| 1. |
- Abdul Hamid, Akram, et al.
(författare)
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Literature review on renovation of multifamily buildings in temperate climate conditions
- 2018
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788. ; 172, s. 414-431
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Forskningsöversikt (refereegranskat)abstract
- In Sweden, approximately 1.4 million dwellings were built 1946–1975. Today, a considerable part of these are in need of renovation for various reasons. Research results, as well as experiences and outcomes from renovation projects could facilitate in performing more efficient renovations. As an aid for further research, this paper aims to compile and review relevant literature that may support in choosing a renovation strategy as well as decisions on renovation measures. The focus of this paper is research on status determinations, renovation strategies and renovation measures. Differences and similarities within these areas are presented through the analysis of 234 relevant references. The results show that renovation of multifamily buildings in temperate climate conditions is widely researched. The included research has a strong energy focus, and while other aspects of renovation are researched as well, they are not as strongly represented. Status determinations are often based on data from national databases that include useful information that could help alleviate decision making in the renovation process. This study suggests that future research should be conducted on the effect of such databases on the renovation process. This study also shows that there are numerous renovation strategies, and while there are both in-depth and broader strategies, these are seldom connected. Finally, there are many references evaluating various effects of the application of renovation measures, but some effects and measures are more widely researched than others. This study lays a strong foundation for further in-depth research on the reviewed articles, reports, and theses.
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| 2. |
- Abdul Hamid, Akram, et al.
(författare)
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Measuring the impact of MVHR on the energy efficiency and the IEQ in multifamily buildings
- 2019
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788. ; 195, s. 93-104
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Tidskriftsartikel (refereegranskat)abstract
- Renovating and improving the current building stock is a matter of both need and importance. In order to know if the implemented renovation measure has had an impact on the building as a system it is important to verify the impact through measurements. The aim of this project is to isolate the impact of a measure on the energy efficiency of a building as well as the indoor environmental quality. This, through detailed measurements that enable the exclusion of the impact of other factors that might affect the energy use. For this reason a mechanical ventilation system with heat recovery was installed in two apartment buildings and measurements were conducted before and after installation. Measurements were also conducted in two almost identical reference buildings, that were used as a control group for the experiment. Together with acquired data for the surrounding climate, measurements were conducted on 1)the district heat carriers to and from the buildings, 2)the temperature and relative humidity in the apartments, 3)the global horizontal radiation on site, and 4)the temperature outdoors. A survey was also conducted with the inhabitants for the assessment of the impact on the perceived indoor environmental quality. Correcting for the outdoor temperature only, a yearly reduction by 22% and 24% is achieved in the affected buildings. Changes in the global horizontal radiation clearly impact the results, however, can not be corrected for. By using the control group as a reference, further corrections can be made and the energy reduction might be determined to 15% and 34%, instead of 22% and 24% respectively.
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| 3. |
- Amin, Rucha, et al.
(författare)
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The influence of a student’s ‘home’ climate on room temperature and indoor environmental controls use in a modern halls of residence
- 2016
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788. ; 119, s. 331-339
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Tidskriftsartikel (refereegranskat)abstract
- Adaptive comfort theory states that over time people adapt to their normal environment. Therefore, people from different climates are expected to have different thermal preferences and behaviours, which could lead to ‘performance gap’ in buildings with occupants of diverse climate backgrounds. This study investigates the influence of occupants’ thermal history on use of controls and indoor temperature preference in a newly built halls of residence building complex in Southampton, UK, which provides 1104 rooms to international and UK students. A total of 223 questionnaire responses along with monitored temperature data and thermal comfort surveys from 30 rooms are used in this analysis.The results indicate that residents’ ‘home’ climate is impacting the reported use of environmental controls in rooms with similar typological characteristics. The average indoor temperature of residents from warm climates was 2.3 °C higher than that of residents from cool climates in February 2015 (winter heating season). This difference cannot be explained by room orientation alone. Comparison of room temperatures to design values indicates that UK design standards may not account for the comfort needs of residents accustomed to warmer climates. A simple management approach to comfort optimisation is suggested, locating students on the appropriately orientated facade to reflect their ‘home’ climate.
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| 4. |
- Andersson, Martin, 1988, et al.
