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  • 1.
    Abed, Ahmed Ghafel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energieffektivisering vid renovering av Lamellhus på Mariehemsvägen2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In Sweden more houses than ever before are being built, and the house production is moving forward. At the same time, awareness of the energy use of buildings and its accompanying impacts on climate and sustainability are increasing. Therefore, Boverket constantly raises the demands for the energy performance of newly built and refurbished buildings.

    According to current requirements from Boverket (BBR, 2017), the primary energy value for apartment buildings may not be more than 85 kWh per square meter of tempered floor space and year. This also applies according to future requirements in 2021, but with the difference that the average U-value will decrease from 0.4 to 0.35 W/m2 K which means that apartment buildings must be built in an efficient way to reduce energy use. A large part of new construction and newly refurbished apartment buildings must then implement energy efficiency measures on their buildings to meet future requirements.

    This degree project has been carried out in collaboration with Rikshem AB who wants to investigate the impact of various energy efficiency measures on their apartment building ”Lamellhus”. The aim is to theoretically reduce apartment buildings ”Lamellhusets” specific energy use from 187,4 to 70 kWh/m2 Atemp, year and thus reduce the primary energy enough to meet future requirements according to BBR near-zero energy building.

    To theoretically reduce specific energy use and thus primary energy value, the project through manual calculations and with the help of computer tools examined various energy efficiency measures on the building's construction and installation system.

    The results show that the measures on the property climate shell are sufficient to meet the requirements. If all the measures according to package 1 or 2 on the design are combined, specific energy use according to BBR 16 (2010) will be at 83-94 kWh/m2 Atemp, year and the primary energy value according to BBR 25 (2017) will be at 68-77 kWh/m2 Atemp, year.

    The results also show how much of a building's energy use is ventilated. Replacing the ventilation system from F-systems to FTX-systems on the reference house in the base case, is the measure that gives one of the greatest impacts with a heat saving of (25.5-26.7%). In combination FTX-system with district heating, specific energy consumption can be reduced as low as possible. If the operation with the FTX-system is applied together with the existing district heating and all measures on the construction according to package 1 or 2, this gives a reduction of approximately (70-75 %) compared to the base case corresponding to 42-51 kWh/m2 Atemp, year according to BBR 16 and according to BBR 25, the figures are even lower. If the calculation considers thermal bridges and air leakage in the house, the result will increase.

    The results also show that the investment repays itself after 15-16 years with a simplified payback. With a calculation rate of 5 %, it is profitable over 30-31 years or more, but with a calculation rate of 8 % it is not profitable.

  • 2.
    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.

  • 3.
    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.
    Hassan, Osama
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Methods for air tightness analysis for residential buildings in Nordic countries2012In: Methods for air tightness analysis forresidential buildings in Nordic countries, Southampton: WIT Press, 2012, p. 311-322Conference paper (Refereed)
    Abstract [en]

    Envelope air tightness is one factor that has impact on the energy performance ofbuildings. The goals of the directive 2010/31/EU, on energy performance ofbuildings, raise the importance of building energy performance analysis in theprocess. Measurements of air tightness can be useful both when evaluatingbuilding energy performance and developing new building techniques. The aimof this paper is to review and evaluate methods to measure air tightness in bothnew and existing residential buildings in Sweden, Norway and Finland, based onan international literature study and a survey. The methods are categorized basedon a number of criteria to determine their suitability in different situations.Advantages and disadvantages of the methods are discussed, as well ascommonly used methods in the three countries. The review shows that thestandard ISO 9972 is used for verification in all three countries, but alternativesexist that might be more suitable in certain situations. Simpler methods are usedin the building process to increase air tightness. To achieve a comparablemeasurement, both common methods and commonly defined units are needed.

  • 4.
    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.
    Hassan, Osama A. B.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Methods for energy analysis of residential buildings in Nordic countries2013In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 22, p. 306-318Article, review/survey (Refereed)
    Abstract [en]

    To meet the goals of the directive 2010/31/EU on the energy performance of buildings, the building sector in Europe now faces a transition towards more energy efficient buildings. Research and development of new energy solutions and technology will be necessary for the transition and the importance of analyzing building energy performance increases. This paper aims to review and evaluate different methods that are commonly used to analyze energy performance in residential buildings in Nordic countries, primarily in Sweden, Norway and Finland. A short international review of regulations is also included. The goal is to find commonly used methods and possibilities for the future. The introduced methods are summarized, categorized and compared based on their advantages and disadvantages. Although the three Nordic countries have similar climate conditions and building traditions, the review shows relatively large variations in the definitions of energy performance for residential buildings, as well as variations in how measurements and calculations are used in the methods for energy performance analysis. In the conducted review, methods, or parts of methods, are also found to be used. The methods used to analyze energy performance are found to be more similar than the concepts of energy performance itself in the three countries. These aspects may be considered in further work to develop an international policy practice for energy performance of residential buildings in cold climate.

  • 5.
    Ambertsson, Birger
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Stabilisering av lätta trähus2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Med Tommy Persson kvalitets- och produktchef vid Masonite Beams AB i Rundvik diskuterades problemet kring infästning av väggelement med hög färdighetsgrad till grunden. Det bestämdes att arbetet skulle fokusera på en- och tvåbostadshus och att endast fenomenet stjälpning skulle beaktas.

    Lastfördelningen gjordes enligt vad Klas Nyman skrivit i sitt examensarbete Tredimensionella effekter vid horisontalstabilisering av volymbyggda trähus. Beräkningar av lyftkraft gjordes enligt den plastiska metoden med syllen förankrad mot lyft medan frontregeln inte är förankrad mot lyftning som Bo Källsner och Ulf Arne Girhammar beskriver i sin bok Horisontalstabilisering av träregelstommar. För beräkning av skruvars bärförmåga tillämpades Eurokod 5. För beräkning av 5-percentilsvärden från provning tillämpades SS-EN 14358:2006 Träkonstruktioner.

    Resultat; de två studerade fästmetodernas dimensionerande bärförmåga är 1.61 kN och 1,23 kN, lyftkraften i syllen är i storleksordningen 3-19 kN/m.

    Rapporten kan ses som en fingervisning på hur stora lyftkrafter som uppstår i syllen när det blåser och ett alternativ på hur man ska beräkna dessa lyftkrafter. Med mer tid skulle en bättre infästning av väggelement till grunden kunna utformas.

  • 6.
    Andersson, Christer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Verifiering av objektsbaserade 3D-modeller.: En fallstudie av arkitektmodell upprättat av Link Arkitektur med avseende på kvalitetssäkring i Solibri Model Checker inför import i IDA ICE.2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Export and import of BIM-models via IFC has in some cases shown to be problematic regarding ability to carry nessicary information such as for exampel geometry between different application. Good IFC-models is said to be the answer when it comes to creating a good informationflow in the construcion-sector, but seems to fail alot of the times today. This problem can be deived to lack of knowlege how IFC-models needs to be created in order to fulfill a specific purpose. This report preforms a quality controll of a existing IFC-model created at Link Architecture in Umeå, in order to be importabel in IDA ICE, and gives a detailed describtion of how its done. The control is done using Solibri Model Checker and the resaults of the test shows that there are some major innacuracies in the model that makes it not importable in IDA ICE. This report establish the fact that it might be important to preform continius controls of througout a BIM-project in order to avoid misstakes during the modelling-process.

