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  • 51.
    Falk Dikici, Selina
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Visualisering och kvantifiering av klorparaffiner: En studie av flödet av klorparaffiner på Rörverk 98, Sandvik AB2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Sandvik AB is an industrial group with operations throughout the world. One of the company's three business areas, Sandvik Materials Technology, develops and manu-factures stainless steel products. In production, they seek to replace hazardous mate-rials/substances with less hazardous alternatives or minimize the use of them. A sus-pected environmentally hazardous substance used in industry is chloroparaffins. Sandvik AB manufactures seamless stainless steel tubes with pilgering, where chlo-roparaffins (chlorine oil) are used as lubricants and coolants and these have an im-portant role for the production and for productivity. Sandvik AB uses chlorine oil containing long-chain chloroparaffins. During pilgering, the lubricant is added in conjunction with the activities that make the steel pipes come into contact with the steel tools. The purpose of the study was to carry out a survey of the flow of chloro-paraffins on one of Sandvik's tube plants, Rörverk 98. This has been done by apply-ing the substance flow analysis method (SFA), which is a tool used for analyzing a single substance in a given system. In this study, SFA was applied through six steps. In steps 1 and 2, study objectives and systems are defined. The aim was to convey new dimensions of information to the company and that the approach would be clearly and comprehensively reported. The system definition was to investigate the chlorine paraffin flow, at Rörverk 98, for 28 months. In steps 3 and 4, an inventory and design of the flow chart were carried out. The survey has been carried out through a literature review of Sandvik AB's reports and visits with interviews at the plant. With information from the inventory, a flow chart was created and flows were quantified. In step 5, the mass balance between incoming and outgoing flows was calculated using layers, this is the primary flow. In the last step, step 6, the re-sult was interpreted by applying the HS-method used to calculate the uncertainty of the results. The uncertainty factor is used to calculate a possible minimum and max-imum flow. The result of the survey has been visualized by creating a clear picture of the system and the chlorine paraffin flow and the risk of spillage on/from the pipeline. Within the study's system boundary, it is identified that there is a risk of spreading via emissions to air as well as by drips from cranes outside the plant. The mass balance resulted in a primary flow with a difference of 2.2% kg Cl between in-coming flow and outgoing flow with bearing. The difference may be due to inaccu-racies in inventory data or knowledge gaps such as unknown emissions. The im-provement measures recommended that Sandvik AB shall carry out regularly docu-mented inventory of flows and stocks, thereby gaining a greater insight into the chlorine paraffin flow. Lack of information about the substance made it difficult to determine how they can behave in the system. Future studies are required to deter-mine the environmental impact of long-chain chlorinated paraffins.

  • 52.
    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.

  • 53.
    Giusti, Matteo
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Connecting land: vision and synergies for nature-connecting habitats2019In: Cities & Health, ISSN 2374-8834Article in journal (Refereed)
  • 54.
    Giusti, Matteo
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Human-nature relationships in context. Experiential, psychological, and contextual dimensions that shape children’s desire to protect nature2019In: PLoS ONE, E-ISSN 1932-6203, Vol. 14, no 12, article id e0225951Article in journal (Refereed)
    Abstract [en]

    What relationship with nature shapes children’s desire to protect the environment? This study crosses conventional disciplinary boundaries to explore this question. I use qualitative and quantitative methods to analyse experiential, psychological, and contextual dimensions of Human-Nature Connection (HNC) before and after children participate in a project of nature conservation. The results from the interviews (N=25) suggest that experiential aspects of saving animals enhance children’s appreciation and understanding for animals, nature, and nature conservation. However, the analysis of children’s psychological HNC (N=158) shows no statistical difference before and after children participate in the project. Analysing the third dimension – children’s contextual HNC – provides further insights. Including children’s contextual relations with home, nature, and city, not only improves the prediction of their desire to work for nature, but also exposes a form of Human-Nature Disconnection (HND) shaped by children’s closeness to cities that negatively influence it. Overall, combining experiential, psychological, and contextual dimensions of HNC provides rich insights to advance the conceptualisation and assessment of human-nature relationships. People’s relationship with nature is better conceived and analysed as systems of relations between mind, body, culture, and environment, which progress through complex dynamics. Future assessments of HNC and HND would benefit from short-term qualitative and long-term quantitative evaluations that explicitly acknowledge their spatial and cultural contexts. This approach would offer novel and valuable insights to promote the psychological and social determinants of resilient sustainable society.

  • 55.
    Giusti, Matteo
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Samuelsson, Karl
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    The regenerative compatibility: a synergy between healthy ecosystems, environmental attitudes, and restorative experiences2020In: PLoS ONE, E-ISSN 1932-6203, Vol. 15, no 1, article id e0227311Article in journal (Refereed)
    Abstract [en]

    Urban nature is and will be the most common provider of nature interactions for humankind. The restorative benefits of nature exposure are renown and creating human habitats that simultaneously support people’s wellbeing and ecological sustainability is an urgent priority. In this study, we investigate how the relationship between environmental attitudes and healthy ecosystems influences restorative experiences combining a place-based online survey with geographical data on ecosystem health in Stockholm (Sweden). Using spatial regression, we predict the 544 restorative experiences (from 325 respondents), with people’s environmental attitudes, natural land covers, ecosystem health, and the statistical interactions among these variables as predictors. Our results show that restorative experiences can happen anywhere in the urban landscape, but when they occur in natural environments, the combined levels of biodiversity and ecological connectivity are better predicting factor than the mere presence of nature. That is, healthy ecosystems seem to be more important than just any nature for restorative experiences. Moreover, the statistical interaction between one’s environmental attitudes and natural environments predict almost all restorative experiences better than when these variables are independent predictors. This suggests that there is synergistic compatibility between environmental attitudes and healthy ecosystems that triggers restorative processes. We call this synergy regenerative compatibility. Regenerative compatibility is an unexploited potential that emerges when people’s attitudes and ecosystems are aligned in sustainability. We consider regenerative compatibility a valuable leverage point to transform towards ecologically sustainable and healthy urban systems. To this end, we encourage multifaceted policy interventions that regenerate human-nature relationships holistically rather than implement atomistic solutions.

  • 56.
    Gomes, João
    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 the impact of stagnation temperatures in receiver prototypes of C-PVT collectors2019In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 12, no 15, p. 2967-2967Article in journal (Refereed)
    Abstract [en]

    Concentrating Photovoltaic Thermal (C-PVT) solar collectors produce both thermal and electric power from the same area while concentrating sunlight. This paper studies a C-PVT design where strings of series-connected solar cells are encapsulated with silicone in an aluminium receiver, inside of which the heat transfer fluid flows, and presents an evaluation on structural integrity and performance, after reaching stagnation temperatures. Eight test receivers were made, in which the following properties were varied: Size of the PV cells, type of silicone used to encapsulate the cells, existence of a strain relief between the cells, size of the gap between cells, and type of cell soldering (line or point). The test receivers were placed eight times in an oven for one hour at eight different monitored temperatures. The temperature of the last round was set at 220 °C, which exceeds the highest temperature the panel design reaches. Before and after each round in the oven, the following tests were conducted to the receivers: Electroluminescence (EL) test, IV-curve tracing, diode function, and visual inspection. The test results showed that the receivers made with the transparent silicone and strain relief between cells experienced less microcracks and lower power degradation. No prototype test receiver lost more than 30% of its initial power, despite some receivers displaying a large number of cell cracks. The transparent and more elastic silicone is better at protecting the solar cells from the mechanical stress of thermal expansion than the compared silicone alternative, which was stiffer. As expected, larger cells are more prone to develop microcracks after exposure to thermal stress. Additionally, existing microcracks tend to grow in size relatively fast under thermal stress. EL imaging taken during our experiment leads us to conclude that it is far more likely for existing cracks to expand than for new cracks to appear. [ABSTRACT FROM AUTHOR]

  • 57.
    Gren, Åsa
    et al.
    The Beijer Institute of Ecological Economics, The Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Colding, Johan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science. The Beijer Institute of Ecological Economics, The Royal Swedish Academy of Sciences, Stockholm, Sweden; The Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden.
    Berghauser-Pont, Meta
    Chalmers University of Technology, Gothenburg, Sweden.
    Marcus, Lars
    Chalmers University of Technology, Gothenburg, Sweden.
    How smart is smart growth?: Examining the environmental validation behind city compaction2019In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 48, no 6, p. 580-589Article in journal (Refereed)
    Abstract [en]

    Smart growth (SG) is widely adopted by planners and policy makers as an environmentally friendly way of building cities. In this paper, we analyze the environmental validity of the SG-approach based on a review of the scientific literature. We found a lack of proof of environmental gains, in combination with a great inconsistency in the measurements of different SG attributes. We found that a surprisingly limited number of studies have actually examined the environmental rationales behind SG, with 34% of those studies displaying negative environmental outcomes of SG. Based on the insights from the review, we propose that research within this context must first be founded in more advanced and consistent knowledge of geographic and spatial analyses. Second, it needs to a greater degree be based on a system's understanding of urban processes. Third, it needs to aim at making cities more resilient, e.g., against climate-change effects.

