| 21. |
- Tettey, Uniben Yao Ayikoe, et al.
(författare)
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Effects of different insulation materials on primary energy and CO2 emission of a multi-storey residential building
- 2014
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Ingår i: Energy and Buildings. - : Elsevier. - 0378-7788 .- 1872-6178. ; 82, s. 369-377
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we analyzed the implications of various insulation materials on the primary energy and CO2emission for material production of a residential building. We modeled changes to the original design ofthe building to achieve reference buildings to energy-efficiency levels of the Swedish building code of2012 or the Swedish Passivhus 2012 criteria. We varied the insulation materials in different parts of thereference buildings from mineral rock wool to glass wool, cellulose fiber, expanded polystyrene or foamglass. We compared the primary energy use and CO2emission from material production of functionallyequivalent reference and optimum versions of the building. The results showed a reduction of about 6–7%in primary energy use and 6–8% in CO2emission when the insulation material in the reference buildingsis changed from rock wool to cellulose fiber in the optimum versions. Also, the total fossil fuel use for onlyinsulation material production was reduced by about 39%. This study suggests that enhancing materialproduction technologies by reducing fossil fuel-use and increasing renewable energy sources, as wellas careful material choice with renewable-based raw materials can contribute significantly in reducingprimary energy use and GHG emission in the building sector.
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| 22. |
- Tettey, Uniben Yao Ayikoe, 1979-, et al.
(författare)
-
Energy savings and overheating risk of deep energy renovation of a multi-storey residential building in a cold climate under climate change
- 2020
-
Ingår i: Energy. - : Elsevier. - 0360-5442 .- 1873-6785. ; 202, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Here, we analyse final and primary energy savings and overheating risk of deep energy renovation of a Swedish multi-storey residential building of the 1970s under climate change and consider overheating control measures to reduce cooling demand and risk of overheating. The energy-efficiency measures include additional insulation to basement walls, exterior walls, and attic floor as well as improved energy-efficient windows and doors, balanced ventilation with heat recovery (VHR), lighting, household appliances as well as water taps and shower heads. The future climates are based on the representative concentration pathways scenarios. We find that implementing improved energy-efficient windows and doors, VHR and additional insulation to external walls give significant final and primary energy savings for space heating. The total operation final and primary energy use decrease averagely by 58% and 54%, respectively when all the measures are cumulatively applied under both current and future climate scenarios. Efficient household appliances and lighting as well as appropriate overheating control measures significantly reduce cooling demand and risk of overheating. The indoor air temperature and overheating risk as well as the final energy savings are influenced by the considered climate scenarios. (C) 2020 Elsevier Ltd. All rights reserved.
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| 23. |
- Tettey, Uniben Yao Ayikoe, 1979-, et al.
(författare)
-
Energy use implications of different design strategies for multi-storey residential buildings under future climates
- 2017
-
Ingår i: Energy. - : Elsevier. - 0360-5442 .- 1873-6785. ; 138, s. 846-860
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Tidskriftsartikel (refereegranskat)abstract
- The effects of climate change on the final and primary energy use of versions of a multi-storey residential building have been analysed. The building versions are designed to the Swedish building code (BBR 2015) and passive house criteria (Passive 2012) with different design and overheating control strategies under different climate scenarios. Future climate datasets are based on Representative Concentration Pathway scenarios for 2050–2059 and 2090–2099. The analysis showed that strategies giving the lowest space heating and cooling demands for the Passive 2012 building version remained the same under all climate scenarios. In contrast, strategies giving the lowest space heating and cooling demands for the BBR 2015 version varied, as cooling demand became more significant under future climate scenarios. Cooling demand was more dominant than heating for the Passive 2012 building version under future climate scenarios. Household equipment and technical installations based on best available technology gave the biggest reduction in total primary energy use among considered strategies. Overall, annual total operation primary energy decreased by 37–54% for the building versions when all strategies are implemented under the considered climate scenarios. This study shows that appropriate design strategies could result in significant primary energy savings for low-energy buildings under changing climates.
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| 24. |
- Tettey, Uniben Yao Ayikoe, 1979-, et al.
