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  • 1.
    Abdulkader, Ammar
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Förseningar i byggprojektering och hur de kan förebyggas2023Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Idag är förseningar inom byggbranschen vanliga och orsakar problem och konsekvenser i byggprojekt. När ett projekt blir försenat uppstår extra kostnader för projektägaren, entreprenören eller båda parter. Med andra ord innebär förseningar ekonomiska förluster och skapar en stressig arbetsmiljö för alla inblandade aktörer och projektmedlemmar. I detta examensarbete identifieras betydande risker som kan orsaka förseningar i projekteringsfasen av byggprocessen, samt presenteras lösningar för att förebygga dem.

    Byggprocessen består av fyra faser: förstudie, projektering, produktion och överlämning. Projekteringsfasen är ett av de viktigaste stegen i byggprocessen och har stor betydelse för att förebygga förseningar. I denna fas utformas och ritas byggnader, och bygghandlingar tas fram med konstruktionsritningar, tekniska lösningar och beskrivningar upprättas för att styra hela byggprocessen.

    Detta arbete fokuserar på förseningar i själva projekteringsfasen och dess påverkan på hela projektet, samt hur de kan förebyggas. Arbetet består av en teoretisk och en praktisk del. Syftet med arbetet är att undersöka orsakerna till förseningar inom projekteringsfasen och att hantera dem på bästa sätt genom att utveckla riskhanteringen. Orsakerna kan vara ofullständig information, förändringar i projektspecifikationer och tekniska problem. Teorin bygger på litteratur om projektering i byggprocessen för att ge en bred kunskapsbas om projektering innan den praktiska delen genomförs. Den praktiska delen baseras på intervjuer med erfarna projektledare inom projektering som har varit involverade i olika försenade projekteringsprocesser. Resultatet presenterar projektledarens svar angående orsakerna till förseningarna i de två projekten. I diskussionen jämförs och analyseras resultaten med teorin, vilket visar att sjukdomar och bristande kommunikation, tillsammans med andra risker, kan vara orsaker till förseningar i projekteringsfasen. Förbättringsförslag inkluderar att skapa en trygg och hälsosam arbetsmiljö som en viktig faktor för projektets framgång, genom att anlita ytterligare konsulter från andra företag vid arbetsbelastning och erbjuda avkopplande aktiviteter som exempelvis spa-besök när det behövs. Andra förslag innefattar att lägga extra tid på riskanalys för att identifiera potentiella problem samt att etablera en kommunikationsmetod för grupper, såsom en grupp på Messenger eller en annan applikation, där all information om projektet regelbundet delas.

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  • 2.
    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.

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    Energieffektivisering vid renovering av Lamellhus på Mariehemsvägen
  • 3.
    Agardh, Ella
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Jämförelse av kostnad och klimatpåverkan för olika typer av bjälklag och bärande innerväggar2023Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Byggnadsdelar av hållbara material är viktigt för att uppnå de miljömål som satts upp för Agenda 2030 samt för att skapa ett mer hållbart samhälle. För att bidra till detta analyserades och jämfördes olika uppbyggnader av bjälklag och innerväggar tillverkade av trä. Byggnadsdelarna ska uppnå de tekniska kraven som ställs och hur de olika skiljer sig i kostnad och CO2e-utsläpp vid olika spännvidder och laster. Bjälklagen och innerväggarnas olika materialskikt kontrollerades för att undersöka vilket skikt som bidrar med det högsta utsläppet, för att göra det möjligt att utveckla materialet i framtiden. En jämförelse utfördes för bjälklagen tillverkade av korslamminerat trä och betonghåldäckets kostnad och undersöka om användningen av träbjälklaget blir mer lönsamt. 

    Arbetet utgick ifrån fyra alternativa typer av bjälklag och två typer av bärande innerväggar till en skolbyggnad som Sweco ansåg intressanta att utvärdera. Utformningen på dessa bjälklag och väggar bestämdes i detalj genom val av materialskikt för att uppfylla de tekniska kraven och dimensionering av de bärande delarna i konstruktionerna. För bjälklagen dimensionerades stommen utifrån spännvidder mellan 4–12 meter och väggarna dimensionerades utifrån antagandet att skolbyggnaden bestod av fyra våningsplan. Efter att detaljutformningen bestämts beräknades materialvolymerna som sedan låg till grund för kostnadsberäkning och klimatpåverkan. Det fyra bjälklagstyperna var baserade på KL-trä, limträ, lättbalk och betonghåldäck som bärande konstruktion för skolbyggnaden medan de två väggtyperna konstruerades av KL-trä och reglar.

    Resultatet bidrar till att undersöka vilken stomme som är mest effektiv utifrån ett kostnads och klimatperspektiv samt ge ökad kunskap om trästommars egenskaper. Jämförelsen visar att bjälklagen tillverkade i trä är mer gynnsamt ur ett klimatperspektiv för alla träbjälklag medan kostnaden varierar beroende på vilket träbjälklag som kontrollerades. Genom att undersöka kostnaden utifrån ett framtidsperspektiv kan trästommar vara mer lönsamt. För bjälklagen var limträbalken fördelaktigast för kostnaden för alla spännvidder. KL-trät var dock mest gynnsam utifrån utsläppet för spännvidderna 4–8 meter medan lättbalken hade det högsta utsläppet. För innerväggarna var kostnaden högst för KL-trät men hade det lägsta utsläppet upp till tre våningar därefter hade regelstommen ett lägre utsläpp. 

