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  • 1.
    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.

  • 2.
    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.

  • 3.
    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

  • 4.
    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.

  • 5.
    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.

  • 6.
    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.

  • 7.
    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.

  • 8.
    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.

  • 9.
    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.

  • 10.
    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.

  • 11.
    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.

  • 12.
    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.

  • 13.
    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.

  • 14. 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)
  • 15.
    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 

  • 16.
    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).

  • 17.
    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.

  • 18.
    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.

  • 19.
    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.

  • 20.
    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
  • 21.
    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.

  • 22.
    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. 

  • 23.
    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. 

  • 24.
    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.

  • 25.
    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.

  • 26.
    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.

  • 27.
    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.

  • 28.
    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. 

  • 29.
    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.

  • 30.
    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.

  • 31.
    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.

  • 32.
    Englund, Anders
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Sundholm, Sara
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Egenproducerad solel i ett småhusområde2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Sverige ska år 2020 ha en energiförsörjning bestående av 50 % förnybara energikällor. Den viktigaste källan till förnybar energi är solen. Solel är dock en dyr investering idag och gällande regelverk försvårar möjligheterna till att tillgodoräkna sig egenproducerad el.

    Byggföretaget JM bygger redan hus med låg energianvändning. Ett sätt att bidra till ett förnybart energianvändande är att installera system som producerar egen el till husen. Detta arbete har genomförts för att undersöka om solel kan komma att bli en konkurrenskraftig produkt att erbjuda JM:s husköpare. I arbetet har ett specifikt område och en av företagets typhusmodeller studerats.

    Dagens solcellsteknik har studerats och ett system för huset har komponerats. Det finns ett flertal typer av solceller men i detta arbete har polykristallina solceller valts utifrån det offertförslag som legat till grund för arbetet. För att kunna dimensionera anläggningen har placering, orientering och solvinklar undersökts. Genom att välja en anläggning har investeringskalkyler och simuleringar kunnat utföras för ett par olika scenarier. Samtliga scenarier bygger på nätanslutna system men skiljer sig mellan dagens regelverk och ett framtida scenario med nettodebitering, dvs. kvittning av egenproducerad el och köpt el.

    Från JM:s sida har det funnits önskemål om att studera hur ett bostadsområde skulle kunna dela på en solcellsanläggning genom ett samfällt system. Den samfällda anläggningen har dimensionerats utifrån fullgott solläge. I aktuellt område innebar det att 16 av 35 hus är lämpligt placerade mot solen, detta kan dock skilja mellan olika områden.

    Resultatet visar att en investering i solel är svår att försvara idag. Med ett statligt stöd på 60 % är återbetalningstiden likväl 20 år. Med ett förändrat regelverk och ett långsiktigt stöd skulle det kunna bli ekonomiskt lönsamt. Genom att solcellstekniken blir billigare och elpriset stiger förbättras läget för solelen. Investeringskostnaden blir lägre per person och öppnar därmed upp för fler investerare.

  • 33.
    Englund, Sofia
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Hedbom, Sara
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Energieffektivisering av gamla herrgården vid Forsmarks bruk: En studie med hänsyn till byggnadens kulturhistoriska värden2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Reducing energy use in buildings requires extensive action regarding energy effectivization in both modern and old buildings.The old mansion in Forsmark was established 250 years ago and is a building in need of energy effectivization in order to reduce its energy consumption, hence ensuring it’s continued use.

    In applying said measures special attention must be given to the mansions care requirements. These requirements are governed by the mansions heritage regulations which were established by the National Heritage Board in Uppsala 1975 in collaboration with the former owner Count Ludvig af Ugglas. The requirements clearly state which parts of the building that are to remain unchanged. This study presents how identification and and measurement of the mansion were conducted in order to validate an energy simulation model of the building, how to apply these measures as well as to see if they are economically feasible. It is of importance in this study to map the mansion in order to determine if possible measures can be adapted in order to accommodate its heritage regulations. Difficulties in validating the nominal energy simulation models with measured data have resulted in the conclusion that the mapping has too many uncertain parameters which themselves have an effect on the mansions energy use. The nominal model, based on measured data and U-values assumed for each part of the mansion, gives a value that is double the measured effect acquired from the buildings heating system. The measured effect acquired from the manors heating system was significantly lower than what is to be expected in such an old building. Consequently a sensitivity analysis of the building’s U-values regarding its exterior walls and foundation was conducted. The results of the sensitivity analysis indicated that uncertainty first and foremost in wall material and construction effect the energy use of the mansion, but also that additional parameters were probable to have an impact on the mansion’s energy use.

