Journal of Building Physics最新文献

{"title":"A comparative study of machine learning methods for identifying the 15 CIE standard skies","authors":"Emmanuel I Aghimien, Danny HW Li, Ernest KW Tsang, Favour D Agbajor","doi":"10.1177/17442591241266836","DOIUrl":"https://doi.org/10.1177/17442591241266836","url":null,"abstract":"For energy-efficient building designs, the solar irradiance and daylight illuminance derived from the CIE standard skies are useful. Over time, the sky luminance distributions have been used to identify these standard skies, but these are sparingly measured. Thus, the use of available climatic variables has become a viable alternative. Nevertheless, it is necessary to determine if these climatic variables could correctly identify these skies. This study addresses the lack of luminance distribution measurement by classifying the standard skies using measured climatic data in Hong Kong. The classification approach was improved by using the machine learning (ML) method. For comparative analysis, five popular ML classification algorithms i.e., decision tree (DT), k-nearest neigbhour (KNN), light gradient boosting machine (LGBM), random forest (RF) and support vector machines (SVM) were used. The findings show that accuracies of 68.1, 73.1, 74.3, 74.5, and 75.4% were obtained for the DT, KNN, SVM, LGBM, and RF models, respectively. Similarly, the F1 scores were 66.6, 70.2, 71.8, 72.1 and 72.9%, for the DT, KNN, SVM, LGBM, and RF models. The result shows that the RF model gave the best performance while DT performed the least. Also, the obtained accuracies and F1 scores show that all models would classify the standard skies with reasonable accuracy. Furthermore, feature importance was done, and it was found that K<jats:sub>d</jats:sub>, T<jats:sub>v</jats:sub>, K<jats:sub>t</jats:sub>, α, sun, and cld are the most important input parameters for sky classification. Lastly, vertical solar irradiance ( G<jats:sub>VT</jats:sub>) and illuminance ( G<jats:sub>VL</jats:sub>) were estimated using the skies predicted by the proposed models. Upon predictions, it was observed that the G<jats:sub>VT</jats:sub> ranged from 14.7 to 24.6% while the G<jats:sub>VL</jats:sub> from 13.8 to 19.9%. Generally, most of the predictions were less than 20%, which shows good predictions were obtained from the models.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141945552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A probabilistic approach for risk assessment of moisture-related degradation of building envelopes","authors":"Bona Ryan, David N. Bristow, P. Mukhopadhyaya","doi":"10.1177/17442591241261078","DOIUrl":"https://doi.org/10.1177/17442591241261078","url":null,"abstract":"The performance and durability of wood-frame building envelopes is affected by long-term moisture transport and its impact. Despite considerable progress in deterministic and prescriptive methodologies aimed at estimating moisture deposition and the consequent risk of mold growth, a consensus in methodology applicable to the analysis of moisture risk in building enclosures is an unfinished agenda. This might partly be caused by uncertainties that exist due to variations in input parameters, model structure, and data scarcity. To address this issue, this study presents a probabilistic risk assessment of building envelope deterioration from moisture accumulation. The proposed methodology integrates the development of meta-models, a full-factorial response surface methodology, and Bayesian analysis. The effectiveness of the proposed approach is demonstrated through a parametric analysis of typical wall assemblies featuring diverse layers and boundary conditions. The findings highlight the influence of input variables and their relative significance on moisture accumulation in the selected climate zones. Additionally, a sensitivity analysis of model parameters and the application of Bayesian analysis in specific contexts are presented, facilitating comparative evaluation of moisture-related risk of building envelopes.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141797687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical and experimental analysis of building walls thermal performance","authors":"Joelle Al Fakhoury, Emilio Sassine, Yassine Cherif, Joseph Dgheim, Emmanuel Antczak","doi":"10.1177/17442591241254789","DOIUrl":"https://doi.org/10.1177/17442591241254789","url":null,"abstract":"The building sector represents a significant proportion of the world’s energy consumption and greenhouse gas emissions. One of the possible contributions to reducing this problem is to improve the energy performance of buildings by acting on their envelope and systems. Consequently, the aim of this work is to develop an experimental and numerical methods for characterizing the thermal performance of a concrete masonry hollow wall, in order to propose a new configuration that can be used to improve its thermal performance. First, this study focuses on the thermal performance of different wall configurations. Then, each case studied at wall scale, was modeled, and simulated in 3D using COMSOL Multiphysics<jats:sup>®</jats:sup> software under the same conditions, properties and dimensions as the one tested experimentally. Finally, this analysis was applied to a real building in Lebanon, consisting of hollow concrete masonry walls, to study its energy and thermal requirements. The conclusions showed that the numerical and experimental results proposed for the hollow masonry block wall confirm a good match. This validates the value of this method in the construction sector by proposing new methods for improving its thermal and energy performance.