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  • 1.
    Abolghasemi Moghaddam, Saman
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    The effects of low-emissivity window films on thermal comfort and energy performance of a historic stone building in cold climate: computer simulations with "IDA ICE"2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Low-emissivity (low-E) window films are designed to improve the energy performance of windows and prevent indoor overheating by solar radiation. These films can be applied to different types of glazing units without the need for changing the whole window. This characteristic offers the possibility to improve the energy performance of the window of old and historic buildings for which preservation regulations say windows should remain more or less unchanged. This research aims to figure out to what extent a low-E window film can improve thermal comfort and energy performance of an old three-storey historic stone building in the cold climate of Mid-Sweden. In this research, first, with help of the simulation software “IDA ICE”, the entire building was modelled without window films in a one-year simulation. Second step was to add the low-E window films (3M Thinsulate Climate Control 75 (CC75)) to all the windows and repeat the simulation. Comparison between the results of the two cases revealed an improvement in energy use reduction as well as the thermal comfort when applying the films. For the application of the window films, a cost analysis using payback method was carried out which showed a long- time payback period. Although an investment with a long-time payback period is considered as a disadvantage, for historic buildings with very strict retrofit regulations specially when it comes to the building’s facades, application of the low-emissivity window films for better energy performance and thermal comfort is among the recommendable measures, but not necessarily the best.

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  • 2.
    Ali, Ali Talib
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Resilient cooling technologies: Simulation study to determine the cooling capacity in old residentialbuildings located in mid-Sweden2022Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Long-term changes in the climate conditions have increased the need foradequate thermal comfort systems. These alternations influence extremeevents, which their intensity and frequency have increased over the past years.Moreover, this study focuses on space cooling and parameters that the systemshould have to be considered as resilient. Literature study was done to presentthe concept of resilience as well as the different methods used to provide spacecooling. In addition, the cooling systems suggested in this study, which aredistrict cooling and absorption cooling, were presented and explained.Furthermore, the study focuses on cooling demand in a group of residentialbuildings based on different thermal characteristics, which were implementedbased on building regulations from late 1960s to early 1980s. The buildingthermal properties were used as input to obtain their cooling demand by usingbuilding energy simulation tool. Based on the acquired results, an evaluationhas been made for the cooling demand of those buildings. Further analysispresented a correlation between the cooling demand and thermal properties ofthe buildings and aided in the determination of the required cooling capacity.The selection of the capacities was based on the resilience criterion as the systemhas to be able to provide adequate performance and safety for the occupantsduring extreme events. Furthermore, an assessment was done to compare thesuggested system based on their capacities and the primary energy use.

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  • 3.
    Ali, Sabir
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Building Information Modelling for Energy Analysis and Environmental Assessment: The comparison of LEED and Miljöbyggnad for two school buildings in Gävle, Sweden2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The building sector is one of the largest energy consumers and there are global efforts toward sustainable and energy-efficient new buildings and existing buildings retrofit. The application of Building Information Modelling (BIM) in environmental assessment was practiced and studied following the increasing number of projects adopting the BIM workflows and pursuing green building certifications. The interest of this thesis is to study the use of different Building Information Modelling tools used globally for energy and environmental assessment to examine their practical benefits and challenges. Case studies of two primary school buildings that achieved the Swedish Miljöbyggnad system were used to compare what could have been achieved with Leadership in Energy and Environmental Design (LEED) categories of energy and atmosphere and indoor environmental quality to what has been achieved in similar Miljöbyggnad areas. A review and summary of energy and atmosphere and indoor environmental categories in the LEED version 4 user’s guide is presented to evaluate the case study potential score in them.

    The early adoption of modeling in the evaluation from the conceptual design is the best approach to achieve better performance. It will improve the way of working and result in a more efficient and sustainable building.

    The Building Information Modelling software can be used directly in assessment using the integrated modules within the popular authoring tools such as Revit’s lighting and Insight the cloud base service or by transferring the model data to a stand-alone tool like IDA-ICE. The energy plug-ins of the authoring tools such as Revit are still lacking full control over the analytical model and the limited input options.

    The identified and discussed advantages of Building Information Modelling implementation are collaboration, accuracy, time, and cost saving. Data exchange issues, knowledge, and the differences in assessment tools were discussed as implementation barriers.

    Although the full comparison of certification systems is difficult, the comparison between the potential LEED score and achieved Miljöbyggnad rating showed some differences and similarities in the rating systems. The comparison requires rearranging the rating system indicators into unified categories. The framework that compares the scope, structure, content, and aggregation, would give a meaningful comparison. The way that the LEED and Miljöbyggnad are rewarding the indicators and the aggregation of aspects towards the final rating is totally different.

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  • 4.
    Andersson, Michael
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Jonsson, Axel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Strorheter vid bedömning av energieffektivitet för byggnader: En fallstudie för indikator 1 och 3, Miljöbyggnad 3.12021Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

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

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

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

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

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  • 5.
    Arizcun Zúñiga, Paula María
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Ram pump hydraulic air test. Pressure conditions and flow measurements: Experimental research and case study2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study consists of the development of a ram pump, which will allow the pumping of water without the need of external energy sources. It is considered an analysis of interest since, once it is finished; it can be applied in reality improving and facilitating different activities related to agriculture and health.

    Previous studies have been made related to the ram pump; however, in this case, it is intended to understand the system that has been built in the laboratory in order to find the best combination of parameters that will lead to obtain the highest possible efficiency. 

    The study will be carried out by studying scientific literature and by experimenting in the laboratory. Encompassing the experimental and literary field, it is expected to understand perfectly the advantages and disadvantages of the ram pump in order to determine if it is worth it to install in certain places.

    After the study, the most favourable parameters for the operation of the Bruzaholms Bruk pump have been obtained. It has been found that the use of a longer drive pipe favours the operation of the system, as it is possible to obtain a higher efficiency, although it must be taken into account that the mentioned length needs to be controlled, as it could reduce the working rhythm of the pump. It has also been seen that the pump gives better results if the impulse valve is completely opened. Finally, it has been proven that, as long as the height difference between the two tanks is enough, increasing the height of the water source will favour the operation of the system.

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  • 6.
    Berner Wik, Petter
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Värmereglering utifrån byggnadens tidskonstant i en värmetrög fastighet: Prognostiseringar utav värmeenergianvändningen och dess ekonomiska kostnader2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In order to continue the development towards a more sustainable city of Gävle, Gävle Energi AB will implement a new season-based capacity model by the year 2019. It creates economic incentives for energy efficiency in real estate’s within Gävle's district heating network.

    This report investigates how the heat energy is used for a building that risks an increased heat energy cost, due to the new pricing model. The aim of the study is to reduce the heat energy usage without investing in the building, which is made possible by regulating the thermal energy supply to the building.

    By programming one year of historical data of temperatures, solar radiation, power- and heat effects the heat supply is forecasted the same way as the building's control system Kabona Eco-pilot is working. The control system applies a floating indoor temperature, which contribute that the thermal inertia of the building is included in the heat load control.

    The study includes two forecasts that are compared to the actual heat energy use and the new capacity price model. Forecast 1 is based on an annual cycle and forecast 2 is based on the range of November 2017 to Mars 2018. The aim of forecast 2 is to apply a strategic heat load control to reduce the heat capacity needed at -10˚C.

