| 1. |
- Janson, Ulla, et al.
(författare)
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Demolish, recycle, build new or renovate – energy use throughout the life cycle.
- 2022
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315.
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Konferensbidrag (refereegranskat)abstract
- The building industry has a major impact on the global carbon emissions, the use of natural resources and generation of waste. A drastic change is needed for this industry to be a part of a sustainable future. Within this research, a case study is performed to investigate how cultural values of a building can be preserved when energy efficiency measures are taken, with a low global warming potential (GWP). Keeping the cultural values of the red brick façade, the original window shape and the natural stone in the plinth, there is still an energy saving potential of halve the energy use for space heating. The GWP of the measures taken is strongly dependent on the energy mix in the district heating system.
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| 2. |
- Akperov, M., et al.
(författare)
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Trends of intense cyclone activity in the Arctic from reanalyses data and regional climate models (Arctic-CORDEX)
- 2019. - 1
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Ingår i: Turbulence, Atmosphere and Climate Dynamics. - : IOP Publishing. - 1755-1307. ; 231
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Konferensbidrag (refereegranskat)abstract
- The ability of state-of-the-art regional climate models (RCMs) to simulate the trends of intense cyclone activity in the Arctic is assessed based on an ensemble of 13 simulations from 11 models from the Arctic-CORDEX initiative. Some models employ large-scale spectral nudging techniques. Cyclone characteristics simulated by the ensemble in winter and summer are compared with the results from four reanalyses (ERA-Interim, NCEP-CFSR, NASA-MERRA2 and JMA-JRA55) in winter and summer for 1981-2010 period.
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| 3. |
- Arfvidsson, J., et al.
(författare)
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A method for status determination and risk assessment of energy measures in historic buildings
- 2021. - 1
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Ingår i: IOP Conference Series : Earth and Environmental Science - Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 863
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Konferensbidrag (refereegranskat)abstract
- Implementing energy efficiency measures in historic buildings is a challenging task and require knowledge in a number of different disciplines. The measures to reduce energy use must create a good indoor environment without jeopardizing the loss of important cultural historical values or entailing damages to building materials or load-bearing structures. Building antiquarian-, building biological- and building physical aspects are central, and must be taken into account in the entire process, from planning to implementation of energy update measures in historic buildings. This paper presents a methodology for status determination and risk assessment of energy measures in historic buildings. The method (KuReRA) has been developed in collaboration between curators, building biologists and building physicists.
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| 4. |
- Bramryd, Torleif, et al.
(författare)
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Engineered MSW landfills as a future material resource and a sink for long-term storage of organic carbon
- 2020. - 1
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Ingår i: XVII-th INTERNATIONAL YOUTH SCIENCE AND ENVIRONMENTAL BALTIC REGION COUNTRIES FORUM "ECOBALTICA" 16-17 July 2020, Saint-Petersburg. Russian Federation. - : IOP Publishing. - 1755-1307. ; 578
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Konferensbidrag (refereegranskat)abstract
- A controlled, highly engineered landfill has many similarities to natural peatlands or other natural anoxic sediment deposits. In anaerobic MSW landfills, generally about 30-50 percent of the total carbon content in the waste can be converted into biogas and be collected as resource for energy or chemical industry. Remaining long-lived organic carbon, e.g. from lignin remains un-degraded, Organic carbon in fossil derived hydrocarbons, like plastics, will remain rather unaffected in the landfill. In a future with less remaining oil resources, landfill mining of these polymers can be valuable, making the landfill to a future "resource bank". New reactor cell landfill technologies have shown that up to over 90 % of the produced biogas can be collected and used. Approximately 150-250 m3 of biogas per tonne waste can be extracted from a landfill reactor-cell over a 10-year period. Sequestration of a long-lived organic fraction in a landfill, with an annual input of 100 000 tons of waste, can compensate for annual CO2 emissions from about 20 000 to 25 000 cars. If more than about 60 % of produced biogas can be collected from the landfill, it has positive net effects on climate change. If the waste instead would have been incinerated this would lead to major emissions of fossil CO2, as about 30-50 % of the CO2 in the stack gasses from a waste incinerator has fossil origin.