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141786321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of mathematical correlations to predict performance of forced ventilated Photovoltaic-DSF system in hot composite climate","authors":"Sajan Preet, Sanjay Mathur, Jyotirmay Mathur, Manoj Kumar Sharma, Amartya Chowdhury","doi":"10.1177/17442591241247327","DOIUrl":"https://doi.org/10.1177/17442591241247327","url":null,"abstract":"Performance of Photovoltaic-double skin façade (Photovoltaic-DSF) system in summer has been critical. Owing to high solar ingress, cooling requirement of a building significantly increases. Photovoltaic-DSF system provides a shield and controls the heat gain through fenestration in the interior spaces. In the present article, mathematical correlations are developed to analyse energy behaviour of forced-ventilated Photovoltaic-DSF system in India’s hot summer zone, that is, Jaipur. The Photovoltaic-DSF system has been installed and monitored for Jaipur’s summer months (May to July). L25 Orthogonal array of design parameters (air cavity thickness, air velocity and PV panel’s transparency) and their respective levels have been developed using Taguchi design to perform experiments. Based on experimental results, multiple linear regression has been used to forecast solar heat gain coefficient, PVs electrical power and daylighting illuminance indoors as function of design factors. The statistical significance of mathematical relationships is supported by variance analysis, which is found to be in good accord with field measurements ( R<jats:sup>2</jats:sup> &gt; 0.90). The proposed correlations are pragmatic in designing Photovoltaic-DSF systems for hot summer conditions. The Photovoltaic-DSF system with 30% transmittance and air velocity of 5 m/s in 200 mm air cavity thickness achieved maximum energy performance in hot summers.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141502655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational and experimental analysis of PCM-infused brick for sustainable heat regulation","authors":"Amira Dellagi, Rabeb Ayed, Salwa Bouadila, AmenAllah Guizani","doi":"10.1177/17442591241255966","DOIUrl":"https://doi.org/10.1177/17442591241255966","url":null,"abstract":"Examining the thermodynamics of phase change materials (PCMs) when merged into construction materials is a significant subject within the realm of building science and environmental responsibility. When infused to construction materials like bricks, PCMs have the capacity to elevate a building’s temperature regulation by minimizing the energy required for thermal contentment. This research is dedicated to learn about the thermal conduct and the consequences of the fusion of calcium chloride hexahydrate mineral (CCHPCM) within the pores of a masonry unit. To achieve this, we implemented a practical testing specifically designed to scrutinize how CCHPCMs alter the thermal performance of studied compounds. Multiple configurations were designed by adjusting the arrangement of CCHPCM within the bricks, resulting in three distinct setups. The first set involved filling one row of the bricks, the second set entailed filling two rows, and the final configuration entailed filling all the pores with PCM. Additionally, a computational modeling was executed to survey the thermic behavior of bricks infused with CCHPCM, operating with COMSOL Multiphysics application program. The elaborated work concluded to having an enhancement of the brick’s thermal storage capacity, for Set-3, in which all rows of bricks are filled with PCM, a delay of 2 h is observed compared to Set-0 the brick without CCHPCM. This simulation also encompassed comparative findings regarding the thermal performance of CCHPCM when incorporated into the masonry unit. Overall, this study supplied the valorization of CCHPCMs infused in masonry units and their usage in distinct layouts on upgrading its candidature to achieving environmental responsibility.