Journal of Building Physics最新文献_第6页

Characterizing the induced flow through the cavity of a wall solar chimney under the effects of the opening heights 在开孔高度的影响下，研究了壁式太阳能烟囱腔内的诱导流特性

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2022-12-17 DOI: 10.1177/17442591221140465

Y. Nguyen, V. T. Nguyen

{"title":"Characterizing the induced flow through the cavity of a wall solar chimney under the effects of the opening heights","authors":"Y. Nguyen, V. T. Nguyen","doi":"10.1177/17442591221140465","DOIUrl":"https://doi.org/10.1177/17442591221140465","url":null,"abstract":"Using solar chimneys in buildings can enhance the thermal insulation of the building envelope and provide sufficient ventilation and cooling. The performance of a solar chimney is strongly affected by its configurational factors. This work examines the effects of the opening heights on the flow field in the cavity of a wall solar chimney with a Computational Fluid Dynamics (CFD) model. Both cases of equal and unequal opening areas were considered. The results show that the induced flow rate increases with the opening height and gradually becomes constant as the opening height is about 2.0–3.0 and 5.0–6.0 times the air gap for heating the left wall (HLW) and the right wall (HRW) of the air cavity, respectively. Particularly, using equal inlet and outlet heights that are equal to the air gap reduces the flow rate of 27% for HLW and 85% for HRW compared to the maximum ones. The optimal design of a wall solar chimney to achieve maximum flow rate is proposed for two cases of heating, that is, (a) for HLW, equal opening heights which are twice the air gap, and (b) for RHW, the inlet height equal to the air gap, and the outlet height equal to five times the air gap.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"297 1","pages":"630 - 653"},"PeriodicalIF":2.0,"publicationDate":"2022-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73168307","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}

引用次数: 0

Experimental study and numerical analysis of radiative losses of single-channel solar chimney 单通道太阳能烟囱辐射损耗的实验研究与数值分析

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2022-10-20 DOI: 10.1177/17442591221127279

CE Torres-Aguilar, J. Arce, J. Xamán, E. Macias-Melo

{"title":"Experimental study and numerical analysis of radiative losses of single-channel solar chimney","authors":"CE Torres-Aguilar, J. Arce, J. Xamán, E. Macias-Melo","doi":"10.1177/17442591221127279","DOIUrl":"https://doi.org/10.1177/17442591221127279","url":null,"abstract":"Solar chimneys provide natural ventilation for buildings, reducing the energy consumption of mechanical systems. Therefore, analyzing energy losses through solar chimney components and inlet/outlet of air channel is critical to develop a suitable design for this passive ventilation system. In this study, the performance and energy losses analysis of a single-channel solar chimney (SC-SOCH) is described; a parametric study under laboratory conditions was conducted regarding the air gap (0.10, 0.15, and 0.20 m) and heat flux of absorber plate (100, 200, 300, 400, and 500 Wm−2). The energy losses were analyzed with temperature sensors, heat flow transducers, and a net radiation transfer model. The parametric study results showed that between 10% and 15% of the total energy supplied to the absorber plate was dissipated to the laboratory environment through the glass cover. Furthermore, combining the different thermal insulation layers on the backside of the absorber plate and sidewalls of the air channel permitted only energy losses below 8% of the total energy supplied. The highest energy losses occurred due to radiative exchange; the radiative losses through the inlet and outlet of the air channel were between 9.38% and 25.78% of the total energy supplied. However, the radiative energy loss rate decreased as airflow increased; the volumetric flow rate was from 34.11 to 94.92 m3h−1, which was enough to satisfy the requirements of total ventilation rate for spaces of 9, 18, and 36 m2 according to ASHRAE 62.2–2019. Therefore, solar chimney designs must be optimized to minimize energy losses and increase airflow for natural ventilation.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"2 1","pages":"340 - 371"},"PeriodicalIF":2.0,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90088191","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}

引用次数: 2

Multivariate analysis for assessing the thermal performance of vertical opaque envelopes in extended regions 扩展区域垂直不透明信封热性能评估的多变量分析

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2022-10-19 DOI: 10.1177/17442591221127280

L. P. Thomas, B. M. Marino, N. Muñoz

{"title":"Multivariate analysis for assessing the thermal performance of vertical opaque envelopes in extended regions","authors":"L. P. Thomas, B. M. Marino, N. Muñoz","doi":"10.1177/17442591221127280","DOIUrl":"https://doi.org/10.1177/17442591221127280","url":null,"abstract":"We introduce a statistical methodology to evaluate the thermal performance of vertical opaque envelopes and provide the most adequate design of energy-efficient buildings located across extended regions. The analytical procedure was applied to the extensive Argentinian territory with a variety of climates and a limited number of networked meteorological stations. Although the study was conducted over a full year, results are presented for January and June, when the building energy demand for heating and cooling is most significant, taking into account the local climate, the thermal properties of the walls and the effects of the daily variation in the solar radiation. By using the Fourier series expansion of the sol-air temperature and multivariate analysis, we first correlated the weather data and the steady-state and time-dependent heat fluxes transmitted by conduction through five types of typical walls facing north and south in 10 climatically differentiated cities where full weather data were recorded. Then, the mean values of the sol-air temperature and the amplitude of its time variations were interpolated throughout the territory, thus yielding the spatial distributions of these parameters for a typical day in the months of interest. Finally, the calculation of the heat fluxes exchanged through building opaque envelopes was extended to the whole country.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"7 1","pages":"259 - 291"},"PeriodicalIF":2.0,"publicationDate":"2022-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78953839","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}