  • 58.
    Gutierrez Saenz, Juan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Energy analysis and cost estimation of a potential On-shore Power Supply system in the Port of Gävle2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Port of Gävle is one of the most important harbours in Sweden as far as size and freight capacity is concerned. Marine traffic is increasing greatly, thus environmental pollution as well as noise and vibrations are of major concern in port cities. Shore to ship power supply systems might be a feasible solution to curtail emissions because the Auxiliary Engines are instead shut down while the ship stays alongside the quay. The literature review shows they are reliable and very appealing in all respects, thereby contributing to sustainable development. Taking into account the kind of vessels that call at the Port of Gävle, a High Voltage Shore Connection is recommendable, in compliance with the International Standards. An own technical survey is developed to gather all the information, as well as personal interviews to collect first-hand data. Technical issues such as the synchronisation procedure and the ground system with regard to safety are briefly discussed. Due to the lack of data, calculations consist of average values: peak and average demand, and fuel consumption during a typical call. Considering updated energy prices for both electricity and fuel, results show that an on‑shore power supply system make energy costs decrease by 71% at berth in comparison with burning marine fuel, which is saved by around 4 tonnes per call. Additionally, up to 5126 tonnes of CO2 are avoided per year, among other pollutants. Shore‑side power has proven to be profitable and appealing to the Port of Gävle; however, vessels need to be retrofitted, which implies relatively high investments. Collaboration agreements and shipping companies’ willingness to undergo changes are key issues that still need to be solved.

  • 59.
    Guven, Huseyin
    et al.
    Istanbul Technical University, Civil Engineering Faculty, Environmental Engineering Department, Istanbul, Turkey.
    Wang, Zhao
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Eriksson, Ola
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Evaluation of future food waste management alternatives in Istanbul from the life cycle assessment perspective2019In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 239, article id 117999Article in journal (Refereed)
    Abstract [en]

    In developing countries like Turkey, food waste has the highest share compared to other municipal solid waste components. A detailed life cycle assessment has been performed to evaluate different food waste management options (i.e., landfilling, anaerobic digestion, thermal treatment, co-treatment with municipal wastewater) for Istanbul which is the largest city of Turkey and Europe. The current waste management has the worst environmental performance compared to proposed waste management scenarios as follows: Anaerobic digestion, thermal treatment and co-treatment with municipal wastewater. The thermal treatment scenario has been found to have the best environmental performance in most of the impact categories including climate change. The anaerobic digestion scenario ranks in the first place only in freshwater eutrophication, which is attributed to avoided fertilizer use in this scenario. A drastic improvement with 866% has been found in this category if the anaerobic digestion scenario was followed. Co-treatment with municipal wastewater refers to use of food waste disposers at households and provides improvements especially in marine eutrophication and ecotoxicity. Lower effluent emissions by means of biological wastewater treatment in the co-treatment scenario compared to other proposed scenarios lead to better performance in these categories. Various sub-scenarios have also been investigated such as using biogas as vehicle fuel, replacing a combined heat and power with a condensing plant and increasing food waste addition to sewer lines. Important improvements are not achievable in the first two sub-scenarios; however, increasing food waste addition to sewer lines reduces various environmental impact categories by −41% and −60%. © 2019 Elsevier Ltd

  • 60.
    Hansen, Victor
    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 värmeförluster i andra och tredje generationens fjärvvärme: Genom simuleringar2019Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    District heating is the most common type of heating in Sweden. More than 50% of all premises and homes use district heating as a heat source. The concept of District heating is to centralize heat production and produce heat on a large scale at one or more heating plants. The heat from the heating plants is distributed to premises and houses with heat demand via district heating pipes that are buried in the ground. At each customer who is connected to the district heating network, there is a district heating center with a heat exchanger. In the heat exchanger, the district heating water exchange heat to the property's internal heating system. The cooled district heating water is pumped back into a return line to the heating plant to be reheated.

     

    The district heating distribution system has developed over the years. In Sweden, the sytems in use is second-generation district heating and third-generation district heating, which is the method used today. In order to reduce emissions from production facilities and achieve national and global environmental goals, the energy companies work to achieve more efficient energy use. One way of making energy use more efficient is to minimize the heat losses in the district heating distribution system. This thesis aims to investigate differences in heat losses of second-generation district heating systems and third-generation district heating systems. The work investigates whether it is economically feasible to replace the older lines with regard to heat losses.

     

    Simulations of the various systems calculates the energy losses in the supply system in watts per meter. Repayment time and environmental impact are calculated using input data from the energy companies. The energy companies have assisted with input through a structured interview.

     

    The result shows that the heat losses cannot justify the exchange of the pipes on their own. Along with other factors such as water leakage and repair costs, heat losses can be an important factor to consider in a reinvestment calculation. Considering district heat production mainly using renewable fuels, it is not possible to see any positive environmental effects either by replacing the pipes.

  • 61.
    Hansson, Kajsa
    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 VAV- och CAV-ventilationssystem för nybyggd skola och dess känslighet för ökad personbelastning: En simuleringsstudie med IDA ICE2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    To reduce the energy use is as much a global goal as it is an international goal. The Swedish goal is to increase the efficiency of energy use with 20 % by year 2020. This means that almost all the sectors are affected, that includes the housing and service sector which accounts for almost 40 % of Sweden’s energy use. The ventilation system is one thing that can contribute to saving energy. In this study a new built primary school has been simulated, regarding energy use and thermal comfort, where different ventilation system has been tested to determine which system are the most profitable in economically, energy and comfortably. The ventilation system different in the flow control. Two main types of flow control have been tested: Variable Air Volume (VAV) and Constant Air Volume (CAV). The building, which is well insulated and has a heavy body has also been simulated with increased personal load to see how it affects the ventilation system. The method used to perform the work is a comparative type simulation study. The computer program IDA ICE 4.8 has been used to build the model and do the simulations. The model that has been simulated resemble the primary school Stigslundsskolan in Gävle in both construction, ventilation and degree of use. Data has been collected from the consulting company Ramboll’s database with information on the planning of the school. Personal communication has also been used to collect information. The simulations have been performed for a school year and a schedule for the personal load has been set for each hall to imitate the schedule that the students are following today. The result of the simulations showed that the VAV ventilation system, which resemble the planned case, cover the ventilation requirements, uses less energy than the CAV system and create a very good thermal climate in the building. The result also shows that the increased personal load had a great influence on the VAV ventilation system and increased the repayment period from 11 to 30 years.

  • 62.
    Hasan, A. S. M. M.
    et al.
    Department of Electrical and Electronic Engineering, Bangladesh Army International University of Science and Technology, Cumilla, Bangladesh.
    Hossain, R.
    Department of Electrical and Electronic Engineering, Bangladesh Army International University of Science and Technology, Cumilla, Bangladesh.
    Tuhin, R. A.
    Department of Computer Science and Engineering, East West University, Dhaka, Bangladesh.
    Sakib, T. H.
    Department of Electrical and Electronic Engineering, Bangladesh Army International University of Science and Technology, Cumilla, Bangladesh.
    Thollander, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology. Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Empirical investigation of barriers and driving forces for efficient energy management practices in non-energy-intensive manufacturing industries of Bangladesh2019In: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 11, no 9, article id 2671Article in journal (Refereed)
    Abstract [en]

    Improved energy efficiency is being considered as one of the significant challenges to mitigating climate change all over the world. While developed countries have already adopted energy management and auditing practices to improve energy efficiency, the developing countries lag far behind. There are a limited number of studies which have been conducted in the context of developing countries, which mostly revolve around highly energy-intensive sectors. This study looks into the existence and importance of the challenges to and motivating forces for the adoption of energy management practices in Bangladesh, a developing country, focusing on the non-energy-intensive manufacturing industries. Conducted as a multiple case study, the results indicate the existence of several barriers towards adopting and implementing the management of energy practices in the non-energy-intensive industries of Bangladesh, where among them, "other preferences for capital venture" and "inadequate capital expenditure" are the most dominant. This study also identified a number of driving forces that can accelerate the acceptance of energy efficiency practices, such as the demands from the owner, loans, subsidies, and a lowered cost-benefit ratio. Findings of this study could assist the concerned stakeholders to develop beneficial policies and a proper regulatory framework for the non-energy-intensive industries of developing countries like Bangladesh. © 2019 by the authors.