(författare)
-
Impacts of parameter values interactions on simulated energy balance of residential buildings
- 2017
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Ingår i: 11th Nordic Symposium on Building Physics, NSB2017, 11-14 June 2017, Trondheim, Norway. - : Elsevier. ; , s. 57-62
-
Konferensbidrag (refereegranskat)abstract
- In this study we use dynamic simulation to explore the interactive impacts of different uncertain parameter values in energy balance modelling of existing and improved variants of a Swedish multi-storey residential building. We modelled variations as well as interactive influence of different simulation assumptions and parameters encompassing outdoor microclimate, building thermal envelope and technical installations including household equipment. The results indicate that the interactive influence of the parameters on calculated space heating of buildings seems to be small and relatively more evident for a low-energy building than for a conventional building. The influence of the interactions between the parameter combinations becomes more evident as several parameters are varied simultaneously. The results also indicate that calculated space heating demand of a building is noticeably influenced by how heat gains from household equipment and technical installations are modelled. The calculated final energy for space heating for the analysed building versions varied between 13-43% depending on the energy efficiency levels for household equipment and technical installations as well as their interactions with other parameter values variations. This study shows the importance of appropriate input parameters and assumptions for building energy balance calculation.
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| 25. |
- Tettey, Uniben Yao Ayikoe, 1979-, et al.
(författare)
-
Primary energy and CO2 emissions implications of different insulation, cladding and frame materials for residential buildings
- 2019
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Ingår i: SBE 19 - Emerging Concepts for Sustainable Built Environment 22–24 May 2019, Helsinki, Finland. - : Institute of Physics (IOP). ; , s. 1-11
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Konferensbidrag (refereegranskat)abstract
- In this study, we analyse and compare the primary energy use and carbon dioxide (CO2) emissions associated with different insulation, cladding and frame materials for a constructed concrete frame multi-storey residential building in Sweden. Our approach consists of identifying individual materials giving the lowest primary energy use and CO2 emissions for each building envelope part and based on that, modelling different material combinations to achieve improved alternatives of the concrete frame building with the same operation energy use based on the Swedish building code or passive house criteria. We analyse the complete materials and energy chains, including material losses as well as conversion and fuel cycle losses. The analysis covers the primary energy use to extract, process, transport, and assemble the materials and the resulting CO2 emissions to the atmosphere. The results show wide variations in primary energy and CO2 emissions depending on the choice of building envelope materials. The materials for external walls contribute most to the primary energy and CO2 emissions, followed by foundation, roof and external cladding materials. The improved building alternatives with wood construction frames, wood external cladding, expanded polystyrene as foundation insulation and cellulose insulation in the external walls and roof result in about 36 - 40% lower production primary energy use and 42 - 49% lower CO2 emissions than the improved concrete alternative when achieving the same thermal performance. This study suggests that strategies for low-energy buildings should be combined with resource-efficient and low carbon materials in the production phase to mitigate climate change and achieve a sustainable built environment. © 2019 IOP Publishing Ltd. All rights reserved.
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| 26. |
- Tettey, Uniben Yao Ayikoe, 1979-, et al.
(författare)
-
Primary energy implications for low-energy buildings with different frame construction systems under varying climate scenarios
- 2019
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Ingår i: eceee 2019 Summer Study on energy efficiency. - : European Council for an Energy Efficient Economy (ECEEE). - 9789198387841 - 9789198387858 ; , s. 1407-1417
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Konferensbidrag (refereegranskat)abstract
- In this study, a 6 storey prefabricated concrete building in Sweden is used as reference to explore life cycle primary energy implications of different frame construction systems under various climate scenarios. The building was redesigned as a low-energy building to the Swedish passive house criteria with frame construction systems in cross laminated timber, prefabricated timber modules and concrete. Using a system perspective approach, we account for relevant energy and material flows linked to the production, construction, operation and end-of-life phases of the building alternatives, including thermal mass effects under recent (2013) as reference and future (2090-2099) climate periods based on representative concentration pathways (RCP) 2.6, 4.5 and 8.5 scenarios. Results show that the buildings' heating and cooling demands vary significantly under the climate scenarios. The timber systems give lower production primary energy and higher biomass residues than the concrete alternative. The concrete system requires slightly lower operation energy due to thermal mass benefits but still, the timber systems give overall lower life cycle primary energy balance. This study shows that low-energy timber buildings with efficient energy supply can play an important role in mitigating climate change for a resource-efficient and sustainable built environment under current and future climate scenarios. © 2019 European Council for an Energy Efficient Economy. All rights reserved.
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| 27. |
- Tettey, Uniben Yao Ayikoe, 1979-, et al.
(författare)
-
Primary energy implications of different design strategies for an apartment building
- 2016
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Ingår i: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 104, s. 132-148
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we explored the effects of different design strategies on final and primary energy use for production and operation of a newly constructed apartment building. We analysed alternatives of the building “As built” as well as to energy efficiency levels of the Swedish building code and passive house criteria. Our approach is based on achieving improved versions of the building alternatives from combination of design strategies giving the lowest space heating and cooling demand and primary energy use, respectively. We found that the combination of design strategies resulting in the improved building alternatives varies depending on the approach. The improved building alternatives gave up to 19–34% reduction in operation primary energy use compared to the initial alternatives. The share of production primary energy use of the improved building alternatives was 39–54% of the total primary energy use for production, space heating, space cooling and ventilation over 50-year lifespan, compared to 31–42% for the initial alternatives. This study emphasises the importance of incorporating appropriate design strategies to reduce primary energy use for building operation and suggests that combining such strategies with careful choice of building frame materials could result in significant primary energy savings in the built environment.