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| 5. |
- Davidsson, H., et al.
(författare)
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Decentralized ventilation unit for window frame integration
- 2022. - 1
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 1085, s. 32-32
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Konferensbidrag (refereegranskat)abstract
- Swedish National Board of Housing, Building and Planning reported in "Energi i bebyggelsen"that 80 % of the detached houses in Sweden were under-ventilated, and had a flow of 0.23 l/(s·m2) on average instead of, by the code, required 0,35 l/(s·m2). Well known concerns here are lacking indoor environmental quality and a risk of moisture problems in certain rooms and in the envelope. The naturally ventilated houses have a higher airflow at low outdoor temperatures which increases the energy use for heating. Adding proper ventilation to all Swedish detached houses could according to Besmå's pre-study "Potential för energieffektivisering i småhus (2019)"increase the annual energy need by 5.5 TWh. Many of these use electric heating resulting in a heavy pressure on the electricity production and distribution. One way to solve this problem is to install mechanical ventilation with heat recovery. Installing such system in older houses is however often costly and often carries technical and practical problems. Ducts must be installed in every room in the building, requiring space which often leads to reconstruction of walls and ceilings. Another way to solve this is reinforce the existing ventilation in the house with a decentralised ventilation unit with heat recovery. The technical solution is to mount several smaller ventilation unit with heat recovery in the building skin in order to ventilate individual rooms. The solution does not require any ducts to be installed. This simplifies the installation and reduces the maintenance. In this report we study a decentralised ventilation unit with heat recovery intended to be installed in window frame to lower the cost of the combination of ventilation and window renovation. In this report we measure draft, short-circuiting between inlet and outlet air, air mixing in the room, noise and heat recovery efficiency of the ventilation unit. The results show that no draft and no short-circuit occurs and that the mixing of the air in the room is high and an efficiency of the heat recovery of approximately 70 %.
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| 6. |
- Fredriksson, Sam, 1966, et al.
(författare)
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Near-surface physics during convection affecting air-water gas transfer
- 2016
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 35:1, s. 012007-
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Konferensbidrag (refereegranskat)abstract
- The gas flux at the water surface is affected by physical processes including turbulence from wind shear, microscale wave breaking, large-scale breaking, and convection due to heat loss at the surface. The main route in the parameterizations of the gas flux has been to use the wind speed as a proxy for the gas flux velocity, indirectly taking into account the dependency of the wind shear and the wave processes. The interest in the contributions from convection processes has increased as the gas flux from inland waters (with typically lower wind and sheltered conditions) now is believed to play a substantial role in the air-water gas flux budget. The gas flux is enhanced by convection through the mixing of the mixed layer as well as by decreasing the diffusive boundary layer thickness. The direct numerical simulations performed in this study are shown to be a valuable tool to enhance the understanding of this flow configuration often present in nature.
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| 7. |
- Hellström, M., et al.
(författare)
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The ICOS Atmosphere use case : From raw data to knowledge of societal relevance
- 2020. - 1
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Ingår i: 11th International Symposium on Digital Earth (ISDE 11). - : IOP Publishing. - 1755-1307. ; 509
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Konferensbidrag (refereegranskat)abstract
- In order to effectively tackle the on-going changes in global climate, stakeholders and policy makers across the globe need timely and accurate information they can trust on a wide range of topics. Here we briefly describe how observational data on greenhouse gas concentrations collected from the ICOS network of measurement stations in Europe is transformed via atmospheric modelling into information on how emission and uptake of greenhouse gases vary over time and space, and interpreted by experts to create knowledge usable by decision makers.
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| 8. |
- Hennig, Katarina, et al.