  • 7.
    Andersson, Pär
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Frakt-och paketritning för KL-trä i Tekla2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this project has been to set up a freight drawing with accompanying packages drawing for CLT-wood in the program Tekla. This is based on the requirements for freight according to the Transport Agency and what applies to handling of the CLT boards regarding the working environment hazards. Based on the problems and requests from Martinsons, this project resulted in a freight drawing with accompanying package drawing. The package drawing is going to be a helpful tool for the project manager in the manufacture of the CLT boards. The freight drawing is going to provide comprehensive information about how to load the packages on the loading platform.

    The project is based on a reference model called Tallbocken, which is the model that Martinsons have used before. The model is basically a building, four floors tall, made almost entirely of CLT wood. An instruction has been made, based on this model, for the establishment of freight- and package drawing. A study has been made to ensure the demands from the Transport Agency regarding the shipping of compound elements. By visiting the production line in Bygdsiljum it was clear that the staff wanted a change in how to handle the CLT boards. Information about how to handle this was also an important message on meetings with the project manager and the production staff at the fabric in Bygdsiljum. To make sure that the drawings keep in line with the recommendations, there is an explanation for the review of building documents 90’s.

    This working project has resulted in an instruction for how to manage the establishing of freight- and package drawing. The instruction is attached as a supplement to this essay. This instruction explains the procedure step by step for how to create a freight drawing for CLT wood in Tekla structures by using a complete project template. 

  • 8.
    Andersson, Tomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Optimering av balkonglösning2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This dissertation describes the theory behind a specific solution for balcony attachment for concrete constructions designed by Prefabmästarna. The purpose is to get a deeper understanding of design according to Eurocode and EKS (Swedish application of eurocode) and to optimize the current solution for balcony attachment in view of reduced material usage. The design is based on a prefabricated balcony slab is fasten to a T-section whose flanges are molded in a prefabricated DFS-slab. Two tie-rods is threaded into the balcony slab and fasten to the T-section with a washer. After mounting of the balcony slab the DFS slab is molded on which stabilizes the T-section from instabilites. The results show that the structure is largely optimized but that there are room for improvements in specific places. For balconies with a length of 2.0 meters the T-section can be reduced with 10 kg of steel, which corresponds to more than 50 % of the T-section weight compared with the reference solution. Also at the 2.5 meter balconies the T-section can be reduced with 7 kg of steel, which corresponds to a 38 % reduction in material use compared with the reference solution. A common standard for the T-section is possible for balconies with a length of 2.0 and 2.5 meters.

  • 9.
    Arljung, Jerry
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Byggfysik vid prefabricerade träväggar2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The work is about prefabricated houses with wooden frames. The company that I am doing thesis examination work in units Attacus Jämtlandshus Ltd whose business is to manufacture timber frames to the building industry. This work demonstrates Jämtlandshus work process and the methods used to reach to the final product. These methods are documented in detail for possible identification activities likely to affect final product quality negatively. Also reported a large number of calculations and other values that indicate what the quality of the final product is given to heat, moisture and air tightness. The report also shows how the industries that are working with production systems use them to be as effective as they can and as competitive as possible. In reaching the above, the author used a lot from their previous experience as an employee of this company, this is above all the documentation of work processes. To perform the calculations presented, the author has made use of prior knowledge from the course, building physics, and some contact with outside professionals. The work aims to, if it is possible, to identify any weak points in production and to assess how good quality the final product is given to tightness. Both the author and Jämtlandshus think it is strange that this building technique is not bigger and more "recognized" in the market than is currently the case. By reading this report, the reader can get up their interest in prefabrication to a greater extent and start weighing the advantages and disadvantages compared with site construction. This work demonstrates the quality of these houses, and some advantages of making wooden houses by prefabrication. The author's hope through this work is that more people will open their eyes to this building techniques and that, generally, people begin to talk about these types of houses.

  • 10.
    Berggren, Oscar
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    COMSOL Multiphysics - Ett energitekniskt analysverktyg vid numerisk simulering av köldbryggor och analys av fukt i konstruktionesdetaljer2014Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
    Abstract [en]

    Berggren, O. (2014) COMSOL Multiphysics – An analysis tool for energy applications when conducting numerical simulations on thermal bridges and analysis of moisture in construction details. Master thesis in Energy Engineering. Department of Applied Physics and Electronics at Umeå University.

    The consultant company Tyréns has at its office in Umeå decided to evaluate the application of the software COMSOL Multiphysics.  The evaluation consisted of a simulation on an energy engineering problem with its origin from a project at Tyréns, performed in COMSOL Multiphysics.

    The chosen project for this task was a part of the design plans of the culture house Väven in Umeå. These design plans includes the analysis of a thermal bridge and moisture on a variety of construction details, where one of them was selected to be investigated further.

    The main purpose of the investigation was to analyze if the results obtained from the simulations performed in COMSOL Multiphysics were equivalent compared to the results from the design plans. The investigation also included the presentation of an overall cost estimation for the software COMSOL Multiphysics.

    The obtained results from the analysis of the thermal bridge and moisture in the construction were in both cases slightly raised compared to the results from the design plans, in average an increase of 20 %.

    The work undertaken concludes that there is fully possible to recreate the previously executed simulations extracted from the design plans in accordance to the requirements and standards that are set. The obtained results are equivalent, even though a minor difference, compared with the results from the design plans and are valid too be used in a real life scenario.

    The obtained conclusions are that it is possible to prevent moisture in the construction detail. However, the overall U-value, , indicates that the energy efficiency of the entrance square is not good enough to reach the requirements of the SNBBP (Swedish National Board of Housing, Building and Planning). Even though the U-value for the construction detail, , can be assumed to meet the criteria’s of the SNBBP.

    Due to the fact that the simulations were conducted with COMSOL Multiphysics without any major problems and provided valid results, it is considered that the software is an appropriate tool to perform simulations at Tyréns. However, the cost for a floating license of the software Flixo is much less then for COMSOL Multiphysics. COMSOL Multiphysics is at the time of this study four times as expensive as Flixo. COMSOL Multiphysics has though an advantage because it can treat problems with a multiphysical nature in one, two and three dimensions with the use of only its standard edition. To ensure that the use of COMSOL Multiphysics can be economical viable, it is necessary that the software is used in multiple applications besides performing simulations on thermal bridges and moisture in construction details.           

  • 11.
    Berglund, Johan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Projekterings- och granskningsförbättringar: Identifiering av brister och förbättringsförslag för dessa i projekterings- och granskningsprocessen av arkitekthandlingar2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Fastec Sweden AB specializes in turnkey contracts of sports centers, industrial and commercial buildings. The overlap between design and production in turnkey contracts makes the process sensitive to defects and shortcomings in construction documents. Therefore, Fastec wants to investigate its shortcomings in the design and review process of architectural documents and see what can be improved. The purpose of the thesis is thus to identify possible shortcomings and deliver adapted proposal routines and improvement proposals for Fastec Sweden.

    For the identification of possible shortcomings, three projects have been selected to be reviewed, they´ve been projected by internal and external architectual planners and led by project managers at Fastec in Skellefteå. Documents that form the basis for and completed architectural documents have been reviewed, as well as deviation reports from the worksite. Interview talks and discussions with participants in the projects as well as other experienced and knowledgeable employees from the organization have been completed. Even previous projects evaluation documents and general shortcomings in the design work have been discussed in the interview talks.