    Forecast 1 indicates a potential heat energy saving of 26% even though Diös Fastigheter AB does not invest in any energy saving technology. A saving of approximately 44 700 SEK is forecasted for the annual cycle. The building has an energy class D and has the potential to achieve energy class C after the change of control system parameters.

    Forecast 2 indicates a potential capacity reduction corresponding to 46,1% while the variable heat energy consumption decreases. Overall, there is an approximated heat energy saving potential of 47,8%, which corresponds to 216 700 SEK, during the range of 2017-11-01 to 2018-03-31. Due to the consequence of a lower indoor temperature.

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  • 7.
    Björklund, Lina
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Energy Audit and Energy Saving Measures of a Large Office Building: Bern 9 in Örnsköldsvik2020Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    There is a large potential in making the residential and service sector more energy efficient and the first step towards achieving a more efficient use of energy is to implement an energy audit. In this study a property with an approximate area of 8 000 m2, consisting of a main building and three building extensions from different eras has been examined. The main building and its extensions were built in different stages and the first one in the early 20th century and some parts of the last building extension were modified at the time that the examination was carried out. This indicates that there is a vast energy savings potential in the property and an energy audit was performed. The main aim of the study was to examine where the energy was being used and where energy could be saved. Energy saving measures has been suggested together with a calculated approximate energy decrease and payback period. The total energy savings potential for the measures is approximately 146 MWh. The energy audit showed that a large amount of electricity was being used during non-work hours and that energy was lost through the building envelope. The electricity use during non-work hours was examined during the night walk, however, it is suggested to carry out further examinations regarding the property’s vast electricity use during non-work hours. To add loose wool in the roof of B2 has an energy savings potential of 33 000 kWh/year. Another measure is to clean the heat exchangers, this measure has an energy savings potential of 26 000 kWh/year. Also it is suggested to optimize the operational hours for the lighting by implementing presence control and to decrease the energy use for ventilation by cleaning the heat exchangers. Further examinations that would improve the study would be to do measurements of the electricity and temperatures to get a better understanding of the buildings energy use. Also to model the building in a simulation tool would give a calculated energy loss that is more like the actual energy loss of the building and make the results more reliable.

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  • 8.
    Choudhury, Meghdeepa
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Pre-renovation considerations for a Swedish single-family house: Analysis of energy saving potential2021Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
    Abstract [en]

    According to United Nations 7th sustainable development goal, increased use of fossil fuels in energy accounts for around 60 percent of total global greenhouse gas emissions and in order to debacle this crisis of global warming, the European Union aimed to reduce energy use by 32.5 % within 2030 by improving energy efficiency. Whereas, the Swedish energy goals include reducing energy use by 50% in 2030 compared to 2005 and at producing 100% electricity from renewable sources by the year 2040. In the year 2018, the housing and service sector contributed to 40 per cent of the total final energy use in Sweden according to energimyndigheten. For this reason, energy conservation in the residential sector is given a priority. Furthermore, the emissions from old houses are much higher compared to that of newly built homes, which demonstrates higher scope of introducing energy efficient renovation measures in Swedish buildings. During the year 1965 to 1976, there was an enormous construction work to build up single family housing areas in Sweden under the million homes program which are now in need of renovation. Therefore, an old single-family villa from million homes program was selected for the purpose of energy efficient renovation.There are different environmental certification systems to assess energy performance of a building which are commonly expressed in terms of kWh/m2 and year. Among them, the seven energy classes from A to G was chosen for building rating in this project. The aim was to improve the current energy rating of the house from D without compromising the indoor air quality and cost effectiveness. At the same time, objective was also set to increase the amount of green energy as fuel for electricity production in the building. At first, a literature review was performed to observe the renovation strategies previously applied in similar projects. A study of the construction used for the million homes villas was also conducted to assess the original construction of the reference villa in Valbo. The research was conducted with the help of energy simulation software IDA ICE and LCC software BELOK Totaltool. The theory behind the application of these software in this project was analyzed in the beginning. Then, the building model was created with the help of building floor plan. The input parameters were set according to the standards of FEBY and Boverket regulations. After forming a base model for the existing construction of the building, different sensitivity analyses were performed with various renovation measures for one month or for one year. The results obtained from the sensitivity analysis helped in choosing the most energy efficient measures for renovation. Then the economic analysis of the model was conducted to investigate the most cost-effective measures. Later on, these expensive measures were omitted from the renovation plan to yield both energy efficient and cost-effective renovation of the villa. Next, the indoor air quality and green footprint in the building were compared before and after renovations. The results indicated that, it was possible to maintain good indoor air quality and increase green energy footprint in the building when the building rating was changed from D to B. In the end, the simulation results were compared with that of the literature review. It was found that both the qualitative and quantitative results have common realizations. Overall, it was possible to reduce the energy consumption in the house by 46.82%.

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  • 9.
    Drewes, Carl
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Effektförlustutredning: Effektförlustutredning av en mindre sodapanna tillhörande ett medelstort massabruk, en fallstudie.2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The industrial sector in Sweden stands for 38 percent of the total energy use. Within these 38 percent the pulp and paper industry stand for about half of the energy use. Due to the extent of the energy use it is important that we do what we can to keep the energy usage as low as possible within our industries. In this bachelor thesis a case study is performed regarding a problem with a recovery boiler which belong to one of Stora Ensos pulp mills in a small town called Skutskär in Sweden. The problem with the recovery boiler is that it does not reach the temperature of the outgoing steam for which the soda boiler was designed, which causes the efficiency to suffer. The problem with the recovery boiler is not sustainable either in terms of energy use or economy. Recovery boiler 6 (RB6) as it is called is one of two recovery boilers belonging to the pulp mill. Both boilers are designed to produce high pressure steam at 56 bar and 450°C. The high-pressure steam produced goes through a back-pressure turbine where the pressure is lowered to the working pressure of the remaining factory while electricity is produced. Steam at a lower temperature results in lower enthalpy, which in turn will affect the electricity generation in the back-pressure turbine. The purpose of the study is to quantify the loss in electricity generation caused by the lack of steam temperature of RB6. As well as investigating the causes of the lack of heat transfer where the goal is to locate the problem area.

    A literature study was conducted regarding the efficiency of the recovery boiler, where much emphases was placed on the function of the superheater and the soot system. The superheater accounts for about 30 percent of all heat transfer in a recovery boiler and is directly crucial for reaching the final temperature of the steam. In the literature study, among other things, the design and fouling of superheater is studied to see that if affects the heater transfer. Further, the soot system effect on the heat transfer is also studied and it shows that the soot system has a greatly influence of the final heat transfer.

    The method used to conduct the study is primarily data analysis. The pulp mills internal analysis program WinMops is used in combined with Excel to analyze operational data. First, the magnitude of the problem was investigated by calculating the effect of RB6’s lack of steam temperature on the total enthalpy of the steam reaching the turbine. Calculations were made for electricity generation in normal cases and under the influence of RB6, where the difference was considered as lost electricity generation. Once the size of the problem was determined, the investigation of causes of heat transfer began, with the superheater coming into focus.

    The results of the case study show that RB6’s lack of steam temperature causes a loss of electricity production equivalent to 7 million SEK in a normal year and a year with a low electricity price, this amount to 3 million SEK. Whit regard to the second investigation, it is very likely that the superheater causes the temperature drop. However, the study shows that the superheater has no smaller heat transfer surface in relation to the other recovery boiler and that the heat transfer rate is also not deviant. The superheater shows a hint of fouling at the same time as the flow of soot steam is slightly lower on RB6, unlike the mill’s other recovery boiler. An interesting phenomenon that emerges in the study is that the tertiary air flow tends to have a greater effect on RB6 outgoing steam flow than expected.