    De slutsatser som kan dras utifrån arbetet är att trästommar är mer lönsamt ur ett hållbarhetsperspektiv dock har trä en relativt hög kostnad i dagsläget. Limträbjälklaget och regelväggen har en relativ låg kostnad i jämförelse med de andra och ett lågt utsläpp som skulle kunna användas för att bidra till de uppsatta klimatmålen. En minskad kostnad av trä skulle göra att respektive träbjälklag är mer lönsamma utifrån både kostnaden och klimatet i jämförelse med betong. 

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  • 4.
    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.

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  • 5.
    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.

  • 6.
    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.

  • 7.
    Allard Stolterman, Ingrid
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Regulating energy performance of residential buildings in cold climate: a study of indicators, criteria, and evaluation methods2021Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Building energy performance has been important in Fennoscandia ever since the early vernacular houses, to combat the cold climate. Due to EU directive 2010/31/EU on the energy performance of buildings (EPBD recast), building energy performance has become even more relevant in northern Europe the last decade. Objectives for improving building energy performance may include reducing cost and CO2-emissions, increasing energy independency, and improving the indoor climate. Different indicators, criteria, and evaluations methods may be used to reach these objectives. This dissertation addresses indicators, criteria, and evaluation methods used to regulate energy performance of residential buildings in Sweden, Norway, Finland, and Russia. Four research objectives are covered: (RO1) comparing criteria and evaluation methods used to regulate energy performance of residential buildings in Sweden, Norway, and Finland, (RO2) studying the perspective of professionals with experience in building energy performance evaluation on (a) methods for evaluating envelope air leakage of residential buildings in Sweden and Finland and (b) potential energy performance indicators in the Swedish procurement process of multi-family buildings, (RO3) developing an approach for analysing the performance gap between design predictions and measurements that can be used to verify compliance with requirements on building energy use in practice, and (RO4) comparing the stringency of the energy performance criteria for residential buildings between the Swedish, Norwegian, Finnish, and Russian national building code. Many differences were found between how energy performance of residential buildings was regulated in the four countries. In Sweden, measurements were used more for evaluating building energy performance than in the other countries. As of 1st January 2020, the Finnish building code was characterized by its focus on the building heat loss and stringent energy performance criteria compared to the other countries. The Norwegian building code was characterized by a relatively narrow system perspective on energy performance, with no regulation of the energy production efficiency or energy source. The Russian building code also had a narrow system perspective but was also characterized by its focus on the form factor – the relationship between building volume and enclosing area. The practitioners wanted to minimize the influence from building operation and user behaviour on energy performance evaluations in the Swedish building procurement process of multi-family buildings. Hence, they preferred component-focused indicators or indicators with a narrow system boundary. An approach has been developed for analyzing the performance gap between design phase predictions and measurements. The approach can be used to verify the finished building’s energy performance, with minimal influence from occupant behavior and building operation.

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  • 8.
    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.

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  • 9.
    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.

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  • 10.
    Andersson, Erik
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Jämförelse mellan stål och limträ som stommaterial i en industrilokal2023Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The construction industry accounts for a significant portion of greenhouse gas emissionsworldwide. When choosing construction materials for building structures, there are many factorsto consider, and the environmental impact is becoming increasingly important. Other factorsinclude cost, assembly time, and the size of structural components. Building larger structures usingwood is becoming more common as environmental concerns gain prominence. Wood is consideredone of the better alternatives from an environmental perspective as it is a completely renewablematerial. All types of materials have different properties, and when choosing constructionmaterials for a building, it is important to consider these factors to ensure proper utilization of thematerial.The purpose of this project was to demonstrate an alternative design for an industrial facility usingwood as the primary construction material instead of the original steel. The wooden building wasthen compared to the original steel building to highlight the differences in material usage betweensteel and wood. The comparison of material usage could be utilized during the initial phase ofdesigning similar buildings where the amount of steel is known, and one wants to estimate theapproximate amount of wood if the choice is made to design with wood instead.The building designed in this project was dimensioned using manual calculations and computertools. The design of the building was based on drawings from the reference project in steel, wherea section of the steel building was chosen as the starting point for the entire wooden construction.A comparison was also made to show the differences in internal area and internal ceiling heightswhen choosing wood as the construction material. The environmental impact of the choice ofstructural material was also compared. This was done using “ByggsektornsMiljöberäkningsverktyg”, where material-specific values from manufacturers' EnvironmentalProduct Declarations (EPDs) were inputted into the tool to obtain the most accurate possiblecomparison for this specific project. The comparison showed that, overall, the amount of glulamused in the entire building was 1.22 times greater than the amount of steel in terms of weight. Thedifference in internal height averaged 20% lower in the wooden building due to the high trussbeams in the roof structure. The environmental comparison showed that the wooden constructionhas a significantly smaller carbon footprint than the steel construction. The steel constructioncontributes to approximately 20 times more greenhouse gas emissions than the woodenconstruction.The conclusion of this project is that it is entirely possible to design a structure in this manner, butcertain adjustments must be made if starting from the same specified dimensions as a steelconstruction. If the option exists to raise the entire building instead of needing to lower the internalceiling height, it may be recommended to retain more volume inside the building. This, of course,depends on the specific purpose of the building. In terms of environmental impact, there is asignificant advantage to using glulam compared to steel.

