| 1. |
- Alinejad, T., et al.
(författare)
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Thermo-environomic assessment of an integrated greenhouse with an adjustable solar photovoltaic blind system
- 2020
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Ingår i: Renewable energy. - : Elsevier Ltd. - 0960-1481 .- 1879-0682. ; 156, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- Optimum energy consumption and renewable energy utilization reduce environmental impacts and are cost-effective. They are the key aspects of achieving sustainable energy management, such as in the agricultural industry. The contribution of the horticultural section in the global energy demand is approximately 2%, and among its various sections, greenhouses are one of the main systems in modern agriculture that have a great share on energy consumption. In this study, a rose greenhouse is examined and modeled in EnergyPlus as a greenhouse reference (GR). Validation of the developed greenhouse model is carried out with a site experimental measurement. Using the GR as the basic model, 14 various configurations of greenhouses have been assessed by considering a solar photovoltaic blind system (SPBS) in checkerboard arrays 1 m above the greenhouse roof. These modified greenhouses called solar-blind greenhouses (SBGs) have different shading rates and SPBS sizes. To perform a Thermo-environomic assessment, the effects of various parameters, including temperature, relative humidity, natural gas consumption, electricity consumption, and carbon dioxide (CO2) emission reduction, are studied. Results indicate that covering 19.2% of the roof, with no significant change in the illumination level on the plant canopy, will annually reduce natural gas consumption, electricity demand, and CO2 emission by 3.57%, 45.5%, and 30.56 kg/m2, respectively. Moreover, with the SPBS, the annual electricity production is approximated at 42.7 kWh/m2. © 2020 Elsevier Ltd
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| 2. |
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| 3. |
- Dall'Orto, Francesco, et al.
(författare)
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Economic Aspect of Hybrid Heating and Cooling Systems in a Residential Building
- 2019
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Konferensbidrag (refereegranskat)abstract
- District heating is a well-established technology; however, the use of individual heat pumps has been expanding and is now the main competitor to district heating. The prices for both electricity and district heating often vary over time because of the variation of raw material prices in the marketplace. Consequently, for the building owner it would be cost effective if they had the possibility to integrate both district heating and heat pumps. Aiding in the flexibility to switch between the two systems in order to choose the one with the lowest operating cost throughout the year. In the presented work, the modeling and control of a detached house integrated with both district heating and a heat pump are developed. The operating costs of both systems are computed considering the marketplace prices and the coefficient of performance of the heat pump, related to the external temperature. The results show that heat pumps can be well exploited during the spring and fall to cover base loads, and in the summer can be used for ambient cooling.
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| 4. |
- Effatpisheh, Aref, et al.
(författare)
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Mathematical Modelling of Active Magnetic Regenerator Refrigeration System for Design Considerations
- 2020
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Ingår i: Energies. - : MDPI AG. - 1996-1073. ; 13:23
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Tidskriftsartikel (refereegranskat)abstract
- A magnetic refrigeration system has the potential to alternate the compression system with respect to environmental compatibility. Refrigeration systems currently operate on the basis of the expansion and compression processes, while active magnetic refrigeration systems operate based on the magnetocaloric effect. In this study, a single layer of Gd was used as the magnetocaloric material for six-packed-sphere regenerators. A one-dimensional numerical model was utilized to simulate the magnetic refrigeration system and determine the optimum parameters. The optimum mass flow rate and maximum cooling capacity at frequency of 4 Hz are 3 L.min(-1) and 580 W, respectively. The results show that the maximum pressure drop increased by 1400 W at a frequency of 4 Hz and mass flow rate of 5 L.min(-1). In this study, we consider the refrigeration system in terms of the design considerations, conduct a parametric study, and determine the effect of various parameters on the performance of the system.
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| 5. |
- Jalilzadehazhari, Elaheh, 1985-, et al.