(författare)
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Social interaction in local public squares after dark
- 2022
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Ingår i: The 8th International Light Symposium : Re-thinking Lighting Design in a Sustainable Future (Light Symposium 2022) - Re-thinking Lighting Design in a Sustainable Future (Light Symposium 2022). - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 1099
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Konferensbidrag (refereegranskat)abstract
- This paper explores social interaction in local public squares under different lighting conditions. At its best public squares are social spaces that engender a sense of belonging, increase the quality of life and wellbeing of individuals. It is proposed that outdoor lighting would be essential to the use of the public realm after dark, but empirical results regarding lighting conditions and social aspects of life in public squares are limited. Based on a socio-physical conceptual model of the transactional relationship of the user, the lit environment andthe behavioural outcome, this study investigated active social interaction in daylight compared to after dark. A field study was conducted in two local public squares in Malmö, Sweden. The occurrences of which visitors were being alone, in pairs, or in groups of three or more (N=2522), and verbal or non-verbal interaction amongst those in company of another person were recorded.The lit appearance of the two squares after dark, was assessed with HDR-photography and photometric measurements; portraying dissimilar spatial, spectral and intensity characteristics.The results of social interaction show dissimilar patterns of the two squares; an increase in social interaction in EL after dark was observed in one of the squares, while a decrease in the afternoon and no significant difference was displayed in the evening after dark in the other square. It is suggested that lighting may sustain patterns of social interaction after dark, however it might be, that the company of another is especially important after dark.
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| 9. |
- Javanroodi, Kavan, 1988, et al.
(författare)
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A multi-objective optimization framework for designing climate-resilient building forms in urban areas
- 2020
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 588:3
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Konferensbidrag (refereegranskat)abstract
- With the increasing global awareness about the impacts of climate change on the built environments, the need for improving the climate resilience of buildings is being more acknowledged. Despite the high number of relevant studies, there is a lack of frameworks to assess the resiliency of buildings and urban areas. This study presents a multi-objective framework to optimize the form of buildings against its energy performance and thermal comfort considering its resiliency to the uncertainties of climate change during three thirty-years periods (2010-2099) of a warm region. Three performance sections related to building's form are identified and categorized for the impact assessment including (1) urban form, (2) orientation, and (3) transparency with ten influencing parameters. The analysis of non-dominated solutions out of the optimization process showed that the annual energy performance (cooling and heating demand) of the urban areas can improve about 34% in both typical and extreme weather conditions whilst maintaining thermal comfort by optimizing the overall form of the buildings with similar built density and heights. Moreover, Buildings with 15 to 30-degree rotations and 33% glazing ratio showed the highest energy performance. Finally, the top 20 resilient building forms with the highest energy performance and climate resiliency were selected out of the database of results to derive design suggestions.
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| 10. |
- Johansson, D., et al.
(författare)
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Defrosting and Frost Protection Measurements of Heat Recovery in Cold Climate
- 2019
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Ingår i: 1st Nordic conference on Zero Emission and Plus Energy Buildings 6–7 November 2019, Trondheim, Norway. - : IOP Publishing. - 1755-1307. ; 352
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Konferensbidrag (refereegranskat)abstract
- The installation of technical solutions for heat recovery from the ventilation air is a very important step, both with respect to improving the indoor climate and as an energy-saving measure. Ventilation without heat recovery use a substantial part of an entire building's heating use, especially if the building is a low energy building. To realize a large implementation of heat recovery property owners must increase their knowledge about how these systems work and they must be able to rely on them functioning properly. The function and performance of a ventilation system when it comes to heat recovery can be a problem as soon as temperatures drop far below zero. When freezing occurs some form of defrosting is required and this can lead to indoor climate problems and to little or no heat recovery being obtained, which will reduce the energy efficiency and, at the same time, may compromise moisture safety. The goal of this project is to increase knowledge about how heat recovery systems for residential buildings with respect to defrosting and frost protection measures in heat exchangers. The knowledge can thereafter be used to develop effective defrosting strategies and frost protection measures so that the energy use and power requirements are minimized. Measurements were performed for heat recovery systems placed in dwellings in north Sweden to investigate occurrence of frost formation. The paper will present these measurements and some comparing simulations which can serve as a basis for further development of good defrosting strategies.
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