    The conclusion of this study is that the old mansion at Forsmark has a relatively low energy use regarding its size, age and that it is possible to take action in order to reduce its energy use. The first of which is to adjust the heating system as it has been discovered that it is incorrectly dimensioned.

  • 34.
    Engvall, David
    University of Gävle, Department of Technology and Built Environment.
    Klimatsimulering av nybyggnation2008Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Detta examensarbete på C-nivå har genomförts i samarbete med ÅF Infrastruktur AB, Borlänge och syftar till att simulera inomhusklimatet för valda delar inom nybyggnation Experium, Lindvallen samt med hjälp av simuleringarna beräkna effekt- och energibehovet för dimensionering av en fjärrvärmeinstallation alternativt installation av elpanna samt kylcentral.

    ÅF Infrastruktur AB har uppdragen installationsprojektering samt installationsledning åt beställaren Skistar som skall upprätta Experium. Vilket skall resultera i en upplevelsearena på 17 000 m2 innehållande äventyrsbad, bowlinghall, eventyta samt restauranger mm.

    Författarens uppgift är att hjälpa ÅF Infrastruktur AB att klimatsimulera eventytan samt bowlinghallen på Experium med ett typiskt dygnsförlopp i beaktande. Då speciellt kolla på operativa temperaturer, relativa fuktigheter samt koldioxidnivån som uppstår i respektive lokal. För dessa simuleringar har datorprogrammet IDA Klimat & Energi 3,0 använts.

    Simuleringen av ett typiskt dygnsförlopp på eventytan med 3000 personer samtidigt i lokalen på en afterski eller konsert, samt efterföljande 1500 samtidigt sittande personer skall resultera i om projekterat flöde räcker för att upprätthålla ett behagligt inomhusklimat. Simuleringen visar på att 3000 personer på samma gång är i översta laget, 1500 personer är mera realistiskt.

    Simuleringen av bowlinghallen syftar till att utreda om den relativa fuktigheten som ett bowlinggolv kräver, normalt 40-50 %, upprätthålls utan befuktare under vinterhalvåret. Det visar sig att under vinterhalvåret ligger den relativa fuktigheten på 20-30 %, en befuktare krävs för att upprätthålla den relativa fuktigheten på 40-50 %.

    En effekt- och energibehovsberäkning omfattande transmissions-, ventilations- och poolförluster samt energiåtgången för uppvärmning av tappvarmvatten skall tas fram som underlag för dimensionering av uppvärmningssystemet. Resultatet av dessa beräkningar blev att uppvärmningssystemet bör klara av 1,4 MW.

    Simuleringar och beräkningar tas upp under kapitlet resultat och slutsats, beräkningarna återfinns sedan i bilagorna.

  • 35.
    Ersson, David
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Yngvesson, Robert
    Permakultur i Byggandet: En utredning inför uppförande av en miljöanpassad utbyggnad av skola i Ljusdal2011Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Calculations show that the current population on earth and with a western life-style takes up to seven earth-like planets to sustain a sustainable lifestyle. Today Europe and the U.S. consume 2/3 of the resources on earth of which many are already over-used. The current population is overconsuming the resources on earth with 120% above the sustainable level. With the standard that the western citizen demands, the earth would only be able to house only one billion citizens in a sustainable way.

    The suggestion to solve this problem is mostly to invest in energy saving technologies and to invest in energy saving solutions. Of course, energy savings indeed are important but technical solutions can not alone provide a solution. It is often shown that investments in energy efficiency and in energy saving technology leads to higher instead of lower energy consumption. This is known as Jevons paradox.

    A way to solve this paradox is to create awareness among the energy consumers. By decreasing the distance between energy use and energy production, the awareness among the consumers is likely to increase. Thus, the use of natural resources will no longer remain difficult to grasp and feel remote but will be something everyone can relate to. When it comes to the built environment, the best solution would therefore be to utilse relatively small units with a high grade of self supply.