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| 28. |
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| 29. |
- Tettey, Uniben Yao Ayikoe, et al.
(författare)
-
Primary energy implications of different wall insulation materials for buildings in a cold climate
- 2014
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Ingår i: Energy Procedia: INTERNATIONAL CONFERENCE ON APPLIED ENERGY, ICAE2014. - : Elsevier. ; , s. 1204-1207
-
Konferensbidrag (refereegranskat)abstract
- In this study, we investigate the influence of different external wall insulation systems on the primary energy use of a case study building in southern Sweden. We vary the insulation material of the external walls from rock wool to glass wool or expanded polystyrene (EPS) to achieve different energy-efficiency standards of the building. We apply appropriate thicknesses of the different insulation materials to achieve similar thermal transmittance (U-value) of the external walls under the different energy-efficiency standards. The different options are based on the same architectural design. We calculate and compare the primary energy for production of the insulation materials and for operation of the buildings. Rock wool gives the lowest primary energy for production, followed by glass wool and EPS for each energy efficiency standard, although the difference between rock wool and glass wool is small.
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| 30. |
- Tettey, Uniben Yao Ayikoe, 1979-
(författare)
-
Primary energy use of residential buildings : implications of materials, modelling and design approaches
- 2017
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Buildings can play an essential role in the transition to a sustainable society. Different strategies, including improved energy efficiency in buildings, substitution of carbon intensive materials and fuels, efficient energy supply among others can be employed for this purpose. In this thesis, the implications of different insulation materials, modelling and design strategies on primary energy use of residential buildings are studied using life cycle and system perspective. Specifically, the effects of different insulation materials on production primary energy and CO2 emission of buildings with different energy performance are analysed. The results show that application of extra insulation materials to building envelope components reduces the operating primary energy use but more primary energy is required for the insulation material production. This also slightly increases the CO2 emissions from material production. The increases in primary energy use and CO2 emissions are mainly due to the variations in the quantities, types and manufacturing processes of the insulation materials. Thus, choice of renewable based materials with energy efficient manufacturing is important to reduce primary energy use and GHG emissions for building material production.Uncertainties related to building modelling input parameters and assumptions and how they influence energy balance calculations of residential buildings are explored. The implications on energy savings of different energy efficiency measures are also studied. The results show that input data and assumptions used for energy balance simulations of buildings vary widely in the Swedish context giving significant differences in calculated energy demand for buildings. Among the considered parameters, indoor air temperature, internal heat gains and efficiency of ventilation heat recovery (VHR) have significant impacts on the simulated building energy performance as well as on the energy efficiency measures. The impact of parameter interactions on calculated space heating of buildings is rather small but increases with more parameter combinations and more energy efficient buildings. Detailed energy characterisation of household equipment and technical installations used in a building is essential to accurately calculate the energy demand, particularly for a low energy building.The design and construction of new buildings present many possibilities to minimise both heating and cooling demands over the lifecycle of buildings, and also in the context of climate change. Various design strategies and measures are analysed for buildings with different energy performance under different climate scenarios. These include household equipment and technical installations based on best available technology, bypassing the VHR unit, solar shading of windows, combinations of window u- and g-values, different proportions of glazed window areas and façade orientations and mechanical cooling. The results show that space heating and cooling demands vary significantly with the energy performance of buildings as well as climate scenarios. Space heating demand decreases while space cooling demand and the risk of overheating increase considerably with warmer climate. The space cooling demand and overheating risk are more significant for buildings with higher energy performance. Significant reductions are achieved in the operation final energy demands and overheating is avoided or greatly reduced when different design strategies and measures are implemented cumulatively under different climate change scenarios.The primary energy efficiency of heat supply systems depends on the heat production technology and type of fuel use. Analysis of the interaction between different design strategies and heat supply options shows that the combination of design strategies giving the lowest primary energy use for space heating and cooling varies between heat supply from district heating with combined heat and power (CHP) and heat only boilers (HOB). The primary energy use for space heating is significantly lower when the heat supply is from CHP rather than HOB. Operation primary energy use is significantly reduced with slight increase in production primary energy when the design strategies are implemented. The results suggest that significant primary energy reductions are achievable under climate change, if new buildings are designed with appropriate strategies.
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