  • 63.
    Hayati, Abolfazl
    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.
    Akander, Jan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Mattsson, Magnus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Simulation of Ventilation Rates and Heat Losses during Airing in Large Single Zone Buildings in Cold Climates2019In: Cold Climate HVAC 2018: Sustainable Buildings in Cold Climates / [ed] Johansson, D., Bagge, H., Wahlström, Å., Springer, 2019Conference paper (Refereed)
    Abstract [en]

    Airing can be a solution to introduce extra ventilation in large single zone buildings, especially where there are large aggregations of people such as churches or atriums. In naturally ventilated domestic and ancient buildings, opening of a window or door can introduce extra fresh air and remove particles and other contaminants emitted from people and other sources such as lit candles in churches. However, the energy use might be an issue in cold climates, where airing might lead to waste of heated air, at the same time as indoor air temperatures can be uncomfortably low. In the present study, the energy loss and ventilation rate due to airing in a large single zone (church) building is investigated via IDA-ICE simulation on annual basis in cold weather conditions. The results can be used in order to prepare airing guidelines for large single zone buildings such as atriums, churches, industry halls and large sport halls. According to the results, one-hour of airing in the studied church building resulted in 40-50 % of exchanged room air and, if practiced once a week, an increase of around 1 % in heating energy.

  • 64.
    Hayati, Abolfazl
    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.
    Mattsson, Magnus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Sandberg, Mats
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    A wind tunnel study of wind-driven airing through open doors2019In: The International Journal of Ventilation, ISSN 1473-3315, E-ISSN 2044-4044, Vol. 18, no 2, p. 113-135Article in journal (Refereed)
    Abstract [en]

    Temporarily enhanced natural ventilation of indoor environments can be achieved by opening windows and/or doors, i.e. airing. In this study, wind driven airing rate through doors was measured by tracer gas at a building model in a wind tunnel. Both single opening and cross flow airing was investigated, with doors placed in centrally on the long side of an elongated building model. It was found that cross flow airing yielded 4–20 times higher airing rate than single opening airing; lowest value occurring with opening surfaces perpendicular to wind direction. At single opening airing, windward positioned door yielded about 53% higher airing rate than leeward positioned. Inclusion of a draught lobby (extended entrance space) lowered airing rate by 27%, while higher wind turbulence increased it by 38%. Advection through turbulence appeared a more important airing mechanism than pumping. At cross flow, however, turbulence and draught lobby had practically no effect.

  • 65.
    Hellström, Emma
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Energikartläggning av smältverk 08: En fallstudie över Sandvik AB2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 66.
    Holmgren, Mattias
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Andersson, Hanna
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Decision, Risk and Policy Analysis.
    Marsh, John E.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Bell, Linden J.
    Eliminating the Negative Footprint Illusion by Fostering a Summative Mindset using a Transfer ParadigmManuscript (preprint) (Other academic)
    Abstract [en]

    People’s belief that an environmentally friendly item that is added to a set of conventional items has the ability to reduce the total environmental impact of these items could lead to unwanted environmental consequences. An averaging bias seems to underpin this negative footprint illusion: people make their estimates based on the average of the environmental impact produced by the items rather than their accumulative sum. We report a study using a problem-solving transfer paradigm to explore if this preoccupation to think in terms of an average can be eliminated by fostering a summative mindset. The results demonstrate that, participants can correctly estimate that environmental impact will increase when a “green” car is added to a set of petrol cars, but only when this task is preceded by a task that engenders a summation judgment. Our evidence indicates that the negative footprint illusion can be tempered by problem-solving transfer whereby a primed concept (summation) is used adaptively on subsequent judgments, thereby correcting for bias in environmental judgments.    

  • 67.
    Holmgren, Mattias
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Kabanshi, Alan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Langeborg, Linda
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational Health Science and Psychology, Psychology.
    Barthel, Stephan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Colding, Johan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science. Beijer Institute of Ecological Economics, The Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Eriksson, Ola
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Sörqvist, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Deceptive sustainability: Cognitive bias in people's judgment of the benefits of CO2 emission cuts2019In: Journal of Environmental Psychology, ISSN 0272-4944, E-ISSN 1522-9610, Vol. 64, p. 48-55Article in journal (Refereed)
    Abstract [en]

    People's beliefs in the actions necessary to reduce anthropogenic carbon dioxide (CO2) emissions are important to public policy acceptability. The current paper addressed beliefs concerning how periods of small emission cuts contribute to the total CO2 concentration in the atmosphere, by asking participants to rate the atmospheric CO2 concentration for various time periods and emission rates. The participants thought that a time period with higher emission rates combined with a period of lower emission rates generates less atmospheric CO2 in total, compared to the period with high emission rates alone – demonstrating a negative footprint illusion (Study 1). The participants appeared to base their CO2 estimates on the average, rather than on the accumulated sum, of the two periods' emissions – i.e. an averaging bias (Study 2). Moreover, the effect was robust to the wordings of the problem presented to the participants (Study 3). Together, these studies suggest that the averaging bias makes people exaggerate the benefits of small emission cuts. The averaging bias could make people willing to accept policies that reduce emission rates although insufficiently to alleviate global warming.

  • 68.
    Hongyu, Yang
    et al.
    Sun Yat-sen University, Guangzhou, PR China.
    Chen, Taihan
    Sun Yat-sen University, Guangzhou, PR China.
    Lin, Yuanyuan
    Sun Yat-sen University, Guangzhou, PR China.
    Buccolieri, Riccardo
    University of Salento, Lecce, Italy.
    Mattsson, Magnus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Zhang, Ming
    State Power Environmental Protection Research Institute, Nanjing, China.
    Hang, Jian
    Sun Yat-sen University, Guangzhou, PR China.
    Wang, Qun
    Department of Mechanical Engineering, University of Hong Kong, Hong Kong.
    Integrated impacts of tree planting and street aspect ratios on CO dispersion and personal exposure in full-scale street canyons2020In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 169, article id 106529Article in journal (Refereed)
    Abstract [en]

    Validated by experimental data, this paper performs computational fluid dynamics (CFD) simulations to investigate the influence of tree plantings on urban airflow and vehicular CO exposure in two-dimensional (2D) street canyons with various aspect ratios (building height/street width, AR = H/W = 0.5, 1, 3, 5) and ground-level source. The impacts of tree canopy bottom height (Htb = 2 m, 6 m), tree stand density (y-density = 0.33, 0.67, 1) and leaf area density (LAD = 0.5, 1, 2 m2/m3) are considered. Personal intake fraction (P_IF) and its spatial mean value in leeward and windward sides (<P_IF>lee, <P_IF>wind) and for entire streets (street intake fraction, <P_IF>) are adopted to assess overall pollutant exposure.

    For cases without trees, only one main vortex exists in shallow streets with AR = 0.5-3 and <P_IF> as AR = 3 (5.80 ppm) slightly exceeds AR = 0.5-1 (3.98-3.84 ppm). However, two counter-rotating vortexes appear in deep streets (AR = 5), inducing 1-2 orders smaller pedestrian-level velocity (U/Uref~10−4-10−3) and one-order greater <P_IF> (46.80 ppm) than shallow streets. Trees always weaken wind in streets and raise <P_IF> more in shallower streets by 46.0% as AR = 0.5 (3.98 ppm-5.81 ppm), 26.0-45.9% as AR = 1 (3.84 ppm to 4.84-5.60 ppm), 16.2-50.3% as AR = 3 (5.80 ppm to 6.74-8.72 ppm), but only 8.5-23.4% as AR = 5 (46.80 ppm to 50.78-57.73 ppm). Particularly, as AR = 1, trees raise <P_IF>lee (5.87 ppm) by 27.1-57.2%, while <P_IF>wind (1.80 ppm) only by 0%-23.3%. Higher Htb, smaller y-density or LAD produce less increase of <P_IF>. As AR = 3, vegetation increases <P_IF>lee (8.84 ppm) by 21.2%-66.4% but little affects <P_IF>wind (2.76 ppm). Lower Htb produces smaller <P_IF> differing from AR = 1. As AR = 5, vegetation increases <P_IF>wind (63.97 ppm) by 15.1-36.6% but reduces <P_IF>lee (29.63 ppm) by 5.2-8.5%. Although further investigations are still required for design purpose, this paper provides effective methodologies to quantify how vegetation influences street-scale pollutant exposure.

  • 69.
    Hosseini, Zohal
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Ändring i hemmet för utökad tillgänglighet för äldre och individer med funktionsnedsättningar2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Accessibility is an important factor to consider when it comes to new construction, remodelling or extension of housing. Considering the fact that the number of elderly people will increase in the coming years, must accessibility of housing be increased.

    According to some studies, are 80% of old homes consist at least of a risk factor that leads to falls. In order to remove these risk factors in the home, the construction of available housing must be incresed.      

     

    The purpose of this study was to increase the availability of the home for elderly people and people with disabilities, in order to create a favorable and safe environment for these individuals. The study included both theoretical and practical parts. The first part, which was a qualitative research, was aimed to studying the human body and how it changes with aging. This part was mainly focused on the physical impairments that were affected by inaccessibility in housing which are impaired mobility, impaired vision and impaired hearing. The information would then be used in the second part of the report, in order to adapt the housing design to the conditions and needs of the elderly people.