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  • 11.
    Andersson, Erik
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Kupolhuset: Laster och lasteffekter för en liten limträkupol2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis is about frame verification and material optimisation of a radial ribbed type dome house with glued laminated timber arches. The analysis is based on an existing house in the shape of a spherical dome with a radius of just over 6 meters and a height of about 7.5 meters. The frame is constructed with two layers of glued laminated timber arches that form an inner and an outer dome, with insulation between the two layers to prevent thermal bridges. The cross section of the arches is 90x160 mm and the material is GL24h. The total number of arches in the frame is 72, with 36 in each layer. The construction company is interested in verifying the frame with respect to dead loads, snow loads and wind loads in the Umeå region and to know whether it's possible to reduce the amount of material for their future dome house projects.

    Six different load cases are analyzed with a method for computer-aided manual analysis, where the support reactions and the reaction forces in the apex of the dome are calculated. The bending moment, normal force and shear force in the arches are then determined using free body diagram and mechanical equilibrium. The arches are controlled for compression stresses, shear stresses, tensile stresses perpendicular to the fiber direction and stability along the strong and the weak axes. The interaction between the inner and the outer arches is estimated using a model in the software Frame Analysis.

    The arches met the design requirements for compression stresses, shear stresses and tensile stresses perpendicular to the fiber direction. The arches did not meet the design requirements for stability, neither along a weak nor the strong axes. Based on these results, it is proposed that the cross section be increased to 115x320 mm, that the inner row of arches be abolished and that the number of arches be reduced to 24. With these changes, the arches would meet the design requirements and the amount of material in the frames would decrease by about 15 %.

    These results are based on a simplified geometrical model of the dome and should be considered as a first estimate. It is recommended that a more in-depth analysis be performed using the finite element method.

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    Kupolhuset
  • 12.
    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. 

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  • 13.
    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.

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  • 14.
    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.

  • 15.
    Azizi, Shoaib
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    A multi-method assessment to support energy efficiency decisions in existing residential and academic buildings2021Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Rapid decarbonization of building stock is essential for the energy transition required to mitigate climate change and limit the global temperature rise below 1.5 °C. The decision-making for the adoption of energy efficiency measures (EEMs) is often complex and involves lasting consequences and risks. The strategy to direct and support the decision makers can significantly increase the adoption rate of EEMs in buildings. This Ph.D. project focuses on facilitating sustainability improvement in buildings by supporting the decision makers who are accountable for the consequences of adopting the EEMs. Energy efficiency improvement is decided and managed differently in various types of buildings and contexts and encounters different challenges and opportunities. Accordingly, it is required to understand the needs to select adequate strategies and to devise effective supporting interventions for energy efficiency improvement.

    The owners of single-family houses are often the occupants who are in charge of the most decisions to improve energy efficiency in their dwellings. The situation is rather different in multi-family buildings and academic buildings in which organizational management adds more complexity and the decisions affect various stakeholders. The studies in this project are based on qualitative and quantitative data collected from single-family houses, multi-family buildings, and university buildings in northern Sweden. Surveys were used to elicit the decision makers' perceptions of different types of buildings. Moreover, sensor data from university buildings were used in the case studies to develop informative metrics for space use efficiency and to analyze the effect of sensor positioning on monitored data.

    The initial work involved understanding the opportunities and challenges of improving energy efficiency in buildings and the tradeoffs between the perceived benefits and barriers. This part of the thesis provided the foundation and inspiration for the rest of the project, including investigating how to bundle several measures and use information and communication technologies (ICT) for building sustainability. The findings show lack of information and evidence that could justify the beneficial outcomes of EEMs is a major barrier for effective decision-making. Clear information on potential improvements allows sharing the responsibilities among different stakeholders and increases the management capacity to handle projects and adopt EEMs. Using feedback tools (for example, space use and/or energy use visualizations) might be an effective strategy to influence decision makers.

    Various studies incorporated in this multidisciplinary Ph.D. thesis develop and investigate strategies to support decision makers to improve energy efficiency in buildings. The findings provide insights to policymakers and businesses to devise intervention strategies for energy efficiency in buildings.

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    PhD Dissertation_Shoaib Azizi
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  • 16.
    Azizi, Shoaib
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Rabiee, Ramtin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Nair, Gireesh
    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.
    Application of occupancy and booking information to optimize space and energy use in higher education institutions2020In: E3S Web of Conferences, E-ISSN 2267-1242, Vol. 172, article id 25010Article in journal (Refereed)
    Abstract [en]

    Building in higher education institutions (HEIs) are characterized as energy intensive Experience from practice showing large discrepancies between predicted and actual energy performance. The deviation can sometimes reach 100%. Explanations often originate from occupant’s behaviour along with building operation. IoT-based smart tools can provide extensive information about building usage to improve the building management, often associates with opportunities, for significant energy saving. The analysis in this study investigate space use based on occupancy and booking information in eight different lecture rooms at Umeå University. The results suggest interventions for significant saving potentials, such as modification of access permission and closing down redundant lecture rooms.

