Energy and Buildings最新文献

{"title":"Optimizing graphite-enhanced composite PCMs for superior thermal transport in shell and tube latent heat storage systems","authors":"Amit Shrivastava,&nbsp;Narender Kumar,&nbsp;Prodyut R. Chakraborty","doi":"10.1016/j.enbuild.2024.115008","DOIUrl":"10.1016/j.enbuild.2024.115008","url":null,"abstract":"<div><div>Latent heat thermal energy storage (LHTES) systems are designed to store excess thermal energy, addressing supply-demand mismatches during periods of low supply. Integrating such systems in the field is challenging due to the slow charging caused by the low thermal conductivity of phase change materials (PCM). This shortfall can be mitigated using composite PCM (CPCM) as the thermal storage medium, consisting of form-stable porous graphite foam impregnated with PCM. Compressed expanded graphite (CEG) is one such easily accessible form-stable porous material. The graphite foam in the CPCM causes a significant improvement in the effective thermal conductivity of the storage medium; however, it causes reduced latent heat storage capacity. Existing literature on CPCM mainly emphasizes positive aspects like enhanced thermal conductivity and reduced melting time while overlooking the adverse impact on latent heat storage capacity. This trade-off must be addressed while designing such a system, particularly when the storage unit is of fixed size and shape. This study aims to find the optimal volumetric proportion of CEG in CPCM, striking the best balance between these two conflicting attributes. Objective parameters such as energy storage ratio (<em>ESR</em>) and capacity ratio (<em>CR</em>) are introduced, along with charging duration, and they are optimized based on control parameters like CEG foam porosity (<em>ε</em>), HTF inlet temperature (<span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>i</mi><mi>n</mi></mrow></msub></math></span>), and flow Reynolds number (<em>Re</em>). The analysis, obtained from a volume-averaged numerical model, involves diffusion-dominated energy transfer in the CPCM domain and provides crucial design guidelines for fixed-geometry LHTES units with CPCM as the storage medium.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"325 ","pages":"Article 115008"},"PeriodicalIF":6.6,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of supervised and unsupervised learning for enhancing energy efficiency and thermal comfort in air conditioning scheduling under uncertain and dynamic environments","authors":"Minseo Kim,&nbsp;Soongeol Kwon","doi":"10.1016/j.enbuild.2024.115028","DOIUrl":"10.1016/j.enbuild.2024.115028","url":null,"abstract":"<div><div>Air conditioning (AC) plays a major role in building energy management because it generally requires a large amount of energy to maintain indoor thermal comfort. The main objective of this study is to develop a novel method for scheduling AC operations to minimize energy costs and ensure the thermal comfort of occupants under uncertainty. The key challenge is the uncertainty and variability in time-series data and their serial dependence in determining AC operation. To address this challenge, we propose an optimization-informed learning approach that integrates unsupervised and supervised learning techniques with a stochastic optimization model. This method derives energy-efficient and thermal comfort-aware AC operation schedules through a comprehensive interpretation of uncertainties and variabilities in time-series data. Numerical experimental results demonstrate that the proposed approach can reduce energy costs by up to 15.6% and decrease thermal comfort violations by up to 63.6% compared to the Deep Q-learning method, while also reducing energy costs by 1.8% and decreasing thermal comfort violations by 37.5% compared to the forecast data-driven AC scheduling method.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"325 ","pages":"Article 115028"},"PeriodicalIF":6.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hybrid photovoltaic and gravity energy storage integration for smart homes with grid-connected management","authors":"Fazal Hussain ,&nbsp;Qi Huang ,&nbsp;Jawad Hussain ,&nbsp;Baqir Ali Mirjat ,&nbsp;Kashif Manzoor ,&nbsp;Syed Adrees Ahmed","doi":"10.1016/j.enbuild.2024.114984","DOIUrl":"10.1016/j.enbuild.2024.114984","url":null,"abstract":"<div><div>This paper introduces a dynamic Smart Home Energy Management System (SHEMS) integrating a hybrid photovoltaic (PV) and gravity energy storage (GES) system aimed at minimizing environmental impacts and household energy consumption. The novel SHEMS features a one-week dynamic forecasting model that adapts to variable electricity prices, smart appliance schedules, solar output, and energy storage states. These results demonstrate that the system not only reduces household energy usage but also cuts electricity bills significantly, supplying power autonomously for up to 8.5 hours daily. By leveraging real-time data from the Dark Sky API on cloud cover and temperature, this model accurately predicts solar radiation and PV generation, aligning it with both grid and residential demands. The forecasting accuracy was assessed using Root Mean Square Error (RMSE) and Mean Absolute Percentage Error (MAPE), which improved to 12.55% and 4.91% respectively, from initial values of 22.46% for RMSE and 11.78% for MAPE. These advancements enhance grid stability and optimize energy storage during peak periods, reducing dependence on fossil fuels. The integration of innovative renewable energy technologies and sophisticated forecast modeling significantly boosts the system's efficiency, promoting the sustainable use of energy resources in line with environmental and economic goals.