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  • 10.
    Elofsson, Fredrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Optimering av last och produktion i Gävles fjärrvärmenät: Reducering av effekttoppar via värmelagring i byggnader2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    District heating is today the most common way of providing a building with heat and hot water in Sweden. It is an environmentally friendly product mostly used with renewable fuel. However, at power peaks most companies use production units that are more expensive and worse for the environment and should therefore be avoided as much as possible. This can be done with a method called load management. When a power peak occurs, the heat supply to buildings connected to the district heating system can be temporarily reduced. The heat energy can later be returned when the heat demand is lower. Thanks to the heat inertia of the buildings, the indoor temperature will not fall within the time frame for the load management. Historical data has been analysed to identify when and why power peaks occur in the district heating network. Power peaks throughout the district heating network have proved difficult to identify. However, for individual consumers clear patterns of power peaks have emerged. These power peaks mainly occur because of large use of hot water but also because of the shifting outdoor temperature. In order to see how the production cost would differ from the actual outcome load management was applied for Gävle's district heating 2018. The load management was calculated manually by identifying the most expensive production unit on an hourly basis. If a cheaper production unit had the potential to deliver higher power the next hour, the production was moved to the cheaper production unit. The process was repeated for each hour during 2018. After carrying out load management for Gävle's district heating network, 1 457 MWh had been shifted to a cheaper production unit. This resulted in a financial saving of 1,0 % of the total production cost. The environmental savings showed a reduction from 6.1 to 5.9 g CO2eq /kWh a total of 197 tonne CO2eq. In the exact same way, a load management was performed for a scenario where Gävle and Sandviken's district heating network were connected. The gain for a load management with Sandviken will be considerably larger, a reduced production cost of 3.6 % is possible. The environmental savings showed a reduction from 8.4 to 7.8 CO2eq /kWh a total of 575 tonne CO2eq. For future efficient load management, buildings should be divided into different classes depending on the building's time constant. User patterns for the entire district heating network have proved difficult to detect. Artificial intelligence can be an option for short-term forecasting of the power output

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  • 11.
    España Campillo, Fernando
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Comparison of energy efficiency simulations in a school through the energy simulation tools IDA-ICE and CE3X2020Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    As of 2010, from Directive 2010/31/EU of the European Parliament and the Council of 19 May 2010 on the energy performance of buildings, and other related directives, it was established that the Member States of the European Union should implement regulations to promote energy efficiency certifications in buildings.

    In Spain, the CE3X energy simulation program can be used to meet this requirement, however, the program uses a simplified simulation method that may not be accurate. In Sweden, on the other hand, the program IDA Indoor Climate and Energy (IDA-ICE) is widely used. Will it be possible to obtain similar results if we use both programs to simulate the same building?

    In the thesis, for the above reasons, the energy behaviour of the same building is studied with these two different programs. IDA-ICE, which uses a detailed simulation method, and the CE3X software, which uses a simplified simulation method. Also, the operation of the program is explained in detail.

    In addition to simulating the building, different energy efficiency measures are studied, and the results obtained between the two programmes are compared.

    It is important to take into consideration that, thanks to the simplifications, while a technician with a minimum of experience can complete a simple simulation with the CE3X program in one working day, the simulation with IDA-ICE requires a greater knowledge of the computer program, and two or three days are needed if the simulation is to be completed in maximum detail.

    However, this is inevitably reflected in the result. The results obtained in the two simulations carried out in the thesis show differences in the calculated energy usage of around 14%. In addition, the thesis includes an assessment of the proposed improvement measures, which also make it possible to study the different behaviour of the two computer programs when faced with the same reference situation. Improvements in lighting efficiency is evaluated as well as improvements in the thermal envelope or building enclosure. While the result obtained ensures that improvements in lighting are always cost-effective, any improvements in the thermal envelope (changing windows, for example), from an economical point of view, are not profitable.

    The result obtained is consistent with the information found in the literature review (this type of simulation must be always considered within a wide margin of error). The criterion used by each technician in how the input data are used or introduced in the software can make the results vary an additional high percentage. Moreover, sometimes it is not possible to determine which criterion used is more valid.

    For all these reasons, the comparison made in the thesis allows to state that the CE3X programme allows compliance with the Spanish regulations and gives fast results that can be considered relatively reliable in some cases, after comparing them with the results obtained from IDA-ICE. However, IDA-ICE allows results of higher quality.

  • 12.
    Etxeberria, Aitor
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    CFD simulation and analysis of glazing bar effects on heat and airflow inside a two-pane window2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
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  • 13.
    Ferrero Andrés, Javier
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Assessment of calculation methods for Primary Energy Factors: Case Study of Swedish electricity mix2022Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The use of the concept of "primary energy" is present in all types of regulations at both European and national level, so that all aspects related to the reduction of energy use and energy efficiency measures speak in terms of primary energy and Primary Energy Factors, necessary for its conversion. The existing consensus on the use of the term is not such in terms of the methodology for calculating the Primary Energy Factors to be adopted, which is the reason for the search for a methodology that acquires the status of global and standard.

    Using an analytical methodology, this study will analyze and compare the main methods used by agencies and institutions: the Physical Energy Content Method and the Partial Substitution Method, together with another less widely used method, the Exergy Method. The three calculation methodologies will be applied to the case study of the Swedish electricity production mix. The main objective of this thesis is to analyze the advantages and disadvantages of those methodologies, as well as discuss the difficulties of defining some variables such as efficiencies and system boundaries.

    The results obtained in this study demonstrate the complexity of trying to analyze a system as complex as the energy consumption of a country based on the calculation of a single number or Primary Energy Factor. The system boundaries affect the results. At the same time, the use of the Physical Energy Content Method is discarded because it incurs thermodynamic discrepancies. On the other hand, the use of the Partial Substitution Method and Exergy Method is encouraged, since they reflect more accurately the primary energy consumption, as long as the values of efficiencies that they use are clearly defined and referenced. However, there is a more widespread use of the Physical Energy Content Method in the institutions since the other methods present the great difficulty of establishing a consensus on the energy and exergy efficiencies values adopted.

    The complexity of choosing a calculation methodology is not only due to the choice of efficiencies but other factors, such as system boundaries, also influence the final results and they have to be reflected in some way. Therefore, it is difficult to decide on a single solution and future studies on other indicators and variables affecting primary energy usage are needed, for instance, CO2 emissions associated with generation technologies.

