this project results in a final slab frame bridge, whose input data is controlled parametric from a visually programmed script in Grasshopper. The definition is structured in such way that it is easy to understand, the user is able to control the input data without having to go deeper into the visual programming.

     

    This technology and the use of pre-programmed scripts is an interesting solution, and could theoretically be very useful. On the other hand, the work contrariwise that it is required that the user fully understands the programming to address problematic issues, and the solution is often more complex and complicated than in custom modeling tools.

  • 10.
    Holmqvist Sten, Katrin
    Umeå University, Faculty of Social Sciences, Centre for Regional Science (CERUM).
    Arkitekturen och universitetet2014In: Konstvandring på Umeå universitet: En guide till konsten på campus / [ed] Brita Täljedal, Ann-Catrine Eriksson, Patrik Förberg, Umeå: Umeå universitet; Akademiska hus; Statens konstråd , 2014, p. 108-119Chapter in book (Other (popular science, discussion, etc.))
  • 11.
    Holmqvist Sten, Katrin
    Umeå University, Faculty of Science and Technology, Umeå School of Architecture.
    The Architecture and the University2014In: Art Trail at Umeå University: A guide to the works of art on campus / [ed] Brita Täljedal, Ann-Catrine Eriksson, Patrik Förberg, Umeå: Umeå universitet; Akademiska hus; Statens konstråd , 2014, p. 108-119Chapter in book (Other (popular science, discussion, etc.))
  • 12.
    Jacobsson, Jonatan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    BIM - Detaljeringsnivåer av byggnadsmodeller: En studie i hur olika detaljeringsnivåer påverkar informationsinnehållet av byggnadsmodeller2016Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [en]

    BIM, Building Information Modelling, is not a new concept for the construction industry and the subject is well reviewed in theory. The practical application has not yet reached out to the whole Swedish construction industry and the lowest implementation of BIM can be found in facility management. For BIM to reach this part of the industry, clients’ needs to understand the functions that BIM can assist with and set BIM requirements for their projects. Since there is no upper limit on the level of information a model may contain, clients also needs to define which information is necessary for the sought functions. This study aims to clarify how the information content of a model is affected by different levels of detail. Through a compilation of existing standards and level system has an education facility of 150sqm been modeled using Autodesk Revit Architecture. With the help of this model and the compiled theory, following conclusions has been drawn. It is possible to ensure the information needs of the client's organization with the help of a system for level of development. Different buildings have different functional needs and require different levels of detail. A general level of detail to be included with these models should be possible to determine. A prerequisite for successful BIM project is that clear instructions and requirements are established for the modeling process and that these are anchored in the needs of the project and management.

  • 13.
    Lind, Gustav
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Installation av frikyla och vilka kostnader det innebär: Projektering och kostnadsberäkning för användning av frikyla i kylsystem2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this work, a refrigeration centre with the use of free-cooling has been projected, drawn and then cost-calculated. The work began drawing a flowchart for the cooling system in the cooling centre, this flowchart were drawn in a program called Autodesk Autocad. After that, the work continued by drawing and projecting the cooling centre with the reality of a threedimensional modeling. This projection was done in Autodesk Autocad´s MagiCAD plug-in. Meanwhile when these flowcharts and model drawings were constructed, communication with manufacturers and suppliers of the major machines in the system was done parallel with the modeling. This was made to get the correct values, measurements and budget sacrifices. Once both the flowchart and the three-dimensional, realistic looking model were completed, a product calculation was initiated in Wikells Sektionsdata. The calculation includes all products in the entire refrigeration centre, as well as things that were previously unpublished. Examples of items that were not in the flowchart nor the three-dimensional model, but included in the product calculation are welding work, bolt joints, primary and secondary works. A product calculation was made for the system both with and without free-cooling, just to see how much the free-cooling installation will cost. The result was that the freecooling installation will cost 1 225 725 SEK. Subsequently, calculations were made to see how profitable it is for the company to invest in free-cooling. These calculations were made largely from an energy calculation from Ramböll. With those calculations, there was a result in the form of payback time. The payback time for free-cooling was calculated to just under 8,3 years.