(författare)
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Achieving a trade‐off construction solution using BIM, an optimization algorithm, and a multi‐criteria decision‐making method
- 2019
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Ingår i: Buildings. - Basel, Switzerland : MDPI. - 2075-5309. ; 9:4, s. 1-14
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Tidskriftsartikel (refereegranskat)abstract
- The Energy Performance of Building Directive obligated all European countries to reduce the energy requirements of buildings while simultaneously improving indoor environment quality. Any such improvements not only enhance the health of the occupants and their productivity, but also provide further economic benefits at the national level. Accomplishing this task requires a method that allows building professionals to resolve conflicts between visual and thermal comfort, energy demands, and life‐cycle costs. To overcome these conflicts, this study exploits the incorporation of building information modelling (BIM), the design of experiments as an optimization algorithm, and the analytical hierarchy process (AHP) into a multi‐criteria decision‐ making method. Any such incorporation can (i) create constructive communication between building professionals, such as architects, engineers, and energy experts; (ii) allow the analysis of the performance of multiple construction solutions with respect to visual and thermal comfort, energy demand, and life‐cycle costs; and (iii) help to select a trade‐off solution, thereby making a suitable decision. Three types of energy‐efficient windows, and five types of ground floors, roofs, and external wall constructions were considered as optimization variables. The incorporation of several methods allowed the analysis of the performance of 375 construction solutions based on a combination of optimization variables, and helped to select a trade‐off solution. The results showed the strength of incorporation for analyzing big‐data through the intelligent use of BIM and a simulation in the field of the built environment, energy, and costs. However, when applying AHP, the results are strongly contingent on pairwise comparisons
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| 6. |
- Jalilzadehazhari, Elaheh, 1985-, et al.
(författare)
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Profitability of various energy supply systems in light of their different energy prices and climate conditions
- 2020
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Ingår i: Buildings. - : MDPI. - 2075-5309. ; 10:6, s. 1-17
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Tidskriftsartikel (refereegranskat)abstract
- The majority of the single-family houses in Sweden are affected by deteriorations in building envelopes as well as heating, ventilation and air conditioning system. These dwellings are therefore in need of extensive renovation, which provides an excellent opportunity to install renewable energy supply systems to reduce the total energy consumption. The high investment costs of the renewable energy supply systems was previously distinguished as the main barrier in the installation of these systems in Sweden. House-owners should therefore compare the profitability of the energy supply systems and select the one, which will allow them to reduce their operational costs. This study analyses the profitability of a ground source heat pump, photovoltaic solar panels, and an integrated ground source heat pump with a PV system, as three energy supply systems for a single-family house in Sweden. The profitability of the supply systems was analysed by calculating the payback period (PBP) and internal rate of return (IRR) for these systems. Three different energy prices, three different interest rates, and two different lifespans were considered when calculating the IRR and PBP. In addition, the profitability of the supply systems was analysed for four Swedish climate zones. The analyses of results show that the ground source heat pump system was the most profitable energy supply system, since it provided a short PBP and high IRR in all climate zones when compared with the other energy supply systems. Furthermore, results show that increasing the energy price improved the profitability of the supply systems in all climate zones.
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| 7. |
- Jalilzadehazhari, E., et al.
(författare)
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Profitability of various energy supply systems in light of their different energy prices and climate conditions
- 2020
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Ingår i: Buildings. - : MDPI AG. - 2075-5309. ; 10:6
-
Tidskriftsartikel (refereegranskat)abstract
- The majority of the single-family houses in Sweden are affected by deteriorations in building envelopes as well as heating, ventilation and air conditioning systems. These dwellings are, therefore, in need of extensive renovation, which provides an excellent opportunity to install renewable energy supply systems to reduce the total energy consumption. The high investment costs of the renewable energy supply systems were previously distinguished as the main barrier in the installation of these systems in Sweden. House-owners should, therefore, compare the profitability of the energy supply systems and select the one, which will allow them to reduce their operational costs. This study analyses the profitability of a ground source heat pump, photovoltaic solar panels and an integrated ground source heat pump with a photovoltaic system, as three energy supply systems for a single-family house in Sweden. The profitability of the supply systems was analysed by calculating the payback period (PBP) and internal rate of return (IRR) for these systems. Three different energy prices, three different interest rates, and two different lifespans were considered when calculating the IRR and PBP. In addition, the profitability of the supply systems was analysed for four Swedish climate zones. The analyses of results show that the ground source heat pump system was the most profitable energy supply system since it provided a short PBP and high IRR in all climate zones when compared with the other energy supply systems. Additionally, results show that increasing the energy price improved the profitability of the supply systems in all climate zones. © 2020 by the authors.
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| 8. |
- Jalilzadehazhari, Elaheh, 1985-, et al.