     

    This study also contains certain rules and laws regarding housing design and housing accessibility, for instance Swedish Standard, Plannings and construction law, Planning and Buildind Act etc. These laws describe for example how the housing environment could be designed to satisfy the requirements for accessibility for older individuals and individuals with disabilities.

     

    The second part of the study focused on the building construction and building design in the home, for increased accessibility. This part was delimited in the bathroom and the purpose was to make the bathroom available for the elderly people and people with disabilities. This section was based o two alternatives and the porpuse was to compare wich one of the alternatives was most useful to implement in practice. The first option was about new construction of a bathroom, which would replace one of the bedrooms that was placed in the house¢s first floor. The other alternative aimed at remodelling an existing bathroom wich was placed on the second floor and to facilitate the use of the renovated bathroom, a chair lift would be installed on the stairs for people with disabilities. Through an interview with Gävle municipality, it provided the approximate costs of new constructions of an available bathroom and costs of remodeling an existing bathroom for increased accessibility. These alternatives were compared based on cost, work, space and use. With regard to these points, the most favorable housing adjustment was chosen.       

  • 70.
    Hughes, Robert W.
    et al.
    Deparment of Psychology, University of London, Egham, UK.
    Marsh, John Everett
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science. School of Psychology, University of Central Lancashire, Preston, UK.
    When is forewarned forearmed?: Predicting auditory distraction in short-term memory2019In: Journal of Experimental Psychology. Learning, Memory and Cognition, ISSN 0278-7393, E-ISSN 1939-1285Article in journal (Refereed)
    Abstract [en]

    Two experiments critically examined a predictive-coding based account of the vulnerability of short-term memory to auditory distraction, particularly the disruptive effect of changing-state sound on verbal serial recall. Experiment 1 showed that providing participants with the opportunity to predict the contents of an imminent spoken distractor sentence via a forewarning reduced its particularly disruptive effect but only to the same level of disruption as that produced by ‘simpler’ changing-state sequences (a sequence of letter-names). Moreover, a post-categorically unpredictable changing-state sequence (e.g., “F, B, H, E …”) was no more disruptive than a post-categorically predictable sequence (“A, B, C, D …”). Experiment 2 showed that a sentence distractor was disruptive regardless of whether participants reported adopting a serial rehearsal strategy to perform the focal task (in this case, a missing-item task) whereas, critically, the disruptive effect of simpler changing-state sequences was only found in participants who reported using a serial rehearsal strategy. Moreover, when serial rehearsal was not used to perform the focal task, the disruptive effect of sentences was completely abolished by a forewarning. These results indicate that predictability plays no role in the classical changing-state irrelevant sound effect and that foreknowledge selectively attenuates a functionally distinct stimulus-specific attentional-diversion effect. As such, the results are at odds with a unitary, attentional, account of auditory distraction in short-term memory and instead strongly support a duplex-mechanism account.

  • 71.
    Hurlov, Almedina
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Värmeåtervinning med spillvatten i flerbostadshus2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 72.
    Hwit, Emil
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Rekommenderad framledningstemperatur i fjärrvärmenät baserat på rökgaskondensering: En beräkningsundersökning av rökgaskondensering och fjärrvärme i en medelstor svensk stad2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The most common way of heating buildings in Sweden is by district heating, more than half of all the locales and homes is heated this way. Flue gas condensation is the third largest contributor of energy in district heating at 11 %. The importance of its efficiency is thereby big.

    Flue gas condensation can be installed at combustion boilers to increase the efficiency, it can be used in combination with most fuels that exhaust steam. The flue gas condensation has an important role by harnessing the energy in flue gases and cleansing it from environmental hazards.

    The flue gas condensation unit on Stora Enso Kvarnsveden Mill is owned by Borlänge‑Energi. They want to know if the condenser is operating as effective as it could be. This report investigates how the condenser and external heater at Stora Enso Kvarnsveden Mill is affected by different supply and return temperatures as well as what the production costs of the energy is.

    The calculations have been accomplished by using the density, specific heat capacity, flow- and temperature differences in Excel. All the calculations have originated from the median value for each month and used in comparison. The basis of the calculations is data that has been collected in the period of January 2015 to December 2018.

    The results indicate that increasing the supply temperature to 95 °C increases the energy costs by about 2 500 000 SEK per year. These costs can be reduced by 400 000 SEK per year by decreasing the return temperature to 40 °C. If the supply temperature is instead decreased to 75 °C when the temperature outside is higher than -1 °C, the costs decreases. A low supply temperature leads to less wear on the pipes, less heat losses, less fuel consumption and less emissions. This temperature reduction can decrease the costs by 620 000 SEK per year.

    If the return temperature is reduced but the supply temperature retained as it is today the costs could decrease by over 400 000 SEK per year. And by reducing both the supply and return temperature a cost saving of over 1 000 000 SEK per year could be achieved.

    The recommendation is therefore a lowering of the supply temperature to 75 °C when the temperature outside is warmer than -1 °C.

    The recommended supply temperature is:

    • 75 °C when the temperature outside is warmer than -1 °C
    • 80 °C between -2 and -4 °C
    • 85 °C at -5 °C,
    • 90 °C between -6 and ‑7 °C
    • 95 °C between -8 and -11 °C
  • 73.
    Igartua Irazustabarrena, Amaia
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Analysis of the reduction of the energy demand of a house by using a glass structure2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study focuses on the effects that a greenhouse can have in the energy demand of a regular Swedish dwelling. Based on the layouts and information that Fiskarhedenvillan house constructor company supplied, a simulation model was built on IDA ICE and a greenhouse was placed attached to the house. The results show an energy reduction of 12 % in heating by placing a greenhouse next to the house in the south façade, as well as the possibility to use the space for growing plants. An analysis about the change in the orientation of the house was done in which it was proved that south orientation implies the lowest energy demand. Lastly, the possibility of installing a heater in the greenhouse was studied by making an energy analysis of it, in order to consider the chance to use the greenhouse as another common area all over the year.

  • 74.
    Jahedi, Mohammad
    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.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology. Department of Management and Engineering, Linköping University.
    Quenching a rotary hollow cylinder by multiple configurations of water-impinging jets2019In: International Journal of Heat and Mass Transfer, ISSN 0017-9310, E-ISSN 1879-2189, Vol. 137, p. 124-137Article in journal (Refereed)
    Abstract [en]

    Experiments have been conducted to analyze quenching of a hot rotary hollow cylinder by one and two rows of water-impinging jets. Sub-cooled water jets (ΔTsub = 45–85 K) with flow rate 8006 to 36,738 impinged on hollow cylinder with rotation speed 10 to 70 rpm at various initial wall superheat temperatures from 250 to 600ºC. Jet-to-jet and jet-to-surface spacing varied between 4 to 10d and 1.5 to 7d respectively and angular position of impinging jets were tested from 0 to 135º. Effectiveness of the defined parameters on stagnation point’s local average heat flux was found lower in the film and nucleate boiling compare to transition boiling regime where rotation speed had the highest impact. Characteristic of maximum heat flux (MHF) at stagnation point and upwash flow point were analyzed based on surface heat flux, time and temperature corresponding to MHF. Same maximum heat flux levels were captured in the both points which reveals importance of the flow behavior at the upwash flow point. The effectiveness of the parameters to improve average heat transfer was studied based on cooling area of each water impingingjet in the multiple configurations. Higher average heat transfer was obtained by increasing flow rate and subcooling temperature and lower initial wall superheat temperature corresponding to onset of transition boiling regime.

  • 75.
    Jahncke, Helena
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational Health Science and Psychology, Occupational Health Science. University of Gävle, Centre for Musculoskeletal Research.
    Keus van de Poll, Marijke
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Viktiga frågor glöms bort i debatten om kontorslandskap2019In: Göteborgs-Posten, ISSN 1103-9345, no 18-sepArticle in journal (Other (popular science, discussion, etc.))
  • 76.
    Jakobsson, Malin
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Lund, Elin
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Organisatoriska förutsättningar vid implementering av kommunala miljöstrategier2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The following study deals with organizational conditions that affect the implementation of municipal environmental strategies. It aims to increase understanding of and contribute with material of empirical studies of implementing the environmental responsibility of municipalities. The aim of the study was to identify how organizational conditions affect the implementation of environmental strategies and to present solutions to how municipalities can handle the challenges that occur when environmental strategy work is to be incorporated and implemented in a municipality. In order to provide answers to whether there were any, and in that case which, organizational conditions that could promote or hinder municipalities' ability to implement environmental strategies, a literature study and a case study of a medium-sized Swedish municipality was conducted with the aim of collecting experience-based knowledge. The result shows that it is difficult to point out the influence of individual organizational conditions on the implementation process, as they interact. However, the implications are that the organization's structure, culture and leadership influence the work process. Limitation of or the uncertainty on access to resources is highlighted as an obstacle in the work with the environmental strategy. It is pointed out that it will most likely not be an increased resource supply, but instead it is necessary to prioritize what the tax money will be used for. Furthermore, the existence of target conflicts has proved to be a challenge that municipalities need to handle. Target conflicts have been spotted between environmental goals and other municipal goals. Because municipalities generally work on the basis of many, and sometimes conflicting, goals, the ability to prioritize is central. To succeed with the environmental work, municipalities are recommended to identify and enable synergies between the environmental goals and other welfare goals.

