| 1. |
- Abdul Hamid, Akram, et al.
(författare)
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Ventilation measures for heritage office buildings in temperate climate for improvement of energy performance and IEQ
- 2020
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Ingår i: Energy and Buildings. - : Elsevier BV. - 1872-6178 .- 0378-7788. ; 211
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Tidskriftsartikel (refereegranskat)abstract
- Heritage buildings are usually culturally protected as well as naturally ventilated. As such, it is difficult to control the airflow, which depends on the temperature outdoors as well as the wind. This causes issues with the thermal comfort and the indoor air quality. In this study, status determinations were conducted for 12 heritage buildings with offices, across Sweden. Field measurements on temperature, relative humidity, CO2, and air change rates in the indoor climate, together with a survey with the occupants, confirmed these issues in these buildings. In addition, for two of the buildings, field measurements were used together with building energy performance simulations in order to determine the impact of two different ventilation measures on the indoor environmental quality (IEQ) and the energy use. A mechanical ventilation system with heat recovery, hidden inside a chimneypot, was shown to reduce CO2 concentrations and potentially reduce the energy use by up to 39 kWh∙m-2. Dampers for the reduction of the air change rates out-of-hours, installed in the pathways for the natural airflow through chimney pots, were shown to potentially reduce the energy use by up to 11 kWh∙m-2.
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| 2. |
- Abugabbara, Marwan, et al.
(författare)
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Bibliographic analysis of the recent advancements in modeling and co-simulating the fifth-generation district heating and cooling systems
- 2020
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788. ; 224
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Forskningsöversikt (refereegranskat)abstract
- District heating and cooling systems have evolved through several development stages in order to improve their energy efficiency. The latest development reached the fifth generation where customers can be producers and/or consumers of thermal energy flows towards the network. The variety and complexity of system configurations and interactions between connected customers poses a challenge in adopting a suitable modeling paradigm capable of simulating each design case. Modelica language and the Functional Mock-up Interface standard are computational tools opted by the International Energy Agency for simulating building and community energy systems. This work aims to analyze the current status in literature where these tools are utilized in building and energy simulation with focus on district heating and cooling systems. Bibliographic maps and networks are presented to analyze the literature based on different bibliometrics. Among others, the analysis shows that coupled simulation between district and building energy models is a novel research area and can benefit in reducing the oversizing of space heating and cooling systems. In addition, the analysis demonstrates that the fifth generation district heating and cooling systems require advanced control strategies. These strategies need accurate and upfront specifications to decide a proper control strategy for each design case.
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| 3. |
- Allard, Ingrid, 1986-, et al.
(författare)
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Energy performance criteria for residential buildings : A comparison of Finnish, Norwegian, Swedish, and Russian building codes
- 2021
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Ingår i: Energy and Buildings. - : Elsevier. - 0378-7788 .- 1872-6178. ; 250
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Tidskriftsartikel (refereegranskat)abstract
- Building code are considered to be an effective policy tool to reduce energy use in buildings. In practice, national priorities influence the indicators and criteria adopted in the building codes. Consequently, neighbouring countries with similar climate conditions may use different criteria in their building codes to regulate the energy performance. In this paper, the energy performance criteria and their relative stringency in the latest residential building codes of Finland, Norway, Sweden and Russia are compared. The study is based on energy performance evaluations of one single-family building and one multi-family building, located in the north of Sweden. Both buildings complied with the Norwegian and Russian building code. However, the buildings did not comply with the specific fan power and heat loss criteria in the Finnish building code. Additionally, the single-family building did not comply with the specific primary energy and electric powerdemand criteria in the Swedish building code when heated by an electric heater. The national standard input data were found to have a large influence on the buildings’ compliance with the studied energy use criteria. Policy implications of the results are discussed.
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| 4. |
- Arghand, Taha, 1982, et al.
(författare)
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A comparative study on borehole heat exchanger size for direct ground coupled cooling systems using active chilled beams and TABS
- 2021
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788. ; 240
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Tidskriftsartikel (refereegranskat)abstract
- Direct ground cooling is a method for cooling buildings whereby free cooling is provided by circulating water through borehole heat exchangers (BHEs). Since no refrigeration cooling is involved, supply water temperature to the building’s cooling system is dependent mainly on BHE sizing. This study investigates the sizing of BHEs for direct ground cooling systems, with a particular focus on the influence of terminal unit types and their operating strategies. Experimental results using a direct ground-coupled active chilled beam (ACB) system are used to develop a simulation model for an office building. The model is also modified for thermally activated building systems (TABS). The simulation results show that using TABS instead of ACBs for a similar BHE reduced the ground peak hourly loads, resulting in a lower borehole outlet temperature. Resizing BHE depth to reach similar maximum borehole outlet temperatures according to the actual heat extraction rate from the cooling systems resulted in a significantly shorter BHE depth with TABS compared to ACBs. However, indoor temperature was generally warmer with TABS, due to their slower heat extraction rate from the room. The findings are practical for analysing the design and operation of BHEs for different types of terminal units.
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| 5. |
- Arghand, Taha, 1982, et al.
(författare)
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Influence of system operation on the design and performance of a direct ground-coupled cooling system
- 2021
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788. ; 234
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Tidskriftsartikel (refereegranskat)abstract
- Sizing of borehole heat exchangers (BHEs) for direct ground cooling systems (DGCSs) is a critical part of the overall system design. This study investigates the thermal performance and sizing of a DGCS with two different operation strategies using experimental and simulation approaches. The traditional on/off operation strategy keeps a constant room temperature. The continuous operation strategy has the potential to reduce the building peak cooling loads by precooling the space and having a variable room temperature measures. The experimental results from the laboratory-scale setup show the differences in the hourly room heat extraction rates and the room temperature pattern for the operation strategies applied. The experimental data is also used to develop a simulation model. The simulation results show that applying the continuous strategy reduces the building peak cooling loads and lowers the heat injection rates to the ground. For new BHEs, applying the continuous strategy can result in shorter BHEs, owing to the significantly lower ground heat injection rates. For existing BHEs, applying the continuous strategy can decrease the borehole outlet fluid temperature and thus, increase the cooling capacity of the building cooling system. The findings of this study have implications for developing the widespread use of DGCSs.
