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  • 1.
    Abdul Hakim, Faisal
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Said, Shazad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    En studie av småhusentreprenader: Varför går det fel?2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study was to investigate the single-family home construction industry and what problems arise. Furthermore, it was intended that this study would give the public a better idea of why conflicts arise between customers and contractors and how home suppliers work to counteract these problems.

    To achieve the purpose and get answers to the research questions, we used a qualitative research method in the form of semi-structured interviews. The reason why this interview technique was applied was to give respondents the freedom to talk openly about their experiences and views. The respondents interviewed were four representatives of house suppliers, three clients, a building inspector and an inspection manager.

    The results of the interviews showed that there was a common opinion among clients and house suppliers on certain issues, but then there were also opinions that differed. The study showed that customers experience the construction of detached houses as a slow and energy-intensive process. The problems that are common in detached house contracts are that there is a difference in language and knowledge between the involved parties. This results in a lack of communication which in turn can lead to various conflicts.

    Home suppliers are aware of the problems that exist in the industry and work continuously to develop solutions. One such solution is to place great emphasis on documentation and contracts because they are the ones that are legally binding. The conclusion of this study was that good communication results in fewer misunderstandings and conflicts. Conflicts, on the other hand, cannot be completely avoided, but will always arise due to human factors. 

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  • 2.
    Abu Sulaiman, Iyad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Ibrahim, Miran
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Framställning av dränerande bärlager från bergtäkt2023Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Bearing layers are used in road and building constructions as underlying soil layers to provide stability and support to the top layer that takes up the load. A normal bearing layer contains different amounts of materials such as stone, gravel, and filler. That mixture of materials contains a large amount of filler to give the product tightness and stability. Draining bearing layers usually contain less filler than ordinary bearing layers, because their purpose is to improve the drainage properties and reduce the risk of damage due to water collection.This thesis work took place at NCC's quarries in Sälgsjö and Hammarby. At NCC's rock quarry, there already is a standard bearing layer with a grain size of 0/32 and a filler content of approximately 4–5%. In this degree project, a production process has been created to obtain a drain bearing layer where the filler content is reduced to approximately 2–3%. The requirement for a draining carrier layer is 2–3% filler content and this requirement has been followed in this production process. The draining bearing layer has been produced based on a standard product with the same grain size.There are practical limitations in how the operations work and what capabilities are required. Moisture in the material has also been a limitation. In this project, work is done with freshly crushed material, which has a relatively low moisture content (1–2%). A vibration-free screen like the function of the harp has been designed and built. Then the standard product was run through the harp at different gradients and the new product was analyzed in the lab to see what filler content was achieved. A simulation test was performed using a FEM design program called Digiroad at Chalmers University of Technology in Gothenburg.The results demonstrate that the utilization of the developed models of harp screens reduces the proportion of filler in the material. Additionally, the conducted harp screen analyses confirm that the designed harp screens are effective in transforming a standard bearing layer into a draining bearing layer, which helps to prevent water accumulation under roads or buildings and thus reduces the risk of damage and problems. The efficient production process for producing draining bearing layers can be of great importance to ensure a sustainable and safe infrastructure.

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  • 3.
    Abushaqfa, Omar
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Bakero, Daniel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Materials brandförmåga för mellanväggar2023Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Nowadays, architects, designers and engineers pay a lot of attention to fire safety in buildings.Due to the high number of accidents, fire safety in construction is becoming increasinglyimportant.In order to use more fire-resistant material in the structure, attention was paid to the propertiesof the materials used. The material has begun to be evaluated for standard resistance and somestandard tests have been developed. Based on how long the material did not show anysignificant damage, these materials were evaluated and graded. This classification can beaccessed from Eurocodes (Svensk trä,2022).Timber was used in construction even before history was written. Since the ancient civilization,wood has been an important building material.Wood exhibits great resistance to fire due to its self-insulating property.When wood burns, it first chars to a certain depth. Then the outer charred layer acts as a barrierand suppresses the fire. This fire-extinguishing property in itself is the wood's self-insulatingproperty. (Swedish wood, 2021).Fire exposure usually occurs according to the standard fire curve that describes a fullydeveloped fire as defined in EN 1363-1. Building parts must withstand fire for a certain time,for example 60 minutes. With wooden constructions, it is possible to achieve high fire resistancewith the help of insulating material (EI). (Swedish wood, 2021).In the first part of the thesis, the properties of wood as a building material are discussed. INthe next part discusses the fire classes Br0, Br1, Br2 and Br3 for buildings. After that, the readercan learn about how a building can be divided into sections depending on its fire rating. Amaterial investigation will be done to be able to see the fire properties of certain materials thatwe will add to or remove from the wall such as extra plasterboard or insulation material withoutchanging the thickness of the wall to make them more fireproof and to be able to last longerwithout the fire spreads to the other spaces with the help of better material ability. (Swedishwood, 2021).This work also presents the theory behind wall fire sectioning in terms of materials and thevarious fire engineering solutions with some examples of calculations relating to the fireresistance of the materials, with references to the instructions in SS-EN 1995-1-2:2004/AC:2010. Finally, the results are analyzed and compared with different materials. Usingthe results of reactions of different types of materials and insulation, the fire resistance ofwooden walls can be discussed in more detail.Results show that gypsum boards combined with stone wool is the best choice of material forcreating fireproof partition walls. The results of our calculations show that double gypsumboards on each side with a thickness of 15 mm combined with stone wool with a thickness of95 mm provides fire resistance up to 109 minutes. Compared to a partition wall with a gypsumboard on each side without insulation, fire resistance is up to 48 minutes. This has beenemphasized with a study where the fire resistance has been investigated for walls, they havefound that double gypsum board combined with stone wool with the right conditions providesfire resistance up to 142 minutes. However, it is crucial for fire resistance to work that theinstallation is carried out correctly. All resulting screws must be placed correctly, there must beno holes on the gypsum boards and the number of gypsum boards and insulation thicknesstogether with the correct assembly provides better fire protection. This is based on the resultsthat have been obtained from articles, calculation during this work and from interviews withthe companies that work with requirements, manufacture and installation of fireproof partitionwalls. 

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  • 4.
    Agebro, Andreas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Datormodellering av en värmelagrande betongväggs inverkan på det termiska klimatet i ett växthus2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report describes the building of a computer model that makes it possible to simulate the thermal climate in a greenhouse. The computer model is built on the physical theory of heat exchange that occur in a greenhouse, such as radiation and convective heat exchange. The model also includes the heat storage that is active in a greenhouse.

    The computer model is used to simulate the thermal climate in a greenhouse under three periods, winter, spring and summer. It also investigates which effect a concrete wall has on the thermal climate in a greenhouse. The purpose of putting a concrete wall in the greenhouse model is to investigate the possibility to store heat during the day and then use this heat when the temperature drops during the night.

    The result from the simulations shows that a concrete wall levels the big difference in temperature that normally occurs under a day in a greenhouse. It also shows that heat is stored in the concrete wall and during the night the wall temperature is higher than both the outdoor temperature and the greenhouse temperature. This makes the wall a source of heat during this time.

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  • 5.
    Ahmed, Ali Mohamed
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Rashid, Obaidullah
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Optimering av flervåningsbyggnadsstruktur genom att ersätta bärande väggar med pelare och balkar2023Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I takt med att den globala befolkningen fortsätter att växa, ökar efterfrågan på nya bostadsbyggnader avsevärt. Samtidigt har behovet av bostäder och byggande vuxit över hela världenunder de senaste decennierna, vilket har lett till en ökad efterfrågan på byggmaterial. Betong ärdet viktigaste byggmaterialet för flervåningsbyggnader pga. sin hållfasthet, men det bidrarbetydligt till utsläppen av växthusgaser. För att minska koldioxidavtrycket och främja hållbarhet är det avgörande att minimera materialanvändning med moderna byggmetoder.Syftet med denna studie är att optimera flervåningsbyggnadsstrukturer genom att ersättabärande väggar med pelare och balkar. Studien använder en referensbyggnad belägen iSandvikens kommun och verktyget StruSoft FEM-Design. Studien genomförs i två steg.I steg 1 utförs modellering, design och analys av referensbyggnaden med bärande väggar(byggnad 1). I steg 2 genomförs en förändring av byggnadsstrukturen genom att ersätta debärande väggarna med pelare och balkar av armerad betong (byggnad 2). Samma procedurersom i steg 1 upprepas för den omkonstruerade strukturen. Resultaten jämförs medreferensbyggnaden med hänsyn till utnyttjandegrad, deformation, spänningar, reaktioner, viktoch stabilitet.Ersättningen av bärande väggar med bärande pelare och balkar av armerad betong har variteffektiv. Båda strukturerna uppfyller de nödvändiga kraven. Baserat på resultaten ärdeformationen 9 mm för byggnad 1 och 7 mm för byggnad 2, vilket indikerar att skillnaden ideformation mellan de två strukturerna inte är signifikant.Byggnad 1 har en maximal utnyttjandegrad på 87%, medan byggnad 2 har en högre maximalutnyttjandegrad på 99%. Detta innebär att byggnad 2 kan utnyttjas i större utsträckning änbyggnad 1. Reaktionskrafterna är 563,6 respektive 476,4 kN i båda byggnaderna, vilketindikerar att reaktionskrafterna i byggnad 2 är 15% lägre än i byggnad 1. Båda strukturerna ärstabila, men det finns en skillnad i byggnadernas totala vikt. Vikterna på byggnaderna är 4169respektive 3 143 ton. Resultatet indikerar att byggnadens totala vikt minskar med ca 25% vidanvändning av betongpelare och betongbalkar.

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  • 6.
    Albeman, William
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Lif, Emma
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Hur kan en gammal industribyggnad med kulturhistoriskt värde göras om till bostäder?: En fallstudie av lokstallarna i Bollnäs2022Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In Sweden there is a shortage of housing whilst old, abandoned industrial buildingstake up space on desirable land. These buildings generally do not live up to today’s standards regarding comfort and energy efficiency and are therefore not used today. If these buildings were to be renovated into housing, they could help remedy the housing shortage. However, many of these buildings are protected from distortion by law which makes renovation and remodeling difficult. The purpose of this work has been to provide solutions for how an old industrialbuilding with cultural-historical values can be remodeled into housing. The solutions consist of floor plans and drawings modeled in Autodesk Revit. The possibilities and difficulties with this kind of project as well as solutions to expected problems are also presented in the report. This work was executed as a case study on one of the old locomotive depots in Bollnäs. Since the building for this project is an old locomotive depot, it is positioned close to the railroad. Noise and ground pollution are therefore important to consider and demand certain measures, for example retaining walls, noise barriers and excavation of polluted soil. An energy simulation of the building was made using BV2 to determine the energy usage of the building. The walls, roof and slab were additionally insulated for the purpose of meeting the demands of energy efficiency and comfort defined by BBR 29. The insulation had to be internally constructed in order to avoid distortion of the facade. Additionally, all windows and doors had to be made energy efficient while remaining aesthetically preserved. Internal insulation is generally problematic due to problems with moisture. The solution to this problem was to insulate the walls with polyurethane foam and the slab with cellular plastic. In order to make the building energy efficient, the building should be heated using district heating in combination with photovoltaic panels. This building is well suited for solar panels due to the large, black metal sheet roof and shadow free placement. The study shows the complexity of refurbishing this type of building. The renovation is extensive, and the floor plans are characterized by compromises. It is possible to renovate the building without distorting it. A better alternative would be to use the building for other functions such as a store, restaurant or bar. 