  • 77.
    Jiménez, Marcela
    et al.
    Universidad Nacional Autónoma de México.
    Pérez-Belmont, Patricia
    Universidad Nacional Autónoma de México.
    Schewenius, Maria
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science. Stockholm Resilience Centre, Stockholm University.
    Lerner, Amy M.
    Universidad Nacional Autónoma de México (UNAM).
    Mazari-Hiriart, Marisa
    Universidad Nacional Autónoma de México (UNAM).
    Assessing the historical adaptive cycles of an urban social-ecological system and its potential future resilience: the case of Xochimilco, Mexico City2020In: Regional Environmental Change, ISSN 1436-3798, E-ISSN 1436-378X, Vol. 20, no 1, article id 7Article in journal (Refereed)
    Abstract [en]

    As the bulk of the world’s population becomes urban, maintaining urban ecosystem services for environmental and social well-being in cities is crucial. According to resilience theory, maintaining such services requires for a complex adaptive systems perspective that helps in identifying key elements and dynamics behind cross-scale social-ecological interactions. In this context, the objective of this article is to use a resilience “lens” to problematize the imminent loss of an urban wetland using the adaptive cycle model as a heuristic tool. Our case study focuses on the Xochimilco wetland, located in the southern periphery of Mexico City. Xochimilco is characterized by the presence of a complex system of raised bed wetland agriculture (the chinampa system), which was established over 1000 years ago; currently, despite having a recognized cultural and environmental value, it is threatened by increasing urban sprawl, over-exploitation of the aquifer, and water contamination. By conducting a historical analysis of the Xochimilco social-ecological system, we assess how it has gone through phases of the adaptive cycle. As a result, we identify critical elements of the system’s historically maintained resilience and main drivers of system change. From such findings, we present some insights on the possibilities of maintaining the system’s resilience and guidance for future management strategies for the Xochimilco wetland. Lastly, we reflect on the scope and limitations of using a resilience-based approach and an adaptive cycle analysis for addressing urban sustainability problems, especially in cities in the Global South.

  • 78.
    Johansson, Ida
    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.
    Mardan, Nawzad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Cornelis, Erwin
    Tractebel Engineering S.A., Brussels, Belgium.
    Kimura, Osamu
    Socio-Economic Research Center, Central Research Institute of Electric Power Industry, Tokyo, Japan.
    Thollander, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Designing Policies and Programmes for Improved Energy Efficiency in Industrial SMEs2019In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 12, no 7, article id 1338Article, review/survey (Refereed)
    Abstract [en]

    Climate change, due to anthropogenic emissions of greenhouse gases, is driving policymakers to make decisions to promote more efficient energy use. Improved industrial energy efficiency is said to play a key role in the transition to more carbon-neutral energy systems. In most countries, industrial small and medium-sized enterprises (SMEs) represent 95% or more of the total number of companies. Thus, SMEs, apart from using energy, are a major driver in the economy with regard to innovation, GDP growth, employment, investments, exports, etc. Despite this, research and policy activities related to SMEs have been scarce, calling for contributions in the field. Therefore, the aim of this paper is to critically assess how adequate energy efficiency policy programmes for industrial SMEs could be designed. Results show that scientific publications in the field differ in scope and origin, but a major emphasis of the scientific papers has been on barriers to and drivers for energy efficiency. Scientific contributions from studies of energy policy programmes primarily cover energy audit programmes and show that the major energy efficiency measures from industrial SMEs are found in support processes. The review further reveals an imbalance in geographic scope of the papers within the field, where a vast majority of the papers emanate from Europe, calling for scientific publications from other parts of the world. The study synthesizes the findings into a general method on how to design efficiency programs for the sector.

  • 79.
    Johansson, Ida
    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.
    Thollander, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Non-energy benefits in energy audit and energy efficiency network policy programs for industrial SMEs2019In: Eceee 2019 Summer Study Proceedings, 2019, p. 225-233Conference paper (Refereed)
    Abstract [en]

    Improved energy efficiency is a key component towards sustainable and climate-neutral industrial energy systems. The potential for industrial energy efficiency varies between sectors and processes but is stated to be high. Implementation of energy efficiency measures and activities could also result in benefits in addition to energy cost savings, benefits that are more difficult to quantify in economic terms. Research shows that additional gains from investments are underestimated as non-energy benefits (NEBs) are often neglected when the financial attractiveness of energy efficiency investments are evaluated. In the literature, great attention has been given to realise industrial energy efficiency potential through industrial energy policies and programs, in order to promote investments and implementation of new, more efficient technologies and processes. The most internationally common industrial energy policies for industrial SMEs are energy audit programs, but energy efficiency networks have also received increased attention from policymakers. However, there is a scarcity of studies exploring NEBs in relation to industrial SME energy audits and energy efficiency network policy programs. The aim of this study was to identify and compare NEBs from two key energy efficiency policies: energy audit and energy efficiency network programs. Semi-structured interviews were conducted with executives at two groups of industrial companies: companies that participated in the regional Swedish energy efficiency network policy program, and participants from the national energy audit program, Swedish Energy Audit Program (SEAP). The overall most commonly mentioned NEBs were related to production, such as increased lifetime of equipment and more reliable production. However, while participants from the energy audit program related these NEBs mainly to technical installations, network participants also saw these types of NEBs from energy management practices. If NEBs were to be included in energy audit programs the benefit of the audits could be increased, but will then particularly affect the technical installations. NEBs in terms of network participation were shown to lead to an increase in the general benefits of the networks, and for network companies NEBs are also linked to measures related to operation and maintenance, i.e., energy management practices. One difference between the two groups was that NEB improved the company’s environmental image. Two of the companies participating in the network policy program had presented their participation on their public webpage perceiving this as a very important benefit, while respondents from the energy audit program could not relate their company image to their energy audit. One additional NEB that was found, not previously mentioned in the scientific literature on NEBs, was that among the network participants, establishing contacts with other companies in the region was considered of great importance, and further contacts that would not have been established outside of the network. Results even found new customer relationships as a result of the network. This finding is of a general nature, thus apart from the other commonly known NEBs, an additional NEB that primarily relates to participation in energy efficiency networks that this study found is establishing new relationships with other companies in the region.

  • 80.
    Jönsson, Petra
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Mattsson, Julia
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    "Jag har inget emot kollektivtrafiken om jag säger så, men...": En kvalitativ studie om män och kvinnors resvanor och inställningar till arbetspendling2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The traffic sector is responsible for the greatest amount of greenhouse emissions in Sweden because of its combustion of fossil fuels. Sandviken is the municipality in Gävleborg county that uses the least amount of public transportation in form of bus traffic. The aim of this study is to gain an understanding through qualitative research how the individual looks and reflects upon their own commuting, and to identify which factors that mostly affects the individuals commuting habits. The study is geo-graphically delimited to look to Sandbacka Park. The amount of interview partici-pants was in total 18, seven women and eleven men. The main themes that could be identified from the interviews was stress, environmental awareness, flexibility, effi-ciency and control. The average distance to the workplace was about 19,25 km. In total stated 73% of men and 57% of women that car was the main mode of transport to the workplace. This means that more men than women travelled by car to the workplace, and also show more positive feeling to car use. Many of the par-ticipants of the interview had knowledge of climate change and the connection it has to transportation but could still defend their own individual car use. Some of the men that were interviewed claimed to have a greater need of flexibility and maintain status, which can be an explanation as to why the need of car use is greater with men than women. 42% of women and 27% of men commutes which more sustainable modes of transportation, such as public transportation and walking or bicycling. Two of the women who commuted with public transportation expressed content with their mode of transportation. They had also during the interviews mentioned an environmental awareness, which shows that there is a connection between mak-ing sustainable choices and being content with the chosen more sustainable mode of transportation. The results from Sandbacka Park is generalizable to other work-places with the same kind of prerequisites. This study shows that men have more positive emotions connected to car use and uses the car more as a mode of commut-ing to work. During future studies it may be of importance to focus more on longer interviews timewise to create an even greater understanding of the individuals need and prerequisites when commuting. With a greater sample size a more generalisable result could have been achieved.Key words: Commuting, stress, public transportation, commute mode, travel mode choice, gender

  • 81.
    Kabanshi, Alan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Are We Overestimating the Benefits of Emission Reduction Measures?2020In: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 12, no 3, article id 808Article in journal (Refereed)
    Abstract [en]

    When people evaluate the environmental impact of both “environmentally” and “non-environmentally” friendly objects, actions, or behavior, their judgement of the total set in combination is lower than the sum of the individual components. The current communication is a personal perspective article that proposes a human cognitive framework that is adopted during evaluations, which consequently results in wrong reasoning and the reinforcement of misconceptions. The framework gives plausible interpretation of the following: (1) “compensatory green beliefs”—the belief that environmentally harmful behavior can be compensated for by friendly actions; (2) the “negative footprint illusion”—the belief that introducing environmentally friendly objects to a set of conventional objects (e.g., energy efficient products or measures) will reduce the environmental impact of the total set; and (3) “rebound effects”—sustainability interventions increase unsustainable behavior directly or indirectly. In this regard, the framework herein proposes that many seemingly different environmentally harmful behaviors may sprout from a common cause, known as the averaging bias. This may have implications for the success of sustainability interventions, or how people are influenced by the marketing of “environmentally friendly” measures or products and policymaking.