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  • 17.
    Azizi, Shoaib
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Rabiee, Ramtin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Nair, Gireesh
    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.
    Effect of the positioning of multi-sensor devices on occupancy and indoor environmental monitoring in single-occupant officesManuscript (preprint) (Other academic)
  • 18.
    Azizi, Shoaib
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Rabiee, Ramtin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Nair, Gireesh
    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.
    Effects of Positioning of Multi-Sensor Devices on Occupancy and Indoor Environmental Monitoring in Single-Occupant Offices2021In: Energies, E-ISSN 1996-1073, Vol. 14, no 19, article id 6296Article in journal (Refereed)
    Abstract [en]

    The advancements in sensor and communication technologies drive the rapid developments in the applications of occupancy and indoor environmental monitoring in buildings. Currently, the installation standards for sensors are scarce and the recommendations for sensor positionings are very general. However, inadequate sensor positioning might diminish the reliability of sensor data, which could have serious impacts on the intended applications such as the performance of demand-controlled HVAC systems and their energy use. Thus, there is a need to understand how sensor positioning may affect the sensor data, specifically when using multi-sensor devices in which several sensors are being bundled together. This study is based on the data collected from 18 multi-sensor devices installed in three single-occupant offices (six sensors in each office). Each multi-sensor device included sensors to measure passive infrared (PIR) radiation, temperature, CO2, humidity, and illuminance. The results show that the positions of PIR and CO2 sensors significantly affect the reliability of occupancy detection. The typical approach of positioning the sensors on the ceiling, in the middle of offices, may lead to relatively unreliable data. In this case, the PIR sensor in that position has only 60% accuracy of presence detection. Installing the sensors under office desks could increase the accuracy of presence detection to 84%. These two sensor positions are highlighted in sensor fusion analysis as they could reach the highest accuracy compared to other pairs of PIR sensors. Moreover, sensor positioning can affect various indoor environmental parameters, especially temperature and illuminance measurements.

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  • 19.
    Babaahmadi, Arezou
    et al.
    Chalmers University of Technology, Gothenburg, Sweden.
    Figueira, João
    Umeå University.
    Chloride binding in slag containing composite cements2023In: International RILEM conference on synergising expertise towards sustainability and robustness of cement-based materials and concrete structures: SynerCrete’23 - volume 1 / [ed] Agnieszka Jędrzejewska; Fragkoulis Kanavaris; Miguel Azenha; Farid Benboudjema; Dirk Schlicke, Cham: Springer, 2023, 1, , p. 13p. 645-657Chapter in book (Refereed)
    Abstract [en]

    Higher availability of grand granulated blast furnace slag compared to coal fly ash has attributed lots of attention to this supplementary cementitious material in recent years, especially with respect to applications in infrastructure. Therefore, further research on long term performance of slag containing binders in chloride containing environments is promoted. In this article chloride binding in a high slag containing composite binder (70% substitution) with respect to the changes in structure of CSH gel prior and after exposure to chlorides and its effect on chemical and physical chloride binding is accounted for. The changes in the structure of CSH are accounted by NMR analysis and the effect of these changes on chloride binding is addressed through adsorption tests. The results are compared with a ternary binder of cement-silica fume-metakaolin, given the relatively similar chemical composition between these two composite binders, as well as a reference Portland cement binder. The results infer that the slag containing binder exhibits higher chloride binding capacity compared to the metakaolin-silica fume containing. Moreover, a higher share of chemically bound chloride (meaning a lower physical binding) in SCM containing binders is foreseen compared to pure Portland cement system, due to the increased C(-A)-S-H chain length and Al/Si molar ratio in these binders. Furthermore, it is shown that exposure to NaCl causes a higher share of chemically bound chlorides compared to the CaCl2 exposure while the total bound chloride content increases upon exposure to CaCl2.

  • 20.
    Bask, Rasmus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Korslimmade träbjälklag i anslutning mot stålstomme: Inverkan av minskad egentyngd hos bjälklag samt utformning av förband för enklare montage2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This project investigates CLT against steel beams. The focus of the survey is on constructionability of cross laminated timber CLT in relation to prefabricated concrete floorings where joint details as well as the impact of reduced self-weight in the flooring are the main areas. CLT is a relatively new product and in line with stricter environmental requirements, an increasingly obvious choice for many customers. Much experience is unavailable to designers outside the major wood construction companies. The purpose of the survey is therefore to provide guidance on some of the problems involved in using CLT on steel beams.

    The installation of CLT to steel beams has been shown to be mainly via the lower edge of the floor, which at high ceilings becomes a problem in the sense of working environment. Joint solutions that facilitate assembly are therefore one of the components investigated in this project. The solutions have been applied to a concrete-floor reference project to get an idea that its design is sufficient for the loads when compensating for concrete floors. The result was three different designs where the assembly takes place from the top of the floor.