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  • 7.
    Aljaberi, Saif
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Majeed, Aram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Energisimulering i modulhus: Fallstudie för uppskattning av energiprestanda och därefter energieffektivisera enligt passivhusstandaren2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    The Building sector is today an important sector in our society, which means that more people move from the urban area to the big cities, which in turn increases building production. The building and service sector is the largest energy waste in Sweden and internationally, which is about 40% of Sweden's total energy use and 60% of that energy goes to heating. The EU Directive Energy Performance of Buildings Directive (EPBD), implemented the concept of near zero-energy houses, which comes into full force in 2020, which means that all newly-built buildings must be energy-efficient with better energy performance than todays buildings. This is in connection with the need of houses/buildings and rental costs continuing to increase. For this reason, Ljusbo Hyreshus AB has invented a solution that includes both climatesmart rental apartments and cheap rental costs, which has attracted more than 20 communes (kommuner in Sweden) to offer land for these apartments. The purpose of this thesis is to find out the energy performance of one of Ljusbo Hyreshus AB's prototype module houses. Furthermore, improvement proposals would be developed to make the module house more energy efficient. The prototype house consisted of a single-storey modularhouse that stay in Söderhamn, which has been chosen in this thesis for further investigations. The house had a total area of 45 m2 and consisted of 3 rooms and kitchen. In this case study, the energy performance has been developed using analysis methods in the form of hand calculations and the energy signature method. Subsequently, the result of the analysis would be validated and would form the basis for later identification of various energy efficiency measures that contributed to the reduction of energy performance in the house and thereby achieved the passive house standard. The result shows that the modularhouse does not fullfil BBR's requirements at present, because the house misses important components which is important for energy performance. For this reason, improvement proposals, specifically regarding the climate shell, on energy efficiency measures have been developed in this report. With the help of these energy efficiency measures, which mainly consist of additional insulation and energy-efficient windows and with an energy-efficient ventilation system with heat recovery (FTX) and an installed air-water heat pump, the passive house standard has been possible to achieve. Future measures, such as the installation of solar cells, have also been examined in the report. This is due to converting the building from a passive house to a plus energy house.

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    Energisimulering i modulhus
  • 8.
    Almberg, Stina
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Michel, Gabriella
    University of Gävle, Faculty of Engineering and Sustainable Development.
    Analys av energianvändningen i kvarteren Carolina och Jenny: en fallstudie2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    An energy study has been performed on two blocks in an area called Gävle Strand. The buildings are owned by a tenant-owner’s association called brf Carolina and were built by the company Skanska 2008. The builder as well as brf Carolina are pussled by the fact that electricity use is higher than expected while heating is less. Skanska is also very interested in finding out how much heat recovery from stale exhaust air through a geo-thermal heat pump is contributing to the general heating requirement and energy balance in four out of the ten buildings located on the properties.

    To find possible answers to the higher electricity use a literature survey on user behaviour was conducted. Simulations were executed in the energy simulation program BV2 testing the efficiency of a mechanical ventilation system with fans dispatching the used stale air with heat recovery through the geo-thermal heat pump in comparison to a HRV-system. As BV2 can’t simulate heat pumps its impact was instead calculated manually and added to the result from BV2.

    The result show that there are significant differences in both water and electricity use between households. The mean value in brf Carolina is also higher for both water and electricity use than the typical pattern value most commonly used in energy simulations for new buildings. The simulations and calculations show that a HRV-system is practically equal to the system chosen for these buildings. The geo-thermal heat pump make a substantial contribution to the heating requirements but also increases the electricity use in comparison to the HRV-system.

    The buildings over all have a good energy performance. The chosen heat recovery system is working well. If the source for energy is also valued a HRV-system is still preferable since it requires less electricity.In regards to user behaviour the under floor heating installed in the bathrooms and operated by the occupants is very likely to have a substantial impact on the higher than average electricity use. There are however many other factors that could have an impact on energy use due to behaviour factors. This is also a factor when varations between households are viewed.

    Key words; energy, energy simulation, user behaviour

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  • 9.
    Al-Mulla, Tiba
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Jämförelsestudier mellan olika typer av korslimmat träbjälklag:: Undersökning av konsekvenser vid ändring från betong- till korslimmat trä- bjälklag i ett flervåningshus2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Timber is one of the most common materials that had been use for a long time. The need for new buildings will affect the climate negatively, that is why it’s necessarily to find new ways to build quickly and sustainably. Cross-laminated timber (CLT) product came in the 1990- century. The material was developed to be used in high residential wood constructions buildings.

    The material considered to have good properties compared with other types of wood material, some of the studies showed the possibilities of building high residential with the CLT material. Such high rises buildings work best when CLT wood constructions combined with other materials, which called, Composite constructions.

    Case study preformed theoretically in Fullriggaren building in Alderholmen in Gävle city, the building have 14 floors and about 40 m high. With the purpose of trying to investigate the consequences that occur when the concrete floor slabs were replaces  with CLT wood floor slabs, taking into account the rules and standards for fire safety, acoustics, oscillations and vibrations. In order to achieve this and to determine the most suitable alternatives, the different types of CLT-wood floor slabs was compared.

    The building studied in its design and execution, and a simpler model created in Revit 2018. The challenge was that the building has a long span of maximum 10 m. The different types of CLT floor slabs which compared in the study was, CLT timber joist slaps, flat floor slab and CLT wood floor slabs in combination with steel hat beams and other beam steel types. Each type of floor slabs had its advantages and disadvantages, but the results and studies showed that timber and concrete composite floor slab combined with steel hat beams are the best possible options for the construction in Fullriggaren building, where the floor slab height is the shortest compared to other CLT wood floor types. With the chosen floor slab, the problem of vibration and oscillations will minimize. When using such a floor slab, the building height will increase, which means in this case, removing an entire floor from the building.

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  • 10.
    Amiot, Victor
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Torung, Rikard
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Oliksidig krympning i betong2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Concrete is one of the most commonly used building materials in foundation construction. Concrete is highly resistant to external stresses and hence makes it a very useful material in many different situations. However, there are problems that can arise with the use of concrete. One of the more common is cracking. There are several reasons why this might occur, for example, external impact, creep and moist-related movements. The concrete slab is one of the elements that often encounter this problem. Since concrete slabs are frequently used as foundation, it is of great interest to find solutions for this matter. In order to do that, the causes are needed to be specified more clearly. This study investigated experimentally how a concrete slab reacts when differences in humidity exposing the top and bottom after curing period, and if this may contribute to sufficient deformation to cause cracking. Six specimens were made and observed where three where exposed to a moisture content of 100% on the bottom. The remaining three samples have been placed in dry conditions in order to make a comparison possible. A relative humidity of 25% was measured in the surrounding air. The experiment showed clear differences in deformation between the two situations. The samples exposed to differential humidity exhibited sufficient stresses to cause cracking seen from the moment that occurred in the concrete. This shows that different prevailing humidity on the top and bottom of a slab can create sufficient stress to cause cracking.

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    Oliksidig krympning i betong
  • 11.
    Andersson, Christine
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Linderdahl, Sofia
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Ett förslag till arbetsmiljöplan för underhållsarbete inom bygg: en förenkling av rutiner för arbetsmiljöarbetet2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    According to the Swedish Work Environment Authority (Arbetsmiljöverket), accidents among construction workers occur twice as often as other workers. In 2015 the construction industry had over three thousand work accidents resulting in sick leave, which corresponded to eleven percent of Swedens total reported work accidents with sick leave. Considering what a worker in the building and construction industry expose themselves to in their daily work, it is obvious that focus must be towards safety.

    This study has been carried out on the building department for maintenance work at BillerudKorsnäs Gävle Bruk. At the company, there is a need for improving the establishment of safety and health plans within the existing working environment work. The aim and objective of the study is to create a draft template for the safety and health plan that is user friendly and includes the 13 works with special risks according to AFS 1999:3. Hopefully the template will contribute to a simplification of existing procedures in the construction working environment planning, lead to increased safety on site and fewer work accidents.

    To receive a better understanding of the viewpoint of BillerudKorsnäs Gävle Bruks construction workers regarding working environment and risks on site, semi-structured interviews were conducted and together with statistics on accidents and incidents, served as the studies results. In addition, a literature review has been conducted to provide an overview of previous studies in the field.

    The importance in carrying out risk assessments has been confirmed through interviews and becomes more evident as the conditions in the daily construction work varies in large proportion. Every work situation and risk is unique, therefore a risk assessment can not only consist of the 13 works with special risks. The interviews have confirmed the need for a simplification and improvement in the process of establishing a safety and health plan. A template for the safety and health plan should include how the work environment shall be conducted such as general information about the work and a risk assessment.

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    Examensarbete 2016 Sofia och Christine
  • 12.
    Andersson, Martin
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Jonsson, Andreas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Nyström, Niklas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Insvällning av olimmade och limmade trädymlingar2019Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    Wood is a renewable material, unlike many other building materials. The amount of wood used in the construction industry can be increased by using wooden dowels as a substitute for screws and nails. Screws and nails are made of metals, which are non-renewable materials. The manufacturing process of metal-based materials is more energy consuming than it is for wooden materials and therefore it has a greater impact on our global environment.The purpose of this study was to investigate the adhesion capacity of wooden dowel-joints, non-glued and glued made out of beech and pine. The attachment of the non-glued wooden dowels was achieved by swelling of the wood. Swelling was achieved by first drying the wooden dowels in an oven and then letting them acclimatize with the surrounding materials and the relative air humidity. The adhesion capacity of the wooden dowels should be able to compete with the withdrawal strength of nails to be practically useful.Tensile strength tests have been carried out in the laboratory in house 45 at the University of Gavle to determine the adhesion capacity of wooden dowel-joints. The tensile strength tests were performed with a Shimadzu AG-X machine. The results of the tests have been compared with the theoretical withdrawal strength for nails. Characteristic strength values have also been calculated from the tensile strength test results for the wooden dowels.The results of the study shows that only the glued wooden dowels can compete with the withdrawal strength of nails. Glued wooden dowels can therefore be a substitute for screws and nails. The calculated characteristic values for glued beech-dowels and glued pine-dowels are 5,2 kN respectively 4,3 kN.