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    Final Master Thesis
  • 14.
    Färnström, Dennis
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Energibalans av två glödgningsugnar inom ett integrerat stålverk2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The steel industry occupies the whole 7 % of the global carbon dioxide emissions caused by human factors and 5 % of the global energy usage. The steel industry is an energy intense industry and it’s therefore important to analyze its energy use for its future sustainability. Furnaces are driven on non-renewable fuels and are one of the devoting components to the high energy consumption, so studies of this are of high relevance.  Regarding modern techniques of furnaces in today’s mode are much concentrated on the combustion, which means the combustion of the fuel that supplies the furnaces with heat.  Oxy-fuel technology means that the fuel is combusted with pure oxygen instead of air, and its purpose is to increase the combustion efficiency. A second modern technology is the usage of burners that are able to recycle flue gases as an increase of energy efficiency.  Outokumpu is a world leading company in the manufacture of stainless steel and the plant in Avesta is an integrated steel mill, which means the steel production cover the entire process from scrap and raw material to finished product. The plant consists of three main works called the steel mill, hot rolling mill and KBR L76 which is the department for these annealing furnaces.  The main objective of this report is to present an energy balance of two annealing furnaces at the Outokumpu plant in Avesta. The boundary of the study is clear, the energy balance will take part from the inlet of the first furnace to the outlet of the second one. It’s the thermal energy efficiency that has been studied, that is to say how much energy you get from the fuel that is added. Information has been collected using historical data on the operation of the furnaces during a three month period of time, also manual temperature measurements has been carried out.  By calculations an efficiency has been developed for each furnace and the furnaces together. This has been carried out by weighing the proportion of the amount of heat that all material have accumulated, with the amount of oil used during the same time.  The results of this study mainly indicate that the furnaces are effective in heating the steel, and its heat losses from the surrounding areas are small. On the other hand, there is potential for recycling more heat regarding the use of flue gases in the exhaust-boiler.

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  • 15.
    Hayati, Abolfazl
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    NUMERICAL STUDY OF 2D PARTICLE FLOW IN A DUCT2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
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  • 16.
    Höglund, Marcus
    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.
    Stenås, Anton
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Komfort- och energianalys vid installation av markiser på Högskolans i Gävle glasfasader: Mätningar och IDA ICE-simuleringar2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The University of Gävle plans to install solar shading awnings on the southern glass facades of the main entrances. Since construction, the main entrances Rävhallen and Fårhallen have suffered from poor thermal indoor comfort due to heat leakage and overheating due to the windows on the facades.

    This thesis was done in order to map and investigate the thermal indoor comfort in the University of Gävle's main entrances. The work also aimed to simulate and analyze annual energy consumption and thermal indoor comfort before and after the installation of solar shading awnings on the building's glass facades, in the simulation program IDA ICE.

    A comfort survey was conducted by measuring thermal comfort and indoor temperature ranges on two occasions in April. The measurements were made during a cloudy day and a sunny day at the same outdoor temperature, to investigate the effect of solar radiation on the building's thermal comfort and indoor temperatures. The comfort survey showed that the thermal comfort in Rävhallen and Fårhallen was insufficient as overheating occurs at high solar radiation.

    Data necessary for modeling and simulation was collected through observations, estimates, and dialogs with operating technicians from Akademiska hus. After data collection, a model was constructed in the simulation program IDA ICE. Before simulation, the model was validated using previously measured temperatures during the month of April. Then the building's energy consumption and thermal indoor comfort were simulated over a whole year, without awnings, and with awnings.

    The results showed that the thermal comfort was significantly improved by the awnings installations. High peak temperatures that previously occurred in the building decreased because of the reduced solar radiation through the glass facade. The total annual energy demand increased from 605 MWh to 635 MWh. However, the annual energy demand for cooling decreased from 3,4 MWh to 3,2 MWh. The increase in energy consumption was due to the awnings reducing useful heat from solar radiation, especially during the heating season. Prior to further research, a more efficient control technique of the awnings and a more detailed model to improve the simulation results are proposed. When applying better adapted control of the awnings, the energy saving potential is considered to be greater. It was concluded that awnings can significantly improve indoor thermal comfort, but that energy consumption may increase depending on control technology.

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  • 17.
    Kifleyesus, Biniam Okbaendrias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Eneregy Management In Industries: Analysis of Energy Saving potential by Steam conedensate recovery2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When speaking about energy it means speaking about life, activity, economy, growth and environmental issues. The issue of energy has been the main article all over the world in recent years, this is due to the importance of energy to life and its impact on the environment. For example, Paris climate change meeting in 2015 is one of the recent global meeting which directly related to the energy use by nations. The meeting was mainly focused up on the restriction of greenhouse gas emission which implies that industries should think about other alternative energy resources rather than fossil fuel for positive impact on climatic change. This is one of the cases that led industries into greater competition in the global market. Industries must consider energy alternatives which is safe for the environment and by using such energy a competitive product with better quality and quantity should be produced. This challenge has motivated industries to look and study the energy that they are using currently.

    Studies and researches show that one of the main and most abundant energy resources that most of these industries can get is by improving the energy efficiency or managing the energy that they currently use. The main aim of this thesis is to provide Arizona chemical plant (Kraton) at Sandarne on the potential energy saving by managing their energy use. The first wisdom in energy utilization is managing and using the energy they possess efficiently. In Arizona plant at Sandarne, the product named “Pitch” (a natural viscoelastic polymer or rosin) is a fuel used as the primary energy supply for the production of steam by boilers. The steam may be utilized well but the energy in the condensate (after steam loses its latent heat) is not addressed well enough. Hence this paper has studied on how significant is the energy lost by the steam condensate is and how its recovery can be used to save energy and cost.

    The plant produces about an average of 11.42 ton of steam each hour in a year. This steam can be returned or fully recovered (100%) as condensate from the law of conservation of mass since only energy is lost from the steam. But the plant returns a maximum of about 3ton of condensate each hour. This amount is relatively low compared to the amount of condensate recovery possibility. Recovery possibility of condensate return showed that the plant at Sandarne can return at least 8.5 ton of condensate  each hour. In comparison with the current return estimated 5.5 ton of condensate is being lost simply as waste each hour leading to about 400 SEK minimum cost loss. The calculation of cost is in minimum because the charge from water supply and condensate effluent disposal charge are not considered. In this paper only recovery from the easily recoverable steam condensate is being considered (25% of the system) which resulted in payback time of the proposed investment 1.88 years without considering the above explained charges.

    It is much motivating study considering the generalized approach and over simplified method. If a deeper investigation is made on the potential, it can be clearly shown that how significant the potential is in securing and sustaining energy and environmental issues. Ensuring the security and sustainability of energy which addresses the environmental issue precisely will help the plant to stay on the race of global market competition.

     

    Keywords: Energy efficiency, Boiler efficiency, Energy management, Condensate recovery,

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  • 18.
    Lloret, Eduard
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Analysis of energy usage in supermarkets: Representation and streamlining of the global supermarket energy system2017Independent thesis Advanced level (degree of Master (Two Years)), 12 HE creditsStudent thesis
    Abstract [en]

    The thesis performed in this research is focused on a particular type of energy system, energy systems in supermarkets. As supermarkets are high-energy using buildings, their energy system optimization has been investigated in recent years, with the main focus in the refrigeration system, which can take up to 50% of the total energy of the supermarket. However, the complexity and interconnections of the different systems increase the difficulty of the task.

    The aim of this work is to contribute in SuperSmart project, an EU project which main objective is to reduce the impact of the supermarket sector overall Europe, through the development of an ecolabel criteria. To simulate the energy use in supermarkets, CyberMart software is bring forward. This tool is used both to determine the parameters which have a higher impact in the supermarket energy system and perform energy representation based on those parameters. Finally, the design of the most energy efficient store is also presented.

    According to CyberMart, some of the most determinant parameters in the supermarket energy system are refrigeration capacities, plug in cabinets used, lights power, heating system technologies used and whether the cabinets are covered or not. Using some of these parameters plus other important characteristics from the store, two energy representations are performed. Whereas the quadratic representation provides the final results concerning heat or electricity demands with a high accuracy, the linear representation presents the increase or decrease of kWh per each parameter, enabling supermarkets owners to compare different parameters within the global system.