    The resulting most frequently identified shortcomings are partly the agreement and the choice of external consultants and shortcomings in the target image that the design should work for, ie. what the production expects from the architectural documents. The design of doors and associated formation drawings and the use of too many wall types in the projects is also a common problem. So is the lack of utilization of the drawing and review programs the organization has at its disposal, as well as the low frequency of feedback and deviation reporting from the worksites.

    Proposals and improvement measures based on identified shortcomings can be found at the end of the thesis. Those who this thesis have come to the most frequent and important to change is to create a clearer target image for the early stage of the design process together with the other participants in the projects, especially the production management. To clearify what level of detail is expected of the construction and architectural documents. Rationalize the design with functional descriptions for door suppliers who are required to complete the design, as well as utilize capacity on a larger scale than today in the CAD and reviewing programs available to the organization.

  • 12.
    Billmark, André
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Delreparationer av våtrum ur ett hållbart perspektiv2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Varje år anmäls det uppskattningsvis 80 000 vattenskador i fastigheter till en kostnad på nära fem miljarder kronor för de svenska försäkringbolagen. Folksam som är ett av de största försäkringsbolagen i Sverige står för cirka 26 % av de svenska villaförsäkringarna och beställer byggreparationer för uppskattningsvis 800 miljoner kronor årligen till dessa fastigheter. Som beställare av arbeten på 800 miljoner kronor finns det möjligheter att ställa krav på byggbranschen, vilket även görs.Det är inte bara Folksam som ställer krav, försäkringsbolagen sammarbetar ofta för att hjälpa till att effektivisera byggbranschen. I nuläget fokuserar försäkringsbolagen på hållbarhet, de sammarbetar med olika branschorganisationer för att möjliggöra delreparationer i våtutrymmen. Detta är något som tidigare inte varit möjligt då det inte funnits anvisningar till hur detta ska genomgöras och materialtillverkare har inte haft monteringsanvisningar för detta, delreparationer kan därför inte utföras på ett fack-mannamässigt sätt. Då det inte utförs fackmannamässigt följs inte de branschregler som idag finns i Sverige, behöriga företag utför enbart arbeten som följer branschreglerna de är certifierade inom. Exempel kan de vara certifierade inom Byggkeramikrådets branschregeler eller Säkra våtrumAv de 800 miljoner kronor som Folksam betalar ut i byggskador finns det ett mörkertal på en kostnad av skador som egentligen inte ska ersättas. Genom att öka försäkringstagares kunskaper angående fördelarna med delreparationer ska mörkertalet minskas. Det är inte bara utgifterna på 800 miljoner som kan minskas utan även en minskning av den negativa miljöbelastningen och den ohälsa som finns hos fastighetsbrukare. Uppskattningsvis kan upp till 90 % av materialet i ett våtrum sparas genom att utföra en delreparation. Utförandetiden och kostnaden av delreparationer kan minska till 1/5 genom att undvika heltäckande reparationer. Minskad utförandetid minskar perioden som de boende inte kan bruka våtrummet. Skadan åtgärdas i ett tidigt skede vilket bidrar till att motverka de boendes ohälsa som kan uppstå till följd av mögel eller liknande.Fastighetsägaren kan ta till sig denna information och se värdet i att kunna utföra delreparationer och samtidigt bidra till en hållbar utveckling.Genom djupgående studier ska information som ökar fastigetsägarnas vetskap om de framtida möjligheterna med delreparationer, samt för- och nackdelar med dessa metoder.

  • 13.
    Brajerski, Thomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Stability design of multi-storey timber structures2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Stability design of buildings is an extremely important discipline within the field of structural engineering.

     

    This report demonstrates, with help of a worked example, the theory behind the stabilisation of multi-storey timber structures. The worked example is an existing 6-storey building, primarily made with cross laminated timber (CLT). The construction project is located in central Umeå and is designed and managed by Martinsons Byggsystem. The building uses an array of CLT wall panels as a stabilising system.

     

    A number of key points that will be looked at in the worked example; firstly, analysing the loads acting on the building, specifically the calculation of lateral wind loads and their effect on stabilising CLT panels; secondly, a deeper look into the methods of stabilisation using CLT walls. This will include the stability checks for overturning, sliding and shear and counter measures taken against any potential instability. Finally, a look into how CLT walls can be designed by hand calculations according to Eurocodes. There is no particular predefined method to do this, so this report will show how to design a CLT wall by treating CLT as either a homogeneous material or a non-homogeneous/composite material.

  • 14.
    Brembilla, Christian
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Modelling and simulation of building components: thermal interaction between multilayer wall and hydronic radiator2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background and Scope The scope of this thesis is to investigate the thermal behaviour of building components as hydronic radiator and multilayer walls subjected to dynamic conditions. The modelling and simulation of these building components provide information on how these components thermally interact among each other. The thermal interaction is fundamental to know how the energy is used in buildings. In particular, the thermal energy used in rooms can be expressed as the efficiencies for emission in a space heating system. This thesis analyzes the efficiencies for emission of a space heating system equipped with hydronic radiator for Swedish buildings by providing a comprehensive and detailed approach on this topic.

     

    Methodology The methods used in this thesis are: experiment, modelling of multilayer wall and hydronic radiator, the dynamic simulation of the building and the efficiencies for emission of a space heating system. Here, the experiment, known as step response test, shows the heating up process of a hydronic radiator. The observation of the qualitative measurements suggests the most suitable technique of modelling the radiator known as transient modelling with multiple storage elements. The multilayer wall has been discretized both in space and time variable with a Finite Difference Method. Dynamic simulation of the building provides the efficiencies for emission of a space heating system.

     

    Findings The experimental results show how the radiator performs the charging phase. The performance of the transient model is compared with lumped steady state models in terms of temperature of exhaust flow and total heat emitted. Results of the dynamic simulation show how buildings located in a Northern climate use the energy in a better way than Southern climates in Sweden. Heavy active thermal mass provides higher efficiencies for emission than light thermal mass. Radiators with connection pipes located on the same side react faster at the thermodynamic changing of the mass flow rate by providing higher efficiencies for emission than radiators with connection pipes located on the opposite side.

     

    Conclusion and Outlook This thesis increases the knowledge about the modelling and simulation of hydronic radiators and multilayer walls. More research is needed on this topic to encompass modelling details of building components often ignored. The modelling and simulation of building components are the key to understand how building components thermally interact with each other. The thermal interaction among building components is a fundamental parameter for the assessment of efficiencies of emission of the space heating system. In the near future, the concept of efficiencies of emission can be implemented in National Building Code, therefore, this study provides guidelines on how to assess these efficiencies.

  • 15.
    Brembilla, Christian
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Vuolle, Mika
    EQUA simualtion.
    Östin, Ronny
    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.
    Practical support for evaluating efficiency factors of a space heating system in cold climates: modelling and simulation of hydronic panel radiator with different location of connection pipes2017In: Energy Efficiency, ISSN 1570-646X, E-ISSN 1570-6478, Vol. 10, no 5, p. 1253-1267Article in journal (Refereed)
    Abstract [en]

    Plenty of technical norms, included in the EPBD umbrella, assess the performance of buildings or its sub-systems in terms of efficiency. In particular, EN 15316 and its sub-sections, determine the system energy requirements and the system efficiencies of space heating system. This paper focuses on the estimation of efficiencies for emission of hydronic radiators. The assessment of efficiencies for emission occurs by evaluating the amount of heat emitted  from the heat emitter and the extra thermal losses towards building envelope. The heat emitted from radiators varies during the heating up/cooling down phases. A factor that influences the heat emitted during these phases is the location of connection pipes of the radiator. Connection pipes can be located on opposite side or at the same side of the radiator. To better estimate the heat emitted from radiators a transient model with multiple storage elements is used in a building simulation model. Sensitivity analysis encompasses all  the possible variations on extra thermal losses due to the building location in different climates, the heaviness of active thermal mass and the type of radiator local control. The final outcome of this paper is a practical support where the designer can easily assess the efficiencies for emission of hydronic radiators  for Swedish buildings. As main result, (i) the efficiency for control of space heating system is higher in Northern climates than in Southern climates, (ii) heavy active thermal masses allow higher efficiencies for emission than light active thermal masses, (iii) connection pipes located on the same side of the radiator enable higher efficiencies for emission than pipes located on opposite side.