  • 14.
    Lundberg, Petter
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Investigation of the transient nature of rolling resistance on an operating Heavy Duty Vehicle2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    An operating vehicle requires energy to oppose the subjected driving resistances. This energy is supplied via the fuel combustion in the engine. Decreasing the opposing driving resistances for an operating vehicle increases its fuel efficiency: an effect which is highly valued in today’s industry, both from an environmental and economical point of view. Therefore a lot of progress has been made during recent years in the area of fuel efficient vehicles, even though some driving resistances still rises perplexity. These resistances are the air drag Fd generated by the viscous air opposing the vehicles propulsion and the rolling resistance Frr generated mainly by the hysteresis caused by the deformation cycle of the viscoelastic pneumatic tires.

    The energy losses associated with the air drag and rolling resistance account for the majority of the driving resistances facing an operating vehicle, and depends on numerous stochastic and ambient parameters, some of which are highly correlated both within and between the two resistances. To increase the understanding of the driving mechanics behind the energy losses associated with the complexity that is rolling resistance, a set of complete vehicle tests has been carried out. These tests were carried out on the test track Malmby Fairground, using a Scania CV AB developed R440 truck equipped with various sensors connected in one measurement system. Under certain conditions, these parameters can allow for an investigation of the rolling resistance, and a separation of the rolling resistance and air drag via explicit subtraction of the air drag from the measured traction force. This method is possible since the aerodynamic property AHDVCd(β) to some extent can be generated from wind tunnel tests and CFD simulations.

    Two measurement series that enable the above formulated method of separation were designed and carried out, using two separate measurement methods. One which enables the investigation of the transient nature of rolling resistance as it strives for stationarity, where the vehicle is operated under constant velocities i.e. no acceleration, and one using the well established method of coastdown, where no driving torque is applied.

    The drive cycles spanned a range of velocities, which allowed for dynamic and stationary analyses of both the tire temperature- and the velocity dependence of rolling resistance. When analysing the results of the transient analysis, a strong dependence upon tire temperature for given constant low velocity i.e. v ≤ 60 kmh−1 was clearly visible. The indicated dependency showed that the rolling resistance decreased as the tire temperature increased over time at a given velocity, and vice versa, towards a stationary temperature and thereby rolling resistance. The tire temperature evolution from one constant velocity to another, took place well within 50 min to a somewhat stationary value. However, even though the tire temperature had reached stationarity, rolling resistance did not; there seemed to be a delay between stationary tire temperature, and rolling resistance. The results did not indicate any clear trends for v ≥ 60 kmh−1, where the results at v = 80 kmh−1 were chaotic. This suggests that some additional forces were uncompensated for, or that the compensation for air drag was somehow wrongly treated at higher velocities.

    Several factors ruled out any attempts at proposing a new rolling resistance model. These included: the chaotic results for v = 80 kmh−1, the delayed rolling resistance response upon tire temperature stabilization, and the lack of literature support for the observed tendency. The results from the coastdown series on the other hand, showed good agreement with a dynamical model suggested in literature. The stationary temperature behaviour for the considered velocity range at assumed constant condition is also supported in literature.

    Finally, an investigation of the aerodynamic property AHDVCd inspired by ongoing work in ACEA (European Automobile Manufacturers’ Association), was carried out assuming both zero and non-zero air drag at low velocities. The results indicated surprisingly good agreement with wind tunnel measurements, especially when neglecting air drag at low velocities: as suggested by ACEA. 

  • 15.
    Lundmark, Linus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Effektivisering av broprojektering i Tekla Structures tilläggsfunktion Bridge Creator2019Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    Digitalization gives opportunities to new and more efficient workflows within all different type of industries. New software programs and add-on features are often released and there is a lot of new information to process for the people adjusting to these new software programs and add-in features. Even though these digital solutions have benefits in both cost- and economy point of view it can be difficult to change the workflow and implement new routines on the workplace.