    It is concluded from these representations, which distinguish between heat recovery and floating condensing technologies, that the most important parameters in the global system are the temperature inside at winter and the refrigeration capacity. However, some unreasonable events appear, like the decline of electricity demand when the height of the building increases or the drop of heat demand with the rise of opening hours. These facts occur due to the high complexity of the global system, implying different connections between the sub-systems within CyberMart.

    Concerning the most energy efficient store located in Stockholm, the obtained results show the most energy efficient supermarket is composed by CO2 refrigeration and heating systems, and a R410_A air conditioning system. The optimal electricity use of each establishment size from large to small area is 382, 394, 390 and 281 kWh/m2*year respectively, with the highest values obtained in Supermarkets and Discount stores, due to their higher rate of refrigeration power per store area.

    Keywords: Supermarket, refrigeration system, SuperSmart, CyberMart, heating system, refrigeration capacity, plug in cabinets, lights power, heating system technology, covering of the cabinets, energy representation, heat recovery technology, floating condensing technology, air conditioning system, Discount store.

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  • 19.
    Lukkarinen, Christoffer
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Uvärdering av simulering med Winsun PV: En jämförelsestudie med PVGIS och fältmätningar2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I den här studien utvärderades Winsun PV, ett webbaserat program för PV-simulering som vid den här tidpunkten var under utveckling. Winsun PV är tänkt att genom enkla inputs och med högkvalitativa klimatdata bli ett standardprogram för PV-simulering i Sverige. Studiens syfte var att jämföra Winsun PV med PVGIS, jämföra Winsun PV med fältmätningar hämtade från andra studier samt ge en introduktion i solgeometri. Simuleringarna utfördes i Winsun PV och PVGIS för PV-system med olika riktningar och lutningar i 12 olika städer. Därefter jämfördes resultaten för solinstrålning och elproduktion. Resultaten för instrålning visade sig i de flesta fall vara snarlika med en skillnad på ca ± 3%. Skillnad i elproduktion var något högre på ca ±5%. Dock stack några fall ut med större skillnader och för dessa fall utfördes ytterligare simuleringar. Dessa fall var: Göteborg som uppvisade stora skillnader på ca -10% för samtliga fall. Umeå som i vissa fall hade nästintill obefintliga skillnader, men i andra fall erhölls de största skillnaderna i hela studien där den största låg på hela -23,7% elproduktion för azimut och lutning 45°. Visby som uppvisade en form av kaotiska resultat där Winsun PV visade en lägre instrålning men en högre elproduktion.

    I jämförelsen av fältmätningar uppvisade Winsun PV en skillnad på + 5–10% för både instrålning och elproduktion, dock saknades viss information kring dessa system varför en del antaganden gjordes.

    Det mest noterbara resultatet för hela studien kom från skillnader i horisontell instrålning mellan Winsun PV och PVGIS jämfört med skillnader mellan PVGIS och fältmätningar. Resultaten visade sig vara tvärtom mot förväntningar. I nästan samtliga fall visade PVGIS en högre instrålning än fältmätningar där tidigare PVGIS hade visat lägre instrålning än Winsun PV. Om dessa resultat stämmer betyder det att Winsun PV inte bara har samma felaktigheter som PVGIS, men också förstärker dem.

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  • 20.
    Lumbier Fernandez, Mikel
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Alternative energy supply study for a cottage in Vifors2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The present master thesis was done during the spring of 2018. A cottage located in Vifors is studied with regard to its heating requirements. At the time of the study, the house could not be inhabited the whole year because there was no tap hot water available and the space heating demand was covered by electricity. Thus, an alternative heating supply is required to be developed. As a strategic prerequisite, the solution should be achieved considering both solar thermal collectors and a heat pump.First, the characteristics of the building were collected/determined in order to obtain the total heating demand per month and hence annually. Parameters such as the U-values, roof orientation, room dimensions, ventilation rates and internal gains were required to configure the building model in the software IDA ICE 4.8. In addition, the amount of tap hot water required per year was determined as 17 m3 per year. Cold water at 5 °C had to be heated until 55 °C to obtain the tap hot water.Once the heating requirements were known, the most suitable solution was to use a combi system (solar thermal collectors and a heat pump). Solar energy could fulfil the demand in the summer and the heat pump provided energy in the winter. For a commercial model of the flat solar thermal collector (Vitosol 100-F) the solar system was sized according to the heating demand in the summer time. The maximum energy that could be obtained from the solar collectors in summer was calculated, the rest of the demand had to be fulfilled by a heat pump, model WPL-18 E.The achieved solution is compounded by the heat pump and 3 solar thermal collectors with a surface of 2.33 m2 each. The solar energy obtained is 1 843 kWh per year, which covers 9 % of the total annual heating demand (20 098 kWh). However, the 98 % of the heating demand during the summertime comes from the solar collectors. The investment cost is 113 900 SEK and the payback period is estimated in 8 years.

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  • 21.
    Malysheva, Alexandra
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Rutiner för insamling av indata för energisimuleringsmodeller av skolbyggnader i Norra Sverige (Gävle): En studie baserad på litteraturundersökning och analys av simuleringsmodellen av Stigslundsskolan i Gävle2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Energianvändning i befintlig byggnadsstock utgör en stor del av den totala energianvändningen i Sverige. I dagens läge är minskning av energianvändning av hög prioritet. Moderna simuleringsteknologier ger möjlighet till uppskattning av energianvändning i befintliga hus och utveckling av effektiviseringsåtgärder samt till beräkning av energiprestanda av byggnader i projekteringsfas. Korrekta indata och indatakällor avgör osäkerhetsnivå hos modellen. I detta sammanhang är det viktigt att utveckla rutiner för insamling av indata och specificera osäkerhetskällor. Arbetet fokuseras på utveckling av förslag till rutiner för insamling av indata för energisimuleringsmodeller av skolbyggnader i Norra Sverige, identifiering av termograferings roll vid renovering och ombyggnation samt känslighetsanalys vid byggnadssimulering och framställning av källhierarki. Projektet baserades på litteraturanalys och intervjuning av beträdande konstruktörer. Dessutom utreddes mätdata samlade i samband med renovering av Stigslundsskolan i Gävle och utarbetade simuleringsmodellen av den här skolan. Resultatet av denna studie beskriver rutiner för insamling av indata som omfattar byggnadens lokalisering och klimatdata; specifik konstruktionsdata för simulerad byggnad/del av byggnad; inomhustemperatur, luftflöde vid ventilation och infiltration samt interna värmekällor och data om innevånare och HVAC-system. Dessutom identifierades möjliga osäkerhetskällor och åtgärder för att höja noggrannhet hos modell. Källhierarki för indatakällor bestämdes vilket är angeläget vid modellkalibrering.  Termografin av Stiglundsskolan visade att det finns ett antal bristfälliga delar i klimatskallet som ger upphov till värmeförluster, framför allt fönstren, entrépartierna och sockeln. Fönstren och dörrarna behöver bytas och bristande delar av stommen isoleras. Slutsatserna som kan göras utifrån detta projekt är att det bör väljas indata från källor som står överst i källhierarki för att få fram en modell med låg osäkerhetsnivå. I verkigheten vid simulering av skolbyggnader är hög precision sällan ett krav. I regel prioriteras det tid och bekostnad så länge osäkerheten ligger inom bestämda gränser.