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    Insvällning av olimmade och limmade trädymlinga r
  • 13.
    Andersson, Michael
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Jonsson, Axel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Strorheter vid bedömning av energieffektivitet för byggnader: En fallstudie för indikator 1 och 3, Miljöbyggnad 3.12021Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    Sweden uses a large amount of energy within the housing and services sector and there is a greatneed to reduce the energy usage & heat demand of buildings. Using environmental certifications it ispossible to reward buildings that are dimensioned for lower energy usage and low heat demand fromrequirements demanded by the Swedish National Board of Housing, Building and Planning(Boverket). Miljöbyggnad 3.1 (Swedish Green Building Council) Indicator 1 Heat demand is todayassessed in relation to the inside enclosing area of the building, W/m2,Aoms, while Indicator 3 Energyusage is assessed in relation to heated floor area, kWh/m2,Atemp. Previous research indicates that thesequantities do not take into account how well the building is used but only how well it is dimensionedin terms of construction technology. Therefore it might be appropriate to introduce a quantity thattakes into account how well the building is used.

    The purpose of this case study is to raise a discussion if Boverket and Miljöbyggnad 3.1 today usessuitable quantities when it comes to grade energy efficient building and how different quantities cancome and affect a grading.

    This research presents a case study where an elementary- and a preschool using IDA ICE-modelsevaluates based on simulations for energy usage and heat demand. The results from the simulationsare compiled in diagrams to be able to see how different cases affect the grading based on whichquantities are being used. The quantities that are being used in this study is based on previousresearch and the different cases have been made to see which parameters affect the quantities.

    The study shows that depending on what is considered to be an energy efficient building, differentquantities may be applied for the assessment. The quantities used today in Miljöbyggnad 3.1 forIndicator 1 Heat demand and Indicator 3 Energy usage favors different types of buildings.kWh/m2,Aoms favors buildings with higher floor heights while kWh/m2,Atemp favors buildings withlower floor heights.

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  • 14.
    Andersson, Niklas
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Energieffektivisering av byggnad med enkla medel: en fallstudie på Hofors mödravårdscentral2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the central parts of Hofors a healthcenter is located which is included in Hoforshus AB's building stock, the building itself is divided into a main building and a smaller one in which the child health center and maternity care is located. The buildings are connected by a corridor substantially glazed. Now they are interested in maping the building's energyusage as this is relatively high, in addition, the users of the building had been dissatisfied with the indoor climate in both summer and winter. Because of the healtcare activities the owners were most interested in finding solutions that would not interfere with it.

    The study conducted has had a primary focus on the building envelope and above all on the glazed corridor’s impact on the rest of the building. One can assume that the high proportion of glass in this part of the building affects the indoor climate negatively keeping in mind the low U-value of the glass and the solar heat load, this gives during the summer when heat gain is not desired. A literature study to investigate how people perceive the climate as well as how to make a reliable simulation model of a building has been completed. The study resulted in an understanding of how the indoor climate is perceived and quantified, and also in an understanding of what is important in the collection of data for the simulation model.

    Keeping in mind how data should be collected according to the literature reviwe- have as much data as possible measured through surveys and own observations, blueprints have been studied and their validity has been investigated by measuring the building, blower door has been performed and temperature- and relative humidityloggning. Instantaneous values of the FTX system was made to calculate its efficiency. Linear thermal bridges have been investigated by finite element method in the program COMSOL Multiphysics 3.5. For validation of the simulated model the results of it were compared with the acutal measured energyconsumption of the building. The simulations were performed in BV2.

    The results of the study show, as expected, the glazed corridor’s negative impact on the building's indoor climate. Temperature was logged between 160412-160509 highest temperature was 30 ° C and minimum 15 ° C, which is more widespread than in other areas where the temperature was logged. The simulations that were performed on the glazed corridor shows that it consumes between 5000-5500 kWh on the area of 13.5 m2. Finally the study resulted in recommendations for the building that includes additional insulation of the attic, replacement of a smaller wall section, lowering the temperature by 1 ° C, as well as some maintenance measures to improve the indoor climate. The measures are believed to be possible to implement without significant interference with the health care acitivities. In addition the proposed measures seem profitable according to the pay of method.

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  • 15.
    Andersson, Nils
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Lindberg, Samuel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Dynamisk energieffektivisering med hjälp av elektrokroma fönster i ett svenskt klimat: En fallstudie av en simulerad kontorslokal med geografisk variabilitet.2022Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Det används stora mängder energi inom kontorslandskap för att reglera inomhusklimatet. Intresset har ökat för energisparande åtgärder både politiskt och privat. För kontorsbyggnader är fönster en stor andel av klimatskärmen vilket har en stor påverkan på värme- och kylvärmeenergin som tillförs in i kontorsbyggnaden.

    Elektrokroma fönster kan, genom att skicka en spänning till ett av fönstrets skikt, aktivt förändra sina egenskaper för att steglöst begränsa solinstrålning i en byggnad.   

    Denna fallstudie är framtagen för att undersöka var och hur elektrokroma fönster kan användas för att effektivisera inomhusklimatet, med betoning på kylbehov, i Sverige.

    Undersökningen gjordes genom att göra flertal simuleringar på en kontorslokal i IDA ICE där lokalen simuleras på olika orter. Orter varieras från norr till söder och från kust till inland. Fönsterfasaden simulerades även i olika väderstreck.

    Resultaten visar att användning av tekniken sänker inkommande värmeenergi genom fönster med runt 60 procent oavsett på omgivande medeltemperatur. Därför motiveras användandet bäst på sydliga fasader och vid orter nära kust eller stora vatten där solvärmelasten är som störst.

     

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  • 16.
    Andersson, Robin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Energibalansberäkning för flerbostadshus: projekterad energianvändning jämfört med beräknad energianvändning med uppmätta värden för Gävle Strand Etapp 12011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The estimated amount of energy that a building consumes during one year indicates whether it contributes to a sustainable society or not. The communal company, AB Gavlegårdarna , that rents out apartments, works not only with designing proposals for solutions for the future housing , they also work with improving their stock when it comes to energy consumption. The multi-family buildings of Gävle Strand Phase 1 were completed in 2008 with a population of twelve buildings that are shaped in four ways.

     

    During the planning phase a consultant was hired to calculate the how much energy these buildings would have to purchase and came up with an energy use of 92 kWh/m2,year. Gavlegårdarna’s own calculations are based on the actual values obtained for each apartment and in September 2009 and they showed a mean value for the whole stock, which was 114 kWh/m2,year.

     

    AB Gavlegårdarna want to find a solution to the problem and reduce the extra cost that Gävle Strand Phase 1 has given rise through increased use of energy. They want to perform precise calculations on each building's energy use. The problem can be formulated as follows:

    How much influence does the malfunction of a heat exchanger in a balanced ventilation system have on the total energy consumption in apartment buildings? Can a house among the various geometrically designed houses of a stock be considered to be representative when calculating the energy use of the stock as a whole?

    The report deals with a number of U-value and area calculations, ventilation and air leakage assessments, domestic hot water use and energy user behavior of the residents, to work out how much a simulated building uses in terms of specific energy, with unit kWh/m2,year. An building simulation program called BV2 2010was utilized.

    The results show that the majority of the buildings located in Gävle Strand Phase 1 have higher energy consumption than the consultant's basic case. This is due to several factors but the main causes of the high residential energy use is the low temperature efficiency in the FTX-system heat exchanger, the residents’ behavior and in some cases relatively high usage of hot water.

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  • 17.
    Arghand, Taha
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Human subjective response to combined radiant and convective cooling by chilled ceiling combined with localized chilled beam2015Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    The aim of the present research is to identify human subjective response (health and comfort) to the micro-thermal environment established by integration of individually controlled localized chilled beam and chilled ceiling (LCBCC) system and to compare its performance with the performance of mixing ventilation combined with chilled ceiling (CCMV).Experiments were carried out in mock-up of an office (4.1 m × 4.0 m × 3.1 m, L× W× H) with one person under two summer temperature conditions (26 °C and 28 °C). To mimic direct solar radiation in the room, five radiative panels on the wall together with electrical sheets on the half of the floor were used. The test room was set-up with two desks, as two workstations, and one laptop on each table. The main workstation (WS1) was located close to the simulated window. The second work station (WS2) was placed in the opposite side of the room. The room was equipped with two types of ventilating and cooling systems.  The first system consisted of a localized active chilled beam (LCB) unit together with chilled ceiling (CC) panels. The LCB was installed above the WS1 to create micro-environment around the occupant sitting at the desk. The supply flow rate from the LCB could be adjusted by the occupant within the range of 10 L/s to 13 L/s by means of a desk-mounted knob. The integration of mixing ventilation (MV) system and chilled ceiling panels was the second ventilating and cooling strategy. Twenty- four subjects (12 female and 12 male) were exposed to different indoor environment established by two cooling systems. Each experiment session lasted 120 min and consisted of 30 min acclimatization period and 90 min exposure period. The performance of the systems was identified and compared by physical measurements of the generated environment and the response of the human subjects.

    The study showed that perceived air quality (PAQ), overall thermal sensation (OTS) acceptability and local thermal sensation (LTS) acceptability clearly improved inside the micro-environment by using LCBCC system. Moreover, at the main workstation, OTS and LTS votes were close to “neutral” thermal sensation (ASHRAE seven point scale) when LCBCC system was used. However, OTS and LTS votes increased to the “slightly warm” side of the scale by applying CCMV system which implied the better cooling performance of the LCBCC system. Acceptability of work environment apparently increased under the room condition generated by LCBCC system.

    In agreement with human subjective study, the results from physical measurements and thermal manikin study showed that uniform thermal condition was generated all over the room. Air and operative temperature distribution was almost uniform with no difference higher than 1 °C between the measured locations in the room. Thus, both LCBCC and CCMV systems performed equally well outside of the micro-environment region. The use of the chilled ceiling had impact on the airflow interaction in the room and changed the airflow pattern. It can be concluded that the combination of convective and radiative systems can be considered as an efficient strategy to generate acceptable thermal condition in rooms.

