| 1. |
- Petrovic, Bojana, et al.
(författare)
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Life cycle assessment of a wooden single-family house in Sweden
- 2019
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Ingår i: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 251, s. 1456-1465
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Tidskriftsartikel (refereegranskat)abstract
- To understand the reasons behind the large environmental impact from buildings the whole life cycle needs to be considered. Therefore, this study evaluates the carbon dioxide emissions in all stages of a single-family house in Sweden from the production of building materials, followed by construction and user stages until the end-of-life of the building in a life cycle assessment (LCA). The methodology applied is attributional life cycle assessment (LCA) based on `One Click LCA' tool and a calculated life span of 100 years. Global warming potential (GWP) and primary energy (PE) are calculated by using specific data from the case study, furthermore the data regarding building materials are based on Environmental Product Declarations (EPDs). The results show that the selection of wood-based materials has a significantly lower impact on the carbon dioxide emissions in comparison with non-wood based materials. The total emissions for this single-family house in Sweden are 6 kg CO2e/m2/year. The production stage of building materials, including building systems and installations represent 30% of the total carbon dioxide equivalent emissions, while the maintenance and replacement part represents 37%. However, energy use during the in-use stage of the house recorded lower environmental impact (21%) due to the Swedish electricity mix that is mostly based on energy sources with low carbon dioxide emissions. The water consumption, construction and the end-of-life stages have shown minor contribution to the buildings total greenhouse gas (GHG) emissions (12%). The primary energy indicator shows the largest share in the operational phase of the house.
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| 2. |
- Petrovic, Bojana, et al.
(författare)
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Life cycle assessment of building materials for a single-family house in Sweden
- 2019
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Ingår i: Energy Procedia. - : Elsevier. - 1876-6102. ; 158, s. 3547-3552
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Tidskriftsartikel (refereegranskat)abstract
- The Nordic countries have shown great interest in using Life Cycle Assessment (LCA) in the building sector compared to the past years. Sweden has set up an objective to be carbon neutral (no greenhouse gas emissions to the atmosphere) by 2045. This paper presents a case study of a single-family house "Dalarnas Villa" in the region Dalarna, Sweden within a 100-year perspective. The assessment is implemented using a new software based on hard data agreed by Environmental Product Declarations (EPDs). It focuses on building materials, transport distances of the materials, and replacement of essential construction materials. The LCA in this study demonstrates the environmental impact related to building materials from production and construction phase including transport, replacement and deconstruction phase. The study does not cover energy use and water consumption. The results show that the building slab made by concrete is the part of the construction most contributing to CO2e, while the wood frame and cellulose insulation have low environmental impact. Replacement of materials takes nearly half of total environmental impact over 100 years. Having a large share of wood-based products, make greenhouse gas emissions remains low. © 2019 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of ICAE2018 - The 10th International Conference on Applied Energy.
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| 3. |
- Garman, Ian, et al.
(författare)
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Demand control and constant flow ventilation compared in an exhaust ventilated bedroom in a cold-climate single-family house
- 2024
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Ingår i: Intelligent Buildings International. - : Elsevier. - 1750-8975 .- 1756-6932. ; 15:4, s. 175-188
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Tidskriftsartikel (refereegranskat)abstract
- A convertible, zoned ventilation system was field-tested in a modern, airtight Swedish home when occupied either by an experimental team or by a family. Indoor air quality in the master bedroom was monitored under four ventilation strategies. Relative to constant air volume strategies (CAV), demand-controlled ventilation (DCV) that was responding to CO2 concentration extracted more air when people were present, but less in total over 24 h. This elevated the indoor air humidity, beneficial in climates with dry winter air. Multiple monitors within the bedroom indicated that vertical CO2 stratification occurred routinely, presumably due to low mixing of supply air from a wall-mounted diffuse vent, spreading the air radially over the wall. This seemingly improved air quality in the breathing zone under local (ceiling) extract ventilation but worsened it during more typical, centralised extract ventilation, where air escapes the room via an inner doorway. The local extract arrangement thus seemed to yield both improved ventilation efficiency and reduced contaminant spread to other rooms. The noted air quality variations within the room highlight the importance of sensor placement in demand-control ventilated spaces, even in small rooms such as bedrooms.