  • 16.
    Brembilla, Christian
    et al.
    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.
    Olofsson, Thomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Predictions' robustness of one-dimensional model of hydronic floor heating: novel validation methodology using a thermostatic booth simulator and uncertainty analysis2018In: Journal of Building Physics, ISSN 1744-2591, E-ISSN 1744-2583, Vol. 41, no 5, p. 418-444Article in journal (Refereed)
    Abstract [en]

    Hydronic floor heating models provide predictions in estimating heat transfer rates and floor surface temperature. Information on the model performance and range of validity of its results are often lacking in literature. Researchers have to know the accuracy and robustness of the model outcomes for performing energy and climate comfort calculations. This article proposes a novel validation methodology based on the uncertainty analysis of input data/parameters of one-dimensional model of hydronic floor heating tested in a thermostatic booth simulator and compared with experimental measurements. The main results are: (1) prediction accuracy between 0.4% and 2.9% for Tf and between 0.7% and 7.8% for qup when the serpentine has tube spacing (p) of 0.30 m, (2) prediction accuracy between 0.5% and 1.4% for Tf and between 8.7% and 12.9% for qup with p = 0.15m and (3) Tfld mostly affects predictions with oscillations between 6.2% and 2.2% for qup. This model provides robust and reliable predictions exclusively for qup when p = 0.30m.

  • 17.
    Bretting, Viktor
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Bärverk i passivhus: Utformning och dimensionering av en limträ stomme till en passivhus skola2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
  • 18. Cheng, Xiaogang
    et al.
    Yang, Bin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Liu, Guoqing
    Olofsson, Thomas
    Li, Haibo
    Atmospheric visibility detection based on total variation and piecewise stationary time series for fog and haze weather2018In: Sustainable cities and society, ISSN 2210-6707Article in journal (Refereed)
  • 19.
    Cheng, Xiaogang
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. College of Telecommunications and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing, China.
    Yang, Bin
    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.
    Liu, Guoqing
    Li, Haibo
    A pilot study of online non-invasive measuring technology based on video magnification to determine skin temperature2017In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 121, p. 1-10Article in journal (Refereed)
    Abstract [en]

    Much attention was paid on human centered design strategies for environmental control systems of indoor built environments. The goal is to achieve thermally comfortable, healthy and safe working or living environments in energy efficient manners. Normally building Heating, Ventilation and Air Conditioning (HVAC) systems have fixed operating settings, which can't satisfy human thermal comfort requirements under transient and non-uniform indoor thermal environments. Therefore, human thermal physiology signal such as skin temperature, which can reflect human body thermal sensation, has to be measured over time. Several trials have been performed by minimizing measuring sensors such as i-Button and mounting measuring sensors into wearable devices such as glasses. Infrared thermography technology has also been tried to achieve non-invasive measurements. However, it would be much more convenient and feasible if normal computer camera could record images, which could be used to obtain human thermal physiology signals. In this study, skin temperature of hand back, which has a high density of blood vessels and is normally not covered by clothing, was measured by i-button sensors. Images recorded by normal camera were amplified to analyzing skin temperature variation, which are impossible to see with naked eyes. The agreement between i-button sensor measuring results and image magnification results demonstrated the possibility of non-invasive measuring technology by image magnification. Partly personalized saturation-temperature model (T = 96.5 × S + bi) can be used to predict skin temperatures for young East Asia females.

  • 20. Cheng, Yuanda
    et al.
    Yang, Bin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China.
    Lin, Zhang
    Yang, Jinming
    Jia, Jie
    Du, Zhenyu
    Cooling load calculation methods in spaces with stratified air: a brief review and numerical investigation2018In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 165, p. 47-55Article, review/survey (Refereed)
    Abstract [en]

    Due to vertically thermal stratification in indoor spaces, the cooling load calculation is always a challenge in the design of stratified air distribution systems (STRAD), which in turn is crucial to determine the supply air flow rate and the cooling load to be removed by the air conditioning system. In this paper, several cooling load calculation methods, developed in the past 20 years and focused on STRAD systems, were briefly reviewed. It attempts to clarify these methods in terms of their advantages, limitations and suitable ranges of applications. Furthermore, series of numerical simulations with a total number of 56 cases were conducted, and the applications of a novel cooling load calculation method in STRAD systems were investigated. The reliability of the method was validated for STRAD systems with separated locations of return and exhaust grilles, when adopted in three typical spaces with different building heights, namely a small office, a large terraced classroom and a terminal building. Databases of effective cooling load factors (ECLF;) for different heat sources distributed in the three spaces were obtained and presented, which can be conveniently used to calculate cooling loads. In addition, the influences of return grill height on the occupied zone cooling load as well as the energy saving potentials of STRAD systems were also clarified. The results presented in this paper are helpful for the design and optimization of STRAD systems.

  • 21.
    Daerga, Per-Anders
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Girhammar, Ulf Arne
    Kallsner, Bo
    A complete timber building system for multi-storey buildings2014In: Construction materials and structures, 2014, p. 1164-1171Conference paper (Refereed)
    Abstract [en]

    The Masonite Flexible Building (MFB) system is a complete timber building system for commercial and residential multi-storey houses. The system is for tall and large buildings with long floor spans. The MFB system uses prefabricated wall, floor and roof elements which are delivered in flat packages and erected on the construction site. The MFB system might be classified as a panel construction, where the load-carrying structure consists of composite lightweight timber I-beams mechanically integrated with a composite laminated wood panel called PlyBoard T. The I-beams and the panel form a strong and rigid carcass for wall and floor elements, making the system well suited for high rise construction. A key feature of the MFB system is the connection technique which enables swift erection of the system units on site. The PlyBoard T panels are provided with a continuous slot along the periphery. The slot is used as a general connection interface for the joining of the wall elements. The floor elements are suspended and hooked onto the bearing walls using sheet steel hangers, allowing swift assembling of the floor deck and enabling direct vertical wall-to-wall load transfer parallel to grain. The paper presents the construction principles, system components and units, erection technique, functional and architectural aspects of the Masonite Building System.