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  • 18.
    Arghand, Taha
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Karimipanah, Taghi
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Awbi, Hazim
    School of Construction Management and Engineering, University of Reading, United Kingdom.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Larsson, Ulf
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Linden, Elisabet
    University of Gävle, Faculty of Engineering and Sustainable Development, BMG laboratory.
    An experimental investigation of the flow and comfort parameters for under-floor, confluent jets and mixing ventilation systems in an open-plan office2015In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 92, p. 48-60Article in journal (Refereed)
    Abstract [en]

    There is a new trend to convert the workplaces from individual office rooms to open offices for motivating money saving and better communication. With such a shift the ability of existing ventilation systems in meeting the new requirements is a challenging question for researchers. The available options could have an impact on workers' health in terms of providing acceptable levels of thermalcomfort and indoor air quality. Thus, this experimental investigation focuses on the performances of three different air distribution systems in an open-plan office space. The investigated systems were: mixing ventilation with ceiling-mounted inlets, confluent jets ventilation and underfloor air distribution with straight and curved vanes. Although this represents a small part of our more extensiveexperimental investigation, the results show that all the purposed stratified ventilation systems (CJV and UFAD) were more or less behaving as mixing systems with some tendency for displacement effects. Nevertheless, it is known that the mixing systems have a stable flow pattern but has the disadvantage of mixing contaminated air with the fresh supplied air which may produce lower performance and in worst cases occupants' illness. For the open-plan office we studied here, it will be shown that the new systems are capable of performing better than the conventional mixing systems. As expected, the higher air exchange efficiency in combination with lower local mean age of air for corner-mounted CJV and floor-mounted UFAD grills systems indicates that these systems are suitable for open-plan offices and are to be favored over conventional mixing systems.

  • 19.
    Aurusell, Louise
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Ytbehandling baserad på hampolja2008Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The varieties of paint are today very big, but many of the more popular paints are less than environmental friendly. The uses of fossilized fuel in paints are common because these paints dry fast and are color true. It would be beneficial for the environment if more renewable source were used to produce paint. Linseed oil is an old base for oil paints. It is renewable and easily procured. But linseed oils have some aspects that give it a bad reputation. There are problems with the slow drying and the color turning yellow when exposed to darkness for long periods of time. Researchers at KTH have connected the yellowing to linolenic acid, one of the common fatty acids in linseed oil (Svensson, M. Johansson, M, Stenberg, C. Samuelsson, J. 2003). Hempseed oil is also a drying oil like linseed, but hempseed oil contains a larger amount of the fatty acid linoleic acid and a smaller amount of linolenic acid (http://en.wikipedia.org/wiki/Hempseed_oil). This might mean that oil paint based on hempseed-oil instead of linseed-oil might have fewer problems with yellowing.Experiments with the two oils have been executed side by side in order to compare results. Two oil paints have also been produced and tested. Test pieces painted with the two different oil paints were exposed to moisture, daylight and complete darkness and then compared.

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  • 20.
    Axelsson, Amelia
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Permarv, Lylan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Varför når de flesta byggnader som certifierats med Miljöbyggnad Silver och inte Guld?2020Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The environmental impact from the construction sector in Sweden is increasing and to meet the environmental challenges, environmental assessment tools is a way to be more aware of the choices you make during the construction and designing stage.

    There are severeal environmental assessment tools in Sweden, one of them is Miljöbyggnad. Miljöbyggnad is designed for the swedish climate, building regulations and rules. Miljöbyggnad contains several manuals, one of them is Miljöbyggnad 3.0 for new constructions. The assessment tool is based on 15 different indicators in areas energy, indoorclimate and material.

    Statistics from year 2020 shows that 1570 buildings have been certified with Miljöbyggnad. 1148 buildings has reached the building grade Silver while 177 have reached Gold. We are trying to find out why significatly more buildings certified with Miljöbyggnad achieved Silver and not Gold.

    Answering the question was done through a case study, interviews and litteraturestudy. In the case study two buildings are studied and compared with the manual Miljöbyggnad 3.0 for new construction. In order to gain more knowledge when literature is scarce in the area, interviews were assessed to add more knowledge to the issue. All of the respondents from the interviews felt that the solar thermal load and daylight indicators are contraindications. In order to secure good daylight in the building daylight simulations should be done in a early stage. The case study for Building 1 clearly showed that solar thermal load and daylight work against each other. The solar thermal load for that building met the requirements for Gold whilst daylight met the requirements for Bronze.

    The reasons we conclude why clients chose to invest in Silver instead of Gold are many. One reason can be that Silver is a good grade that requires more time and effort throughout the entire process.  Bronze is the current legal requirement and Gold means that the buildings have a well-stated environmental profile. Therefor it is clear that the cost to design, certify and verify against Miljöbyggnad is one of the main reasons why Gold is seldom achieved. It would be too expensive and costly, which leads to higher rents. Certain pieces such as indicator 15, frame and the foundation's climate impact seemed to be more difficult to achieve high grade according to the interviews and the case study.

    The gradingsystem in Miljöbyggnad is strict, this means that no indicator can have the grade Bronze when you want to achieve Gold for the building. All aspects that Miljöbyggnad assesses must be well thought out and elaborated if the grade Gold is to be achieved. Silvergrade is more forgiving because it allows a certain number of indicators with the grade Bronze.

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  • 21.
    Axner, Emil
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Att utvändigt värmeisolera köldbryggor i utkragade balkonggolv: En fallstudie om energianvändning, kostnader och påverkan av byggnadens yttre gestaltning2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In order for Sweden to reach its goals for a sustainable future, the government continues to increase demands on improving energy efficiency of buildings. A first step should be to improve the buildings ability to keep its heat. This means that the thermal insulation of the envelope should be improved and effect of thermal bridges in various constructions be minimized. A recurrent problem when renovating already existing buildings is the requirement of preservation and how that affects the possibilities on how to renovate. All buildings constitute a storytelling that illustrates how society has developed over time. Building characteristics and expressions must be preserved even if it leads to higher renovation costs. This thesis aims to study the energy use caused by thermal bridges in balcony slabs and how the energy use is affected by insulating the balcony slabs. It also investigates how the overall building appearance is affect by this figuration. And last, the study aims to explore however the investment in material is defensible when comparing it with the cost for energy in a life cycle perspective. The result shows that the thermal bridges caused by the balcony slabs increase the energy use by almost 4000 kWh per year and building and by adding insulation to the slabs, the energy usage decline by almost 75 %. In view of the buildings appearance, the additional insulation has a minimal affect. When comparing the investment cost in a life cycle perspective with the saving of energy, results shows that the costs in material is too high and at the same time the price for energy is too low for obtaining any profit for the given time period.

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  • 22.
    Azizian, Dawod
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Jämförelse av strukturella prestanda för limträbalkar och armerade betongbalkar i flervåningsbyggnad2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    With the prevailing population increase, the forecast of housing supply indicates that more housing needs to be built to meet the housing need. The construction industry today accounts for about 20% of the total carbon dioxide emissions in Sweden. For this reason, there is a need to develop more environmentally friendly and sustainable technologies to meet the set requirements regarding sustainable construction. Wood and constructed wood products are considered an environmentally friendly material and should be used as frame materials for buildings to a greater extent than is done today.

     

    This work includes comparing the structural performance of glulam beams and reinforced concrete beams in multi-story building. As a starting point, an existing building is modeled on the basis of the documents provided by drawings and other instructions for the intended reference building. The structural analysis was performed in FEM design for the purpose of checking the behavior of glulam beams in deflection, stress, cross-sectional dimensions and load-bearing capacity. The work was carried out in two stages, the reference building's reinforced concrete structure is carefully modeled in the first stage. In the second stage, reinforced concrete beams are replaced by glulam beams in order to compare their structural performance.

     

    The results show that the light weight of glulam leads to a reduction of about 24% in the total weight of the building. Rigidity properties are the biggest disadvantages of glulam beams compared to reinforced concrete beams, since a replacement of the beams with a similar dimension in 8 m span gave rise to about 65% increase in deformations. When using glulam beams, the span of 8 m must be halved, and larger glulam cross-sections and columns must be placed to meet the set requirements regarding serviceability and ultimate limit states.

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  • 23. Barthel, Stephan
    et al.
    Colding, Johan
    Erixon, Hanna
    Ernstson, Henrik
    KTH, Historiska studier av teknik, vetenskap och miljö.
    Grahn, Sara
    Kärsten, Carl
    Marcus, Lars
    Torsvall, Jonas
    Principles of Social Ecological Design: Case study Albano Campus, Stockholm2013Book (Other academic)
  • 24.
    Bengtsson Asplin, Björn
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Norén, Tommy
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Fasadpanelens fuktskydd: Har droppnäsan någon betydelse?2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The moisture content of wooden façades changes over time due to external factors, for example the frequency of driving rain. Wooden façades can take damage from penetrating moisture and therefore should be protected so they do not lose their primary function of stopping snow and rain from getting inside the climate shell of the building. Science studies have shown that a fundamental protection from moisture can be created through surface treatment of the façade and choosing the right type of wood. Another known moisture protecting advice within the field of construction is to mitre the corners on the lower part of the façades (also known as dripping channel) but no studies could be found that confirmed that it actually effect the moisture content of the material. To investigate this a little further an irrigation model was created which the purpose to find out the significance of the dripping channel for the moisture protection of the façades. Hypothesis 1 was that façades with dripping channels generally absorb less moisture then façades with an end grain without a mitred corner, regardless of treatment. This was based on the assumption that a more narrow angle on the end grain causes the water from the water film to drip of the façades instead of getting trapped on the surface, and be absorbed by capillary forces. Hypothesis 2 was that treated façades with dripping channels absorb less moisture then treated façades without dripping channels, based on the attempt to mimic the advice regarding mitre and surface treatment, where the surface treatment is used for the purpose of reducing capillary uptake.

    The experiment consisted of three testing riggs with vertical wooden façades which were sorted by the angle of the end grain and surface treatment. The results from the three testing riggs could then be compared to each other to evaluate the reliability of the study. To mimic the water film that can appear during driving rain, the façades were irrigated through a wooden gutter.

    The results showed that the moisture ratio for façades with dripping channels was fluctuating under and above the moisture ratio for façades where the corner of the end grain was not mitred, regardless of treatment. The same results could be seen even when the treatment was considered. Façades with mitred end grains could therefore not be seen as better then façades without mitred end grains, so none of the hypotheses could get any support. However, a slightly smaller moisture ratio could be observed on surface treated façades, regardless the angle of the end grain.

    The conclusion based on the used irrigation model was that the dripping channel is of no significance for the moisture protection of the wooden façades. Instead there were indications that it is the surface treatment which makes a difference on the moisture content, something that is supported by existing research.

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  • 25.
    Bennhult, Linnea
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Engren, Karolina
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Bedömning av området energi: En jämförelse mellan Miljöbyggnad, Svanen, FEBY12 och PHI2015Independent thesis Basic level (professional degree), 180 HE creditsStudent thesis
    Abstract [en]

    The Swedish building and property management sector are responsible for about 30 % of the total energy use. In order to take environmental consideration, different environmental assessment tools and standards are used. Miljöbyggnad, Svanen, FEBY12 and PHI are some of these. There has been increased interest to certify buildings and therefore it is of interest to evaluate the assessment of the energy field to see if relevant energy aspects are assessed. First a literature review was carried out with delimitation to evaluate the systems manuals and guidelines for new produced multi-apartment dwellings in Sweden. Then a comparison between the systems assessments and methods of calculations for the energy field as well as the systems considerations for the energy’s environmental effect was carried out. The comparison was based on emissions related to production and use and also depletion of non- renewable resources. Finally the theory from the literature review and the results from the comparison were discussed and that led to some recommendations for the systems.