    Permaculture, which is a concept captured from the world of farming, provides tools to investigate and to make this idea real. What permaculture and the planning tools of permaculture do is that it focuses on small scale solutions close to the end users. Permaculture is also a concept that allows implementation on levels that can be adapted to every single case. This means that there can be different levels of self sufficiency in every unique project.

    The method that is presented in this paper focuses in investigating the conditions of the site and the project, and to find the technical solutions that fulfill the prerequisites of the actual case. The purpose is not necessarily just to create a working technical solution but to create a solution that makes the inhabitants aware of their energy use.

    Therefore this paper focuses a lot on a real example: The Freinet School Tallbacken in the Swedish municipality of Ljusdal. The school is about to build a sports hall and a canteen using these principles. This paper shows the considerations made in that actual case and provides therefore a model for anyone who is interested in the implementation of these principles in any other project. 

  • 36.
    Evertsson, Anna
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Walfridsson, Helen
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Ändring av befintligt ridhus: Gävle Fältrittklubb2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 37.
    FERRI, JUAN CARLOS
    et al.
    University of Gävle, Department of Technology and Built Environment.
    MARIN, SAMUEL
    University of Gävle, Department of Technology and Built Environment.
    CREATION OF A MODEL FOR THE STUDY OF THE VENTILATION AIR DIFFUSION OF THE FALUN HOSPITAL: a CFD Based Integrated Approach2008Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    The main aim of the project is the creation of a CFD model for a plant in the Falun Hospital in Sweden. CFD is a new area of engineering that appears because of the great improvement in the computers last years. Creating a CFD model is a difficult process but the model is capable to give a great amount of data and also the model allows predicting the results when parameters of the system are changed so the model lets to save money and time and becomes an interesting tool to choose the optimal solution for the system.

    In this case the system studied is the air distributed by the ventilation system inside a plant of the Falun Hospital. The model have to predict the characteristics of the airflows inside the plant, how the air moves through the different areas of the plant and how these airflows affects in the distribution of temperature inside the plant.

    Also the model has to become a use tool to analyze possible changes in the ventilation system to improve it. And a tool to get boundary conditions to study specific areas of this zone in future studies.

    The project its part of a bigger project performed by the department of energy technology from Gävle university “Consequences in comfort and inside environment at energy optimization within the health care sector”. The project it is a study of the use of energy in health care buildings in Sweden after the analysis of the energy usage a study to optimize the use of the energy and how these changes affects the patient and workers climate comfort in these buildings.

    The CFD model have to be a tool that helps in the study of the ventilation system and the relation with the comfort in the Falun Hospital and also a tool to choose an optimal solution for the ventilation system after changes to improve the energy usage in the building avoiding the use of experimental changes in the hospital.

  • 38.
    Fornstedt, Joachim
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Sena ändringar: studie av sena ändringar under produktionsfasen av Kv. Valhall2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Sena fördyrande ändringar under produktionsfasen i byggprojekt är vanligt

    förekommande i byggbranschen. Skanska Mora är inte ett undantag och har börjat se

    dessa fördyrande ändringar som ett problem som de vill undersöka. Syftet med detta

    arbete har varit att definiera och minimera fördyrande sena ändringar under

    produktionsfasen. Målet har varit att ta fram en rekommendation till Skanska Mora på hur

    de kan förebygga kostsamma sena ändringar under produktion. Förhoppningen har varit

    att detta på sikt ska leda till möjligheter till fler lyckade byggprojekt på många plan för

    Skanska Mora, och att skapa diskussion för att belysa grundproblematiken i området.

     

    Arbetet grundar sig främst på en litteraturstudie i områden om fördyrande sena

    ändringar, ändringshantering i projektarbeten och andra delar i byggbranschen. En studie

    på tre fördyrande sena ändringar i Skanska Moras projekt Kv. Valhall har genomförts

    parallellt med en skriftlig intervjuundersökning som skickats ut till en utvald del av

    projektpersonalen. Litteraturstudien har format studien av projektet för att identifiera och

    utreda dessa sena ändringar. Utifrån studierna formulerades en rekommendation till hur

    Skanska Mora ska kunna arbeta för att förebygga dessa sena fördyrande ändringar.