  • 22.
    Daerga, Per-Anders
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Girhammar, Ulf Arne
    Luleå University of Technology.
    Källsner, Bo
    Linnæus University.
    Masonite Flexible Building System for Multi-Storey Timber Buildings2012In: World Conference on Timber Engineering 2012 (WCTE 2012) / [ed] Pierre Quenneville, 2012Conference paper (Other academic)
    Abstract [en]

    ABSTRACT: The Masonite Flexible Building (MFB) system is a complete timber building system for commercial and residential multi-storey houses. The system is subdivided into two market variants; XL and Light. The XL version is for tall and large buildings with long floor spans while the Light version is adapted for smaller buildings with lower loads. Though differing in technical performance, the functional criteria are the same for both variants. The MFB system uses prefabricated wall, floor and roof elements which are delivered in flat packages and erected on the construction site. The MFB system might be classified as a panel construction, where the load-carrying structure consists of composite light-weight timber I-beams mechanically integrated with a composite laminated wood panel called PlyBoard™. The I-beams and the panel form a strong and rigid carcass for wall and floor elements, making the system well suited for high rise construction. A key feature of the MFB system is the connection technique which enables swift erection of the system units on site. The plyboard panels are provided with a continuous slot along the periphery. The slot is used as a general connection interface for the joining of the wall elements. The floor elements are suspended and hooked onto the bearing walls using sheet steel hangers, allowing swift assembling of the floor deck and enabling direct vertical wall-to-wall load transfer parallel to grain. The paper presents the construction principles, system components and units, erection technique and functional and architectural aspects of the Masonite Building System.

    KEYWORDS: Masonite Flexible Building system, multi-storey timber buildings, slotted-in connections, suspended connections, functionality requirements.

  • 23.
    Daerga, Per-Anders
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Girhammar, Ulf Arne
    Luleå University of Technology.
    Källsner, Bo
    Linnæus University.
    Slotted-in Steel-Plate connections for Panel Wall Elements - Experimental and Analytical Study2012In: World Conference on Timber Engineering 2012 (WCTE 2012) / [ed] Pierre Quenneville, 2012, p. 451-460Conference paper (Other academic)
    Abstract [en]

    ABSTRACT: This paper presents an experimental and analytical study of a steel plate connection for joining walls in the Masonite Flexible Building (MFB) system. These connections are used partly for splicing the wall elements and partly for tying down uplifting forces and resisting horizontal shear forces in stabilizing shear walls. The steel plates are inserted in a perimeter slot in the plyboard panel (a composite laminated wood panel) and fixed mechanically with screw fasteners. The load-bearing capacity of the slotted-in steel plate connections are determined experimentally and derived analytically for different failure modes. The test results show ductile post-peak load-slip characteristics, indicating that a plastic design method for shear walls can be applied to calculate the horizontal load-bearing capacity. The slotted-in steel plate connection concept can also be used for joining shear walls to transverse walls for tying down purposes in order to simplify the stabilization system of the building. The use of transverse walls for resisting uplifting forces introduces a three-dimensional behaviour of the wall junction and a more effective load transfer.

    KEYWORDS: Slotted-in steel plate timber connections, timber wall elements, multi-storey timber building, Masonite Flexible Building system.

  • 24.
    Daerga, Per-Anders
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Girhammar, Ulf Arne
    Luleå University of Technology.
    Källsner, Bo
    Linnæus University.
    Suspended Floor Element Connections for the Masonite Flexible Building System2012In: World Conference on Timber Engineering 2012 (WCTE 2012) / [ed] Pierre Quenneville, 2012, p. 465-472Conference paper (Other academic)
    Abstract [en]

    The authors present an experimental study of a suspended floor element connection (sheet steel hangers) employed in the Masonite Flexible Building (MFB) system. The hangers are mounted with screws and are pre-attached to the floor elements at manufacturing. This arrangement makes the design of the hanger critical with respect to safety and load transfer redundancy, since the screws transfer all the loads, both withdrawal and shear forces can act simultaneously. Tests have been carried out to examine the structural behaviour of the hanger. The two most critical load cases, vertical floor load and horizontal wind suction load, and three different screw joint configurations were investigated. The results indicate that the vertical distance between the screw joint and the upper edge of the rim beam should be increased and that withdrawal forces on the screws should be kept as low as possible. Some suggestions for improving the present design are given and a modified design is proposed to enhance the load-bearing capacity and to improve the overall safety and redundancy.

  • 25. Dong, Jiankai
    et al.
    Zhang, Long
    Deng, Shiming
    Yang, Bin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Huang, Shun
    An experimental study on a novel radiant-convective heating system based on air source heat pump2018In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 158, p. 812-821Article in journal (Refereed)
    Abstract [en]

    Air source heat pump (ASHP) has been widely applied to many parts of the world due to its simple structure and low initial cost. To save energy consumed for spacing heating and enhance the indoor thermal environment, improving the performances of ASHP has become one of the research focus in the relevant field. Currently, the most conventional heating terminal of ASHP system for spacing heating is finned tube heat exchanger coupled with air fan, which may cause strong draught sensation and dry eye problem and make users feel uncomfortable during convective heating. On the other hand, radiant heating is attracting more and more attention due to its comfortable indoor thermal environment. In this paper, a novel radiant-convective heating terminal was presented and coupled into an ASHP system. Both the operating characteristics and heating performances of the novel system were experimentally investigated. The experimental results showed that the novel system took about 28 min to enter a steady operating stage, during which the radiant panel surface temperature and outlet air temperature for the novel heating terminal, and COP of the novel system were 40.9 degrees C, 32.1 degrees C, and 3.11, respectively, under a standard heating condition. In addition, all parameters mentioned above saw a linear increase when the outdoor air temperature increased from -4.0 to 10.0 degrees C, and their respective rising rates were 0.41 degrees C, 0.28 degrees C and 0.04 per increased outdoor air temperature. Furthermore, the experimental results also demonstrated that adjusting the indoor air flow rate could effectively allocate the amount of heat generated by different heat transfer modes, which may have significant effects on the indoor thermal environment.

  • 26.
    Edlund, Olov
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Svikt i bjälklag2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    For wooden joists with long spans to meet the requirements with respect to springiness or deflection caused by a static midpoint load, composite action, load sharing and possibly frame action need to be used. The elements developed and produced by Lättelement AB are designed to include these type of actions.

    In this thesis work, the vertical deflection of Lättelement AB’s floor elements of different designs, are evaluated. The deflection criteria according to Eurocode 5 and the Swedish standards is then used to determine the acceptability of the different floor designs. A generalized program has been developed to calculate the deflection, where different parameters such as material quality, geometrical dimensions, cross-section properties and span lengths easily can be varied. Using this program, the behavior and and design of the floor elements can more easily be improved.

    A parameter study has been conducted to evaluate the influence of varying the directions of the components and the effect of the frame action.

    Most of Lättelement AB’s floor designs pass the criterion for springiness due to the fact that composite action, load sharing and frame action can be utilized.

  • 27.
    Elfving, Marcus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energieffektivisering genom behovsstyrning av inomhusklimat2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report deals with an energy efficiency project of a cinema in Umeå by controlling the indoor climate depending on the situation and by that way reduce energy consumption for heating and ventilation systems, yet managing to maintain a good indoor environment for occupants and that existing rules and laws are not broken. This energy efficiency was done by Schneider Electronic on one of Norrporten’s properties.

    Studies of various laws and sets of rules, including the “Boverkets Byggregler” (BBR) and “Socialstyrelsens allmänna råd”, was done to find out how to control the heating and ventilation systems so that the indoor climate can still keep the quality required.

    To know how to control the indoor climate in the theater information was needed about how the heating and ventilation systems were designed. This was investigated by means of field visits, interviews and literature studies. It appeared to be a system where the supply air was heated or cooled by a heating or cooling coil before it was sent out to the premises where the energy to the heat came from the district heating while the coolness was driven by electricity. Some radiators were in the hallways and beneath the windows in the foyer and in the theaters there were air heaters that could be used if necessary.