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  • 22.
    Nilsson, Linnea
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Utredning av rökgaskondensatrening vid kraftvärmeverket i Sandviken2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Globalt sett används fossila bränslen fortfarande till största delen, och industrisektorn är den med störst energianvändning. Därför är det viktigt att fortsätta arbetet med att hitta nya sätt att använda befintliga resurser, att utveckla energibesparande tekniker och att göra detta med hållbarhetsperspektivet i fokus.

    Denna studie är förlagd på kraftvärmeverket i Sandviken, som producerar fjärrvärme och elektricitet. Anläggningen ägs av Sandviken Energi AB som är ett kommunalt energibolag med ansvar för infrastrukturen i Sandvikens kommun. Syftet med studien är att undersöka möjligheten att sänka halten av kväveoxider, NOx, som släpps ut med rökgaserna, samt att rena det kondensat som bildas när rökgaserna värmeväxlas.

    Det finns en stor vinning i att minska NOx-utsläppen ur ett miljöperspektiv, eftersom de orsakar försurning och andra problem i naturen. Tillvägagångssättet är att dosera extra ammoniak vid förbränningen. Vid höga temperaturer reagerar ammoniak med kväveoxiderna och utsläppen av dessa minskar. 90 % av ammoniakutsläppen kan sedan återvinnas med en ammoniakstripper för att även dessa ska hållas inom gränsvärdena.

    Möjligheten att använda det vatten som bildas då rökgaserna kondenserar undersöks också. Många anläggningar skulle teoretiskt sett kunna bli helt självförsörjande i sin vattenanvändning eftersom stora volymer bildas. Det som krävs är att kondensatet blir tillräckligt rent för att kunna användas i de industriella processerna.

    På kraftvärmeverket i Sandviken bildas 30 000 m3 kondensat per år. Det renas och släpps ut via avloppet. År 2016 köptes 21 700 m3 stadsvatten in och användes i produktion och kontor, och även om inte alla processer tekniskt går att ersätta med renat kondensat kan stora besparingar ändå göras. Den enskilda processen med störst potential är processvattnet till de två fastbränslepannorna. Vattenanvändningen till dessa är i genomsnitt 6 000 m3 per år. Det finns även ytterligare potentiella användningsområden för det renade kondensatet som kan öka möjligheten att genomföra en installation.

    Resultatet av utredningen är att en ammoniakstripper skulle möjliggöra att NOx-utsläppen minskade med 10 700 kg per år. Detta resulterar i en kostnadsbesparing på 536 000 SEK och en återbetalningstid på ca nio år. Om rökgaskondensatrening också installeras ökar investeringen, men besparingen kan i bästa fall bli 20 000 m3 vatten per år. Inköpskostnaden för vatten skulle då minska med 800 000 SEK och återbetalningstiden skulle kunna bli ca två år. 67 % av det kondensat som i dagsläget bara släpps ut kan istället användas.

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  • 23.
    Olausson, Jesper
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Energy efficiency in a renovated modern office with activity-based work style2019Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    During renovation Ljusåret 2 was converted to a modern office with an activity based work style (ABW) with a Demand Controlled Volume (DCV) ventilation system connected to a closed-loop duct. Cooling is provided through air handling units and active water based beams, the underfloor heating system was kept.

    Written instruction and specification have been studied for the two different control systems Schneider EcoStructure and Lindinspect. Both control systems have been analyzed according to time schedule, set-point and process value by using different functions in software.

    To be able to perform a energy audit and look at indoor climate for Ljusåret 2 there have been studies according to underfloor heating, constructions of ventilation system, diversity factor for DCV, closed-loop-ducts, heat losses from ducts, cooling demand and energy certification.

    According to this audit, energy performance is calculated to 89.1 kWh/m2 according to building energy, activity energy is not audited or calculated. During design phase, an energy calculation was made by an energy consultant with the result of 81.3 kWh/m2. The estimated performance is a 9.6 % increase. This building is designed for Miljöbyggnad certification of level silver and should be ≤ 109 kWh/m2,year. According to audit and calculation for energy performance this level is possible to keep.

    The estimated energy performance have been calculated with only 4 month of statistics from January until April 2019 because Ljusåret 2 have just been renovated. District heating has been estimated through the energy signature by data from energy meter. Electrical components for the building have been measured and energy usage calculated. Energy produced by compression chiller have been estimated with calculated performance from design phase and adding heat transfer between rooms and supply ducts. Energy between rooms and supply ducts were not included in energy calculation during the design phase.

    According to the control system for the DCV system there have been some issues with high temperature in supply ducts even when they are supplied with 15 ºC from air- handling unit. There have been measurement to the ventilation system 5701-5704 that is connected to a close-loop duct with a result of temperatures between 15.2 ºC up to 21.4 ºC and the velocity has varied between 0.05-2.1 m/s in different measurement spots. This is an increase of 6.4 ºC.

    A heat transfer calculation have been made in Paroc Calculus to estimate heat transfer between room and supply ducts. The results of this calculation indicates the same level of temperature increases as when the system was measured. With no thermal insulation cooling capacity is lost to half after less than 5 m with a velocity of 0.2 m/s, after 15 m with a velocity of 1 m/s and 30 m with a velocity of 2 m/s . This should be compared with supply duct with 20 mm of thermal insulation that has lost its cooling capacity after less than 13 m with a velocity of 0.2 m/s, after 63 m with a velocity of 1 m/s and is increase with 4 ºC after 100 m with a velocity of 2 m/s.

    Using closed-loop ducts with velocity below 2.0 m/s and without thermal insulation combined with under tempered supply air is not a good combination. Even short length with low velocity and lack of thermal insulation is devastating because of heat transfer according to logarithmical temperature difference between room and supply ducts.

    A closed-loop duct is often designed as a pressure chamber and recommended when using DCV and/or VAV ventilation to avoid problems with noise and to be able to reduce the need of dampers. Problems with temperature increasing according to velocity in ducts must be taken in consideration.

    For Ljusåret 2 this will affect district heating usage where ducts are placed because underfloor heating must compensate heat transfer. Chilled water must be provided an extra time for rooms with both DCV and chilled beams and rooms with only DCV is less comfortable which they could been with a correct installation.

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    Energy efficiency in a renovated modern office with ABW
  • 24.
    Patsatzis, Nikolaos
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Parametric Analysis of Thermal Comfort and Energy Efficiency in a Building Located in Different Climate Regions2022Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    One of the biggest challenges of a residential building, when it is designed, is to be energy efficient and to provide simultaneously many hours of thermal comfort throughout the year. So, this was the scope of this thesis: to perform a parametric analysis of thermal comfort and energy efficiency in a house that was designed for the climate of Gotland in Sweden. After that, modifications were introduced to the base model and each scenario was checked for the geographical locations of Thessaloniki, Greece and Barcelona, Spain, in order to decide what option is better.

    The modifications to the base model were changes in the structure of the external wall (insulation materials and total width), the insulation of the internal wall, the thermal bridges (set to good), the windows (3-pane glazing, schedule opening, external window shading, integrated shading), the installation of HVAC system, photovoltaics with efficiencies 15%, 17% and 22% and the introduction of chimney.

    Based on the results, the Gotland scenario that included the base model plus the modifications of the external and internal wall, HVAC system, PVs with 22% and external window shading increased the energy use by 18.7% but improved the thermal comfort as the yearly hours of dissatisfaction reduced to 22 from 882, compared to the base model. Similar results were taken from the case with the integrated shading in which the energy increased to 19.3%, but the hours of dissatisfaction declined to 24 throughout the year.