     

    I rekommendationen föreslås att man börjar arbeta mot ett bättre samarbetsklimat för en

    bättre social miljö mellan alla medarbetare. För att uppnå det så ska arbetet inriktas mot

    att effektivisera kommunikationen och informationsöverföringen och skapa teamkänsla i

    företaget och projekten. Teamkänsla uppnås genom att ledarskapet inriktas mot att värna

    om de inre resurserna, det vill säga människorna i projekten. Att arbeta mot en bättre

    fungerande erfarenhetsåterföring är också en rekommendation som bidrar till att skapa

    god teamkänsla och ger möjlighet att tillsammans arbeta mot mer lyckade projekt utifrån

    att dra nytta av alla värdefulla erfarenheter.

  • 39.
    Frojdén, Jonathan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Betydelsen av brännbart och obrännbart material i ett brandförlopp: En jämförande studie2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I och med de ändringar som trädde i kraft 1993/94 då funktionskrav för konstruktioner infördes istället för de enskilda materialens egenskaper lade grunden till att det numer är möjligt att bygga byggnader som kräver en hög grad av brandskydd i trä och andra material baserade på brännbart material. Denna ändring innebar bland annat att nya och innovativa produkter hade chans att etablera sig på den svenska marknaden, såsom isolering tillverkad av returpapper och träfiber. I och med träets naturliga förmåga att till viss grad motstå brand, bland annat genom att bilda ett skyddande kolskikt, i kombination med tillsats av flamskyddsmedel som försvårar antändning ytterligare resulterar i att dessa material numer har möjlighet att konkurrera mot obrännbara material gällande brandsäkerhet i byggnader.

    De testmetoder som idag avgör en produkts brandklass sker under kontrollerade former med temperaturer som inte motsvarar en fullt utvecklad brand. Detta medför att det utifrån ett materials brandklass, eller s.k. euroklass, inte går att förutse materialets brandmotstånd under en fullt utvecklad brand. Inte heller under ett så kallat Room Corner Test, som ska motsvara brandens tidiga skede, har det visat sig att euroklassen inte alltid motsvarar de krav som ställs för att förhindra vidare förbränning och övertändning. Däremot går det att utifrån euroklass se mönster i dess klassificering och förmåga att sprida glödbrand.

  • 40.
    Fröjdfeldt, Ida
    et al.
    University of Gävle, Department of Technology and Built Environment.
    Leijon, Aino
    University of Gävle, Department of Technology and Built Environment.
    Prefabricerade byggelement: En konceptbeskrivning2008Student paper second term, 10 points / 15 hpStudent thesis
    Abstract [sv]

    Byggandet idag går allt mer åt det industriella hållet. Många företag har övergått från platsbyggnation till att använda sig av mer eller mindre förtillverkade element i sin produktion. Viktiga begrepp inom prefabricering är slutna respektive öppna system och ytrespektive

    volymelement. I Falun finns företaget Panorera AB som med företagsegna (slutet system) prefabricerade komponenter bygger en- och flerbostadshus. De har även utvecklat ett färdigt koncept med standardiserade ytelement som bildar moduler. I denna uppsats beskrivs

    konceptet utifrån främst arkitektoniska aspekter och tanken är att ge företaget ett underlag för säljmaterial. Panorera är inte det enda företaget på marknaden som utvecklat ett färdigt koncept utan det finns ett flertal andra, t.ex. Ikea, Skanska, Lindbäcks Bygg AB och

    Riksbyggen. Dessa företags koncept används för att jämföras med Panoreras för att bilda en uppfattning om det finns några skillnader mellan yt- och volymelement. Trots att koncepten bygger på samma tanke att använda förtillverkade element finns flera olikheter dem emellan. Olikheterna gör att flexibiliteten kan skilja mer eller mindre mellan koncepten vilket gör att vissa koncept kan anses bättre än andra.

  • 41.
    Gellerstedt, Jennifer
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Westman, Simon
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Sambandet mellan radarsignaler och fukthalt i en lättbetongkonstruktion2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Moisture in buildings is common and can lead to damage. The moisture can cause moldand rot, which is not good for human health. The moisture can also affect different properties of the building materials such as strength, thermal insulation and dimensional changes. Because high moisture levels can have a major impact on the materials, it is important to detect and fix the problem at an early stage. The purpose and aim of this report is to see if there is a correlation between radar and moisture content and determine whether radar technology is a useful method of measuring moisture contentin a building element.