    The energy efficiency project was that the heating and ventilation systems would not work as hard, but most important they would be running fewer hours during the day and night. This would be solved by installation of DUCs (Data under centrals) and various different sensors, which together would determine which heating and ventilation requirements needed at a particular time and control the systems based on them.

    During the project a number of shortcomings and side effects were revealed and needed to be addressed. These shortcomings were both those that were due to the project and those that had not been discovered by Norrporten earlier, such as whishing noise, poor efficiency of heat recovery, bad odors and high air velocities.

    The results of this project was beyond the expectations when the estimated savings were a little less than 60 kWh/m2 while the actual savings was just over 100 kWh/m2. The money that was saved the first year were nearly 75% larger than expected from the estimated figure of about 160 000 SEK to the real saving of about 280 000 SEK.

  • 28.
    Eliasson, Thommy
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Fuktsäkerhetsarbete på NCC i Umeå2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Problemen med fuktskador i byggnader är många och kostnaderna för att åtgärda problemen är stora. ByggaF är en metod som riktar sig till hela byggprocessen och den dokumenterar, kommunicerar samt säkerställer fuktsäkerheten genom hela den processen. NCC använder sig idag av en egen metod för att säkerställa fuktsäkerheten och den metoden jämförs i detta arbete mot ByggaF. Arbetet inriktar sig mot produktionsskedet av byggprocessen vilket innebär att fuktsäkerhetsarbetet är granskat i det skedet.

    Syftet med detta examensarbete är att NCC i Umeå ska få en bättre kännedom om vad ByggaF är och hur den metoden kan användas inom byggproduktion. Ytterligare syfte är att visa hur arbetet kan ske för att förebygga fuktskaderisken genom att använda metoden ByggaF, en metod för fuktsäkert byggande.

    Arbetet är utfört på NCCs byggnation på Öbacka strand etapp 4 och det bygget har fungerat som referens för NCCs fuktarbete. Undersökningen har utförts genom observation ute på byggarbetsplatsen, granskning av den upprättade fuktsäkerhetsplanen samt frågeställning till berörda.

    Resultatet som redovisas i denna rapport visar att NCCs fuktsäkerhetsarbete är genomtänkt och upplägget liknar ByggaF. Viktiga punkter som finns upprättade i fuktsäkerhetsplanen är till exempel: krav som beställaren har ställt, mätningar i trä utförs och dokumenteras, materialet förvaras på ett bra sätt samt att åtgärder vid avvikelser fanns formulerade. Där NCC mest skiljer sig i jämförelse med ByggaF är att uppföljning av fuktsäkerhetsplanen inte sker. Enligt ByggaF ska specifika fuktronder utföras med ett visst intervall för att säkerställa att fuktsäkerhetsplanen följs. Fuktronder utförs inte på referensobjektet och det finns inte angivet i NCCs egen metod för fuktsäkerhetsarbete.

    En fuktrond utfördes på referensobjektet för att kontrollera hur fuktsäkerhetsplanen följs. Fuktronden visar att fuktsäkerhetsplanen används vilket är positivt ur fuktsynpunkt.

  • 29.
    Forsgren, Sara
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Byggplatsnät och Utsättning - utfört av huvudentreprenören: Construvtion site network and layout - accomplished by the contractor2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Thanks to the advanced measuring instrument available today, the layout1 work can be carried out more precisely. This however does not guarantee that the work is done correctly. It requires a mix of skills and experience to ensure a good quality of the work performed.

    The purpose of this project was to create a common work process for the measuring technicians at OF Bygg KB in Umeå. After some interviews, field studies and literature studies, two documents were created. The purpose of these two documents were to guide the person responsible for establishing the primary system and the goal was to make the layout work more time-effective, quality-assured and therefore cost- effective.

    Understreck: Step by step template with instructions and recommendations regarding the establishing of the primary system.

    Checklista: Giving the measuring technician and others on the construction site an overview of the work that’s completed and it should contain valuable information regarding measuring equipment, contacts and more.

  • 30.
    Girhammar, Ulf Arne
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Kallsner, Bo
    Analysis of influence of imperfections on stiffness of fully anchored light-frame timber shear walls: elastic model2009In: Materials and Structures, ISSN 1359-5997, E-ISSN 1871-6873, Vol. 42, no 3, p. 321-337Article in journal (Refereed)
    Abstract [en]

    In order to stabilize light-frame timber buildings against horizontal loads, the diaphragm or in-plane action of roofs, floors and walls is often used. This paper deals with the influence of imperfections such as gaps and uplift on the horizontal displacement of fully anchored shear walls. The significance of analyzing the effects of imperfections is evident when evaluating the stiffness of shear walls; tests of walls show that the horizontal displacement is underestimated in calculations using the stiffness of sheathing-to-framing joints as obtained from experiments. Also, in real structures where hold-downs are used according to the elastic design method, the influence of gaps and uplift should be included in order to obtain realistic displacements in the serviceability limit state. A new elastic model for the analysis, based on linear elastic behaviour of the mechanical sheathing-to-framing joints, is presented and the equations for the stiffness and the deflection versus the number of segments in the wall are derived. The fully anchored condition for the shear walls are modelled by applying a diagonal load to the wall. Three types of imperfections are evaluated: gaps at all studs, a gap only at the trailing stud, and gaps at all studs, except at the trailing stud. It is shown that the effect of imperfections on the stiffness of the wall in the initial stage is considerable. Depending on the distribution of the gaps and the number of segments included in the shear wall, the displacement of the shear wall is increased several times compared to that of a fully anchored shear wall with no gaps; e.g. for a single segment wall more than three times. However, for walls with more than six to ten segments, the effect of imperfections can be neglected. Finally, the theoretical model is experimentally verified.

  • 31.
    Girhammar, Ulf Arne
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Källsner, Bo
    Linnéuniversitetet, School of Engineering.
    Gustafsson, Per Johan
    Lunds universitet, Konstruktionsteknik.
    Johnsson, Helena
    Luleå tekniska universitet, Samhällsbyggnad och naturresurser.
    Stabilisering och bjälklag kritiska för höghus i trä2011In: Husbyggaren, ISSN 0018-7968, Vol. 53, no 1, p. 16-21Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    INDUSTRI- OCH KONTORSBYGGANDE Stabilisering och bjälklagsutformning är kritiska moment vid byggandet av flervåningshus i trä. Bjälklagen måste bland annat klara stora spännvidder. Nu finns en nyutvecklad plastisk metod som ska säkra horisontalstabilisering. 

  • 32.
    Girhammar, Ulf Arne
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Pan, Dan H
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Gustafsson, Anders
    Nanyan Technological University.
    Exact dynamic analysis of composite beams with partial interaction2009In: International Journal of Mechanical Sciences, ISSN 0020-7403, E-ISSN 1879-2162, Vol. 51, p. 565-582Article in journal (Refereed)
  • 33.
    Gunchenko, Nataliya
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Bärförmåga hos HD/F-element på flexibla upplag2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Floor structures constructed by using prestressed precast hollow-core slabs is costeffective solution for buildings that require long span floors. Nowadays the most common design for this type of floors consists of HC slabs supported on beams. In this case beams are called flexible supports because of deflection in the beams. These deflections cause addition stresses in the HC slabs that has to be taken into accout. The purpose of this study was to find out which calculation models exist and how they can be used in design process. As s result of project a calculation example is presented in this report which describes one of possible calculation models.