(författare)
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Abatement cost of embodied emissions of a residential building in Sweden
- 2018
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788. ; 158, s. 595-604
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Tidskriftsartikel (refereegranskat)abstract
- In 2010, the world’s buildings accounted for approximately 19% of all greenhouse gas emissions. These emissions stem from both the construction and operation of buildings. In recent years the carbon efficiency of energy sources and energy efficiency of new buildings has been improved in Sweden. Therefore, embodied emissions accounts for an increasing share of the life cycle emissions of new buildings. This study aims to asses the cost effectiveness in abatement of embodied emissions. This was done by assessing the embodied emissions of a case building and several conventional design measures along with the implication on production cost. It was found that many of the measures enabled cost effective carbon abatement. Embodied emissions could be reduced by 15% using cost neutral or nearly cost neutral measures. Abatements up to 18% were found cost effective in relation to abatement of carbon dioxide emissions in other sectors. Abatements up to 24% were possible with minor increases in total production cost (0.22%) even though some of the individual measures were found expensive in relation to abatement of carbon dioxide emissions in other sectors. Some measures entailed increased floor area that could potentially lead to economic gain where exterior area is a limiting factor. Acoustic requirements were found to be a limiting factor in abatement of embodied emissions.
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| 5. |
- Arghand, Taha, 1982, et al.
(författare)
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Control methods for a direct-ground cooling system: An experimental study on office cooling with ground-coupled ceiling cooling panels
- 2019
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788. ; 197, s. 47-56
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Tidskriftsartikel (refereegranskat)abstract
- This article experimentally investigates the performance of two control methods (the supply water temperature method and the water flow control method)for a direct-ground cooling system. The control methods were implemented through three types of indoor feedback controllers: 1)an on/off controller, 2)an on/off controller with a deadband and 3)P controller. The performances of the control methods were evaluated regarding room temperature stability and pump energy use. Ceiling cooling panels were employed to keep the test room air temperature at 25.0 °C under periodic heat gain conditions. The cooling system used a ground heat exchanger with a U-pipe in an 80-meter-deep borehole as a cooling source. The findings show that room air temperature was maintained close to the set-point with both control methods, but it was more stable with the temperature control method. In addition, condensation risk was easily preventable with the temperature control method. A parametric study showed that pump energy use when using two-position controllers could be as low as when using modulating controllers if the on-state flow rate of the circulating pump is selected in relation to the ground temperature and heat transfer characteristics of the heat exchanger.
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| 6. |
- Azizi, Shoaib, 1989-, et al.
(författare)
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Analysing the house-owners’ perceptions on benefits and barriers of energy renovation in Swedish single-family houses
- 2019
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Ingår i: Energy and Buildings. - : Elsevier. - 0378-7788 .- 1872-6178. ; 198, s. 187-196
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Tidskriftsartikel (refereegranskat)abstract
- Single-family houses offer a large potential for energy savings by energy renovation (ER). Homeowners’ motivation to implement ER derives from the benefits and barriers they perceive. Benefits are the positive consequences that can motivate homeowners to act and barriers are the challenges that demotivate them to undertake ER. Different benefits and barriers do not homogenously affect every homeowner. Identifying motivating benefits and demotivating barriers for each specific group among homeowners can shed lights on ER decision-making and enable policies that are more effective. The objective of this study is to contextualize the implementation of ER by understanding how the perceived benefits and barriers influence homeowners. This study links the expected consequences, which are benefits and barriers to the influential factors on ER, which are used to group the homeowners.The analysis is based on a questionnaire survey mailed to 1550 owners of single-family houses in northern Sweden. The perceptions of homeowners on benefits and barriers of ER are significantly different between the groups that are motivated and unmotivated to implement ER. Despite the perceived importance of some of the benefits such as energy cost reduction, they may not be determinative for the homeowners’ decision to undertake ER. The homeowners are more likely to implement ER for reasons other than energy use reduction such as for improving the indoor environment. The barriers such as the difficulty of finding a low-interest loan and reliable information sources are found to impede the intention to implement ER among different groups. Policy implications to facilitate ER in single-family houses are discussed.
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| 7. |
- Birgisdottir, H., et al.
