| 1. |
- Mata, Érika, et al.
(författare)
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Economic feasibility of building retrofitting mitigation potentials : Climate change uncertainties for Swedish cities
- 2019
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 242, s. 1022-1035
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Tidskriftsartikel (refereegranskat)abstract
- Deep and rapid decarbonization of the building sector requires energy demand reductions and the incorporation of renewable-energy sources. Energy retrofitting of existing buildings is a central strategy in climate mitigation and has often been highlighted as a cost-effective strategy. However, decisions on these strategies are often hampered by modeling assessments that are limited by contextual, methodological, parametric, input, or output constraints. Here, we present a novel methodology to investigate the solid economic feasibility in building retrofit evaluations with mitigation measures. We first calculate the variations in the energy saving potentials and costs for 13 energy saving measures and five climate change scenarios. We then compare the obtained uncertainty due to a changing climate to other uncertainties, such as the boundaries for emission inventories and energy system development. Four cities in Sweden are modeled, which are responsible for half of the country's residential energy use. We find that the profitability of the retrofitting actions is primarily determined based on the annualized investments and energy saving potentials. Future climate has a less determinant role, with uncertainties similar to those of future consumer price development and fuel emission factors. Retrofits that only affect the energy need for space heating are more robust than changes in electricity usage. We conclude that strategies for building retrofitting should focus on prioritizing energy savings and mobilizing investments that may not be profitable based on the current techno-economic perspective.
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| 2. |
- Nik, Vahid, 1979, et al.
(författare)
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Assessing the efficiency and robustness of the retrofitted building envelope against climate change
- 2015
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Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 78, s. 955-960
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Konferensbidrag (refereegranskat)abstract
- Evaluating the performance of retrofitted buildings for future climatic conditions can be a challenging task since different scenarios and uncertainties exist both for retrofitting of buildings and for future climate. This paper evaluates the energy performance of four retrofitting measures - applied to the building envelope - of the residential building stock in Gothenburg, Sweden. The energy efficiency of the measures is evaluated both on long and short terms, while their robustness against climate uncertainties and extreme climatic conditions is studied. The assessment is carried out using a statistical method, which has been developed specifically for this kind of analysis. The considered measures are ranked by looking into their average performance and their variations during different time scales, i.e. from one hour to 20 years. The analysis helps to identify the retrofitting measures with the most efficient and the most reliable performance for future climatic conditions.
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| 3. |
- Nik, Vahid, et al.
(författare)
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Future moisture loads for building facades in Sweden: Climate change and wind-driven rain
- 2015
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Ingår i: Building and Environment. - : Elsevier BV. - 1873-684X .- 0360-1323. ; 93, s. 362-375
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Tidskriftsartikel (refereegranskat)abstract
- This work investigates the prospective impacts of climate change on wind-driven rain (WDR) and walls through simulating the hygrothermal performance of rain screen of common vertical wall constructions for the climatic conditions of Gothenburg in Sweden. While a substantial amount of work has been done on the impact of climate change on the thermal performance of buildings, this paper studies its impact - through changes in rain, wind and other climatic parameters - on the amount of water which penetrates the outmost layer of ventilated facades. Importance of three uncertainty factors of the climate data are investigated: uncertainties from global climate models, emissions scenarios and spatial resolutions. Consistency of the results is examined by modelling walls with different materials and sizes, as well as using two mathematical approaches for WDR modelling. Sensitivity of the wall simulations to the wind data is assessed by using synthetic climate with sole wind data. According to the results, higher amounts of moisture will accumulate in walls in the future; climate Uncertainties can cause variations up to 13% in the calculated 30-year average of water content and 28% in its standard deviation. Using sole wind data can augment uncertainties with up to 10% in WDR calculations, however it is possible to neglect changes in future wind data. (C) 2015 Elsevier Ltd. All rights reserved.
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| 4. |
- Nik, Vahid M., et al.
(författare)
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Effective and robust energy retrofitting measures for future climatic conditions—Reduced heating demand of Swedish households
- 2016
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788. ; 121, s. 176-187
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Tidskriftsartikel (refereegranskat)abstract
- This article quantifies the energy saving potential and robustness of nine energy retrofitting measures, as well as four combinations of these, for residential building stocks of three major cities in Sweden and for five scenarios of future climatic conditions, downscaled by a regional climate model (RCM). The retrofitting measures are evaluated for five temporal resolutions of hourly, daily, monthly, annual and 20-years during the period of 1961 through 2100. The evaluation takes into account a very important uncertainty factor of future climate data, induced by different global climate models (GCMs). The application of a statistical method for assessing the retrofitting measures is being evaluated. Results verify the consistency and reliability of the comparative assessment and confirm the possibility of assessing the retrofitting measures without the need for long-term simulations and considering climate uncertainties. Among the considered retrofitting measures, a combination of an improved thermal insulation of the building envelope with energy efficient windows is the most effective and robust retrofitting measure, while tuning the indoor set-point temperature to 20°C can also contribute to significant energy savings.
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