(författare)
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Profitability of various energy supply systems when renovating a single-family house in Sweden : case study
- 2019
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Ingår i: International Conference on Applied Energy (ICAE 2019). August 12-15, Västerås, Sweden.
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Konferensbidrag (refereegranskat)abstract
- The majority of single-family houses in Sweden are affected by deteriorations in building envelopes as well as heating, ventilation and air conditioning systems, since they are about 30 years old. Theses house are therefore in need of extensive renovation, which provides an excellent opportunity to incorporate energy efficiency measures to reduce both the energy consumption and also operational. Although former studies analyzed the cost effectiveness of various renovation packages, they mainly excluded the evaluation of energy price implications on cost effectiveness of different renovation package in Sweden. Accordingly, this study considers three energy prices and quantifies the payback period (PBP) and internal rate of return (IRR) of the packages, when renovating a single-family house in Sweden. The renovation packages included three distinct energy supply systems, commonly installed when implementing energy renovations: ground source heat pump (GSHP), photovoltaic solar panels (PV), and an integrated GSHP and PV system. The analyses of results show that a the GSHP system provides higher IRR and the lowest PBP compared to the other two renovation packages, due to its high performance in reducing energy consumption and its relatively low investment cost. Furthermore, results show that raising the energy price can increase the IRR and reduce the PBP of the renovation packages and respectively. Moreover, increasing the interest rate adds on PBP of renovation packages, since it depreciates the cost for saved energy.
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| 9. |
- Jalilzadehazhari, Elaheh, 1985-, et al.
(författare)
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Subsidies Required For Installing Renewable Energy Supply Systems Considering Variations In Future Climate Conditions
- 2021
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Ingår i: Journal of Building Engineering. - : Elsevier. - 2352-7102 .- 2352-7102. ; 35, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Improving the energy performance of detached houses is expected to play an important role in achieving energy and climate targets in Sweden. The majority of detached houses require energy renovations due to technical deteriorations in heating, ventilation, and air conditioning systems approaching the ends of their lives. Renewable energy supply system implementation leads to total energy use reduction. No previous studies provided information regarding how possible climate futures could affect subsidies required to implement these systems. This study compared the performance of an air-to-water heat pump (ASHP), a ground-source heat pump (GSHP), and an integrated system of a ground-source heat pump and photovoltaic solar panels (GSHP-PV) in reducing the total energy use of a detached house, which was initially supplied by an electric boiler. The performances of the supply systems were analysed in regard to three different climate scenarios, following the Special Report of Emissions Scenarios, A2 storyline. The effects of three different interest rates and two different lifetimes on subsidies were also investigated for all three energy supply systems. The GSHP-PV system was the most efficient system, as it secured 97%–100% of the total energy consumption, followed by GSHP and AWHP. The analyses of the results showed that variations in future climate conditions changed the subsidies required to install the supply systems. Furthermore, the results showed that changes in lifetime had greater impact on subsidies than interest rate growth.
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| 10. |
- Jalilzadehazhari, Elaheh, 1985-, et al.
(författare)
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The profitability of various energy supply systems considering variations in future climate conditions
- 2019
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Ingår i: International Conference on Applied Energy (ICAE 2019). August 12-15, Västerås, Sweden.
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Konferensbidrag (refereegranskat)abstract
- Ambitious targets were set in Sweden to increase the share of renewable energy resources and reduce greenhouse gas emissions. Renovating old detached houses can assist in achieving the abovementioned targets, since they make up a great share of the final energy consumption and carbon dioxide emissions in Sweden. Although, several attempts were taken to improve the energy performance of the detached houses, the implementation of energy efficient renovation is yet low due to mainly high investment cost. Former studies evaluated the cost effectiveness of various energy efficient renovations in renovating detached houses in Sweden, but they provided no information how possible climate futures affect the determination and adoption of energy efficiency policies, such as monetary instruments. Accordingly, this study considered three distinct energy renovation packages and analyzed the subsidies required for implementing renovation packages for given interest rates and lifetimes. Furthermore, three different climate scenarios were considered to analyze the effect of possible climate futures on subsidies required. The analyses of results show that increasing the lifetime have greater impact on required subsidies than increasing the interest rate. Furthermore, the results show that variation in future climate conditions changes the required subsidies when implementing energy efficiency renovations. Results can be used as an aid when adopting energy efficiency policies.
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