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| 4. |
- Gu, Yaxiu, et al.
(författare)
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Techno-economic analysis of a solar photovoltaic/thermal (PV/T) concentrator for building application in Sweden using Monte Carlo method
- 2018
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Ingår i: Energy Conversion and Management. - : Elsevier BV. - 0196-8904 .- 1879-2227. ; 165, s. 8-24
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Tidskriftsartikel (refereegranskat)abstract
- The solar energy share in Sweden will grow up significantly in next a few decades. Such transition offers not only great opportunity but also uncertainties for the emerging solar photovoltaic/thermal (PV/T) technologies. This paper therefore aims to conduct a techno-economic evaluation of a reference solar PV/T concentrator in Sweden for building application. An analytical model is developed based on the combinations of Monte Carlo simulation techniques and multi energy-balance/financial equations, which takes into account of the integrated uncertainties and risks of various variables. In the model, 11 essential input variables, i.e. average daily solar irradiance, electrical/thermal efficiency, prices of electricity/heating, operation & management (OM) cost, PV/T capital cost, debt to equity ratio, interest rate, discount rate, and inflation rate, are considered, while the economic evaluation metrics, such as levelized cost of energy (LCOE), net present value (NPV), and payback period (PP), are primarily assessed. According to the analytical results, the mean values of LCOE, NPV and PP of the reference PV/T connector are observed at 1.27 SEK/kW h (0.127 €/kW h), 18,812.55 SEK (1881.255 €) and 10 years during its 25 years lifespan, given the project size at 10.37 m2 and capital cost at 4482–5378 SEK/m2 (448.2–537.8 €/m2). The positive NPV indicates that the investment on the selected PV/T concentrator will be profitable as the projected earnings exceeds the anticipated costs, depending on the NPV decision rule. The sensitivity analysis and the parametric study illustrate that the economic performance of the reference PV/T concentrator in Sweden is mostly proportional to solar irradiance, debt to equity ratio and heating price, but disproportionate to capital cost and discount rate. Together with additional market analysis of PV/T technologies in Sweden, it is expected that this paper could clarify the economic situation of PV/T technologies in Sweden and provide a useful model for their further investment decisions, in order to achieve sustainable and low-carbon economics, with an expanded quantitative discussion of the real economic or policy scenarios that may lead to those outcomes.
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| 5. |
- Henning, Annette, et al.
(författare)
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Sociala perspektiv på termisk komfort vid renovering av Tjärna Ängar.
- 2019. - 1
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Ingår i: Hållbar renovering ur ett helhetsperspektiv.. - Lund : Lunds universitet. - 9789188722652 ; , s. 41-46
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Bokkapitel (refereegranskat)abstract
- 1960- och 70-talens ”miljonprogram” gav upphov till en snabb tillväxt av nya hyreshus och förortsområden. Idag är de flesta av dessa bostadsområden i stort behov av renovering, och olika insatser görs för att få byggnaderna mer energieffektiva. Ett av de områden som just nu genomgår sådan renovering och energieffektivisering är Tjärna Ängar i Borlänge. Renoveringsarbetet studeras av ett flervetenskapligt forskningsteam vid Högskolan Dalarna, och artikeln utgår från intervjuer och mätningar som genomförts före respektive efter renovering av tre testhus. Resultaten bygger framförallt på intervjuer med representanter för bostadsbolaget och intervjuer med män och kvinnor boende i ett av dessa flerbostadshus. Artikeln diskuterar de boendes negativa upplevelse av termisk komfort, en faktor som inte var så tydlig vid mätningarna, men som blev mycket framträdande i intervjuresultaten. Vi menar att upplevelser av dålig termisk komfort innebär att även renoveringens sociala hållbarhet skulle kunna ses som bristfällig. Utgångspunkten för detta påstående är en definition av social hållbarhet som framförts av Liu, Dijst, Geertman and Cui (2017). Dessa författare har, utifrån en litteraturöversikt av hur begreppet ”social hållbarhet” hittills definierats inom olika discipliner, föreslagit ett begreppsmässigt ramverk för social hållbarhet som består av två kontextualiserade komponenter: välbefinnande och social rättvisa. Bristande termisk komfort bland de boende