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141502656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of the induced flow obtained with 2D and 3D CFD simulations of a solar chimney at different width-to-gap ratios","authors":"Y. Q. Nguyen, T. N. Huynh, Khoa Le-Cao","doi":"10.1177/17442591241252417","DOIUrl":"https://doi.org/10.1177/17442591241252417","url":null,"abstract":"Solar chimneys are among the most common methods for natural ventilation of buildings. Computational Fluid Dynamics (CFD) has been widely applied in research and design of solar chimneys. Most of the previous studies are based on 2D CFD models which ignore the effects of the width (the third dimension) of the air channel. In addition, the applicability of 2D models for the solar chimneys with a low width-to-gap ratio is still questionable. This study investigates both 2D and 3D CFD models for window-sized vertical solar chimneys. The 2D model is applied to the domain comprising the central plane of the channel gap ( G) and height ( H) while the 3D model is applied to the domain consisting of the channel gap, height, and width ( W). The flow fields, flow rates and thermal efficiencies computed with the 2D and 3D models at different heights, gaps, and widths are compared. The results show that W/ G is the most crucial factor. The effects of the side walls are significant at a low W/ G but gradually diminishes as W/ G increases. At W/ G = 15, the side wall effects are confined to a region of about 2.6% W. Particularly, for W/ G>8, the differences between the 2D and 3D flow rates and thermal efficiencies are within ±5%. These findings offer a reference for researchers and engineers to select between 2D and 3D CFD models for a specific solar chimney.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141360459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy efficiency of ecological buildings in Tunisia: Natural fiber composites and passive strategies impact","authors":"Hela Guesmi, Meriem Soussi, Fakhreddine Abbassi, Ali Adili, Leila Dehmani","doi":"10.1177/17442591241246053","DOIUrl":"https://doi.org/10.1177/17442591241246053","url":null,"abstract":"Improving the thermal insulation and energy efficiency of building envelopes is a major objective worldwide and has significantly developed in the recent years. This study aims to evaluate the impact of ecological additive and passive strategies on building energy efficiency. An experimental study was carried out to examine the effect of the incorporation of treated Alfa and Posidonia-Oceanica fibers on the thermal properties of cement and gypsum composite samples. The experimental results were then introduced in a numerical study using TRNSYS software to perform a comparison of the energy efficiency and thermal performance of three individual buildings; two ones constructed with our ecological materials and the third one with typical materials is considered as a reference case under the Tunisian climate. The obtained results indicate that the buildings built with Alfa fibers (BAF) and Posidonia-Oceanica fibers (BPOF) are economically effective since they allow a decrease of about 48.20% and 43.48% in heating, 45.71% and 42.77% in cooling, leading to a reduction in CO<jats:sub>2</jats:sub> emission of 47.90% and 43.40%, respectively, in comparison with the reference case. The investigation also focuses on the improvement of the ecological building envelope by a storage wall integrated on the south front and shaded by solar movable overhangs during the summer season. The indoor climate results reveal that incorporating passive strategies into the building improves indoor air temperature and preserves a comfortable indoor relative humidity. Heating requirements decrease by 82.82% for BAF and by 79.76% for BPOF. The cooling requirements of the reference building are also reduced by 63.46% for BAF and 60.45% for BPOF by the use of natural night ventilation (4 ACH) and the appropriate shading for Trombe walls and windows. Consequently, the implementation of passive strategies on the ecological buildings led to a net reduction in CO<jats:sub>2</jats:sub> emissions by up to 80.55% for BAF, compared to the reference case.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140829133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Specification of a greenhouse in cold climate condition, mathematical model and optimization","authors":"Hosein Faramarzpour, Mohsen Ghaderi, Christopher Reddick, Mikhail Sorin, Michel Grégoire","doi":"10.1177/17442591241240798","DOIUrl":"https://doi.org/10.1177/17442591241240798","url":null,"abstract":"In order to optimize the energy requirements (heating/cooling) of a multi-zone greenhouse, and investigate its heat recovery potential, a mathematical, dynamic energy model, coded in the MATLAB/Simulink platform, is developed. For validation, a case study in cold climate conditions is evaluated. This dynamic model, based on both energy and water vapor mass balances, was able to calculate the year-round monthly energy demand for the case study. The model calculations were compared with actual energy consumption data and were shown to have an accuracy between 6% and 15.5% for different months. The results highlighted the potential of applying a heat recovery strategy, whether with a Phase Change Material (PCM) or a Heat Recovery Ventilator (HRV). It is shown that using a HRV can reduce the energy demand of the greenhouse by 5% for January and 4% for December. Regarding the greenhouse radiation performance, the south roof contributes the most to solar heat gain in winter and summer, while the north wall makes the minimum contribution. Consequently, it is proposed to increase the area of the south roof and insulate the north wall. Thus, an asymmetrical roof configuration can receive 6% more solar radiation. Calculations show that an east-west greenhouse orientation lowers energy demand by 3%.