    Regarding only the energy cost of the house, the best location is Barcelona (without cooling). Nevertheless, when considering the overall thermal comfort, the best place for the house is Gotland, as the building was designed for the cold environment of Sweden and not the hot weather of the other southern cities.

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  • 25.
    Revilla, Iñigo
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Pons, Laia
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Study of a vertical slot fish ladder: Evaluation of flow dynamics through a standardized bypass and the effect of predesigned roughness elements2020Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Migrating freshwater fish population has been significantly declined, mostly by the obstruction of their migratory routes by hydropower dams. To diminish such impacts, fish ladders have been developed to facilitate the passage of migrating fish. However, fish ladders are associated with mortality and migratory failure, resulting in an ecological problem which has been a concern for years. The paper contained in the following pages focuses on studying the viability of an innovative modular design for a fish ladder developed by Fiskvägsteknik AB. The design is based in a vertical slot fishway (VSF) to which some roughness elements are attached to modify the flow. The aim of this bypass system is to restore the original biological continuity and diversity in the Swedish rivers, therefore solving a long-lasting ecological problem that hydroelectric production has caused over the years. Through a computational analysis, the flow has been evaluated as a function of the parameters that present an influence over its behaviour. First, a study of the changes in flow velocity influenced by four different slopes: 5 %, 10 %, 15 % and 20 %, has been performed with the objective to find an appropriate inclination according to the capabilities of the fish species considered. The lowest slopes have resulted to be the most appropriate ones, coinciding with low values of turbulent kinetic energy and lower flow velocities. The second step has been checking the effect of roughness elements on the bottom part of the structure tilted a 5%. The flow velocity has shown a considerable decrease, falling in the range of the fish swimming capabilities established. As for the streamlines of the flow, they were altered compared to the cases without the roughness elements.

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    Master Thesis - Iñigo Revilla and Laia Pons
  • 26.
    Skärberg, Albin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Energikartläggning av en kontorsbyggnad i Mellansverige: Skattehuset i Gävle2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The world over the years has had an increase in energy use that can lead to major problems. The reason is that many countries produce electricity and heat with resources that cause large amounts of greenhouse gas emissions. Sweden responded by introducing a law that an energy audit must be done at least every four years at large companies, so that Sweden can achieve a goal of making energy use more energy efficient between 2003 and 2030. In this study, an energy audit has been done on an office building located in Central Sweden. The purpose was to map how electricity and heat are used in the building and to present measures to reduce energy use. The results show that 770 MWh of district heating and a total of 763 MWh of electricity were used in 2019. Of which the largest energy users in the property are radiators, heating batteries, electrical appliances and fans. By, among other things, taking three energy-efficient measures for ventilation, up to 313,000 SEK can be saved each year. The measures are then to install more efficient heat exchangers for ventilation, lower SFP numbers on four of the property's air handling units and that ventilation systems of the type Demand Controlled Ventilation (DCV) are used instead of Constant Air volume (CAV).

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  • 27.
    Starrin, Susanne
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Simulering och dimensionering av ett solcellssystem på en skola i Mellansverige: En fallstudie med fokus på kostnadsoptimal anläggningsstorlek2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The advancement of photovoltaic systems is growing exponentially both in Sweden and internationally. Reasons for this include decreasing prices, more efficient techniques, reduction in taxes as well as the increasing interest. In many cases, financial incentives like tax reductions or investment incentives are still necessary for photovoltaic systems to become profitable. In this case study, the possibility of installing a photovoltaic system at Västerberg folkhögskola in Storvik is examined. The properties are owned by Region Gävleborg. Bionär Närvärme AB, which is a subsidiary of Gävle Energi AB, provides the properties with heat through a pellet boiler system. In the summer however, electricity is used for the boiler when the heating requirement is less demanding, and there is an interest in producing electricity using solar cells. Since there is only one electricity subscription the PV-system is dimensioned with regards to the whole of the school’s electricity use including heating. The main purpose was to first identify suitable rooftops and then find the most costeffective size of a photovoltaic system for the school. Then, a simulation was performed to find out the annual electricity production and with the help of these results, an economic calculation could be determined. Suitable rooftops were selected with respect to orientation, angle, size and placement of distribution boxes. Quantitative data regarding the properties and electricity use were collected from Region Gävleborg. Subsequently, different photovoltaic system sizes were tested in Winsun to find the system size that yielded the shortest straight repayment time. Next, simulation of the selected system size was performed in PVsyst, where annual electricity exchange was presented as a result. An economic analysis could be carried out with the help of the values of electricity usage, solar-produced electricity, self-used electricity, over-produced electricity (which is sold to the power grid). The result shows that the system size that gives the shortest repayment time is just under 100 kWp. After simulation of selected rooftops in PVsyst, a peak power of 94.6 kWp was achieved. This gave a payback period of 7,8 years.

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  • 28.
    Stenlund, Rickard
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Jämförelse av två olika typer av solavskärmning: I två kommersiella fastigheter, via analys av empirisk data och simuleringar2021Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I Sverige står bostads- och servicesektorn för cirka 40 % av den totala energi- användningen, varav cirka 90 % av går till bostäder och lokaler. År 2018 fastställde EU ett mål om att energianvändningen ska vara minst 32,5 % lägre år 2030 jämfört med de prognoser som finns nu för 2030. För att nå detta krävs att byggnader förses med energieffektiva lösningar för att minska dess värme- och kylanvändning. Ett effektivt sätt att minska kylanvändningen i en byggnad är att undvika övertemperaturer genom att skärma av solinstrålningen innan den tar sig in i byggnaden. I denna rapport jämförs två fastigheter med olika typ av sol- avskärmning, ena byggnaden är försedd med invändiga automatiskt styrda rull- gardiner i kombination med fönster med låga g-värden. Den andra byggnaden är för-sedd med utvändiga vertikalmarkiser av screenväv. Syftet var att ta reda på om det via loggade kyleffekter i utvalda kontorslandskap gick att se tecken på vilken av byggnaderna som har störst påverkan av solvärmelast, samt att via loggade kyl- effekter och kompletterande simuleringar försöka fastställa vilken av byggnadernas solavskärmning som presterar bäst gällande minskad kylanvändning och kyleffektbe-hov.Loggade kyleffekter samlades in för fem utvalda arbetsveckor, vilka valdes då de identifierats som extra varma under åren 2019 och 2020. Studien koncentrerades till fyra utvalda kontorslandskap, ett i varje väderstreck i respektive byggnad. För att ta reda på om skillnader i kyleffektbehov uppstod under dagen beroende på solens position. Datat samanställdes i Excel och ritades upp i diagram för vidare analys. Arbetet fortsatte sedan med kompletterande studier i simuleringsprogrammen IDA ICE och ESBO. Ett våningsplan per byggnad byggdes i IDA ICE, samma kontorslandskap som tidigare simulerades för samma perioder och högsta kyleffekter per kvadratmeter golvyta sammanställdes. Slutligen byggdes testrum i ESBO, med solavskärmning och fönster likt de verkliga byggnaderna simulerades testrummen i de fyra väderstrecken.Studerade kyleffekter för kontorslandskapen tyder på att byggnaden med invändig solavskärmning är mer utsatt för solvärmelaster än byggnaden med utvändig sol- avskärmning. Då de högsta kyleffekterna för kontorslandskapen med invändig sol- avskärmning verkar följa solens position, så som att det västra kontorslandskapet har högre kyleffekt under senare del av dagen, detta ses inte i kontorslandskapen med utvändig solavskärmning. Resultaten från simuleringsstudierna pekar också mot att den utvändiga solavskärmningen presterar bättre gällande minskat behov av kyla.