  • 34.
    Gästrin, Magnus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Konstruktion av platt tak2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Think about the possibility to be able to stay at the top of your roof. The terrace would maybe give you the view to the horizon, or maybe the opportunity to look down to your neighbor without having the neighbors eyes on you. Maybe you have a minor property and you feel importance in using it most efficiently. Possibly you like to sunbathe, or why don´t you place a hot tube on the roof?

    Despite what increased value a flat roof gives to one other, the fundamental idea is that this construction would be something out of the ordinary. However, the question you have to ask yourself:

    - Is it possibly to build a construction for the roof that can handle the demand of strength and closeness with a long expected lifetime without a too expensive cost?

    This report investigate whether a roof construction as a terrace with the opportunity to stay at can be able to carry through in our northern country of Sweden. The construction is a material-cumstudy of concrete, cellular plastic and membrane for keeping the building free from water. The way I see, there are incredibly possibilities when you construct with concrete since concrete is extremely formable. This imply that only the fantasy set bounds to how the colour, surface structure and geometry should be exposed.

    This report describes how the construction is built up, and how to do the dimensioning if you think about the challenge that occurs, for example frost erosion and how to get the building completely close from water, and also how to deal with the water that gathers on the roof. Other examples of challenges are the frequense of fracture in the concrete and how you get an attractive surface on the terrace.

    Welcome to read more about my final work for Bachelor of Science Programme in Civil Engineering at the University of Umeå.

  • 35.
    Hassan, Osama
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Building acoustics and vibration: theory and practice2009 (ed. 1)Book (Refereed)
  • 36.
    Hassan, Osama
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Experimental study on utilizing iron slag to stabilize Cr(VI)-contaminated soil2010In: WIT Transaction on Ecology and the Environment / [ed] V. Popov, H.Itoh, U.Mander and C.A. Brebbia, WIT press , 2010, Vol. 140, p. 337-347Conference paper (Refereed)
    Abstract [en]

    A laboratory study is conducted to test the capacity of two types of iron slag to stabilize Cr(VI)-contaminated soils. The slag samples are incorporated with soils in different proportions and the resulting leachate is tested using batch experiments. The feasibility of using iron is demonstrated as concentrations up to 1000 mg Cr(VI)/kg in the leachate of an alkaline soil are reduced to 0,7 mg Cr(VI)/kg mix after 12 days, but to less than 5 mg Cr(VI)/kg mix after 7 days. Small particles size and L/S-ratio are, in most cases, favoured by the reducing agents to stabilize the contaminated soil. The study demonstrated that the iron slag can effectively stabilize Cr(VI)-contaminated soils.

  • 37.
    Hassan, Osama AB
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    An alternative method for evaluating the air tightness of building components2013In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 67, p. 82-86Article in journal (Refereed)
    Abstract [en]

    In this study, an alternative and general approach is advanced to evaluate the air leakage area and air infiltration rate in building envelope components such as exterior/internal walls and floors. In this method, the leakage area is determined with the help of acoustical and physical methods by measuring the sound reduction index of the building. The air flow rate through air leaks is determined with the help of leakage area and pressure difference over the floor/wall. The heat losses and convective moisture rate through leaks in the building are subsequently evaluated with the help of the calculated air infiltration rate.

    (C) 2013 Elsevier Ltd. All rights reserved.

  • 38.
    Hassan, Osama
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Girhammar, Ulf-Arne
    Luleå tekniska universitet.
    Assessment of human-induced vibrations in composite timbre floors2012In: Proceedings of the 15th European Conference on Composite Materials, Italien, 2012Conference paper (Refereed)
    Abstract [en]

    The authors investigate the human induced vibrations in typical composite timber floors inresidential buildings. Assessment methods given in different design codes and guidelines,such as the Eurocode, are discussed. A case study analysis based on the differentmethodologies is carried out to assess the acceptability of a specific timber floor. Twoextreme cases are considered: full and non-composite action. It is shown that compositeaction improves the floor acceptability for general residential applications. The limitations ofthe different criteria given in the codes and guidelines for assessing floor vibrations in timberfloor structures are discussed and, also, the possible improvement of these criteria.

  • 39.
    Hassan, Osama
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Schedin, Staffan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Girhammar, Ulf Arne
    Luleå University.
    Experimental Analysis of Composite Timbre-Concrete Wall Element2012In: Proceedings of the 15th European conference on composite materials, 2012Conference paper (Refereed)
    Abstract [en]

    The authors present an experimental and theoretical study on a composite or hybrid element used in residential and agricultural buildings. The composite wall element consists of timber studs connected to a concrete plate by means of nail plate shear connectors. Experimental results are presented and compared with an analytical model for partial composite action. A good agreement is obtained between the analytical and experimental results. Also, some suggestions to improve the design of the composite element are discussed.

  • 40.
    Holmström, Linnea
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Dimensionering och praktiska försök av kopplingar i HD/F-plattor2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Hollow core slabs are a common concrete product that reduces material costs and is used, among other things, where you want longer ranges for a more open plan solution. Strängbetong designs, manufactures and assembles prefabricated concrete elements where hollow core slabs are one of the products. To get a stable and robust construction, the concrete elements need to be connected. This in order to avoid progressive collapse of a building in case of an accident, such as an collision or explosion. This dissertation aiming to investigate two so-called collapse-couplings between a hollow core slab and a concrete wall. One of the connections is according to Strängbetong's standard and is designed with a S-reinforcing bar in the hollow core slab void, but this standard solution provides extra work in the manufacture. That's why it's an advantage, if it is practically possible, to assemble the bar in the joint between two slabs instead. The tests are in order to investigate whether the bended reinforcement bar becomes enought enclosed by concrete and that the concrete in the joint does not crack apart. The results from the practical part and from the theoretical calculation are then compiled to see if the reality differs from the theory. The capacity of the jack was 20 ton, which made the tests limited to only note that the pull-out capacity of a hollow core slab joint and void is at least 195 kN. The result of the tests gave material ultimate in the reinforcement. The results show that it is possible to replace today's standard connection in the void by instead assembly the bar in the joint between two slabs. The dissertation can be seen as an attempt to test if the connection is a possible solotion and the work may be the basis for further study.

  • 41.
    Hägne, Angelica
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Passivhus: Checklistor till byggherren, projektörerna, entreprenörerna och brukarna2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A passive house is a type of low-energy house, where the isolation is thicker, the windows have a better U-value and the construction is completely sealed. How much thicker the isolation needs to be and how better U-value that is required depends on the building's location, design, and what kind of climate it is. This type of building makes it possible to reduce the power demand. In south of Sweden, passive houses are only allowed to use 10 W/m 2. But in north of Sweden, passive houses are allowed to use 12 W/m2. It also uses energy-efficient appliances to reduce the energy use. Passive House is a house with low energy costs, high quality and good comfort.

    The purpose of my project is to develop what the engineer and the other actors need to know in the process so they can complete their project. What I came up with was some check lists and a manual that gives the explanation, these check lists and the manual are divided into the different actors.

  • 42.
    Järlstig, Anders
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Hallbyggnad i limträ2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This examination manage the calculations to dimension a hallbuilding. All of the calculations is based on Boverkets Konstruktions Regler (BKR). To perform this examination recent courses in the program Byggteknik, 180hp at Umeå university have been of great assistance, mainly Timber structures, 15hp. Other calculation- and materialcourses have also been of great assistance to complete this paper. The body of the hall is performed in limträ with the quality L40 and for the attachmentdetails I’ve used steal with different strength classes. In retrospect, I have achieved the goals I set at the beginning and I have grown a clear development in the area of dimension.