visade sig i vår studie ha stora kopplingar till både bristande välbefinnande och social rättvisa. Men problematiken har även viktiga kopplingar till möjligheten att spara energi i samband med renovering av miljonprogramområden. Artikeln inleds med några ord om hur den termiska komforten sett ut i byggnaden före respektive efter renoveringen. Därefter påtalas vikten av att se olikheter i upplevelsen av termisk komfort, dels i form av en genusskillnad, dels som en särskild sårbarhet i vissa situationer, liksom olikheter i målsättning och strategier hos bostadsbolag respektive boende. Därefter följer en diskussion om möjligheter och svårigheter i att kombinera energibesparing med välbefinnande och rättvisa. Slutligen dras slutsatsen att varje renovering måste betraktas som unik.
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| 6. |
- Khadra, Alaa, et al.
(författare)
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Development of a Weight Factor Method for Sustainability Decisions in Building Renovation : Case Study Using Renobuild
- 2020
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Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 12:17
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Tidskriftsartikel (refereegranskat)abstract
- Energy efficiency investments have become strategically important for the European Union. In particular, energy efficient renovation and investment in the existing building stock have become major challenges. Renovation of a building should involve a holistic and integrated design process, which considers all aspects of sustainability. The aim of this work is to suggest a mathematical model that weighs economic, social and ecological aspects into a measure that supports housing owners/decision makers to find the optimal renovation alternative from their perspective, taking factors such as budget, energy consumption, etc. into consideration. Multi-criteria decision-making (MCDM) concerns structuring and solving multiple-criteria decision problems. MCDM has become popular in energy planning as it enables the decision maker to pay attention to all the criteria available and make the appropriate decision as per the priority of the criteria. In this study, the concept is introduced based on economic, social and ecological aspects assessed during a renovation project. A pedagogical example illustrates the suggested numerical system for comparing different renovation alternatives. The suggested method will facilitate decision-making processes in renovation projects and will allow decision makers to choose the best renovation alternatives that are in line with their business ideas and principles.
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| 7. |
- Khadra, Alaa, et al.
(författare)
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Economic performance assessment of three renovated multi-family buildings with different HVAC systems
- 2020
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Ingår i: Energy and Buildings. - : Elsevier. - 0378-7788 .- 1872-6178. ; 224
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Forskningsöversikt (refereegranskat)abstract
- The EU has adopted several policies to improve energy efficiency. One of these policies aims to achieve energy efficient renovations in at least 3% annually of buildings in EU. The aim of this study was to provide an accurate economic comparison between three similar multi-family buildings that have undergone the same energy efficiency measures, with essential differences regarding the installed ventilation systems. The selected ventilation systems were: 1) balanced mechanical ventilation with heat recovery; 2) exhaust ventilation with air pressure control; and 3) exhaust ventilation with an exhaust air heat pump. In the latter two cases, radiators pre-heat supply air. Life cycle cost analysis were conducted using real investment and operational costs for the three buildings. Sensitivity analysis was also made for different discount rates and energy price escalation patterns. It was found that the building with exhaust ventilation has the lowest life cycle cost. At 2% inflation rate, 3% real discount rate and 1% real energy price escalation, the building with exhaust air heat pump and the building with mechanical ventilation with heat recovery has 13% and 29% higher life cycle cost than the building with exhaust ventilation, respectively. The sensitivity analysis further showed that a lower discount rate gives higher future costs and gives more profitability of systems with heat recovery with lower future costs. Energy price assumptions have a crucial impact on the results and change the profitability of studied renovation packages.