  • 82.
    Kabanshi, Alan
    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.
    Sandberg, Mats
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Entrainment and its Implications on Microclimate Ventilation Systems: Scaling the Velocity and Temperature Field of a Round Free Jet2019In: Indoor Air, ISSN 0905-6947, E-ISSN 1600-0668, Vol. 29, no 2, p. 331-346Article in journal (Refereed)
    Abstract [en]

    Research on microclimate ventilation systems, which mostly involve free jets, point to delivery of better ventilation in breathing zones. While the literature is comprehensive, the influence of contaminant entrainment in jet flows and its implications on the delivery of supplied air is not fully addressed. This paper present and discuss entrainment characteristics of a jet issued from a round nozzle (0.05 m diameter), in relation to ventilation, by exploring the velocity and temperature fields of the jet flow. The results show a trend suggesting that increasing the Reynolds number (Re) reduces ambient entrainment. As shown herein, about 30% concentration of ambient air entrained into the bulk jet flow at Re 2541 while Re 9233 had about 13% and 19% for Re = 6537/12026 at downstream distance of 8 diameters (40 cm). The study discusses that “moderate to high” Re may be ideal to reduce contaminant entrainment, but this is limited by delivery distance and possibly the risk of occupant discomfort. Incorporating the entrainment mixing factor (the ratio of room contaminants entrained into a jet flow) in performance measurements is proposed and further studies are recommended to verify results herein and test whether this is general to other nozzle configurations.

  • 83.
    Kabanshi, Alan
    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.
    Yang, Bin
    Department of Applied Physics and Electronics, Umeå University, Umeå, Sweden.
    Sörqvist, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental psychology.
    Sandberg, Mats
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Occupants’ perception of air movements and air quality in a simulated classroom with an intermittent air supply system2019In: Indoor + Built Environment, ISSN 1420-326X, E-ISSN 1423-0070, Vol. 28, no 1, p. 63-76Article in journal (Refereed)
    Abstract [en]

    The study reported herein builds on occupant response to an intermittent air jet strategy (IAJS), which creates periodic airflow and non-isothermal conditions in the occupied zone.  Previous research has highlighted the benefits of IAJS on thermal climate and supports energy saving potential in view of human thermal perception of the indoor environment. In this study, the goal was to explore occupant acceptability of air movements and perceived indoor air quality, and to determine a way of assessing acceptable air movement conditions under IAJS. Thirty-six participants were exposed to twelve conditions: three room air temperatures (nominal: 22.5, 25.5 and 28.5 oC), each with varied air speeds (nominal: <0.15 m/s under mixing ventilation (MV), and 0.4, 0.6 and 0.8 m/s under IAJS) measured at the breathing height (1.1 m). The results show that participants preferred low air movements at lower temperatures and high air movements at higher temperatures. A model to predict percentage satisfied with intermittent air movements was developed, and predicts that about 87% of the occupants within a thermal sensation range of slightly cool (-0.5) to slightly warm (+0.5), in compliance with ASHRAE standard 55, will find intermittent air movements acceptable between 23.7 oC and 29.1 oC within a velocity range of 0.4 – 0.8 m/s.  IAJS also improved participants’ perception of air quality in conditions deemed poor under MV. The findings support the potential of IAJS as a primary ventilation system in high occupant spaces such as classrooms. 

  • 84.
    Keus van de Poll, Marijke
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Disruption of writing by irrelevant background speech: what role for number of voices and language?2019Conference paper (Other academic)
  • 85.
    Keus van de Poll, Marijke
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science. Karolinska Institutet, Institute of Environmental Medicine, Division of Intervention and Implementation Research in Worker Health.
    Nybergh, L
    Karolinska Institutet, Institute of Environmental Medicine, Division of Intervention and Implementation Research in Worker Health.
    Lornudd, C
    Karolinska Institutet, Department of Learning, Informatics, Management and Ethics (LIME).
    Kwak, L
    Karolinska Institutet, Institute of Environmental Medicine, Division of Intervention and Implementation Research in Worker Health.
    Lohela Karlsson, M
    Uppsala University, Department of Medical Science.
    Hagberg, J
    Karolinska Institutet, Institute of Environmental Medicine, Division of Intervention and Implementation Research in Worker Health.
    Torgén, M
    Uppsala University, Department of Medical Science.
    Jensen, I
    Karolinska Institutet, Institute of Environmental Medicine, Division of Intervention and Implementation Research in Worker Health.
    Bergström, Gunnar
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational Health Science and Psychology, Occupational Health Science. University of Gävle, Centre for Musculoskeletal Research. Karolinska Institutet, Institute of Environmental Medicine, Division of Intervention and Implementation Research in Worker Health.
    Preventing sickness absenteeism among employees with common mental disorders or stress-related symptoms at work: A cluster RCT conducted at the occupational health services2019Conference paper (Refereed)
  • 86.
    Keus van de Poll, Marijke
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science. Karolinska Institutet, Institute of Environmental Medicine, Division of Intervention and Implementation Research in Worker Health.
    Nybergh, L
    Karolinska Institutet, Institute of Environmental Medicine, Division of Intervention and Implementation Research in Worker Health.
    Lornudd, C
    Karolinska Institutet, Department of Learning, Informatics, Management and Ethics (LIME).
    Kwak, L
    Karolinska Institutet, Institute of Environmental Medicine, Division of Intervention and Implementation Research in Worker Health.
    Lohela Karlsson, M
    Uppsala University, Department of Medical Science.
    Hagberg, J
    Karolinska Institutet, Institute of Environmental Medicine, Division of Intervention and Implementation Research in Worker Health.
    Torgén, M
    Uppsala University, Department of Medical Science.
    Jensen, I
    Karolinska Institutet, Institute of Environmental Medicine, Division of Intervention and Implementation Research in Worker Health.
    Bergström, Gunnar
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational Health Science and Psychology, Occupational Health Science. University of Gävle, Centre for Musculoskeletal Research. Karolinska Institutet, Institute of Environmental Medicine, Division of Intervention and Implementation Research in Worker Health.
    Preventing sickness absenteeism among employees with common mental disorders or stress-related symptoms at work: A cluster RCT conducted at the occupational health services2019Conference paper (Refereed)
  • 87.
    Keus van de Poll, Marijke
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Sjödin, Louise
    Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden.
    Nilsson, Mats
    Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden.
    Disruption of writing by background speech: does sound source location and number of voices matter?2019In: Applied Cognitive Psychology, ISSN 0888-4080, E-ISSN 1099-0720, Vol. 33, no 4, p. 537-543Article in journal (Refereed)
    Abstract [en]

    It is not unusual that people have to write in an environment where background speech is present. Background speech can vary in both speech intelligibility and location of the sound source. Earlier research has shown disruptive effects of background speech on writing performance. To expand and reinforce this knowledge, the present study investigated the role of number of voices and sound source location in the relation between background speech and writing performance. Participants wrote texts in quiet or in background speech existing of one or seven voices talking simultaneously, located in front of or behind them. Overall, one voice was more disruptive than seven voices talking simultaneously. Self-reports showed that sound from the front was more disruptive compared to sound from behind. Results are in line with theory of interference-by-process, attentional capture and the cross-modal theory of attention. The relevance of the results for open-office environments is discussed.

  • 88.
    Khan, Muhammad Shoaib Arshad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Scope of BlockChain Technology in Energy Sector.2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    World energy systems are going through a continuous change. The focus has been shifted from large thermal or hydal power generation to small distributed generation, mainly based upon renewable energy systems. This transition is also backed by some governments. There have also been significant improvements in grid technology, and modern-day smart grid can provide real time bi-directional flow of data i.e. “real time energy deficit and surplus, and also real time prices to both producers and consumers. Smart grid can also accommodate intermittent small suppliers of electricity. This shift in energy generation policy and improvement in grid technology has opened ways for small scale energy producers and consumers to share energy with each other. It has also opened ways to purchase or sale energy to unknown peers over a smart grid. Need has been felt to store these transactions among peers in a secure, non-alterable yet quickly accessible way. Blockchain technology offers to provide this secure, unalterable yet quickly accessible ledger.