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| 6. |
- Attia, Shady, et al.
(författare)
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Overheating calculation methods, criteria, and indicators in European regulation for residential buildings
- 2023
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Ingår i: Energy and Buildings. - : Elsevier. - 0378-7788 .- 1872-6178. ; 292
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Tidskriftsartikel (refereegranskat)abstract
- With the ongoing significance of overheating calculations in the residential building sector, building codes such as the European Energy Performance of Building Directive (EPBD) are essential for harmonizing the indicators and performance thresholds. This paper investigates Europe's overheating calculation methods, indicators, and thresholds and evaluates their ability to address climate change and heat events. e study aims to identify the suitability of existing overheating calculation methods and propose recommendations for the EPBD. The study results provide a cross-sectional overview of twenty-six European countries. The most influential overheating calculation criteria are listed the best approaches are ranked. The paper provides a thorough comparative assessment and recommendations to align current calculations with climate-sensitive metrics. The results suggest a framework and key performance indicators that are comfort-based, multi-zonal, and time-integrated to calculate overheating and modify the EU's next building energy efficiency regulations. The results can help policymakers and building professionals to develop the next overheating calculation framework and approach for the future development of climate-proof and resilient residential buildings.
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| 7. |
- Bontekoe, Eelke, et al.
(författare)
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On the discrepancy of using annual or hourly emission factors for power generation to estimate CO2 reduction of building retrofitting
- 2024
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788 .- 1872-6178. ; 319
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Tidskriftsartikel (refereegranskat)abstract
- Buildings play a significant role in global carbon emissions, and offer substantial potential for energy savings and emission reduction. This research delves into the Emission Factor Discrepancy (EFD)—the variance in CO2 emission reduction projections obtained by employing either annual or hourly average Emission Factor (EF) for electricity generation. Through two detailed case studies in the Netherlands and incorporating emission data from the Netherlands, Sweden, and France, the study uncovers the potential magnitude and country-specific variability of the EFD. By demonstrating how the energy mix of a country influences the EFD, the research offers valuable insights into the accuracy of emission calculations for different circumstances, particularly in the context of transitioning to renewable energy sources. We have found that countries with energy sources having low load-following capability and low EFs exhibit a large EFD. Whereas, countries with high EFs and large deployment of Photovoltaics (PV) show a notably large EFD on emission reduction related to PV production. This highlights the importance of carefully selecting EFs when evaluating building retrofits in the context of smart city initiatives. This research highlights the need for establishing a uniform framework for calculating carbon emissions associated with retrofitting in buildings in conjunction with the granularity of data and the specific energy mix of a country.
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| 8. |
- Dahlström, Lukas, et al.
(författare)
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Advancing urban building energy modelling through new model components and applications : A review
- 2022
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Ingår i: Energy and Buildings. - : Elsevier. - 0378-7788 .- 1872-6178. ; 266
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Forskningsöversikt (refereegranskat)abstract
- Due to rapid urbanisation and the significant contribution of cities to worldwide energy use and greenhouse gas emissions, urban energy system planning is growing more important. Urban building energy modelling (UBEM) draws increasing attention in the energy modelling field due to its inherent capacities for modelling entire cities or building stocks, and the potential of varying data inputs, approaches and applications. This review aims to identify best practices and improvements for UBEM applications by examining previous research, with a focus on the currently least established approaches. Different archetype development procedures are analysed for common problems, six main under-developed input approaches or parameters are identified, and applications for future scenario development are surveyed. By analysing previous studies in related fields, this paper provides an overview of gaps in the published research and possible additions to future UBEM projects that can help expanding the existing modelling procedures. Comprehensive human behaviour models with additional aspects beyond occupant presence are identified as a major point of interest. Further research on socio-economic parameters, such as household income and demographics, are also suggested to further improve modelling. This study also underlines the potential for utilising UBEM as a tool for evaluating future climate change scenarios.
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| 9. |
- Dahlström, Lukas, et al.
(författare)
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Identification of representative building archetypes : A novel approach using multi-parameter cluster analysis applied to the Swedish residential building stock
- 2024
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Ingår i: Energy and Buildings. - : Elsevier. - 0378-7788 .- 1872-6178. ; 303
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Tidskriftsartikel (refereegranskat)abstract
- Building archetype identification is crucial for Urban Building Energy Modeling (UBEM), but is still considered one of the biggest challenges in this field. New methods of data acquisition, along with data mining techniques such as clustering, have recently received attention for the possibility of significantly increasing identification reliability and archetype accuracy. This paper aims to establish a new and simple clustering methodology for developing building archetypes for hybrid UBEM, using open data sets and multiple diverse variables, that is still reliable and possible to validate without the use of metered energy use or real building data. The methodology uses k-means clustering for 10 building parameters simultaneously, including socio-economic parameters obtained using spatial interpolation of statistical values. Building archetypes are successfully developed for the residential building stocks of two case study areas in Sweden. The results also show that the error metric values for multiple iterations diverge after a certain number of clusters, even when using the same clustering methodology on the same data set. This discovered effect, along with the combined use of one well-known and one novel error metric, constitutes a framework well adapted to accurately determining the optimal number of building archetypes.
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| 10. |
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