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"326 ","pages":"Article 114984"},"PeriodicalIF":6.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Size effect of typical hygrothermal properties test values for building insulation materials","authors":"Wen Yang ,&nbsp;Guanjie Zhang ,&nbsp;Jun Wen ,&nbsp;Chengyan Zhou ,&nbsp;Jiaping Liu","doi":"10.1016/j.enbuild.2024.115049","DOIUrl":"10.1016/j.enbuild.2024.115049","url":null,"abstract":"<div><div>Thermal and moisture properties of building insulation materials are crucial input parameters for analyzing thermal and moisture transfer phenomena in building environments. Accurate determination of these parameters under different conditions is essential for the correct application and assessment of materials and envelope structures. However, numerous factors influence thermal and moisture properties, and while extensive research has been conducted on this topic, the effects of specimen size on typical thermal and moisture property test values remain unclear. To address the issue of unreliable data caused by random specimen sizes in thermal and moisture property testing of building insulation materials, this study selects three materials—expanded polystyrene (EPS), extruded polystyrene (XPS), and foamed cement—as test subjects to explore the size effects on typical thermal and moisture property test values. The results indicate that specimen size significantly affects the test values for typical thermal and moisture properties, with only a few experiments showing negligible size effects for certain materials. For foamed cement, recommended specimen sizes for thermal conductivity testing using the guarded hot plate method and the transient plane source method are 300 × 300 × 30 mm and 50 × 50 × 30 mm, respectively. Except for equilibrium moisture absorption experiments, the weight of other moisture property tests is generally represented by thickness &gt; planar dimensions.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"325 ","pages":"Article 115049"},"PeriodicalIF":6.6,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cementitious core–shell particles with optimized radiative and anti-wetting properties for efficient and durable passive building cooling","authors":"Xiantong Yan ,&nbsp;Shirui Peng ,&nbsp;Meng Yang ,&nbsp;Wenhui Duan ,&nbsp;Hongzhi Cui","doi":"10.1016/j.enbuild.2024.115045","DOIUrl":"10.1016/j.enbuild.2024.115045","url":null,"abstract":"<div><div>Developing a building-compatible radiative cooler that exhibits an all-day subambient cooling effect and maintains a clean surface for long-term stability is challenging. This study proposes a liquid marble-derived core–shell particle (LM-CSP) that combines excellent anti-wetting capability, efficient and durable daytime radiative cooling properties, and compatibility with building materials. A series of LM-CSP coated samples were fabricated with varying dosages of BaSO₄ and water-repellent agents, as well as different coating thicknesses. Comprehensive characterization of the as-prepared samples revealed that the optimal LM-CSP exhibited a solar reflectance of 91 % with a mid-infrared emissivity of 0.97 and a water contact angle of ∼151.9° with a roll-off angle of ∼7.8°, respectively. In-depth analyses using XRD, FT-IR, TGA/DTG, and XPS elucidated the underlying mechanisms responsible for the enhanced optical and wetting properties of the LM-CSP. The exceptional durability of the LM-CSP was validated by its subambient cooling effects after being contaminated with muddy slurry (subambient temperature drop of ∼5.4 °C) and after being rain-washed (subambient temperature drop of ∼2.1 °C). EnergyPlus simulations were employed to assess the year-round energy-saving potential of the LM-CSP, and a life-cycle economic and environmental analysis was performed to guide the practical application. The findings of this study are expected to provide new insights into functional cementitious materials with efficient and durable cooling capabilities, ultimately contributing to the advancement of sustainable building design and energy efficiency.