    Different assessment systems that are used for the systems are grading systems, marking systems and certifications. The systems judge similar indicators and subfields for energy. Something that they all judge is building’s annual energy use but they define them differently. Beyond that, the systems distinguish in the judgements of the energy field. The requirements of the inputs for energy calculations are different for the systems. As well as the energy’s environmental impact, all systems take some consideration by judging the energy use. Some of the systems also take into consideration the environmental impact through assessment of energy source’s environmental impact or through energy form factors and primary energy factors for the energy type.

    For all systems the indicators and the subfields are mandatory but the criteria and requirement levels are different. The systems that take consideration to climatic zones allow buildings located in colder climate to use more energy and have more environmental impact, the systems should reformulate the criteria and requirements were consideration is not taken to climate zones. The requirements of the heat effect demand for buildings should not take consideration to the heating system because the heating system does not affect the heat effect demand.

    At the moment the systems are undeveloped when it comes to consideration to the energy’s environmental impacts and should therefore revise this. Some recommendations for the judgements of the energy field is to allocate the energy use/ per person and to judge primary energy or carbon dioxide emissions, other emissions and to judge the energy’s environmental impacts from “the cradle to the grave”. However it can be problematic to judge primary energy because today, there are no standards for how primary energy factors should be calculated currently.

    Key words: environmental assessment tools, Passive house standards, Miljöbyggnad, Svanen, FEBY12, PHI, energy, environmental impact 

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  • 26.
    Bergström, Helena
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Tilläggsisolering av småhus ur ett klimatpåverkansperspektiv2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Vi lever i en tid med klimatförändringar till följd av människans levnadssätt. Energiutvinning ger påverkan på klimatet genom växthusgaser, då främst genom koldioxid. Riksdagen har beslutat att Sverige ska minska energianvändningen i bostäder och lokaler med 20 % fram till år 2020 och med 50 % till år 2050 (Statens Energimyndighet, 2007). Det finns flera sätt att minska energianvändningen för bostäder, att minska transmissionsförlusterna genom klimatskalet är det mest vedertagna. Ett sätt att minska dessa transmissionsförluster är att tilläggsisolera fasaden.

    I denna studie har klimatpåverkan till följd av en tilläggsisolering satts i relation till de minskade emissionerna på grund av reducerat värmebehov. Studie är gjord på sju olika uppvärmningssätt och sex olika tjocklekar på isoleringen. För det beräknade värmebehoven gjordes en jämförelse mellan fyra olika städer i Sverige med olika klimat, en stad i varje klimatzon enligt Boverkets byggregler (BBR). 

    Resultatet visar variationer mellan klimatzonerna, tjocklek på tilläggsisoleringen och uppvärmningssätten. Studeras istället primär energianvändning i det olika fallen skiljer det sig en del från emissioner av växthusgaser. Slutsatsen är att sett över hela isoleringens livstid är det mest klimatsmarta valet att tilläggsisolera. Detta oavsett klimatzon, tjocklek på tilläggsisoleringen och uppvärmningssätt (av de i studien granskade).

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  • 27.
    Berndtsson, Ludvig
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Jansson, Pontus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Skillnader mellan stommaterialets växthusgasutsläpp2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Enhanced global warming is a phenomenon international organizations collaborates tocounteract by setting international standards, stricter environmental requirements, requirements on environmental product declarations (EPD) and to make companies provide statements on how their operation affects the environment. Green building is becoming more attractive which creates higher demand for climate friendly buildingmaterials and construction projects. Steel and glulam are two of the most commonly used structural elements used for framework in hall constructions and their impact on global warming is compared in this study using life cycle analysis (LCA). As a basis for LCA a fictitious hall constructionis built with glulam respective steel framework, geographically located in Fredriksskans, Gävleborg. Indata to LCA originates from product specific EPDs, peerreview articles and other relevant research, calculations are done according to international standards. Results show that greenhouse gas emissions from the materials greatly depends on how the materials are used when recycling. Hall constructions built with steel framework produce 139 % more greenhouse gas emissions than a hall built with glulam if both materials are recycled for environmentally friendly purposes.

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  • 28.
    Birgersson, Hugo
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    En studie av möjligheter och hinder att återanvända rivningsavfall i Gästrikeregionen2020Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    Increased effectivity in resource management in the construction sector is required to achieve the environment goals of Agenda 2030. The largest source of total accumulated waste derives from the construction and demolition area. This thesis contains a literature study about circular economy application in the process of construction- and demolition waste and interviews with local actors that represent the Swedish construction material chain in the Region of Gästrike, Sweden. A cooperation with the municipality property owner Gavlefastigheter AB has provided an opportunity to study the demolition process to examine what actions the building sector requires to increase reusage of demolition waste. Gavlefastigheter AB own and manage a variation of building types such as schools, agencies, sports arenas and other exclusive designs. The result of this study shows that the existing policy instruments of waste management are primarily developed to evaluate climate change impacts and to avoid waste that could cause harm to the environmental and health. In the literature review life cycle assessment was shown to be the most common method to analyze the effects of circular economy. The Swedish construction Federation have recently updated the construction- and demolish waste management directives mainly to help transitioning the construction business towards circular economy. Albeit these directives are not yet practically utilized the result of the interviews of local actors indicated that there were a few practices of demolish with reusage applications. The conclusion summarizes the important subjects that need to be dealt with to increase reusage within future demolition projects in the Region of Gästrike, Sweden.

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  • 29.
    Björling, Mikael
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electrical Engineering, Mathematics and Science, Chemistry.
    Building for Sustainable Ventilation and Air Quality2021In: Urban Transition - Perspectives on Urban Systems and Environments [Working Title]  / [ed] Marita Wallhagen & Mathias Cehlin, InTech, 2021Chapter in book (Refereed)
    Abstract [en]

    Most legislations concerning ventilation are based on comfort criteria, but ventilation is also important for the health of the occupants. The comfort criteria can be viewed as a pragmatic tool to achieve an adequate ventilation for precautionary health measures. From a comfort and health perspective, the ventilation rate and an efficient air distribution are both important for achieving a healthy and comfortable indoor environment. Yet, most legislative requirements concern the ventilation rate. This is not enough, and it is recommended that legislation also address the air distribution. In particular, the efficient distribution of fresh air to the occupied zones or the concentrations of pollutants in the occupied zones. Because there are clear links between ventilation and health, it is extremely worrying that the “energy efficiency first” principle advocated in the Energy Performance of Buildings Directive (EPBD) has led to decreasing ventilation requirements in the European Union legislations, at the same time as the objective is to aggressively tighten the envelopes of the building stock. A second consequence of EPBD is probably that many naturally ventilated buildings will be retrofitted with mechanical ventilation systems. It is not clear that this would be the more sustainable solution in the long run.

  • 30.
    Björling, Mikael
    et al.
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för naturvetenskap.
    Stymne, Hans
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för inomhusmiljö.
    Mattsson, Magnus
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för inomhusmiljö.
    Blomqvist, Claes
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för inomhusmiljö.
    Ventilation measurements combined with pollutant concentration measurements discriminates between high emission rates and insufficient ventilation2007In: IAQVEC 2007 Indoor Air Quality Ventilation and Energy Conservation: sustainable Buildings. P. 2, 2007, Vol. 2, p. 393-400Conference paper (Refereed)
    Abstract [en]

    High local concentrations of a pollutant can be the result of high local emission rates of the pollutant or insufficient ventilation. Using tracer gases to map the ventilation in multi-zone buildings combined with measurements of the local pollutant concentration provide the means to discriminate between these causes. In a similar manner, the propagation rate of pollutants from a source to a target zone and the emission rate of the pollutants at the source may be determined quantitatively.

    The paper presents both the theoretical framework for the techniques and experimental examples of the proposed methods.

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  • 31.
    Blomberg, Emil
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Boqvist, Simon
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Lauridsen, Markus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Tvärkraftsförstärkning av limträ med inlimmade gängstänger2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med studien var att undersöka hur tvärkraftskapaciteten i limträ påverkades om den förstärktes med inlimmade gängstänger samt att studera samverkan mellan limträ och gängstänger.

    En litteraturstudie genomfördes för att ta del av tidigare forskning. Förstärkning av tvärkraftskapaciteten hos limträbalkar är ett område där begränsad forskning skett. Ahlskog och Ross (2015) berörde detta område om hur limträ förstärkts mot tvärkraftbrott med pålimmade träribbor på utsidan. Resultatet från Ahlskog och Ross (2015) visade att deras förstärkningsmetod medförde en ökad tvärkraftskapacitet på 11 %. Denna studie var en vidareutveckling på Ahlskog och Ross (2015) arbete men med en ny förstärkningsmetod med inlimmade gängstänger i olika vinklar mot fiberriktningen.

    Testet bestod av fem olika provserier med åtta prover i varje serie. Provserie 1 var oförstärkt. Provserie 2 och 4 var förstärkta med inlimmade gänstänger i två olika vinklar mot fiberriktningen och testades med avseende för tvärkraftkapaciteten och jämfördes mot den oförstärkta. Provserie 3 och 5 var förstärkta på samma sätt som provserie 2 och 4 men provbitarna var klyvda i mitten och testades med avseende på gängstängernas hållfasthet och jämfördes mot provserie 2 och 4 för att undersöka samverkan. Provbitarna skruvades fast i två anhåll som placerades i tryckprovmaskinen som utsatte provbitarna med belastning tills brott inträffade. Maskinen var kopplad till en dator som registrerade samtliga värden i maskinens datorprogram Trapezium X.

    Studien resulterade i en ökning av tvärkraftkapaciteten på 13 % för provserie 2 förstärkt 45° och 1,0 % för provserie 4 förstärkt 90° jämfört med provserie 1. Samverkan mellan limträ och gängstänger resulterade i 32 % samverkan för provserie 2 förstärkt 45° och 4 % samverkan för provserie 4 förstärkt 90°. Resultatet hade förbättrats och visat en tydligare ökning av tvärkraftskapaciteten om fler felkällor hade beaktats i ett tidigare skede. En av dessa felkällor var torrsprickor, vilket resulterade i att provbitarna gav ett lägre värde gentemot de teoretiska beräkningarna.