    When replacing concrete floors with CLT self-weight has a major impact, which is a motivation to use CLT as it may be crucial in poor soil conditions. Therefore, the impact of self-weight is also something that is being investigated in this project. The same reference project as above has been applied to design a CLT floor that meets the requirements of the concrete flooring in the reference project. As a result, the reduced self-weight of the floor coatings could have a significant impact as the reduction of the forces in the reference project could reach 42%. However, the design of the CLT meant an increased cross sectional height of 213 mm per floor. CLT can thus be a good replacement for concrete flooring if the cross-sectional height of the flooring is allowed to increase on each floor.

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    Korslimmade träbjälklag i anslutning mot stålstomme
  • 21.
    Bengtsson, Gustav
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Dimensionering av träförband: En jämförelse mellan olika typer av förbindare2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In timber construction, different metal dowel-type fasteners are used to attach members in timber frame construction. Therefore, in order to be able to choose a suitable fastener, you must know the differences between them and have knowledge of which rules to apply when calculating the load-carrying capacity.

    The purpose of this report is to show the differences in load-carrying capacity between different fasteners. This is done by comparing the load-carrying capacity of a connection with different fasteners. The focus has been on comparing the load-carrying capacity in ultimate limit state, but also other aspects such as mounting has been mentioned.

    The results show that if you want to maximize the load-carrying capacity of a connection, the best option is to use bolts in small dimensions. However, bolts with a diameter less than 10 mm are rarely used. In practical work, nails are often the best option if you want to maximize the load-carrying capacity. Screws have a lower load-carrying capacity than both nails and bolts for a connection with wood thickness up to 45 mm.

    In Eurocode 5, there are some sections that can be difficult to interpret and understand, for example the effective diameter and axial load-carrying capacity for screws. I have analyzed how the rules should be interpreted and my conclusion is that the interpretations differ also among professors and screw manufacturers. It can therefore be easier to use tabulated values for the load-carrying capacity from the manufacturer than to try to calculate it yourself.

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  • 22.
    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.           

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    Slutversion examensrapport
  • 23.
    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.

  • 24.
    Bergsten, Mathias
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Behovsstyrdventilation för en befintlig kontorsfastighet: )  En LCC-jämförelse mellan DCV och CAV2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Demand controlled ventilation has in this study been investigated in a life cycle cost (LCC) - perspective for an existing office property. The goal was to examine whether a complementary of the existing constant air volume (CAV)-system to a demand controlled ventilation (DCV) -system is profitable.

    This project has been executed on behalf of Fastpartner AB. The studied property is an office building of floor area 6000                          in Stockholm, Sweden.

    Two different types of DCV systems were analyzed: C controlled ventilation and C with temperature controlled ventilation. The software IDA ICE was used in order to examine the energy consumption for district heating, district cooling and electricity for the air handling unit.

    The building has been modelled as accuracy as possible in order to represent the real building. In order to see the effect of various loading rate, simulations with three different occupancy levels for CAV and the DCV-systems was made. The occupancy levels represented organizations with high, low and medium occupancy. In the end nine simulations was made.

    The net present value method was used for each system in the LCC analyses. Costs for installation, purchase and maintenance have been taken into account. The results from the study showed that both of the DCV-systems gives a lower LCC than the existing CAV- system. The most profitable DCV-system is C with temperature- controlled ventilation, that presents a theoretical cost saving up to 250 000 kr.

    The variation of occupancy levels didn’t affect the outcome of LCC for C and temperature controlled ventilation, however C controlled ventilation showed a significant difference depending on low versus high occupancy level. Low occupancy level results in a higher cost saving.

    The fans for the air handling unit had the largest energy saving based on energy sector. Where a reduction up to 75 % can be achieved for C controlled ventilation at low occupancy level.

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  • 25.
    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.

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    Delreparationer av våtrum ur ett hållbart perspektiv
  • 26.
    Bjurbo, Adina
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Flexibel byggnation: Förskola med potentiell verksamhetsförändring till ett gruppboende2023Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
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  • 27.
    Borgenstam, Sebastian
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Livscykelanalys och ekonomisk kalkyl av två KL-bjälklag2020Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    In building construction, there is a constant development in new materials and innovative technical solutions. The desire to reduce our carbon footprint is evident in the world and wood is a sustainable raw material. Forests is one of the big resources we have in Sweden. Cross-laminated timber (CLT) is a massive wood with high load-bearing capacity and stiffness has made it possible to build larger than ever before in wood. The question now is how to optimize the use of this environmentally friendly material. In this study, two different floor slabs with a supporting frame in cross-laminated timber were compared. To be able to compare CO2 consumption, Life Cycle Assessment was used and for the costs, economic calculations was built. The study covered part of the life cycle known as "cradle-to-gate".

    The thickness of the CLT slab was 230 mm. Apart from the slab, the beams differed both above and beneath the slab. One of the floor slabs was constructed with a subfloor system manufactured by Granab AB. The other floor slab was constructed with macadam and a thick layer of putty. That was the significant difference in the construction of the floor slab. There was also a differed connection between the walls and floor slabs. To achieve Boverket sound requirements, an elastic interlayer had to be placed along all the walls where it connects to the floor slab with subfloor system. For the joists with macadam, this was not necessary to achieve the sound requirements, which can easily be explained by the weight of macadam and putty.