    In this work, literature studies, measurements and analyzes have been made. The material used is lightweight concrete that is built up to four walls in two different thicknesses, two large and two small walls. The large test-walls were used for radar measurements and the small ones as sample-walls for the gravimetric method. The walls were built in a tent where relative humidity (RF) and temperature could be controlled. At the beginning of the experiment, the RF in the tent was set to 98-99 % and the temperature of 22 °C, which was then regulated to dry out the walls. Measurements have been made with radar and the gravimetric method in parallel, where the latter was made by weighing the sample-walls light concrete blocks at the same time as the radar measurements. The blocks of the sample walls were then dried in an oven at 105 °C to determine drydensity. The collected data from the radar measurements have been processed by the Radarbolaget’s personnel. The results for the different methods have then been analyzed and compared to see if there is a relationship.

    The results from the study show that there is a connection between moisture content and the signals from the radar measurements. The moisture content can be determined on a light concrete wall with a margin of error of ± 4 kgH20/m3material, which corresponds to about 4 %. It is possible to get a good result with radar measurement. However, the method is complicated, but there may be value for further studies on multilayered structures to determine whether the technology can be useful for existing building constructions.

  • 42. Ghadimi, M.
    et al.
    Ghadamian, H.
    Hamidi, A. A.
    Shakouri, M.
    Ghahremanian, Shahriar
    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, Sweden.
    Numerical analysis and parametric study of the thermal behavior in multiple-skin facades2013In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 67, p. 44-55Article in journal (Refereed)
    Abstract [en]

    The general aim of this research is contributed to the energy performance assessment of single storey multiple-skin facade. To cover this aim; multiple skin facade are studied by means of experiments and numerical simulation. In this research a numerical model for multiple-skin facades with mechanical and natural ventilation has been developed. The numerical model is two-dimensional and based on a cell centered volume method (CVM). As an improvement, radiation and convection are treated separately and by this means an innovative method is applied to calculate the view factors and heat transfer coefficients between surfaces and each cavity. Then the developed numerical model is validated using measurements from the vliet test building. However, there is no multiple-skin facade application in Tehran. Thus the model is used to assess the influence of different multiple-skin facade parameters in Tehran's climate conditions to show its effect on heat losses if this technology would be applied. As a consequence of the diversity of results, designer should be aware that multiple-skin facades do not necessarily improve the energy efficiency of their designs. (C) 2013 Elsevier B.V. All rights reserved.

  • 43.
    Ghahremanian, Shahriar
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. 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 system. Division of Energy Systems, Department of Management and Engineering, Linköping University.
    A study on proximal region of low reynolds confluent jets: Part 2: Numerical prediction of the flow field2014In: ASHRAE Transactions, 2014, no PART 1, p. 271-285Conference paper (Refereed)
    Abstract [en]

    Conventional ventilation systems (mixing and displacement) produce low air quality in industrial premises. A new air supply system (confluent jet system) may improve both ventilation and energy efficiency. When round jets are issued from coplanar nozzles with enough spacing, they converge, merge, and combine at a certain downstream distance, which are called "confluent jets." In this study, the velocity field of the proximal region of confluent jets was recorded by traversing a hot-wire probe across the jets in one column at selected distances from the nozzles' exit in order to examine the performance of SST k - ω turbulence model. The experimental and numerical results from this work are summarized in a set of mapping fields of mean velocity for the confluent jet zones, which are presented in a generalized non-dimensional form. The existence of an initial, a converging, a merging, and a combined region in the confluent jets has been found for three low Reynolds numbers. Three different confluent jets can be seen in the array of jets studied placed six by six symmetrically on the long side of a cylindrical supply device. The streamwise velocity of the geometrical centerline of side jets and corner jets decays faster than that for the fully confluent jets, due to deflection towards their adjacent neighboring jets. Side jets and corner jets deflect to their adjacent jets and finally merge and combine with them, while fully confluent jets normally spread and amalgamate with each other. Low local pressure is responsible for the amalgamation of confluent jets, but the static pressure reaches a minimum value between side jets and their neighboring jets, which results in the deflection of the side jets.