  • 29.
    Wanli, William
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    The Church of Jesus Christ of Latter-day Saints in Trollhättan Energy optimization2021Independent thesis Advanced level (degree of Master (One Year)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    The world is experiencing increasing energy usage owing to environmental impacts suchas climate change, Ozone layer depletion, and global warming. Energy usage is primarily categorized into transport, industrial, residential, and service sectors, with the transportation and industrial sectors taking up a considerable chunk of the energy use; Buildings partly determine the use of energy globally. This review presents a critical analysis of energy demand and uses in the building sector considering the energy optimization for The Church of Jesus Christ of Latter-day Saints in Trollhättan, including the local energy requirements. The modelling software IDA-ICE isused to conduct simulations for different scenarios. The IDA-ICE software links the actual building images with the isometric views done on a computer. The energy balance of buildings is considered with respect to the three methods for heat transfer, the U-value,ventilation, heating load, and cooling load. The study results show that the building relieson electricity and fuel for its energy supply and that fuel consumption takes the highest share, 60 %. Retrofit 1 (where the oil and electric boilers are replaced by geothermal heat pump with COP 4 for heating and domestic hot water), Retrofit 2 (which keeps changes from Retrofit_1 and where a new AHU with a VAV system replaces the existing two AHUs), and Retrofit 3 (which keeps changes from Retrofit_2 and only connects the heating system to district heating) are designed as part of the findings to understand the variation sin comfort reference, supplied Energy, used Energy, utilized Energy, auxiliary Energy, and the Energy of all zones during heating and cooling. The model results indicate that Retrofit2 demonstrates better results than the other two since it has a higher energy-saving capacity. The energy reduction for Retrofit model 1 is about 33.4 %, while Retrofit model 2 has 55% and model 3 has 33%, significantly decreasing the associated costs. The LCC analysis shows payback for the first model 6.73 years with an investment cost of 700 000 SEK, the second model has 5.84 with 1 million SEK investment, and the third model has 3.4 years with 350 000 SEK.

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  • 30.
    Åström, Frida
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Energieffektiviseringsanalys av ventilationssystemet för ett kraftvärmeverk: En fältstudie utförd i samarbete med Bomhus energi AB och ABB2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta arbeta kommer att utreda vilka det vanligaste energiförlusterna för ett kraftvärmeverk är, med fördjupning på förlusterna i deras ventilationssystem.  Kraftvärmeverket som har analyserats i detta arbete är Bomhus energi AB (BEAB) kraftvärmeverk och utredningen har skett i samråd med ABB Energy Efficiency team.    

    Världens energianvändning kan delas in i tre sektorer: industri, transport samt bostad- och servicesektorn. Industrisektorn kan sedan delas in i flera sektorer där massa och pappersindustrin står för majoriteten av energianvändningen i Sverige. Industrisektorn står för ca 64% utav världens el-energiförbrukning. Detta gör att det finns stort intresse i att se över de komponenter som har hög elförbrukning.     

    Fokuset har i detta arbete varit på ventilationssystemet och dess fläktrift. För att få information om vart det kan finnas komponenter som brukar mycket el så har styrsystemets loggar setts över. Besparingspotential har då identifierats i att installera frekvensomriktare till aggregatens fläktar istället för att använda den befintliga spjällregleringen. ABB har tidigare funnit besparingspotential i pumpdrifter för kraftvärmeverk och är därför nu intresserade av att se om det finns någon besparingspotential i ventilationssystemet.

    BEABs ventilation är uppdelad på process och allmänventilation, och genomlysning utav ventilationssystemet är i detta arbete begränsat till allmänventilationen i pannhuset. Detta då processventilationen anses vara korrekt dimensionerat.

    För att få insikt i hur energieffektivisering utav ventilationssystem kan gå tillväga har olika vetenskapliga artiklar rörande ämnet valts ut och analyserats. Som systemet är uppbyggt så sker regleringen utav ventilationen med spjällreglering. Spjällreglering innebär att fläktarna går på konstant flöde och för att uppnå önskad temperatur och tryck i byggnaden så sitter det tryckreglerande spjäll på taket som släpper ut luft ur byggnaden. Denna typ av styrning är inte särskilt energieffektiv, vilket har motiverat detta arbete till att rikta in sig på frekvensomriktare till aggregaten och hur mycket energi som då skulle kunna sparas.  För att få fram besparingspotentialen har hänsyn tagits till aggregatens: nominella volymflöde, fläktverkningsgrad, transmissionsverkningsgrad, flödesreglering, motoreffekt, motorns verkningsgradsklass, matningsspänning, fläkttyp, pumphjulstyp, varaktighetskurva, årgångstid, energipris samt multiplikatorn för Co2-utsläpp. Data har sedan matats in i ABB Energy Save kalkylatorn som då har tagit fram hur mycket energi och pengar som skulle kunna sparas genom att installera en frekvensomriktare.  Om de frekvensomriktare som då har tagits fram för de olika aggregaten skulle installeras så skulle uppskattningsvis ca 67 000 kr/år kunna sparas för kraftvärmeverket. 

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  • 31.
    Östlin, Robert
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Lämplighetsundersökning av olika system för att producera kyla: Fallstudie för en fastighet med bageri, restaurang och kontor2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Cooling is produced with several completely differentiated methods. This report and case study considers four different methods of cooling, vapor-compression-, absorption-, free- and district cooling. A part of the problem is that the systems have vastly different technical configuration and requirement of a facility, such as geography and vicinity to other big technical system such as district cooling and district heating. The cooling systems are compared to find the method that is most suitable and has the most beneficial assessment. The different methods suitablitiy was graded based on, noise level, size and required maintenance. The facility that constitutes this thesis study has a cooling demand of 150kW, which is attributed to a bakery, a restaurant, an office and cooling benches etc. These have a cooling demand during four summer months, where cooling benches etc also have a demand during the rest of the year. Multiple studies showcase and point out that the cooling demand will grow in the future, even if a precise prognosis is not made. It is also clear that these above-mentioned cooling systems have a continuing role to play going forward. This thesis has foremostly used a literature review to answer the research questions. For the review webpages such as Discovery and ScienceDirect was used. To calculate the energy consumption, running hours and total yearly cost Microsoft Excel was used. Especially when cool produced with the compressor unit. The reference unit has four different operating modes depending on the cooling demand, one of the modes is production with free cooling. To value the share and impact that free cooling has, Microsoft Excel is used in combination with statistical data from SMHI (2020). Microsoft Excel is also used to compile the tables and figures in the “results” section. The pricing published in this report is based on personal communications per e-mail and phone interviews with energy producers and manufacturers of different cooling units. The result of the thesis show that district cooling is the most beneficial solution for cooling the facility. As well as the most suitable system since it is completely maintenance free for a customer. The reason for its profitability is attributed to its low investment cost. Using the nearby river for free cooling was deemed impossible because of its high temperature during the summers. Using absorption cooling was also considered unsuitable for the case object because of the low temperature in the local district heating network during summer times, as well as the high investment cost required because of it. To make absorption cooling suitable an additional system for cooling the processes would have to be installed, which this report has not been able to price.

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