    In the study, Östra Station Kvarter A in Umeå was used as a reference object. These buildings are to be built by Balticgruppen AB and during the study were still in the design stage.

    As a result of the comparison, the Macadam joists had a 22.9 percent lower economic cost than Granab, while the subfloor system-joists had a 9 percent lower environmental impact.

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  • 28.
    Boussaa, Youcef
    et al.
    Department of Built Environment and Energy Technology, Linnaeus University, Växjö, Sweden.
    Dodoo, Ambrose
    Department of Building Technology, Linnaeus University, Växjö, Sweden.
    Nguyen, Truong
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Rupar-Gadd, Katarina
    Department of Built Environment and Energy Technology, Linnaeus University, Växjö, Sweden.
    Comprehensive renovation of a multi-apartment building in Sweden: techno-economic analysis with respect to different economic scenarios2024In: Building Research & Information, ISSN 0961-3218, E-ISSN 1466-4321, Vol. 52, no 4, p. 463-478Article in journal (Refereed)
    Abstract [en]

    A wider deployment of nearly zero energy buildings (NZEBs) is expected to contribute to the transition to a decarbonized and energy-efficient building sector in Europe. This study proposed an integrated energy-economic analysis to exemplify the feasibility of NZEB renovation in temperate climate. A parametric analysis was performed to identify technical building system configurations that give minimum share of renewable energy systems contributing to NZEB level. Final energy savings, global costs and cost-effectiveness of renovating a building to NZEB level are analysed, considering active and passive energy efficiency measures (EEMs). The active EEMs included efficient water taps and heat recovery ventilation, and the passive EEMs encompassed insulations to roof, exterior walls and ground floor, and improvements of windows and doors. The building had initial final energy use of 133 kWh/m2 year for space heating, domestic hot water production (DHW) and facility electricity. The results show that NZEB level is achieved with active and passive EEMs, without renewable energy systems for scenarios with low discount rates and high future energy price escalations. The annual final energy use for space heating, DHW and facility electricity is reduced cost-effectively by 37-54%. Furthermore, increasing size of PV-system enhanced cost-effectiveness by lowering total global costs.

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  • 29.
    Boussaa, Youcef
    et al.
    Department of Built Environment and Energy Technology, Linnaeus University, Växjö, Sweden.
    Dodoo, Ambrose
    Department of Building Technology, Linnaeus University, Växjö, Sweden.
    Truong, Nguyen Le
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Rupar-Gadd, Katarina
    Department of Built Environment and Energy Technology, Linnaeus University, Växjö, Sweden.
    Integrating passive energy efficient measures to the building envelope of a multi-apartment building in Sweden: analysis of final energy savings and cost effectiveness2023In: Buildings, E-ISSN 2075-5309, Vol. 13, no 10, article id 2654Article in journal (Refereed)
    Abstract [en]

    A major challenge in building energy renovation is to cost effectively achieve notable energy savings. This paper investigates cost-effective passive energy-efficiency measures for thermal envelope retrofit of a typical Swedish multi-apartment building from the 1970s. Here, the use of different types of insulation materials for the retrofits of roof, exterior walls, and ground floor are analyzed along with changing windows and doors with varying thermal transmittance values. The cost-effectiveness analysis is based on the net present value of the investment costs of the energy-efficiently measures and the achieved energy cost saving. Different economic scenarios and renovation cases are considered in techno-economic analyses to determine the cost-effective energy-efficiency retrofit measures. The results indicate that improved windows reduce energy demand for space heating by up to 23% and yield the highest final energy savings. However, additional mineral wool roof insulation is the most cost-effective measure under all economic scenarios. This measure gave the lowest ratio of cost effectiveness of about 0.1, which was obtained under the stable scenario. The final energy savings that can be achieved in a cost-effective manner vary between 28% and 61%, depending on the economic scenario and renovation case. This analysis emphasizes the influence of different renovation cases and economic parameters on the cost effectiveness of passive energy-efficiency measures.

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  • 30.
    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.

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  • 31.
    Brembilla, Christian
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Efficiency factors for space heating system in buildings2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The thesis focuses on the efficiency of the space heating system. In particular, the efficiency factors measure the efficiency of thermal zone. The efficiency factors measures how the energy is used in a space heating. Efficiency factors relatively close to one mean that the energy is used "efficiently'', by contrast, efficiency factors close to the zero mean that the majority of the energy is lost to the outdoor environment. This method for the appraisal of space heating performance reads as if it is apparently simple and intuitive. In reality, the efficiency factor method has several pitfalls.

    The thesis provides tools, insights and remarks on how to apply the efficiency factor method to space heating systems equipped with hydronic panel radiator and floor heating respectively. Models of the latter heaters together with the multilayer wall were developed and validated to understand the reliability of their predictions. The hypothesis is that the heat stored in the building thermal mass and heaters plays a role in defining the building thermal performance and as a result in the appraisal of the efficiency factors. The validation is based on the sensitivity bands of the models' predictions. The heaters were tested in in a thermostatic booth simulator. Benefits and drawbacks of each model were highlighted to increase awareness of their use in the engineering fields. The results showed how the models accounting for the heat stored performed the charging phase. In addition, results of how the multilayer wall delayed and damped down the heat wave coming from the outdoor environment were presented with the appraisal of the decrement factor and time delay of the indoor temperature. The results of the efficiency factors analysis reveal how the weather affects the efficiency of each locality situated in cold climates. Lastly how different control strategies impact on the efficiency factors of space heating and its distribution system. To conclude, this study highlights the paradoxes around the efficiency factor method. The thesis proposes how such factors have to be interpreted by researchers and scientists tackling the lack of information around this topic.

