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- Piccardo, Chiara, et al.
(författare)
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Retrofitting with different building materials : life-cycle primary energy implications
- 2020
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Ingår i: Energy. - : Elsevier. - 0360-5442 .- 1873-6785. ; 192, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- The energy retrofitting of existing buildings reduces the energy use in the operation phase but the use ofadditional materials influence the energy use in other life cycle phases of retrofitted buildings. In thisstudy, we analyse the life cycle primary energy implications of different material alternatives whenretrofitting an existing building to meet high energy performance levels. We design retrofitting optionsassuming the highest and lowest value offinal energy use, respectively, for passive house standardsapplicable in Sweden. The retrofitting options include the thermal improvement of the building enve-lope. We calculate the primary energy use in the operation phase (operation primary energy), as well asin production, maintenance and end-of-life phases (non-operation primary energy). Our results showthat the non-operation primary energy use can vary significantly depending on the choice of materialsfor thermal insulation, cladding systems and windows. Although the operation energy use decreases by63e78%, wefind that the non-operation energy for building retrofitting accounts for up to 21% of theoperation energy saving, depending on the passive house performance level and the material alternative.A careful selection of building materials can reduce the non-operation primary energy by up to 40%,especially when using wood-based materials
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| 2. |
- Tettey, Uniben Yao Ayikoe, 1979-, et al.
(författare)
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Energy savings and overheating risk of deep energy renovation of a multi-storey residential building in a cold climate under climate change
- 2020
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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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| 3. |
- Truong, Nguyen Le, 1976-, et al.
(författare)
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Implications of supplying district heat to a new urban residential area in Sweden
- 2020
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Ingår i: Energy. - : Elsevier. - 0360-5442 .- 1873-6785. ; 194, s. 1-18
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Tidskriftsartikel (refereegranskat)abstract
- Here we analyze the cost, primary energy and CO2 implications of supplying district heat, considering different supply and return temperatures, to a new residential area in Växjö, Sweden. We explore four land exploitation alternatives consisting different types of buildings with various heated floor areas as well as occupancy densities and two levels of building energy efficiency, based on the Swedish building code and passive house criteria. The analysis shows that energy performance of the buildings and land exploitation alternatives strongly influence the annual heat demand and its profile, which steers the design of the local heat distribution network. Additionally, supply and return temperatures of district heat somewhat influence the design of the network. The distribution heat losses could be reduced by 25% and 50% if district heating systems of 65/30 °C and 50/20 °C, respectively, are used instead of a conventional 80/40 °C system. However, for the same land exploitation alternative, the local distribution heat losses are about the same whether or not the buildings are designed to meet the Swedish building code or passive house criteria, since the same pipe distance is required and the variation of pipe diameters is small. A 50/20 °C system increases electricity use to boost hot water temperature to avoid the risk of legionella bacteria, and this influences quantity of district heat supply, primary energy use and costs. Therefore, a 65/30 °C system appears to be more primary energy and cost efficient than a 50/20 °C system. Increased insulation of district heating network reduces heat losses but this is not cost effective due to increased investment cost. The results are similar whether or not the analysis is based on current energy supply or future renewable based energy supply. This study increases understanding of strategies for planning and designing new urban residential areas and their energy supply systems to reduce primary energy use as well as monetary costs, and to minimize the climate impacts of the built environment.
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