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"325 ","pages":"Article 115045"},"PeriodicalIF":6.6,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation method and enhanced strategy for frosting suppression performance of variable speed air source heat pump based on frosting suppression performance map","authors":"Yao Lin ,&nbsp;Jianfei Luo ,&nbsp;Qing Luo ,&nbsp;Xiaoli Li ,&nbsp;Wei Wang ,&nbsp;Yuying Sun","doi":"10.1016/j.enbuild.2024.115047","DOIUrl":"10.1016/j.enbuild.2024.115047","url":null,"abstract":"<div><div>It is well established that the configuration and operation of variable speed air source heat pumps (VS ASHPs) can significantly influence their frosting performance. However, there is currently no effective method to conveniently and accurately evaluate the frosting suppression performance of these units. This paper addresses this gap by proposing a novel evaluation method based on a frosting suppression map for VS ASHPs. Firstly, an experimental setup with four ASHP units and developed frosting suppression maps is described. Second, a method for evaluating the frosting suppression performance of VS ASHP is developed based on the map. Thirdly, a comprehensive evaluation of the frosting suppression performance of the experimental unit is carried out. It is shown that the <em>β</em> values of the four units under the constitutive configuration were 0.74, 0.12, 0.21, and 0.52, and the frosting suppression performance was evaluated as Good, Poor, Fair, and Average, respectively. It could be enhanced and improved to 0.89 (Excellent), 0.24 (Fair), 0.64 (Good), and 0.63 (Good) after applying the frosting suppression operation method. The proposed novel frosting suppression evaluation method is simple and easy to implement, which could contribute to further guiding manufacturers to improve the frosting suppression performance of VS ASHPs.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"325 ","pages":"Article 115047"},"PeriodicalIF":6.6,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mitigating urban heat island effects using trees in planters with varied crown shapes","authors":"Ivana Bajšanski ,&nbsp;Stevan Savić ,&nbsp;Jelena Dunjić ,&nbsp;Dragan Milošević ,&nbsp;Vesna Stojaković ,&nbsp;Bojan Tepavčević","doi":"10.1016/j.enbuild.2024.115034","DOIUrl":"10.1016/j.enbuild.2024.115034","url":null,"abstract":"<div><div>Urban downtown areas are often overheated and contribute to the creation of urban heat island (UHI) phenomenon. Implementation of trees is considered an effective way to mitigate UHI and improve outdoor thermal comfort (OTC) in densely built-up areas.</div><div>This study aims to investigate the potential of applying additional trees in planters to mitigate UHI effects and improve OTC in open urban areas. Simulation of OTC is performed for hot summer days using Universal Thermal Climate Index (UTCI). In this study, we have devised a method to determine favourable locations for a predetermined number of additional trees, with different crown shapes (cylinder, sphere and cone), to improve OTC conditions. In the proposed method, an evolutionary algorithm based on natural selection was used as it is effective for solving problems that have a large number of combinations. The method considers the geometry of the built environment, the geometry, locations and number of additional trees, weather data and UTCI simulation.</div><div>The method was applied to three different urban morphologies located in the downtown of Novi Sad, Serbia. The results show that, depending on urban geometries and morphologies, different crown shapes lead to different UTCI reduction. Cylinder-shaped and sphere-shaped tree crowns showed to be the most effective in reducing heat stress. The positioning of additional trees reduced the UTCI values at single manikin locations by up to 6.11 °C, indicating that the process of determining their locations is crucial for mitigating the heat and improving OTC conditions during hot summer days.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"325 ","pages":"Article 115034"},"PeriodicalIF":6.6,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GPT-based data-driven urban building energy modeling (GPT-UBEM): Concept, methodology, and case studies","authors":"Sebin Choi ,&nbsp;Sungmin Yoon","doi":"10.1016/j.enbuild.2024.115042","DOIUrl":"10.1016/j.enbuild.2024.115042","url":null,"abstract":"<div><div>Achieving carbon neutrality is a critical global goal, with urban building energy modeling (UBEM) playing a pivotal role by providing data-driven insights to optimize energy consumption and reduce emissions. This paper introduces GPT-based urban building energy modeling (GPT-UBEM), a novel approach utilizing GPT’s advanced capabilities to address key UBEM challenges using GPT-4o. The study aimed to demonstrate the effectiveness of GPT-UBEM in performing UBEM tasks and to explore its potential in overcoming traditional limitations. Specifically, (1) basic analytics of urban data, (2) data analysis and energy prediction, (3) building feature engineering and optimization, and (4) energy signature analysis were conducted in four case studies. These analyses were applied to 2,000 buildings in Seoul and 31 buildings in Gangwon-do, South Korea. Through case study, the findings highlighted the ability of GPT-UBEM to integrate diverse data sources, optimize building features for high accuracy in prediction models, and provide valuable insights for urban planners and policymakers through the use of expert domain knowledge and intervention. Additionally, based on the results derived from GPT-UBEM in this study, the current limitations of GPT-UBEM (L1 to L3) and future research directions (F1 to F4) have been outlined.