    In this study this transition process and role of blockchain technology for future energy systems has been historically reviewed. It has been found out that on top of keeping record of Peer to Peer transactions, blockchain technology can fill many other purposes. However, technology is still not matured for large scale projects, Research projects are underway to decrease the large time and energy consumption for block building computational processes yet keeping them safe and reliable.

  • 89.
    Khosravi Bakhtiari, Hossein
    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. Department of Construction, Gavlefastigheter Company, Gävle, Sweden.
    Akander, Jan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Evaluation of Thermal Comfort in a Historic Building Refurbished to an Office Building with Modernized HVAC Systems2019In: Advances in Building Energy Research, ISSN 1751-2549, E-ISSN 1756-2201Article in journal (Refereed)
    Abstract [en]

    Envelopes with low thermal performance are common characteristics in European historic buildings, causing higher energy demand and insufficient thermal comfort. This paper presents the results of a study on indoor environmental quality (IEQ), with special focus on thermal comfort, in the historic City Hall of Gävle, Sweden, now used as an office building. There are two modern heat recovery ventilation systems with displacement ventilation supply devices. The district heating network heats the building via pre-heat supply air and radiators. Summer cooling comes from electric heat pump ejecting heat into the exhaust ventilation air. A building management system (BMS) controls the heating, ventilation and air-conditioning (HVAC) equipment. The methodology included on-site measurements, BMS data logging and evaluating the occupants’ perception of a summer and a winter period indoor environment using a standardized questionnaire. In conclusion, indoor environmental quality in this historic building is unsatisfactory. Stuffy air, too high, too low and varying room temperatures, lighting problems and noise are constant issues. Although it is equipped with modern ventilation systems, there are still possibilities for improving thermal comfort by improved control strategies, since upgrading the building’s envelope is not allowed according to the Swedish Building Regulations in historic buildings with heritage value.

  • 90.
    Kjörling, Cecilia
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Forsberg, Olivia
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    En byggnads koldioxidavtryck och dess materialavfall vid produktion2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 91.
    Korkmaz, Ebubekir
    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.
    Lundstöm, Jerry
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Böjprovning av spikplåtsskarvad träbalk2019Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    This thesis examines the bearing capacity, stiffness, shear and moment force of a continuous wooden beam and how the parameters of the beam changes when the beam is spliced ​​with nail plate. A literature study has been conducted to examine which studies have been carried out in this field.

    Construction timber is the most common wooden element for wooden constructions but has limitations in available lengths since the maximum length manufactured is 5400 mm. If larger lengths are required, splicing must occur or use of other materials.   The study examines a 2 series, a 3-point series (moment and shear) and a 4-point series (moment). Each series consists off 3 trials in each series to see how shear and moment force affect the strength. The study also shows which off the joints that gives the least strength. The samples are tested in a draw and pressure machine lying on 2 supports and with a point load for the 3-point method and 2-point loads for the 4-point method. In the trials pressure is applied until the beams break. The study investigates the lab results, fracture state and use state for the wooden beams being tested. The result of the study shows that a splicing will lower the wood's carrying capacity between 21-60% compared to a non-spliced beam for the 3-point method and a reduction of 40-66% compared to a non-spliced beam for the 4-point method. Despite the lowered bearing capacity all the experiments are still within the characteristic value and approved for use. A larger dimension on the nail plate would probably have given a better value.

  • 92.
    Kurdia, Ali
    et al.
    Högskolan Dalarna, Borlänge, Sweden.
    Gomes, João
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Pius, George
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Ollas, Patrik
    RISE Research Institutes of Sweden, Borås, Sweden.
    Olsson, Olle
    Absolicon, Gävle, Sweden.
    Quasi-Dynamic Testing of a Novel Concentrating Photovoltaic Solar Collector According to ISO 9806:20132018In: PROCEEDINGS OF THE ISES EUROSUN 2018 CONFERENCE - 12TH INTERNATIONAL CONFERENCE ON SOLAR ENERGY FOR BUILDINGS AND INDUSTRY / [ed] Haberle, A., INTL SOLAR ENERGY SOC , 2018, p. 1262-1273Conference paper (Refereed)
    Abstract [en]

    Testing and certification of solar thermal collectors has been widely researched and improved over the years, however, many of the developments in the test standards has been focused primarily on generic flat plate collectors. In this study, the focus was on depicting the applicability of the current standard in characterizing the performance of a novel concentrating solar collector of design. The applicability of the Quasi-Dynamic Testing (QDT) method for collector certification, by the ISO 9806:2013, is studied to be used in characterizing the novel concentrating PVT collector, and to point out the weaknesses observed, and essential additions required.

  • 93.
    La Fleur, Lina
    et al.
    Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Rohdin, Patrik
    Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology. Division of Energy Systems, Department of Management and Engineering, Linköping University, Linköping, Sweden.
    Energy renovation versus demolition and construction of a new building—a comparative analysis of a Swedish multi-family building2019In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 12, no 11, article id 2218Article in journal (Refereed)
    Abstract [en]

    This study addresses the life cycle costs (LCC) of energy renovation, and the demolition and construction of a new building. A comparison is made between LCC optimal energy renovations of four different building types with thermal performance, representing Swedish constructions from the 1940s, 1950s, 1960s, and 1970s, as well as the demolition of the building and construction of a new building that complies with the Swedish building code. A Swedish multi-family building from the 1960s is used as a reference building. LCC optimal energy renovations are identified with energy saving targets ranging between 10% and 70%, in addition to the lowest possible life cycle cost. The analyses show that an ambitious energy renovation is not cost-optimal in any of the studied buildings, if achieving the lowest LCC is the objective function. The cost of the demolition and construction of a new building is higher compared to energy renovation to the same energy performance. The higher rent in new buildings does not compensate for the higher cost of new construction. A more ambitious renovation is required in buildings that have a shape factor with a high internal volume to heated floor area ratio. © 2019 by the authors.

  • 94.
    La Fleur, Lina
    et al.
    Linköpings universitet.
    Rohdin, Patrik
    Linköpings universitet.
    Moshfegh, Bahram
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology. Linköpings universitet.
    Investigating cost-optimal energy renovation of a multifamily building in Sweden2019In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 203, article id 109438Article in journal (Refereed)
    Abstract [en]

    A significant reduction in energy use in the building stock is a major challenge for the future, and doing this in a cost-effective manner is important. This study uses an optimization approach to identify life cycle cost (LCC) optimal energy efficiency measures (EEMs) to implement as part of a renovation of a multifamily building in Sweden. The studied building is a multifamily building with a lightweight concrete construction and an exhaust air ventilation system, built in 1961. The optimization tool OPERA-MILP is used. The energy renovation approaches are compared to both the performed energy renovation of the building and a validated dynamic energy simulation model in IDA ICE 4.8. The results show that under the given framework conditions and assumptions it is not cost-optimal to improve the thermal performance of the building envelope or to implement heat recovery ventilation measures to reduce the space heating demand in the building when considering a life cycle of 40 years. Balanced mechanical ventilation system with heat recovery is cost-effective when an energy saving target of 40% is introduced. The energy renovation of the building has a slightly higher LCC than the cost-optimal level, and it would have been more cost-effective to add more insulation to the façade instead of the attic to achieve the same level of energy saving. A sensitivity analysis has been performed to reveal the effect of the discount rate, energy price, cost of EEMs, thermal properties of the building envelope and windows’ solar heat gain factors on the LCC.

  • 95.
    Lanca, Miguel
    et al.
    Instituto Superior Técnico, Lisbon University, Portugal.
    Gomes, João
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Hayati, Abolfazl
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Numerical Simulation of the Thermal Performance of Four Concentrating Collectors with Bifacial PV Cells2018In: PROCEEDINGS OF THE ISES EUROSUN 2018 CONFERENCE - 12TH INTERNATIONAL CONFERENCE ON SOLAR ENERGY FOR BUILDINGS AND INDUSTRY / [ed] Haberle, A., INTL SOLAR ENERGY SOC , 2018, p. 810-821Conference paper (Refereed)
    Abstract [en]

    Bifacial photovoltaic cells can produce electricity from the incoming solar radiation on both sides. Used in combination with concentrating solar technology, bifacial photovoltaic cells can see its electrical output further augmented, thus decreasing the cost per kWh. It is known, however, that the efficiency reduction when these cells are exposed to increased temperatures is a relevant factor. This can happen, for example, when they are mounted on a glassed collector or receiver. In this study, a thermal analysis is carried out on four prototypes of concentrating collectors with bifacial PV cells. Results show that, as expected, when glass and gables are removed from the collector, much better heat dissipation is achieved, thus resulting in favorable cell operation conditions.