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  • 32.
    Blomqvist, Claes
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för inomhusmiljö.
    Distribution of Ventilation Air and Heat by Buoyancy Forces inside Buildings: an Experimental Study2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The main task of the ventilation system in a building is to maintain the air quality and (together with the heating or cooling system) the thermal climate at an acceptable level within the building. This means that a sufficient amount of ventilation air at the appropriate temperature and quality must be supplied to satisfy thermal comfort and air quality demands and that this air is distributed to the parts of the building where people reside. Air movements caused by buoyancy forces can determine the distribution of ventilation air within buildings. The purpose of this thesis is to advance the state of knowledge of buoyancy-driven air movements within buildings and to determine their importance both for ventilation air distribution and the maintenance of thermal comfort and air quality in buildings. The work is focused on studying thermally-driven air movements through large openings, both horizontal and vertical (i.e. doorways). The properties of a special type of thermally-driven currents, so called gravity currents, have also been explored. Large vertical openings like doorways are important for air exchange between rooms within a building. Air movements through doorways separating rooms with different air temperatures are often bidirectional and the buoyancy-driven flow rates are often greater than those caused by the mechanical ventilation system alone. Bidirectional flows through doorways can effectively spread contaminants, for example, from a kitchen or a hospital rooms, yet the results of this study indicate that the conversion of a thermally-driven bidirectional flow to a unidirectional flow via an increase of the mechanically forced flow rate requires forced flows that are more than three times greater than the thermally-driven flows. Experiments conducted in this project indicate that the resistance to buoyancy-driven flows in horizontal openings is significantly greater than that in vertical openings. Model tests have shown, however, that this problem may be mitigated if a simple model of a staircase located in the centre of the room (being ventilated) is linked to the horizontal ventilation opening. Gravity currents in rooms occur in connection with so called displacement ventilation as cool gravity currents propagate along the floor that are driven by the density difference of the ventilation air and the ambient, warmer air within the room. As these gravity currents easily pass obstacles and to a certain extent are self-controlling, they can effectively distribute the cool air within rooms in a building. Likewise, warm gravity currents occur when warmer air introduced in a room rises and spreads along the ceiling plane. One application where warm gravity currents may be used to advantage is when converting buildings from electric heating to district hot water heating thus, avoiding the introduction of an expensive hydronic heating system. This report includes a full-scale laboratory study of the basic properties of thermally-driven warm air gravity currents in a residential building and examines the possibilities of using the resulting air movements for the distribution of ventilation air as well as heat. Results from laboratory tests show that this conversion method may prove effective if certain conditions on the layout of the building are fulfilled.

  • 33.
    Bondsman, Benjamin
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Al, Barzan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Hedlund, Felix
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Dimensionering av höga balkar enligt fackverksanalogi: -En parametrisk studie2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
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  • 34.
    Bredeson, Alva
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Dahlhjelm, Julia
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Gröna Tak: En studie om hur bibliotekets sedumtak på Högskolan i Gävle har fungerat i praktiken2023Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Green roofs are a favorable solution to the negative effects of urbanization, such as reduced biodiversity, poorer air and problems with stormwater management. Sedum roofs, meadow roofs and biotope roofs are some of the different types of green roofs available. The sedum roof has many benefits and is well suited to Sweden’s northern climate. The purpose of this study is to study how the library’s sedum roof at the University of Gävle has functioned over a period of 18 years, as well as the reason for choosing the green roof. The questions must be answered using a literature study combined with interviews.

    The literature study highlights that there are several benefits of green roofs such as good stormwater management, increase in birds and insects, better air quality, reduced energy use in buildings, reduced heat island effects and that it is aesthetically pleasing. The benefits are most noticeable in urban environments with a lack of green spaces and in more southerly climates. The maintenance requirement of green roofs depends on several factors. In Sweden, extensive roof systems are most common, which is the thinnest thickness of green roofs. This type requires the least maintenance and costs. Maintenance takes place with fertilization, irrigation and weeding if necessary.

    The result that can be drawn from the interviews is that the green roof of the library was mainly chosen because it was aesthetically pleasing and fitted in well with the surroundings. A competition was organized by Akademiska Hus with the reason to produce the best proposal for the new library, which three different architectural offices participated in. The winning proposal was the library with the green roof designed by Tirsén and Aili Arkitekter (today Stark Arkitekter) which caught the interest of many. From the construction of the green roof to today, hardly any maintenance has been required and the maintenance that has been required has been according to the plan. In the beginning, during the roof's warranty period, it emerged that maintenance was neglected due to a lack of knowledge. Apart from some minor deviations in maintenance and the fact that the green roof has required more careful planning and more complicated foundation work, the roof has worked exactly as planned.

    The conclusion that can be drawn from the work is that a green roof can be a good alternative if the conditions are right. A green roof's benefits are many, but not as obvious in a more northern climate or in a non-urban environment. The literature study shows that the right type of green roof requires minimal maintenance and the interviews also confirm that this is true according to the green roof of the library. The green roof has performed as planned without any complications and will continue to do so if the roof is maintained in a similar manner as it has been since it was built. 

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  • 35.
    Brodin, Sandra
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Moberg, Kasper
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Återanvända och återvinna byggnadsmaterial: En undersökning av materialen trä och betong ur byggnadsstommen2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I denna rapport undersöks återanvändnings- och återvinningspotentialen för stommaterial ur byggnader i Sverige. De två materialen som har undersökts är betong och trä. Rapporten innehåller en litteraturstudie över återanvändning och återvinning. En fallstudie har även utförts på två byggnader. Den första byggnaden är ett småhus med träkonstruktion. Den andra byggnaden är ett flerbostadshus med betongkonstruktion. Byggsektorn står för stora mängder utsläpp och har en stor påverkan på miljön. Av allt material som ligger på deponi står byggbranschen för ca 35 % av allt material. Ett alternativ för att minska byggbranschens påverkan på miljön är att återanvända och återvinna material i högre grad. Hantering av avfall ska prioriteras enligt EUs direktiv gällande avfall. I direktivet finns avfallstrappan som rangordnar avfall efter vad som ska prioriteras över andra alternativ. Betong är ett material som både går att återanvända och återvinna. Att återvinna betong är en vanlig process som innebär att betong krossas och sedan används som ballast till ny betong. Denna process kan innebära att betongens kvalitet ändras. Återanvändning av betong utförs inte i samma utsträckning men har stor potential i framtiden. Materialet trä bör följa kaskadmodellen för att förlänga dess livslängd. Kaskadmodellen beskriver hur träets livslängd kan förlängas innan den går till förbränning med energiutvinning. Fallstudien i denna rapport har utförts på två teoretiska byggnader. Byggnaderna har grundats på undersökningen BETSI och ska representera ett medelvärde av byggnader i Sverige. Fallstudien undersöker hur mycket material som går att återanvända och återvinna ur byggstommen. Resultatet visar på att all betong har en stor potential att återanvändas och återvinnas. Allt trä som används i de två byggnaderna bör följa kaskadmodellen där de komponenter som går att återanvända återanvänds.

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  • 36.
    Buske, Elias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Fuktegenskaper hos Quartzene impregnerat med salter2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Svenska Aerogel AB has developed the material Quartzene® which is of the typeprecipitated silica and contains calcium - magnesium silicate ((Ca, Mg) SiO3). Thematerial is used for molecular filtration of contaminated air. Qartzene™, which is inpellet form, is porous and has a high internal surface which is a requirement for themolecular filtration. With the use of various impregnations, filtration can affect thedesired outcome. As an example Quartzene® can be impregnated with Potassiumhydroxide and clear the air of Sulfur dioxide, SO2 (Svenska Aerogel AB, n.d).Svenska Aerogel AB has developed Quartzene® further and new areas of application hasarosee, one of these areas is how the material function within dehumidification. Thepurpose of this study is to research and analyze how different impregnation salts effecthow Quartzene® function in terms of moisture absorption and moisture desorption.Quartzene® is a hygroscopic material, which is a material that easily absorbs and exudatesmoisture from the air. Materials with high porosity absorb moisture by adsorption andcapillary condensation. A hygroscopic material strives for equilibrium with ambientenvironment which is illustrated in a sorption curve where moisture absorption is set inrelation to relative humidity. In this study the jar method is used to measure moistureabsorption, this is shown with the use of sorption curves. The jar method uses saturatesalt solutions to create environments whit a set relative humidity. Quartzene® – pellets areplaced in jars and weighed at regular intervals to determine the moisture absorption.The results of this study indicate that impregnations affect the way that Quartzene®function in terms of moisture absorption and moisture desorption. Some of theimpregnations affect the material to absorb more moisture than Quartzene® that has notbeen impregnated, while others affect the material to absorb less moisture. The resultsalso show that sodium – based impregnation gives similar results as Quartzene® that hasnot been impregnated.

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  • 37.
    Calance, Marius Alexandru
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Energy Losses Study on District Cooling Pipes: Steady-state Modeling and Simulation2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Distribution losses are a very important factor in district energy systems. By optimizing the losses in such a system, both economical and environmental aspects can be fulfilled. Unfortunately, there is few information regarding losses for district cooling systems. This study focuses on losses in district cooling networks by using both R-network and FEM simulation models. A R-network model composed of thermal conductances has been developed through analytical equations and simulations have been performed for validation. Afterwards, an in-progress construction project of a district cooling network from the city of Gävle, Sweden, is analyzed. The assessment consists of 15 pipe diameters in three configurations (two symmetric cases and one asymmetric), at three ground laying depths (0.8, 2 and 4 meters) for a duration of 7 months (April to October). A particular case in which the main distribution pipes from and to the plant are submerged in the city’s river for a distance of 1 km is investigated in order to estimate the temperature increase of the supply water. A maximum cooling loss below 2% of the total delivered energy during the season for any network configuration resulted from the calculation. Finally, the mixed pipes array seems to be a feasible investment both economically and technically but it cannot be used for the entire network spread since a part of the network has been already built with the non-insulated plastic pipes. The R-network model proved to be effective and reliable in the analysis which provides confidence that it can serve as a solid foundation for a calculation tool - primarily for design purposes and also for estimating energy loss. 

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  • 38.
    Chen, Huijuan
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Linköpings universitet.
    Janbakhsh, Setareh
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Linköpings universitet.
    Larsson, Ulf
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Linköpings universitet.
    Numerical investigation of ventilation performance of different air supply devices in an office environment2015In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 90, p. 37-50Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to compare ventilation performance of four different air supply devices in an office environment with respect to thermal comfort, ventilation efficiency and energy-saving potential, by performing numerical simulations. The devices have the acronyms: Mixing supply device (MSD), Wall confluent jets supply device (WCJSD), Impinging jet supply device (IJSD) and Displacement supply device (DSD). Comparisons were made under identical set-up conditions, as well as at the same occupied zone temperature of about 24.2°C achieved by adding different heat loads and using different air-flow rates. Energy-saving potential was addressed based on the air-flow rate and the related fan power required for obtaining a similar occupied zone temperature for each device. Results showed that the WCJSD and IJSD could provide an acceptable thermal environment while removing excess heat more efficiently than the MSD, as it combined the positive effects of both mixing and stratification principles. This benefit also meant that this devices required less fan power than the MSD for obtaining equivalent occupant zone temperature. The DSD showed a superior performance on heat removal, air exchange efficiency and energy saving to all other devices, but it had difficulties in providing acceptable vertical temperature gradient between the ankle and neck levels for a standing person. 