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    spikblad
  • 32.
    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.

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  • 33.
    Brembilla, Christian
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Olofsson, Thomas
    One dimensional model of transient heat conduction through multilayer walls/slabs: The functionality of insulation and brick materials in terms of decrement factor and time lag2016Manuscript (preprint) (Other academic)
    Abstract [en]

    Multilayer wall is a common type of building envelope used in buildings located in cold climates. The building envelope is typically composed by internal and external masses made by bricks or concrete separated by a large thickness of insulation material. This paper investigates the thermal behavior of a multilayer wall subjected to temperature excitation on both wall sides. The analysis is conducted by discretizing the continuous space and time variables of the mathematical model identified in the heat equation. Euler backwards solves the numerical model of multilayer wall by providing an unconditionally stable solution. The step response test shows the correct working of the model which reaches the steady state solution. The results of this paper are expressed in terms of temperature of each wall layer against the time. In particular, (i) the large thickness of insulation material separates thermodynamically the outside external mass from the internal mass, (ii) 20 cm thickness of insulation material damps the heat wave with a decrement factor of 3.41 °ͦC and a time lag of 1 hour, (iii) the external brick layer damps the heat wave with a decrement factor of 1.97 °ͦC and a time lag of 5 hours.

  • 34.
    Brembilla, Christian
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Renman, Ronny
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Soleimani-Mohseni, Mohsen
    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.
    The impact of control strategies on space heating system efficiency in low-energy buildings2019In: Building Services Engineering Research & Technology, ISSN 0143-6244, E-ISSN 1477-0849, Vol. 40, no 6, p. 714-731Article in journal (Refereed)
    Abstract [en]

    In this study efficiency factors measures the thermal energy performance for space heating. This study deals with the influence of control strategies on the effriciency factors of space heating and its distribution system. An adaptive control is developed and applied to two types of heating curves (linear and non-linear) for a low-energy building equipped with renewable energy sources. The building is modelled with a hybrid approach (law driven + data driven model). The design of the floor heating is calibrated and validated by assessing the uncertainty bands for low temperatures and mass flow rate. advantages and disavantages of linear and non-linear heating curves are highlighted to illustrate their impact on space heating thermodynamic behaviour and on the efficiency factors of the space heating system.

    Practical application: The study reveals that applying commercial building energy simulation software  is worthwhile to determine reliable performance predictions. Oversimplified building models, in particular when considering building thermal mass, are not capable of simulating the thermodynamic response of a building subjected to different control strategies. The application of different heating cuirves (linear and non-linear) to massless building models leaves the amount of mass flow rate delivered to the space heating unchanged when the building is subjected to sharp variations of the outdoor temperature.

  • 35.
    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.

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  • 36.
    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.

  • 37.
    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.
    Soleimani-Mohseni, Mohsen
    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.
    Paradoxes in understanding the Efficiency Factors of Space Heating2019In: Energy Efficiency, ISSN 1570-646X, E-ISSN 1570-6478, Vol. 12, no 3, p. 777-786Article in journal (Refereed)
    Abstract [en]

    Efficiency factors are here defined as the thermal energy performance indicators of the space heating. Until recently, the efficiency factors were assumed as one value for space heating located in any climate. This study addresses the problem of how the outdoor climate affects the efficiency factors of a space heating equipped with 1D model of hydronic floor heating. The findings show how the efficiency factors, computed with two numerical methods, are correlated with the solar radiation. This study highlights the paradoxes in understanding the results of efficiency factors analysis. This work suggests how to interpret and use the efficiency factors as a benchmark performance indicator.

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  • 38.
    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
  • 39.
    Burwall, Anton
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Tvärkraft i betongbalkar med hänsyn till stora hål2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    It is often required to make holes in load-bearing structures for various reasons. Such reasons could be to make room for installations, entries or windows. Holes can lead to major changes in how forces act in the construction and involve substantial reductions in bearing capacity. This must be taken into account when dimensioning and there are methods for this.

    The purpose of this project was to present the required steps to perform the dimensioning of concrete beams affected by large holes. This was done by establishing a step by step instruction that describes the calculation process. To illustrate the dimensioning method and give a better understanding of the information that is presented in this report, the theory was applied in an example.

    The result of the project consists of a dimensioning instruction that was developed on the basis of existing data. The result also includes an example that was solved using the developed instruction. The dimensioning instruction describes an appropriate calculation procedure for dimensioning concrete beams with large holes. The example goes through the dimensioning of reinforcements to enable force transmission in a concrete beam with a door opening.

    After completed work, it is concluded that the developed dimensioning instruction and the example, fulfill the purpose of presenting and illustrating a dimensioning method for concrete beams affected by large holes. However, whether the dimensioning method that is presented is the most optimal is debatable.