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| 8. |
- Khadra, Alaa, et al.
(författare)
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Greenhouse Gas Payback Time of Different HVAC Systems in the Renovation of Nordic District-Heated Multifamily Buildings Considering Future Energy Production Scenarios
- 2024
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Ingår i: Buildings. - : MDPI. - 2075-5309. ; 14:2
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Tidskriftsartikel (refereegranskat)abstract
- The European Union (EU) has implemented several policies to enhance energy efficiency. Among these policies is the objective of achieving energy-efficient renovations in at least 3% of EU buildings annually. The primary aim of this study was to offer a precise environmental comparison among four similar district-heated multifamily buildings that have undergone identical energy efficiency measures. The key distinguishing factor among them lies in the HVAC systems installed. The chosen systems were as follows: (1) exhaust ventilation with air pressure control; (2) mechanical ventilation with heat recovery; (3) exhaust ventilation with an exhaust air heat pump; and (4) exhaust ventilation with an exhaust air heat pump with a Photovoltaic (PV) panel. This study involved a life cycle assessment that relied on actual material data from the housing company and energy consumption measurements. This study covered a period of 50 years for thorough analysis. A sensitivity analysis was also conducted to account for various future scenarios of energy production. The findings revealed that the building with an exhaust air heat pump exhibited the lowest greenhouse gas emissions and the shortest carbon payback period (GBPT), needing only around 7 years. In contrast, the building with exhaust ventilation without heat recovery showed the highest emissions and the longest carbon payback period (GBPT), requiring approximately 11 years. Notably, the results were significantly influenced by future scenarios of energy production, emphasizing the crucial role of emission factors in determining the environmental performance of distinct renovation scenarios.
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| 9. |
- Lidberg, Tina, 1982-, et al.
(författare)
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Comparing different building energy efficiency refurbishment packages performed within different district heating systems
- 2017
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Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 105, s. 1719-1724, s. 1719-1724, s. 1719-1724
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Tidskriftsartikel (refereegranskat)abstract
- This study analyses the differences in primary energy (PE) use of a multi-family building refurbished with different refurbishment packages situated in different district heating systems (DHS). Four models of typical DHS are defined to represent the Swedish DH sector. The refurbishment packages are chosen to represent typical, yet innovative ways to improve the energy efficiency of a representative multi-family building in Sweden. The study was made from a broad system perspective, including valuation of changes in electricity use on the margin. The results show a significant difference in PE savings for the different refurbishment packages, depending on both the package itself as well as the type of DHS. Also, the package giving the lowest specific energy use per m2 was not the one which saved the most PE. © 2017 The Authors.
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| 10. |
- Lidberg, Tina, 1982-, et al.
(författare)
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Environmental impact of energy refurbishment of buildings within different district heating systems
- 2018
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Ingår i: Applied Energy. - : ELSEVIER SCI LTD. - 0306-2619 .- 1872-9118. ; 227, s. 231-238
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Tidskriftsartikel (refereegranskat)abstract
- The refurbishment of existing buildings is often considered a way to reduce energy use and CO2 emissions in the building stock. This study analyses the primary energy and CO2 impact of refurbishing a multi-family house with different refurbishment packages, given various district heating systems. Four models of typical district heating systems were defined to represent the Swedish district heating sector. The refurbishment packages were chosen to represent typical, yet innovative ways to improve the energy efficiency and indoor climate of a multi-family house. The study was made from a system perspective, including the valuation of changes in electricity use on the margin. The results show a significant difference in primary energy use for the different refurbishment packages, depending on both the package itself as well as the type of district heating system. While the packages with heat pumps had the lowest final energy use per m(2) of floor area, air heat recovery proved to reduce primary energy use and emissions of CO2-equivalents more, independent of the type of district heating system, as it leads to a smaller increase in electricity use.
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