  • 39.
    Chen, Huijuan
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering. Division of Energy Systems, Department of Management and Engineering, Linköping University.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering. Division of Energy Systems, Department of Management and Engineering, Linköping University.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering.
    Computational investigation on the factors influencing thermal comfort for impinging jet ventilation2013In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 66, p. 29-41Article in journal (Refereed)
    Abstract [en]

    Impinging jet ventilation (IN) has been proposed to achieve an effective ventilation of an occupied zone in office and industrial buildings. For IJV systems, draught discomfort is the issue of most concern since it supplies cooled air directly to the occupied zone. This study investigated a number of factors influencing draught discomfort and temperature stratification in an office environment equipped with IJV. The factors considered were: shape of air supply device, discharge height, supply airflow rate and supply air temperature. The Response Surface Methodology (RSM) was used to identify the level of the significance of the parameters studied, as well as to develop the predictive models for the local thermal discomfort. Computational fluid dynamics (CFD) was employed to perform a set of required studies, and each simulation condition was determined by the Box-Behnken design (BBD) method. The results indicated that at a low discharge height, the shape of air supply device had a major impact on the flow pattern in the vicinity of the supply device because of the footprint from impinging jet, which consequently affected the draught risk level in the occupied zone. A square-shaped air supply device was found to result in lower overall draught discomfort than rectangular and semi-elliptic shapes. The RSM analysis revealed that the supply airflow rate had a significant impact on the draught discomfort, while the shape of air supply device and discharge height had moderate effects. The temperature stratification in the occupied zone was mostly influenced by the supply air temperature within the range studied.

  • 40.
    Chen, Huijuan
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering. Division of Energy Systems, Department of Management and Engineering, Linköping University.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering. Division of Energy Systems, Department of Management and Engineering, Linköping University.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering.
    Investigation on the flow and thermal behavior of impinging jet ventilation systems in an office with different heat loads2013In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 59, p. 127-144Article in journal (Refereed)
    Abstract [en]

    This paper presents the flow and temperature field within an office using impinging jet ventilation (IJV) under different heat loads ranging from 17 to 65 W per square meter floor area. The measurement was carried out in a full-scale test room to verify the reliability of three turbulence models, i.e., the RNG k-epsilon, SST k-omega and (nu(2)) over bar - f models. It is found that all the tested models show good agreements with measurements, while the (nu(2)) over bar - f model shows the best performance, especially on the overall temperature prediction. The (nu(2)) over bar - f model is used further to investigate a number of important factors influencing the performance of the IJV. The considered parameters are: cooling effect of chilled ceiling, external heat load as well as its position, number of occupants and supplied air conditions. The interaction effect of chilled ceiling and heat sources results in a complex flow phenomenon but with a notable feature of air circulation. The appearance and strength of the air circulation mainly depends on the external heat load on window and number of occupants. It is found that with higher external heat load on window (384 W and 526 W), the air circulation has a strong tendency towards the side wall in the opposite direction to occupant, while with lower power on window (200 W) the air circulation has a strong tendency in the center of the room and extends to a larger area. When two occupants are present, two swirling zones are formed in the upper region. The effects of air circulation consequently alter the temperature field and the level of local thermal comfort.

  • 41.
    Cheng, Cheng
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Adaptation of buildings for climate change: A literature review2021Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In September 2020, Northeast China suffered three unprecedented typhoons in half a month, and there was freezing rain in early November, all of which led to the large-scale urban power failure. The occurrence of these phenomena makes people directly see climate change and its impact on the living environment of human beings. Many studies have shown that the cause of climate change is the increase of artificial greenhouse gas emissions since industrialization. In addition to the increase of extreme weather disasters, the most direct manifestations of climate change are the rising temperature, droughts, and rising sea levels. The building sector accounts for 39% of global greenhouse gas emissions and 36% of energy consumption. To ensure the long-term integrity and normal operation of buildings, we need to understand the impact of climate on buildings, and how to deal with it. This paper reviews the literature on climate change and building energy by searching search engines and literature databases. For extreme weather, most literature talks about the impact of power failure, the main strategy is to improve reliability, resilience, sustainability, and robustness, it can help reduce losses and recover as soon as possible. On the other hand, the methods of adaptation to and mitigation of non-disaster weather are reviewed from the perspective of sustainability. This paper mainly reviews the methods of passive technology and strategy for exemplary buildings, building envelope, passive ventilation, lighting/shading, solar energy, bioenergy, dehumidification, passive cooling, and design strategy. According to the local climate, the geographical characteristics of the building, to develop comprehensive passive technology and strategy, can meet or close to meet their energy saving, emission reduction, comfort needs. This paper can provide a technical and strategic reference for the building sector to deal with climate change.

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  • 42.
    Dahir, Mohamed
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Invändig eller Utvändig tilläggsisolering av ett flerbostadshus- LCC analys av optimal isoleringstjocklekar: Fallstudie på Sicksackvägen 39 i Gävle2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Stadsdelen Sätra som ligger 3 km norr om Gävle centrum uppfördes undermiljonprogrammet mellan 1960-1974. Det är enkelt och ta sig till och från Sätramed både fordon, cykel och till fots. AB Gavlegårdarna har tagit initiativ till attrenovera deras byggnadsbestånd som uppfördes under miljonprogrammet istadsdelen Sätra, däribland Sicksackvägen 39. Byggnaden har byggts 1969 ifunktionalistisk stil i närheten av Sätra Centrum.Syftet med denna studie var att undersöka den kostnadsoptimala isoleringstjocklenvid invändig eller utvändig tilläggsisolering av husets ytterväggar. Med hänsyn tillandra åtgärder som AB Gavlegårdarna vill genomföra vid renovering av denbefintliga byggnaden.För att genomföra denna studie har en okulärbesiktning, litteraturstudie,beräkningar, uppmätningar, undersökningar, samt energisimulering utförts. Därpåjämfördes lönsamheten vid tilläggsisolering med optimala isoleringstjocklekeninvändigt respektive utvändigt.Resultatet av denna studie visar att de komponenter i husets klimatskärm somläcker mest värme är ytterväggar och fönster. Med hänsyn taget till derenoveringsåtgärder som AB Gavlegårdarna ska genomföra blir den optimalaisoleringstjockleken invändigt är 45 mm och utvändigt 170 mm. Den åtgärd som germest lönsamhet är tilläggsisolering utvändigt med 170 mm mineralull i kombinationmed AB Gavlegårdarnas renoveringsåtgärder: fönsterbyte och uppgradering avventilationssystemet till FTX.

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  • 43.
    Dahlin, Linus
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Hedman, Marcus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Undersökning av värmeförluster genom kantbalk vid användning av golvvärme: En simuleringsundersökning i COMSOL Multiphysics2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Through laws and regulations in Sweden, increasing demands regarding energy use are affecting new buildings. A building achieving thermal comfort is attaining its thermal needs and can be done so through several types of distribution systems such as radiators and underfloor heating. Insulation is used to limit the amount of energy lost through the building’s envelope whilst keeping up with the thermal needs.

    This study is meant to examine the thermal leakage around the edge beam installa-tion when using a waterborne underfloor heating system and different sets of insulation are installed in the ground-related construction. The edge beam is the reinforced part located around the perimeter of the building absorbing forces from supporting walls.

    The study started with creating and using a simplified model in COMSOL Multiphysics to look at a two-dimensional edge beam formation. COMSOL Multiphysics is a software used for modeling different static and dynamic simulations via the finite element method.

    Four models were created using two different CC-dimensions (center to center distance) and two different floor materials. After this, three cases were created with improved circumstances regarding the ability to isolate heat around the edge beam. Dynamic simulations were made and calculated a year’s worth of varying outdoor temperatures. When the outdoor temperature changes, the requirements of the underfloor heating output also change which leads to its temperature adapting due to the outdoor temperature.

    The results indicate the edge beam related heat losses make up of about 50 % of the ground-related construction losses in the model. When completing the design with two instances of additional insulation, no major changes were found in the results. However, replacing the L-shaped insulation around the edge beam with a U-shaped insulation reduces heat losses through the edge beam to about 30 %. Ground-related construction losses are the losses transferred from the building to adjacent ground.

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  • 44.
    Dahlvik, Linn
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Öster, Sandra
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Geospatial Sciences.
    Underlag för utformning av nybyggnation i kulturmiljö: En fallstudie i Strömsbro, Gävle2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today residential shortage occurs in several municipalities in Sweden. Densification could be a strategy to solve this problem. Areas where cultural heritage exists are vulnerable to new construction. The aim of this study is to examine how densification on a property could adapt to the surrounding cultural heritage and contribute to good quality of life. The objective is to form criteria for new housing in a cultural heritage environment as a foundation of exploitation. A visualization proposal has also been designed by the criteria. The study is delimited to Strömsbro in Gävle, Sweden and have been exemplified at the property Strömsbro 37:2 that is located in the area.  

    The method DIVE has been used to analyze cultural heritage values and to demonstrate future development opportunities. The DIVE-analysis is performed in four steps: Describe, Interpret, Valuate, and Enable. By performing site visits and inventory in the analysis, values have been identified and a perception over the area have been obtained. Interviews and questionnaires have also been a part of the analysis and have contributed to identification of values, to understand the sense of place and to clarify possible developments. Building volumes have been studied as another method of this thesis. Calculations of volumes and floor area ratio of the surrounding environment have provided guidelines for the visualization.  

    The work resulted in a design proposal of attractive new dwellings, considering the cultural heritage values and seclusion to reduce unwanted observation to create better qualities of life. The design proposal resulted in two apartment buildings, one townhouse and one complementary building that pursue traditional formation with modern details. 

    The result can not represent everyone’s opinion regarding cultural preservation. Cultural heritage is a sensitive subject and citizens might get upset with the result. Residents should therefore be involved in an early stage of planning. 

    Physical qualities that are important when planning for new housing in a cultural environment are coloring, material, building placement, street network, roofing and height scale. Volumes and floor area ratio are also important in the physical environment. The design proposal in this study shows how new housing could be implemented in a cultural district regarding the criteria. 