     

    Tekla Structures is a BIM-tool (building information modelling) owned by Trimble which is used frequently within the building industry. The purpose with this report is to explore and compile the possibilities with Trimbles newly released tool Tekla Bridge Creator in bridge projecting. Today Tekla Structures can be used together with Rhinoceros and its extension Grasshopper through Grasshopper-Tekla Live Link (a more detailed description of the software programs can be found in the reports Theory chapter) but the workflow can be seen as complicated and requires good knowledge with the software program.

     

    This report describes the designing of a bridge model in Bridge Creator and thereafter a similar in Grasshopper. The workflows will be compared to give an understanding for Bridge Creator and an opinion for how it best can be applied in bridge projecting and if it can be of use for the person with the desired goal he or she has.

     

    Bridge Creator has shown to have a lot of limitations concerning modelling of parametric adjustable bridge-models, which is possible in Grasshopper. In short summary this means the possibility to choose a specific parameter, for example the total length and width of the bridge, and the whole model quickly adapts when these changes. For example, if a bridges total length changes, the columns, railings and similar building parts need to be changed manually. In Grasshopper these parts can adjust automatically so if the bridges length is changed these parts follow the length change.

     

    It’s hard to say if Bridge Creator is to recommend or not, it depends on the user’s previous knowledge with bridge design, which bridge constructions that are created, how adjustable they shall be and how big value that lays in being able to reuse in new projects. Bridge Creator is furthermore in an early development phase and is going through improvements over time which means that it can’t be excluded that Bridge Creator in the future can be used like Grasshopper to create parametric adjustable bridge models.

  • 16.
    Mahapatra, Krushna
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK, Växjö.
    Dodoo, Ambrose
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK, Växjö.
    Gustavsson, Leif
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK, Växjö.
    Nair, Gireesh
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling, Östersund.
    System analysis of and stakeholders’ perceptions on end-use energy efficiency measures for existing Swedish multi-family buildings2012In: Conference on Building Energy and Environment, COBEE 12, International Conference on Building Energy and Environment. Boulder, Colorado, USA, August 1-4., 2012Conference paper (Refereed)
    Abstract [en]

    In Sweden, there is opportunity to implement energy efficiency measures in about one million existing apartments that are likely to be refurbished within the next 20 years. System analyses of installation of energy efficient windows, and increased insulation in attic and in exterior walls for an existing multi-story building showed that the primary energy savings for the measures depend on the energy supply system. Energy efficiency potential was higher with installation of efficient windows than improved attic insulation. Responses of 673 chairpersons of co-operative hosing associations to a mail-in survey in 2010 also showed that greater proportion of respondents perceived that energy efficient windows had advantages over insulation improvements. However, majority had no intention to implement such measures during next 10 years and economic factors guide their decisions. Lack of expertise to assess the benefits of energy efficiency measures was the most cited hindrances to energy efficiency investments.

  • 17.
    Nordgren, Hampus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energieffektivisering av Hökensåsskolan2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    An energy efficiency has been performed at a school to measure possible actions which can reduce the buildings use of energy. Options of actions have been measured on two parts of the school, one older part with focus on the construction and one a bit newer with focus on ventilation. The results of these actions are later presented in a life cycle analysis to measure profitability. The project started with the creating of a model of the older part of the building. This were made in IDA ICE to perform simulations of different actions in the construction. Chosen action on construction gave results with reduced energy of 152 607 kWh every year. This corresponds to about 167 868 SEK every year. Calculated in a life cycle analysis resulted in a pay-off time of about 32-44 years. Pay-off time depends on the investment though which most likely will reduce in cost during execution and reduce the pay-off time. Ventilation in the newer building were compared against exchange of the system to a FTX-system. Calculations were made in a calculation form in Excel made by Bengt Dahlgren. The results were that an exchange of the system would reduce energy use by 294 053 kWh every year. This corresponds to about 321 330 SEK every year. Inserted into a life cycle analysis would result into a pay-off time of about 7.1 years.