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140671983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental method for estimating the effect of solar radiation on the inner surface heat flux of opaque building envelope elements","authors":"Irati Uriarte, Aitor Erkoreka, Maria Jose Jimenez, Koldo Martin-Escudero, Hans Bloem","doi":"10.1177/17442591241238436","DOIUrl":"https://doi.org/10.1177/17442591241238436","url":null,"abstract":"There still exists a considerable difference when comparing the real and the design energy consumption of buildings. The difference between the design and the real building envelope energy performance is one of its main reasons. The building envelope can be characterised through the individual characterisation of its different building envelope components such as opaque walls or windows. Therefore, the estimation of parameters such as their transmission heat transfer coefficient (UA) and their solar aperture (gA) is usually implemented. Although building components have been analysed over the years, the thermal characteristics of buildings have mainly been estimated through steady-state laboratory tests and simplified calculation/simulation procedures based on theoretical data. The use of inverse modelling based on registered dynamic data has also been used; however, unfortunately, the models used tend to significantly simplify or neglect the solar radiation effect on the inner surface heat flux of opaque building envelope elements. Therefore, this work presents an experimental, dynamic and inverse modelling method that accurately models non-linear phenomena through the use of a user-friendly simulation programme (LORD). The method is able to analyse in detail the effect of the solar radiation on the inner surface heat flux of opaque building envelope elements, without the necessity of knowing their constructive details or thermal properties. The experiment is performed in a fully monitored test box, where different models are tested with different opaque walls to find the best fit. Finally, the solar irradiance signal is removed from the best models so as to accurately quantify the weight of the solar radiation on the inner surface heat flux of each wall for two extreme periods, one for sunny summer days and other for cloudy winter days.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140567901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hygrothermal response of a wood-frame thick-wall assembly to rainwater wetting under future climate scenarios in Canada","authors":"Alison Conroy, Phalguni Mukhopadhyaya, Guido Wimmers","doi":"10.1177/17442591241238621","DOIUrl":"https://doi.org/10.1177/17442591241238621","url":null,"abstract":"Current exterior wall assembly designs for new low-rise residential buildings targeting low-energy demand in heating dominated countries include split-insulation wall and thick-wall assembly designs. Both have been shown to result in thermal efficiency gains compared to building-code minimum assemblies, however long-term hygrothermal performance can vary depending on boundary conditions and the presence of construction deficiencies. Future climate scenarios estimate many heating-dominated climates will experience a reduction in heating-degree day hours and an increase in annual rainfall. Using validated assembly performance data from a Passive House certified facility, a sensitivity analysis is performed to determine the impact of rainwater wetting, air exfiltration and insulation material properties on the hygrothermal response of a thick-wall assembly. Results show that rainwater leakage values of 0.50% and greater of the adhering rainfall on the exterior surface of the assembly results in the greatest risk for failure. The hygrothermal response of the assembly is then examined under a global temperature rise scenario of 3.5°C for five geographic locations across Canada. Results show that an increase in average annual total rainfall does not directly result in an increase in the failure rate of the assembly when a rainwater leak is present. Additional climatic factors, including outdoor air temperature, driving rain and solar radiation received will influence the hygrothermal response of the assembly and need to be considered when modelling the performance under future climate change scenarios.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140567805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}