  • 43. Kabanshi, Alan
    et al.
    Ameen, Arman
    Hayati, Abolfazl
    Cooling energy simulation and analysis of an intermittent ventilation strategy under different climates2018In: Energy Journal, ISSN 0195-6574, E-ISSN 1944-9089, Vol. 156, p. 84-94Article in journal (Refereed)
  • 44. Kabanshi, Alan
    et al.
    Yang, Bin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Sörqvist, Patrik
    Sandberg, Mats
    Occupants’ perception of airmovements and air quality in a simulated classroom with an intermittent air supply system2017In: Indoor + Built Environment, ISSN 1420-326X, E-ISSN 1423-0070Article in journal (Refereed)
  • 45. kabanshi, Alan
    et al.
    Yang, Bin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Wigö, Hans
    Sandberg, Mats
    Energy simulation andanalysis of intermittent air jets system under different climates.2017Conference paper (Refereed)
  • 46.
    Karlsson, Emma
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utdragsbärförmåga för skruvar i KL-trä: En jämförelse mellan teori och praktik2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Withdrawal capacityof wooden screws in CLT and glulam will be examined in this thesis. This is done by a practical attempt using a testing machine.The purpose ofthis tensile test is to find out how much force the wooden screw can handle before the breaking limit is reached. The results of the tensile tests will be compared with the theory contained in Eurocode and in the Swedish manual of CLT.The tensile test will clarify the amount of traction force that a wooden screw can withstand when placed in CLT and glulam. The wooden screws weretested in four different places along the edge of the CLT. The screws were placed parallel to the grain, perpendicular to the grain, between the layers in the CLT and also between the boards parallel to the grain. This resulted in a varied withdrawal capacity between the tests.There was only a single type of test performed on glulam where the screws were placed perpendicular to the grain.The results from the tensile tests shows that the location of the screws at the edge of the CLT matter and the withdrawal capacity depends on the placement of the screw. It only exists one equation for the withdrawal capacity at the edge of the CLT according to the Swedish manual of CLT.The withdrawal capacityis the same throughout the whole edge of the CLT according to theory, which does not match the test-results from the tensile tests.No clear results wereobtained in the glulam, because too few testswere made.

  • 47.
    Kers, Lisa
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Varningssystem för snölaster2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to investigate whether property owners around the country use some form of warning system that alerts when the weight of the snow is getting too heavy for the construction, in order to avoid collapse of the roof and other damage to the building.

    The subject of this thesis is based on the many incidents in Sweden with roofs collapsing during winter time.

    During the winter of 2009/2010 extraordinary large numbers of incidents with collapsing roofs occurred, one of the affected property owners is Umeå municipality that suffered damage to one of their buildings when the roof collapsed. After that incident they installed a warning system in the building. They are now interested to investigate whether property owners around the country use some form of warning system to alert when the weight of snow becomes too heavy for the roof.

    The thesis contains a theoretical part where the consequences and causes of the roof collapses in the winter 2009/2010 are described. The theoretical part also discusses basic information about snow loads. The results section describes the various warning systems that exist around the country.

    The result of this work is that out of the seven property owners who were contacted, except Umeå municipality, there are only three that use some kind of warning system in their buildings. The most common warning system consists of laser sensors, containing a transmitter and a receiver that detects when the deflection becomes too big in rafters or top plate. Another common way to check the snow load is to weigh the snow by using a snow tube, this method is used by five of the contacted property owners.

  • 48.
    Kjell, Niclas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Jämförelse mellan BKR och Eurokod för träkonstruktioner2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    From May 2011 BKR is replaced by Eurocode for structural engineering work. BKR is the Swedish national rules and Eurocode is a set of European common rules. The purpose of the project is to make a comparison between the two systems for glulam structures. The comparison is made by dimensioning a glulam frame in both BKR and Eurokod to see if there are any major differences. The result shows that pressure perpendicular to the woods fibers and shear force for continuous beams are the major differences. The reason for the deterioration is due to the glulam class L40 in BKR has been replaced with L40c in Eurocode. The values of characteristic strength have been reduced for L40c. Pressure perpendicular to the woods fibers has been reduced from 8 to 2.7 MPa, resulting in a threefold decline. For shear force the value has been reduced from 4 to 2.7 MPa. The consequences are that glulam frames need plates between columns and beams or very large columns compared to BKR.

  • 49.
    Kyrö, Jonna
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Flytt och ombyggnad av kulturbyggnaden "Ingenjörsvillan": Utredning av Boverkets Byggregler2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    At this moment an urban transformation is happening in Kiruna, because of mining that is causing land deformations in the city. Big parts of the central settlement will be moved and a new city core will be created. Most of the buildings will be demolished and replaced by new buildings at a new location. Many buildings in the town is claimed to be of cultural and historical value from the early 1900. Some of the cultural buildings will therefore not be demolished during the urban transformation, instead they will be moved to a new location. One of these buildings is the so called “Ingenjörsvillan”, a 100 year old building that got its name after being built for the structural engineer at the mining-company. Today the building contains two rented apartments let by LKAB Fastigheter AB. In addition to the house being moved a possible reconstruction is planned. If a reconstruction is made the building will be used for conferences, education and temporary overnight stay for LKAB’s guests. A proposal drawing for this reconstruction has been made during this project.

    The purpose of this project has been to evaluate how “Boverkets” building regulations affect a move of a cultural building. The regulations have been analyzed in both cases; when the building is kept as apartments and when a reconstruction is made. A proposition has been made for how to adjust the building so that it meets the regulations.

    The results show that there are no direct regulations to consider when moving a building. Most of the demands can be interpreted differently and needs to be evaluated in each different case. How to meet the regulations depends on the buildings conditions and how it’s going to be used. The buildings cultural value is significant when to consider the regulations and can be a reason to make some exceptions. If the building only is relocated, no larger adjustments needs to be done. But if a reconstruction is made more adjustments are required.  How the regulations are being used depends on the extent of the reconstruction and what the building is going to be used for. If the building is being used by the public the regulations is stricter than for private buildings, above all the demands of accessibility and fire protection.

  • 50. Källsner, Bo
    et al.
    Girhammar, Ulf Arne
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Analysis of fully anchored light-frame timber shear walls: elastic model2009In: Materials and Structures, ISSN 1359-5997, E-ISSN 1871-6873, Vol. 42, no 3, p. 301-320Article in journal (Refereed)
    Abstract [en]

    In order to stabilize light-framed timber buildings against lateral loads, the diaphragm action of roofs, floors and walls is often used. This paper deals with an elastic analysis model for fully anchored sheathed wood frame shear walls. The model is based on the assumption of a linear elastic load-slip relation for the sheathing-to-framing joints. Only static loads are considered. The basic structural behaviour and assumptions for the elastic model are elucidated. Formulas for the load-bearing capacity and the deformation of the shear walls in the ultimate and serviceability limit states, respectively, are derived. Both a discrete point description and a continuous flow per unit length modelling of the fasteners are discussed. Also, the forces and displacements of the fasteners and sheathing are derived. The effect of different patterns and spacing of the fasteners on the capacity and displacement of the wall is illustrated. The influence of flexible framing members and shear deformations in the sheets, and also the effect of vertical loads on the shear wall, both with respect to tilting and second order effects, on the horizontal load-bearing capacity and displacement are evaluated. The stress distribution and the reaction forces at the ends of the different framing members are derived. The elastic model is experimentally verified and an illustrative example is given.

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