  • 96.
    Lane, Anna-Lena
    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. RISE Research Institutes of Sweden.
    Boork, Magdalena
    RISE Research Institutes of Sweden.
    Thollander, Patrik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Barriers, driving forces and non-energy benefits for battery storage in photovoltaic (PV) systems in modern agriculture2019In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 12, no 18, article id 3568Article in journal (Refereed)
    Abstract [en]

    Battery storage has been highlighted as one way to increase the share of renewables in energy systems. The use of local battery storage is also beneficial when reducing power variations in the grid, thereby contributing to more robust and cost-effective energy systems. The purpose of this paper is to investigate barriers, drivers and non-energy benefits (NEB) for investments in battery storage in photovoltaic systems (PV) in the context of farmers with PV systems in Sweden. The study is based on a questionnaire about barriers, driving forces and NEB for investment in battery storage connected to PV. The questionnaire was sent to farmers in Sweden who already have photovoltaics installed and about 100 persons answered, a response rate of 59%. The major barriers found are related to the technical and economic risks of investing in battery storage. One of the main conclusions is that the highest-ranked driver, i.e., to use a larger part of the produced electricity oneself, turns out to be the highest priority for the grid-owner seeking to reduce the need for extensive investments in the grid. The primary NEBs found were the possibility of becoming independent from grid electricity.

  • 97.
    Larsson, Erik
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Småskalig kraftvärmeproduktion för ett medelstort svenskt industriföretag: Potentialen för konventionell Rankinecykel2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The emissions of greenhouse gases need to decrease rapidly over the coming decades. Sweden has set the target to achieve net zero emissions by 2045. The industrial sector plays a crucial role in that conversion by reducing its energy needs and to convert from fossil fuels to renewables.

    This conversion will require a more robust and reliable energy system were todays centralized system has been supplemented by small decentralized production facilities. To produce heat and power closer to the consumers means less transmission losses. Small scale combined heat and power (CHP) production based on biofuels or excess heat could be a solution to reduce greenhouse gas emissions.

    The purpose of this paper is to evaluate the possibility for a mid-size Swedish industrial company to produce its own base load of heat and power with a conventional Rankine cycle. Also to evaluate the production costs depending on the size of the plant.

    The work has consisted of data collection from different manufacturers of steam turbines and steam boilers, a calculation model has been made in Excel to compare different plant sizes and in different operating scenarios. Economical evaluations has been made with the Pay-off method and the net present value method (NPV).

    The result shows that production costs for facilities with steam turbines in the size range of 10 – 100 kWel is well below the price of bought electricity and district heating. The economical evaluation generally shows on short pay-off times and positive NPV.

    A comparison of the CHP plants shows that the electric efficiency is low and the total efficiency sometimes can be lower than for the existing heat supplier of the company. This means that a switch to local CHP will have a negative impact from a system perspective, because of the increased use of primary energy resources.

    There is many parameters that affects the performance of a CHP plant but the most crucial is the operation time. To have a continuous operation over a major part of the year has a great impact on the economic performance. The low electric efficiency means that the major part of the savings gets on the heat production. This means that the CHP plant should be dimensioned to replace primarily the heat requirement.

  • 98.
    Lignell, Moa
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Föroreningsmängder och koncentrationer i dagvattendammars sediment: påverkan från omgivande markanvändning, en studie i Gävle2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis addresses how human activities in the catchment area could influence the contaminant concentrations and amounts of contaminants in the sediments of stormwater ponds. Sediment sampling was done in April 2019. The storm water ponds had different land uses: industrial, residential (detached area) and two land uses of traffic with different intensities; “traffic by Hamnleden” (7000 cars/day) and “traffic by Västerbacken” (2000 cars/day). Samples were taken with a Russian corer and sediment depth was measured to quantify sediment volume. Samples were sent to laboratory for analysis of metals, phosphorus, aliphatics, aromatics and polycyclic aromatic hydrocarbons [PAH].

    The stormwater pond with industry as land use had the highest concentration of contaminants in the sediment, followed by residential area – traffic by Hamnleden – traffic by Västerbacken. The results of this study showed that the land use concentrations of contaminants were all similar, and the patterns of concentration in the graphic figures were similar. The results could be explained by the narrow geographic area in which the three storm water ponds are situated. They could be affected by the same atmospheric downfall which could even out the concentrations. It was not expected that the residential area would have one of the highest concentrations in the sediment. This could be explained by the high content of organic matter, as some contaminants create strong chemical bonding with organic matter.

    Bigger differences were seen for the amounts of contaminants in the sediments and the comparative figure “fixated amount of contaminant per year”. The land use industry had the highest amount of contaminants followed by traffic by Hamnleden – traffic by Västerbacken – residential area. This is probably due to differences in particle quota in the storm water coming from the land uses.

    Calculations were done for the amount of transported contaminants in stormwater, via the watershed management tool and model StormTac. The calculated transportation of contaminants resulted in total amounts of contaminants, meaning both dissolved and particulate fractions. The calculations from StormTac were compared with the comparative figure “fixated amount of contaminant per year” for the land use residential area, and the amounts were significantly higher for the calculated transportation. This could partly be explained by comparing total amounts with particulate amounts.

    A conclusion of this report is that land use affects the amounts of contaminants and sediment volume in the studied storm water ponds, rather than the concentrations.

  • 99.
    Lilja, Grace
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Appelgren, Victoria
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Strategiskt arbete med att minska invasiva växtarters spridningsrisker: Klimatförändringar och trädgårdsavfallets inverkan på spridning2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Invasive species are an increasing problem worldwide, threatening indigenous communities and species. In a world where people travel and trade a lot in a global market, many organisms are transported to new parts of the world where they have never existed before. Most do not survive in the new environment but die, but some thrive and thrive. When such species are established and multiply in places outside their natural range, it can be followed by negative consequences for species that have existed there for a long time - so-called indigenous species. Then the new species are often called alien invasive species. An example of this is the beautiful and colourful plant flower lupin (Lupinus polyphyllus)that people on their travels brought with them from North America, among other things, Europe. Global warming and increased trade between countries is the main reason why foreign species are introduced to new ecosystems while climate change means that habitats can change to become more suitable for an invasive alien species. The invasive species currently causes major economic losses worldwide. Lupins, park slides, and giant sheds are examples of invasive plants that have been introduced in European gardens because they are beautiful and easy to care for. They are also invasive, spread aggressively and are detrimental to our nature because they penetrate our native species. To stop these invasive plants and from damaging Europe's nature, the EU countries have decided to take action against certain species. On January 1, 2015, the EU adopted a regulation on invasive alien species and how to combat it within the Union. On February 5, 2016, the Swedish Environmental Protection Agency submitted the Authority's proposal to the Swedish Government on new rules and measures on how to stop invasive harmful species. Already today, great resources are being devoted to combating invading plants such in our nature reserves. However, an early preventive or direct targeted intervention is much more cost effective than a continuous control of unwanted, invasive species with well-established populations. In order to succeed in this, we need an increased awareness of the problem of alien, invasive species among the public and decision makers, but also a sharp global analysis. Only with knowledge and continuous monitoring can we put in early action against future, aggressive invaders.

  • 100.
    Lim, Eunsu
    et al.
    Toyo university, Tokyo, Japan.
    Chung, Juyeon
    Fukuoka Woman's University, Fukuoka, Japan.
    Sandberg, Mats
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Ito, Kazuhide
    Kyushu University, Fukuoka, Japan.
    Influence of chemical reactions and turbulent diffusion on the formation of local pollutant concentration distributions2020In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 168, article id 106487Article in journal (Refereed)
    Abstract [en]

    The mechanism of structure formation of non-uniform pollutant concentration distributions in indoor environments have been investigated over the past several decades to determine effective ventilation designs. In this study, numerical analyses of local pollutant concentration distributions in indoor environments are performed based on computational fluid dynamics techniques. In particular, the influence of gas phase chemical reactions and turbulent diffusion on the formation of the local pollutant concentration is parametrically analyzed, and the structures are quantitatively investigated using the index for ventilation efficiency, namely the net escape velocity (NEV) concept. The NEV concept represents the substantive velocity scale, combining advection and diffusion velocity of pollutant at a point, and functions as an index to determine the pollutant concentration at that point. Sensitivity analyses as functions of the first Damköhler number (Da) and the turbulent Schmidt number (Sct) were performed, and the influence of Sct on pollutant concentration distributions was more significant compared with that of Da. When Sct was changed from 0.5 to 1.0, the significant NEV increase, especially that in the stagnant flow region, could be attributed to the enhanced pollutant discharge efficiency due to turbulent diffusion in addition to convective flow. Thus, NEV could be used to quantitatively assess the changes in pollutant concentrations accompanying the change in Da or Sct. 

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