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    Tvärkraft i betongbalkar med hänsyn till stora hål
  • 40. Chen, Yuqing
    et al.
    Kang, Yuqiong
    Zhao, Yun
    Wang, Li
    Liu, Jilei
    Li, Yanxi
    Liang, Zheng
    He, Xiangming
    Li, Xing
    Tavajohi Hassan Kiadeh, Naser
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Li, Baohua
    A review of lithium-ion battery safety concerns: the issues, strategies, and testing standards2021In: Journal of Energy Chemistry, ISSN 2095-4956, E-ISSN 2096-885X, Vol. 59, p. 83-99Article in journal (Refereed)
    Abstract [en]

    Efficient and reliable energy storage systems are crucial for our modern society. Lithium-ion batteries (LIBs) with excellent performance are widely used in portable electronics and electric vehicles (EVs), but frequent fires and explosions limit their further and more widespread applications. This review summarizes aspects of LIB safety and discusses the related issues, strategies, and testing standards. Specifically, it begins with a brief introduction to LIB working principles and cell structures, and then provides an overview of the notorious thermal runaway, with an emphasis on the effects of mechanical, electrical, and thermal abuse. The following sections examine strategies for improving cell safety, including approaches through cell chemistry, cooling, and balancing, afterwards describing current safety standards and corresponding tests. The review concludes with insights into potential future developments and the prospects for safer LIBs.

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  • 41.
    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.

  • 42. 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.

  • 43.
    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.

  • 44.
    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.

  • 45.
    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.

  • 46.
    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.

  • 47.
    Diarte Almada, Julio
    The Pennsylvania State University, USA.
    Tapping into urban recycling for low-cost building alternatives: Experimenting with waste cardboard reuse in architecture2021In: Divergence in Architectural Research: Proceeding Book of ConCave Ph.D. Symposium, Georgia Institute of Technology, Atlanta, Georgia, March 5-6, 2020 / [ed] Hayri Dortdivanlioglu; Marisabel Marratt, Atlanta: Georgia Institute of Technology , 2021, p. 125-135Conference paper (Refereed)
    Abstract [en]

    The work presented in this paper is part of a research that explores upcycling waste corrugated cardboard into building components. The research focuses on developing countries where there is a vast low- income population that needs housing but who find standard construction systems unaffordable. The research involves observational studies on the work of cardboard pickers in Paraguay seeking to understand the cycle of waste cardboard in the local context; development of digital tools to design building parts with waste cardboard and generate their fabrication instructions; hands-on work in an academic setting prototyping and testing building parts; and experimenting with the building system in the target context through workshops. This article summarizes several lessons learned during a workshop developed with a group of waste cardboard collectors and discusses the potential alternatives to the shortcomings.

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  • 48.
    Diarte Almada, Julio
    et al.
    The Pennsylvania State University, USA.
    Vazquez, Elena
    Universidad Nacional de Asunción, Paraguay.
    Exploring low-cost acoustic panels with origami patterns for classrooms2022In: ARCC-EAAE 2022 International conference: proceedings / [ed] Chris Jarret; Adil Sharag-Eldin, Architectural Research Centers Consortium , 2022, p. 423-430Conference paper (Refereed)
    Abstract [en]

    The goal of the work presented in this paper was to provide an alternative method to improve the acoustic conditions of classrooms in public schools in low-income contexts by designing, fabricating, and testing low-cost and modular acoustic panels. The panels used are shaped with Origami-patterns, and they were made of waste cardboard sheets collected from the urban waste stream. The exploratory work combined physical prototyping and simulation using Pachyderm, an acoustic simulation plugin for Rhinoceros-Grasshopper. While prototyping focused on assessing fabrication workflow, simulation focused on determining Reverberation time of three types of three-layered Origami-based panels. Fabrication results showed that all panels were easy to produce with simple tools. The simulation confirmed that panels with a denser pattern decreased Reverberation time between 27% to 48% for 125, 250, and 500 Hz frequencies. Further research will explore increasing panels layers and adding alternative and recycled materials to test sound absorption. The solution presents promising results for low-income contexts with a high need to improve the physical conditions of classrooms and other buildings.

  • 49.
    Diarte, Julio
    et al.
    Umeå University, Faculty of Science and Technology, Umeå School of Architecture. Penn State University, Pennsylvania, USA.
    Shaffer, Marcus
    Penn State University, Pennsylvania, USA.
    Cardboard architecture: eight decades of exploration in academic research and professional practice 1940-20192021In: Enquiry, E-ISSN 2329-9339, Vol. 18, no 1, p. 17-40Article in journal (Refereed)
    Abstract [en]

    Explorations in the use of cardboard products in architecture appear in the field’s research literature since the 1940s. However, it was not until the early 1990s, when Shigeru Ban's work emerged, did cardboard products became a potential material for architecture. Since then, cardboard use in architecture has been continuously growing world- wide, and Ban's cardboard buildings have now achieved important recognition. This article is a review of cardboard architecture in academic research and professional architectural practice in the last eight decades. The article sum- marizes the fundamentals of cardboard architectural design and illustrates diverse strategies proposed by different authors to decrease cardboard strength degradation due to the material's weaknesses

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  • 50. 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.

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