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"325 ","pages":"Article 115042"},"PeriodicalIF":6.6,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metadata schema for virtual building models in digital twins: VB schema implemented in GPT-based applications","authors":"Jeyoon Lee ,&nbsp;Sungmin Yoon","doi":"10.1016/j.enbuild.2024.115039","DOIUrl":"10.1016/j.enbuild.2024.115039","url":null,"abstract":"<div><div>A virtual building model (VBM) is a virtual entity that represents the physical behavior of a target building mathematically within a digital twin environment. The creation and synchronization of a VBM are achieved by utilizing various interrelated virtual sub-models, including behavior, correction, and distance models. To achieve continuous digital twinning, it is essential to manage the VBM with virtual sub-models. However, existing metadata schemas have limitations in describing VBMs representing operational building behaviors within the concept of building digital twins (DTs). Therefore, this study proposes a novel metadata schema, termed the virtual building model metadata schema (VB schema), to represent and manage VBMs in DT-built environments. The VB schema is established according to the mathematical and semantic ontology of the in-situ modeling and calibration approach for constructing and correcting virtual models during building operations, and it is linked to physical entities, data, and applications within DTs. Specifically, it involves: (1) determining classes for operational data and virtual models; (2) establishing relationships for interactions between model and data entities, between model classes, between model and physical entities, and between model and applications; (3) defining properties for each class of models; and (4) extending into the exiting metadata schema of Brick. To demonstrate the proposed VB schema, a virtual model describing supply pressure behaviors in a central heating system was developed and represented using the VB schema for DT-enabled building operations. Additionally, the VB schema was utilized for implementing generative pre-trained transformer (GPT)-based DT applications, which highlights its benefits in enhancing ontology comprehension of DTs in the context of VBMs, improving autonomous problem-solving capabilities in real building systems, and providing better interpretation of application results compared to cases where only the Brick schema was used. The VB schema is expected to enable continuous and autonomous in-situ management of VBMs for intelligent building services within the DT.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"327 ","pages":"Article 115039"},"PeriodicalIF":6.6,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing ventilation systems considering operational and embodied emissions with life cycle based method","authors":"Peng Liu ,&nbsp;Jens Tønnesen ,&nbsp;Luis Caetano ,&nbsp;Håvard Bergsdal ,&nbsp;Maria Justo Alonso ,&nbsp;Reidar Kind ,&nbsp;Laurent Georges ,&nbsp;Hans Martin Mathisen","doi":"10.1016/j.enbuild.2024.115040","DOIUrl":"10.1016/j.enbuild.2024.115040","url":null,"abstract":"<div><div>Efforts to enhance the energy efficiency of heating, ventilation, and air conditioning (HVAC) systems have been bolstered by technical advancements and stringent regulations. However, HVAC systems not only emit during operation due to energy consumption but also have significant embodied emissions, which recent studies show can exceed those of the operational phase. This study introduces an optimization framework aimed at minimizing lifetime emissions—both operational and embodied—for ventilation systems, an area previously underexplored. The optimization framework incorporates detailed calculations of pressure drop, fan power and newly developed life cycle ventilation inventory data with a life cycle assessment perspective.</div><div>A case study of ventilation ductwork in a “BREEAM Excellent” certified energy-efficient building in Norway demonstrates the application of this optimization framework. Findings indicate that for this case, optimizing ductwork dimensions can reduce lifetime emissions of the ventilation system by 15 %, compared to the existing designs with an emission intensity of 0.3 kg CO₂/kWh. Further, the study examines how the emission intensity of electricity generation and service lifetime influence total emissions, highlighting the growing importance of embodied emissions as electricity generation becomes cleaner. This underscores the necessity of considering both operational and embodied emissions in design decisions. This study presents an optimization tool for low-emissions ventilation design, capable of processing diverse layouts and aiding in decarbonizing ventilation systems towards achieving zero-emission buildings. Future integration with building information modeling (BIM) and artificial intelligence (AI) could further enhance autonomous low-carbon design and decision-making.</div></div>","PeriodicalId":11641,"journal":{"name":"Energy and Buildings","volume":"325 ","pages":"Article 115040"},"PeriodicalIF":6.6,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}