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  • 45.
    Deniz, Suleyman
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Moalin, Hassan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Vertikal påbyggnad av ett flerbostadshus i Gävle.2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The global population is estimated to rise by 89 million people annually and for this reason there is a need for more housing and buildings worldwide. As cities grow outwards and buildable land becomes scarce, it is necessary to increase the height of buildings in cities, especially where the height of existing buildings is low. For crowded cities, story extensions are an increasingly popular measure that could meet market’s demand for centrally located homes.The main focus of this study is to clarify how a specific existing building handles the addition of a story. The existing building that was used as a starting point is located in Styrmansgatan in Gävle, the district Brynäs. The building has totally three storiesand is a youth residence where HBS is the property owner. The study presents the approach to validate and simulate the existing building.The method of the work is modelling in StruSoft FEM-Design which is a program used for modelling, analysis and design of load-bearing elements of buildings according to Eurocode. With the help of the program, it is investigated whether the existing building can handle an extension and which reinforcements should be made. It is suitable for all different types of design tasks from the entire stability analysis in a building to individual elements. The work is carried out in 3 steps where first the reference building to be used as a starting point is modelled, analyzed and designed. The next step is to add a story and then analyze any additional measures in connection with the extension of the story. The building must be approved according to standards as a starting point with regard to degree of utilization and deflection. Then, a comparison is made between the existing building structure and the superstructure with respect to degree of utilization, deflection, stress, and the base reaction.Results obtained from this study show that if an extension is to be possible, reinforcement solutions should take place for building elements that receive an unacceptable degree of utilization. The reinforcement solutions are resulted with the help of beams, columns, wind brace and changed reinforcement contents in reinforced concrete elements for the load-bearing structure. The study concludes that the story extension is possible with added reinforcement measures

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  • 46.
    Edkvist, Kristin
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Powell, Linnéa
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Lerstensskiva med armering av fårull: Undersökning av böjhållfasthet, ånggenomsläpplighet, brandtålighet,värmekonduktivitet och praktisk användning.2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The focus of this study is aimed at the traditional building material; clay, together withsheep’s wool to act as reinforcement. The combination of the two materials created thebasis for an alternative board material. Soil-based building materials were used to alarge extent in the past. The oldest clay houses found were built as early as 8000 yearsBC. During the Middle Ages in Central Europe, soil and clay were used as fillers in timberframe structures. As new building materials evolved, clay based building methodshave suffered a more secluded position in the western world. New building materialshave caused the characteristics of traditional building materials to be forgotten. Sheep’swool, unlike clay, has previously not been classified as a building material, but ismostly used for textiles. Sheep are bred generally for two purposes; meat productionand wool production. The wool that comes from sheep that are in the meat productionbecomes a by-product that is usually reckoned as waste.The study presented below involves a product development of a board material containingclay and sheep’s wool. Nine different compositions were made in different series.Focus on the three different series was places on variety of sheep’s wool, amountof sheep’s wool and the viscosity of the clay. The manufacturing of the product wasmade by hand with own thought out and manufactured aids.The lack of aggregated material properties complicates the use of clay and sheep’swool. A performance based declaration and the CE marking of a product are requiredfor a building material to become an accepted product in the construction market.Building engineering research was carried out in the laboratory environment, and basedon standardized methods calculations were made on the Clay-wool board such as flexuralstrength, vapour permeability, thermal conductivity, fire resistance and practicaluse.The result shows that the Clay-wool board is comparable to other board materials. Thetechnical characteristics of the Clay-wool board regarding flexural strength reportedvalues between 118 N and 550 N, depending on the composition of clay and wool. Allthe boards showed that the point of breaking was viscous, since the wool held the clayslabs together. When calculation vapour permeability, the result showed values between2,289 x 106 m2/s and 3,571 x 106 m2/s.The thermal conductivity was measured on one single board, the one containing thelargest amount of wool, where the value was established to 0,218 W/m*K. It was noticedthat the thermal conductivity increased when wool was clay–dipped.

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  • 47.
    Eklund, Filip
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Pettersson, Johannes
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Skillnad mellan stående och liggande panel ur en fuktsynpunkt2023Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I Sverige är det vanligt att använda en träregelstomme för att bygga hus med ett yttretäckande skikt bestående av antingen stående eller liggande panel. Livslängden på panelen ärbegränsad, och när den har uppnått sin fulla livslängd måste den ersättas med ny panel. Dettaär ett betydande projekt som är tidskrävande och kostsamt.Fukt är en viktig faktor som påverkar livslängden hos trä, och den största orsaken tillförkortad livslängd hos trä är biologiska angrepp i form av mögel och röta. Därför ärkunskapen om fuktproblem hos trä av yttersta vikt för att kunna uppskatta livslängden hosolika träkomponenter som används utomhus. Fukt i träpaneler kan också bidra till andrakonsekvenser, till exempel deformationer som bågning och sprickor. När trä blir blöttexpanderar det, och när det torkar krymper det, vilket kan leda till att träets dimensionerändras och att sprickbildning kan uppstå. Detta har visat sig vara en betydande faktor sompåverkar livslängden hos träpanelen.Syftet med denna rapport är att se hur fuktskador uppstår på befintliga byggnader medträfasad samt om det finns skillnader mellan stående och liggande panelers fuktskador.Resultatet visar att det för det mesta sker fuktskador längst ner på fasaderna, vilket beror påatt det är det mest utsatta området på väggen. Dessutom konstaterades att det finns skillnadermellan liggande och stående panel, där den stående panelens fuktskador oftast var merallvarliga längst ner på fasaden, medan den liggande panelen oftast precis som den ståendepanelen hade fuktskador längst ner på väggen men även på övriga ställen på fasaden.Förstudien och experimentet visade på att den stående och liggande panelen är väldigt likavarandra i fuktupptagning och uttorkning. Samt att deras design eller utformning intepåverkar panelens livslängd i någon stor utsträckning. Skillnaden mellan de två paneltypernablir emellertid tydlig när det gäller att byta ut skadade paneler. På en fasad med liggandepaneler är det möjligt att byta ut de nedersta brädorna utan att påverka resten av väggen,medan en fasad med stående panel som har skadats längst ner innebär att i princip helafasaden måste bytas ut. Detta innebär att livslängden för en fasad med stående panel kanförväntas bli kortare än för en fasad med liggande panel, även om den skadade ytan på enfasad med liggande panel kan vara lika stor eller större jämfört med en fasad med ståendepanel. Detta i sin tur leder till högre kostnader för den stående panelen.

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  • 48.
    Elizalde, Eduardo
    University of Gävle, Department of Technology and Built Environment.
    WEATHER FORECAST CONTROL: Prestudy of installing a predictive heating control system2008Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    The forecast control for the heating system tries to maintain the buildings’ indoor

    temperature at a desired level, by using technical building characteristics, data on its

    mode of operation, data on the building location and meteorological parameters. By

    forecasting the conditions of the building and calculating the free energies (solar radiation

    and internal heat generation) it is possible to know the amount of additional heat that

    should be supplied to the building every moment, avoiding heat surpluses or deficits.

    By applying the theory developed by Roger Taesler to buildings 92911 and

    92917 placed in Sandvik AB, it is seen that if the desired temperature was 21ºC it would

    be possible to save a 16.3% of energy, 15518 SEK/year, and that the payback time for the

    installation of such a system is 3 years.

    Other efficiency measures as changing the ventilation schedule or installing a

    heat exchanger are also discussed in the present report.

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  • 49.
    Endre, Robert
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Brottsskeden kring infästning av stålpelare2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A infill wall is a non-bearing wall construction, often is made af wood, which has the aim of minimizing the energy consumption of buildings in concrete. The inside the construction is sometimes steel designed for supporting the overlyingstructures. Steel studs are subjected to loads that they must be dimensioned to support. Above and below the colums plates are welded to increase the loaded area and prevent damages to the concrete.

    In this thesis a computer program in Excel has been created, the program dimensions border pillars in steel that follows the Eurocodes.

    Included in the program is punching, local pressure, splitting, distance to concrete, reduction when drilling in concrete, compression load capacity of foot and top plates, and bending torque the plates.

    Punching is a conical damage that occurs in the concrete, the damage occurs without warning and the concrete’s bearing capacity decreases rapidly which can lead to collapse. Local pressure is a local damage of the concrete and splitting, meaning that because of the pressure force arising can lead to a horizontal thrust in the concrete, which can lead to injuries.

    Since it is difficult to perceive the distance between the plates and the concrete edge of structural strength in the Eurocodes a calculation method has been made, equally applies to the consequences when drilling near a pillar.

    Examples of holes can be stairs, elevators or holes for heat strain for radiators.

    The plates are calculated in cross-section class three.

    The program is built so that different dimensions and qualities is selected, then the program calculates the strength of the structure and reports if will support the load. Different dimensions and qualities can be tested to get the optimal structure sollution. Limits have been set, the program only calculates the various injuries mentioned above and applies only to square VKR-sections and plates. Pillar has been calculated as articulated in both secured repository where the only pressure forces dimensioned concrete and plates.

    During the first phase of the work, gathering facts for the various types of damages has been done. Facts have been gathered from literature, reports, studies, researches, previous solutions, discussions with industry experienced and previous and more recent regulations. Since then, the computer program has been made, the goal of the program is to get a quick result and a complete report. Therefore, the program is made so that all damages is on different tabs and can be reported separately. So that the program can used by third parties standard names, images and comments are used. The program has been checked with various calculation examples and applications to achieve a credible / useful result.

    Conclusion: A well-functioning model has been developed and can be used by structural engineers with a education at least of technical college.

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  • 50.
    Engberg, Niclas
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Nordlöv, Marcus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Distansarbetets påverkan för byggnadskonstruktörer: En kvalitativ fallstudie om hur konstruktörers effektivitet & kvalitet påverkats av distansarbete2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    As a result of the Covid-19 pandemic, the construction industry in Sweden has been forced to accelerate the digitalization process, which has contributed to an increased use of digital tools and teleworking. Previous research in the subject indicates both positive and negative consequences of teleworking and recurring factors are the work environment, communication, knowledge sharing and technology. The study examines how designers at a medium-sized construction company in Sweden are affected within the aspects of efficiency and quality in the transition to telework and whether it is a suitable working method to use permanently in the future or not.

    To answer the questions in this study, the authors have chosen to use an interview method to examine the experience of telework and a data collection to check the effectiveness and quality. The interview method in the study is a semi-structured interview with five selected designers at the company that participated in this study. The collection of data for the study was given from the company's internal time reporting system, quality documents from the company’s subcontractors and a supplementary survey.

    The respondents in the study felt that the designers’ efficiency was reduced, which do not correspond with statistical data in the study. The results show that efficiency has increased and the quality of the designers' documents is equivalent in the transition to telework. The authors' assessment after the implementation of the study is that teleworking is a good working method to apply if it is an optional complement for the designers. A permanent transition to teleworking can mean that the designers experience a reduced affiliation to the company, less fellowship with other employees, a more difficult communication and impaired knowledge sharing, which in the long run can affect the efficiency and quality of the designers' documents.

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