(författare)
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IEA ESC annex 57 'evaluation of embodied energy and CO2eq for building construction'
- 2017
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Ingår i: Energy and Buildings. - : ELSEVIER SCIENCE SA. - 0378-7788 .- 1872-6178. ; 154, s. 72-80
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Tidskriftsartikel (refereegranskat)abstract
- The current regulations to reduce energy consumption and greenhouse gas emissions (GHG) from buildings have focused on operational energy consumption. Thus legislation excludes measurement and reduction of the embodied energy and embodied GHG emissions over the building life cycle. Embodied impacts are a significant and growing proportion and it is increasingly recognised that the focus on reducing operational energy consumption needs to be accompanied by a parallel focus on reducing embodied impacts. Over the last six years the Annex 57 has 'addressed this issue, with researchers from 15 countries working together to develop a detailed understanding of the multiple calculation methods and the interpretation of their results. Based on an analysis of 80 case studies, Annex 57 showed various inconsistencies in current methodological approaches, which inhibit comparisons of results and difficult development of robust reduction strategies. Reinterpreting the studies through an understanding of the methodological differences enabled the cases to be used to demonstrate a number of important strategies for the reduction of embodied impacts. Annex 57 has also produced clear recommendations for uniform definitions and templates which improve the description of system boundaries, completeness of inventory and quality of data, and consequently the transparency of embodied impact assessments.
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| 8. |
- Bulut, Mehmet Börühan, et al.
(författare)
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Active buildings in smart grids - Exploring the views of the Swedish energy and buildings sectors
- 2016
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788 .- 1872-6178. ; 117, s. 185-198
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Tidskriftsartikel (refereegranskat)abstract
- The development of smart grids is expected to shift the role of buildings in power networks from passive consumers to active players that trade on power markets in real-time and participate in the operation of networks. Although there are several studies that report on consumer views on buildings with smart grid features, there is a gap in the literature about the views of the energy and buildings sectors, two important sectors for the development. This study fills this gap by presenting the views of key stakeholders from the Swedish energy and buildings sectors on the active building concept with the help of interviews and a web survey. The findings indicate that the active building concept is associated more with energy use flexibility than self-generation of electricity. The barriers to development were identified to be primarily financial due to the combination of the current low electricity prices and the high costs of technologies. Business models that reduce the financial burdens and risks related to investments can contribute to the development of smart grid technologies in buildings, which, according to the majority of respondents from the energy and buildings sectors, are to be financed by housing companies and building owners.
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| 9. |
- Bulut, Mehmet Börühan, 1987-, et al.
(författare)
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Buildings in the future energy system : Perspectives of the Swedish energy and buildings sectors on current energy challenges
- 2015
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788 .- 1872-6178. ; 107, s. 254-263
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Forskningsöversikt (refereegranskat)abstract
- Buildings are expected to play a key role in the development and operation of future smart energy systems through real-time energy trade, energy demand flexibility, self-generation of electricity, and energy storage capabilities. Shifting the role of buildings from passive consumers to active players in the energy networks, however, may require closer cooperation between the energy and buildings sectors than there is today. Based on 23 semi-structured interviews and a web survey answered by key stakeholders, this study presents the views of the energy and buildings sectors on the current energy challenges in a comparative approach. Despite conflicting viewpoints on some of the issues, the energy and buildings sectors have similar perspectives on many of the current energy challenges. Reducing CO2 emissions is a shared concern between the energy and buildings sectors that can serve as a departure point for inter-sectoral cooperation for carbon-reducing developments, including the deployment of smart energy systems. The prominent energy challenges were identified to be related to low flexibilities in energy supply and use, which limit mutually beneficial cases, and hence cooperation, between the energy and buildings sectors today.
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| 10. |
- Camarasa, Clara, 1986, et al.
(författare)
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Diffusion of energy efficiency technologies in European residential buildings: A bibliometric analysis
- 2019
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788. ; 202
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Forskningsöversikt (refereegranskat)abstract
- Many studies have investigated different aspects in the decarbonisation of the European housing stock. However, a comprehensive quantitative analysis of the literature on the diffusion of energy efficiency technologies is still missing. We conducted a bibliometric analysis to better understand the knowledge base in the field energy efficiency technology diffusion in the European residential building stock. After the scanning and screening process, we identified 954 scientific articles pertinent to this topic. Through a co-citation network analysis, we generated a visual knowledge structure of the field and by the further investigation of the bibliography we were able to synthesize the state-of-the-art and answer to our initial research questions. Results of the co-citation network show a scattered and fragmented field in many domains. The descriptive analysis highlights this fragmentation, especially on a cross-country level among EU country members. Findings from this study contribute to map the scientific knowledge base in relation to technology diffusion in European residential building projects, identify relevant topic areas, visualize the links between the topics, as well as to recognize research gaps and opportunities. The methodology utilized in this paper proved to be viable approach to map and characterize the knowledge base within a field and can, therefore, be replicated in upcoming studies with analogous ambitions.
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