  • 44.
    Glaumann, Mauritz
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Assefa, Getachew
    KTH.
    Kindembe, Beatrice
    KTH.
    Norrman Eriksson, Ola
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Miljövärdering av bebyggelse: extern miljöpåverkan, beskrivning av olika miljöpåverkanskategorier2009Report (Other academic)
    Abstract [sv]

    Den här skriften utgör till största delen en översiktlig beskrivning av de miljöproblem som den moderna människans livsföring bidrar till att skapa i sin omgivning och hur samhället arbetar för att motverka dessa. Syftet är att ge en allmän förståelse för dessa miljöproblem och vad de orsakas av samt peka på vilka förändringar som krävs för att undvika eller eliminera dem. Varje kapitel är disponerat på samma sätt med problembeskrivning, mekanismer, den historiska utvecklingen, problemets omfattning, påverkan på människor samt underlag för EcoEffect-beräkningar. Denna allmänna bild har varit nödvändig att ta fram för att utveckla EcoEffect-metoden, som används för att analysera miljöpåverkan från byggande och användning av byggnader. Miljöproblemen som beskrivs är emellertid inte unika för byggsektorn utan gäller i olika grad också alla andra verksamheter i samhället. Därför bör beskrivningarna i rapporten även kunna vara av intresse för andra som vill tillägna sig en grundläggande förståelse för dagens stora miljöproblem. Rapporten utgör samtidigt en redovisning av det beräkningsunderlag som används för att göra miljöbedömningar i EcoEffect. Dessa uppgifter sammanfattas i slutet av varje kapitel och behöver således inte läsas av personer som inte är intresserade av EcoEffect metoden. Dataredovisningen är disponerad efter beräkningarna i EcoEffect som därför sammanfattas här.

  • 45.
    Glaumann, Mauritz
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Malmqvist, Tove
    KTH.
    Miljövärdering av bebyggelse: metodbeskrivning EcoEffect-metoden2009Report (Other academic)
    Abstract [en]

    Environmental assessment in EcoEffect covers internal and external impact. Assessment of internal impact aims at giving a measure of the risk that people who stay in a building or on an estate will be subjected to nuisance caused by the surrounding environment. Assessment of external impact aims at giving a measure of the contribution to negative impact on health and comfort anywhere caused by the use of a real estate, building or building product. Environmental loads are calculated as equivalents contributing to different environmental effects. Aggregated measures are presented as %, which shows the environmental load of the product per user divided by the corresponding load per capita in the country. Environmental loads may also be shown per product or per m2 floor area. At both external and internal assessment is impact of health and comfort the basis for the evaluation: Also problems occurring in the natural environment, as lack of biologic diversity, are interpreted as problems for man. The size of the negative impact is measured as decreased quality of life with respect to certain components used in social medicine. They are: Mobility, Self-care, Daily activities, Pain, Depression and Cognition. Every kind of negative impact taken into account is classified with reference to these components and a disability weight based on the mean value is calculated for each of them. A “damage value” is then calculated for each impact, which equals the disability weight multiplied by the disability time. This concept may be called a further development of the DALY system (Disability Adjusted Life Years). A damage value, which shows the relative significance of any impact, can be calculated in this way. They are used as weights when different kinds of impacts are aggregated. This report describes the calculation of environmental loads, disability weights and damage values for both internal and external impacts in EcoEffect. Also the basis for the development work is reviewed. The method is new and can be applied systematically on all kinds of environmental impacts causing physical or psychological nuisance.

  • 46.
    Glaumann, Mauritz
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Wallhagen, Marita
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Study of international policies, Sweden: National initiatives for reducing the environmental impact of the building sector2006Report (Other academic)
  • 47. Glaumann, Mauritz
    et al.
    Westerberg, Ulla
    Närklimat kring stora hus2018In: Hus mot himlen – hållbar hybris? / [ed] Olshammar, G., Olsson, K. & Siesjö, B., Malmö: Bokförlaget Arena , 2018, p. 200-221Chapter in book (Other (popular science, discussion, etc.))
  • 48.
    Grundberg, Per
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Häll, Fredrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Energieffektivisering av en Hälsingegård med avseende på bevarandekrav2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Sedan år 2012 finns det sju stycken Hälsingegårdar på UNESCOs världsarvslista. Detta har medfört att intresset för dessa gårdar har ökat både inom Sverige men även internationellt. En Hälsingegård karakteriseras av den detaljrikedom och de träarbeten som präglar byggnaden både exteriört och interiört. Husets tapeter och målningar interiört är även något som kännetecknar huvudbyggnaden på en Hälsingegård.