  • 18.
    Nordlund, Andreas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Förspända betongelement: Dimensionering enligt Eurokod 22013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The objective of this thesis is to understand the theory and learn the calculation behind prestressed concrete elements and to compare it with the theory of ordinary reinforced concrete elements. This thesis work was chosen in order to promote the study of prestressed concrete and because it´s broad application in civil engineering. The worked was completed by reading literature and guidance.

    It turned out after the work was completed that some parts of the theory and calculation behind prestressed concrete was similar to that used in the ordinary reinforced concrete. However, there were also many differences that existed. Some of the similarities are obtained when the capacities of moment and shear are calculated. The differences is that many extra steps are required when the design are performed, steps who for the most part due to different controls and are required to be performed to ensure the safety of the design. The controls are to be performed, among other, in the design of the manufacturing process and in the ultimate limit state.

    Finally, it is found that prestressed concrete elements have many benefits, which includes larger spans, smaller dimensions for structures and that smaller deformations can be obtained. However, it will require a larger amount of calculations as compared to ordinary reinforced concrete.

  • 19.
    Olofsson, Thomas
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Ohlsson, K. E. Anders
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Östin, Ronny
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Measurement of the environmental temperature using the sol-air thermometer2017In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 132, p. 357-362Article in journal (Refereed)
    Abstract [en]

    Heat flow measurement with a heat flow meter is a standardized method (ISO 9869-1) to estimate thermal transmittance (U-value) of a building element. The heat flow meter is a thin plate mounted on top of the surface of the element, and measures the heat flux q through the plate. The measured q is the product of the difference in temperatures between exterior and interior environment, and the U-value. The heat transferred from the element is based on the radiant and the convective heat transfer.

    ISO 9869-1 specifies that the environment temperature Te “is a notional temperature" and it "cannot be measured directly” (section A.3.1). The air temperature Ta is proposed as a reasonable approximation for the indoor environment, while overcast conditions and absence of significant solar radiation are specified conditions for replacing Te with Ta for the exterior environment.

    The sol-air thermometer (SAT) measures the sol-air temperature Tsa, i.e. the equivalent temperature of the convective and the radiative environment. In the absence of solar radiation, Te = Tsa. SAT is a sensor consisting of a thin flat solid plate, of high thermal conductivity. The front side of the sensor is exposed to the environment, whose Tsa is to be measured, and the backside is thermally insulated. The temperature of the SAT-plate equals Tsa.

    In this work we propose introduction of the measured Te in the existing standard (ISO 9869-1). The method for measurement of Tsa, using the SAT, has been demonstrated experimentally for different periods, without solar radiation present and under stable climatic conditions.

  • 20.
    Weijl, Terje
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Kvalitetssäkring av modellfiler2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Creating 3D-models is a common feature for the constructor in the planning phase. However, this has proved to be problematic as the models do not meet the right quality. Lacking quality in 3D-models can lead to bad consequences and it is therefore important to perform a quality control on the model. Tyréns in Umeå has seen a need to have a process of controlling 3D-models to ensure that they have the right quality.

    The purpose of this study has been to analyze whether there are any methods for quality control of 3D-models that Tyréns can make use of today. The goal of the work has been to present a working method that Tyréns can use in the future to quality assure 3D-models.

    The work has been completed by studying literature from the university library and city library in Umeå. The law about construction and Boverket website have also helped to carry out the work of the report. To get a picture of how problems can look like in a 3D-model, a couple of reference objects have been used. The information about the reference objects are collected from interviews, investigations and magazines.

    The result of this study shows that there are no general working methods for analyzing 3D-models. On the other hand, there are quality assurance methods in the manufacturing industry that could be used to control the models as well. The problem with these methods is that they are adapted to an industrial environment. This means that they are not developed to detect errors that may occur during the planning phase. Therefore, the quality control methods used in the manufacturing industry are required to be corrected and adjusted so that they can be used to control 3D-models. However, what can be used from industry methods is that the quality control should be planned at an early stage and then carry out the controls. The method developed in this report is a work method that includes planning, control and follow-up, which makes the workflow time consuming. However, the conclusion of the work is that the most important thing about quality control of 3D-models is that it is planned and then performed.

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