    Syftet med denna studie var att undersöka i vilken utsträckning det går att energieffektivisera en Hälsingegård med avseende på problematiken som uppstår genom att byggnaden har ett kulturhistoriskt värde och bevarandekrav. Energieffektiviseringen strävade till en början efter att byggnaden skulle uppfylla krav som ställts av Boverket på specifik energianvändning för småhus i regionen. Idag bedrivs en uthyrningsverksamhet i samarbete med Bo på Hälsingegård som erbjuder turister övernattningsmöjligheter på Hälsingegården under sommarmånaderna. Studien undersökte även vilket energibehov byggnaden har vid en uppvärmning och förlängning av uthyrningssäsongen med två och en halv månad.

     

    Studien genomfördes med följande metoder; litteraturstudier, platsbesök, energibalansberäkningar, fuktberäkningar och en kostnadsberäkning. Stor vikt lades vid platsbesöken vilket sedan använts som underlag för de övriga metoderna. För en av de föreslagna åtgärderna genomfördes en analys för att se om åtgärden bidrog till ökad risk för fuktproblem.

     

    Genomförandet av dessa metoder har lett fram till olika åtgärder som sänker byggnadens energibehov utan att gestaltningen påverkas. Energibehovet under ett år minskade med 38 procent och under sommarmånaderna maj till september minskade energibehovet med 61 procent genom de åtgärder som presenteras i studien. Att klara målet på 75 kWh/m2 Atemp år, var något som inte gick att uppfylla med de åtgärder som föreslogs i denna studie. Fuktanalysen av den kontrollerade åtgärden visar att risken för fuktproblem minskade efter åtgärden.

  • 49.
    Gudmundsson, Kjartan
    et al.
    School of Civil and Architectural Engineering, KTH.
    Sjöström, Christer
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - material science.
    Norberg, Peter
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - material science.
    Trinius, Wolfram
    Twumasi, Ebenezer
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Buildning science - material science.
    Durable and robust vacuum insulation technology for buildings2011In: XII DBMC: 12th International Conference on Durability of Building Materials and Components (Vol. 4) / [ed] Michael A. Lacasse, Vasco Peixoto de Freitas, Helena Corvacho, Porto: FEUP Edições , 2011, , p. 8Conference paper (Refereed)
    Abstract [en]

    Vacuum insulation panels (VIPs) provide unprecedented opportunities for obtaining excellent thermal insulation with light and slender constructions. This article discusses the performance over time of VIPs, and the possibilities to overcome the current problems related to fragility and limited durability. Aerogels are together with fumed silica among the most competitive core materials for VIP's. The use of classical aerogels, as produced in autoclaves is, however, limited due to the high production costs. The fumed silica on the other hand requires vacuum levels that are difficult to maintain with the currently available vacuum envelopes. A material with comparatively smaller pores will on the other hand allow obtaining low thermal conductivity at higher pressure (less vacuum) and will therefore reduce the pressure difference over the envelope. There is therefore much to be gained by reducing the pore size. New cost and performance efficient silica aerogels offers opportunities to enhance the properties of the panels by customizing the pore structure and pore size distribution. Building technologies and how the panels are applied in a manner that improves the structural, thermal and hygroscopic performances of vacuum insulated constructions have been studied and are discussed.

  • 50.
    Hallberg, Daniel
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Stojanovic, Bojan
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för byggnadskvalitet.
    Analytical and numerical thermal modelling & analysis of an building integrated unglazed solar collector: PhD course paper2007In: Mathematics for PhD-students in building science, Stockholm: Architecture and the Built Environment, Royal Institute of Technology , 2007Chapter in book (Other (popular science, discussion, etc.))
    Abstract [en]

    The objective of this report is to derive an analytical and numerical USC model for thermal analysis. These models are meant to calculate USC temperature variation across the USC duct as well as the fluid temperature along the USC. The main purpose of the analytical model is to attain a detailed steady state tool for USC (as in this report) design and dimensioning. The numerical model is meant to calculate the time dependant USC thermal performance as well as being a benchmark for the analytical model.

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