引用次数: 1

Study on influence of geometric characteristics of cracks on HAM coupling transfer and thermal performance of multi-layer cellular concrete wall 裂缝几何特征对多层多孔混凝土墙体HAM耦合传递及热工性能的影响研究

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2022-09-30 DOI: 10.1177/17442591221121918

Jiashuai Wei, Shui Yu, Xiaoting Zhou

{"title":"Study on influence of geometric characteristics of cracks on HAM coupling transfer and thermal performance of multi-layer cellular concrete wall","authors":"Jiashuai Wei, Shui Yu, Xiaoting Zhou","doi":"10.1177/17442591221121918","DOIUrl":"https://doi.org/10.1177/17442591221121918","url":null,"abstract":"The effect of concrete cracks on the evaluation of the thermal performance of walls has not been effectively considered within the assessment of the thermal and hygroscopic performance of buildings. Based on the dual permeability model, a conjugate method is proposed to reconstruct the PDE equation of unsaturated porous materials with cracks. The reliability of the model is verified from three angles: the heat-moisture coupling benchmark of matrix material, the analytical solution of two-dimensional single fracture heat flow coupling problem and the moisture absorption problem of unsaturated cracks. The reliability of the model is verified from three perspectives: the benchmark of thermal and hygroscopic coupling of matrix materials, the analytical solution to the two-dimensional single-break thermal flow coupling problem, and the hygroscopic problem of unsaturated cracks. The effect of heat and moisture transfer in cracked concrete was quantified by detailed modeling of cracks in terms of the probability of over-penetration, crack roughness, crack density, length, and angle of a two-dimensional discrete crack network, showing that cracks contribute to moisture transfer. This is followed by a 10 day experimental simulation of the meteorological environment, comparing the quantities of moisture accumulation, thermal performance, internal surface temperature and humidity within the fractured and non-fractured wall structures, illustrating the potential adverse effects of cracks on thermal performance and moisture transfer in walls under characteristic conditions. Finally, the necessity of applying moisture-proof layer to the damaged wall is demonstrated by comparing the results before and after the application of the moisture-proof layer.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"40 1","pages":"292 - 339"},"PeriodicalIF":2.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84628116","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}

引用次数: 1

Sustainable thermo-acoustical insulation material from cardboard waste and natural fibers: Elaboration and performance evaluation 从纸板废料和天然纤维中提取的可持续热声隔热材料:细化和性能评价

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2022-09-21 DOI: 10.1177/17442591221121924

Mohamed Ouakarrouch, N. Laaroussi, M. Garoum, Said Bousshine, A. Bybi, Abderrahim Benallel, A. Tilioua

{"title":"Sustainable thermo-acoustical insulation material from cardboard waste and natural fibers: Elaboration and performance evaluation","authors":"Mohamed Ouakarrouch, N. Laaroussi, M. Garoum, Said Bousshine, A. Bybi, Abderrahim Benallel, A. Tilioua","doi":"10.1177/17442591221121924","DOIUrl":"https://doi.org/10.1177/17442591221121924","url":null,"abstract":"The main objective of this paper is to elaborate and characterize new ecological composites based on cardboard waste and abandoned natural fibers, in the Drâa-Tafilalet region (South-East, Morocco), for the manufacture of local thermo-acoustical insulation panels. For this study, 25 samples were prepared by mixing 60% of cardboard waste and 40% of vegetable fibers (Reed tree, esparto fiber, fig tree, and Olive tree). The morphological analysis of the different fibers was carried out by scanning electron microscopy (SEM), while, the physical, thermal, and acoustical properties of samples were measured experimentally using standard methods. The experimental results showed that all new composites have better thermal and acoustical performances comparable to those of synthetic insulation materials. The density, thermal conductivity, thermal diffusivity, and sound absorption coefficient of those composites were in the range of 278.6–343.8 kg/m3; 0.072–0.10 W/m·K; 1254.5–1807.5 J/kg·K; 0.4–0.8, respectively. Consequently, the by-products recovered in this study are good candidates for the development of local insulation materials with useful properties for thermal and acoustical insulation applications in buildings, low environmental impact, low cost, and competition with commercialized synthetic insulation materials.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"12 1","pages":"372 - 392"},"PeriodicalIF":2.0,"publicationDate":"2022-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78180680","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}

引用次数: 1

Drainage of infiltrated rainwater in wall assemblies: Test method, experimental quantification, and recommendations 墙组件中渗透雨水的排水:测试方法、实验量化和建议

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2022-09-01 DOI: 10.1177/17442591221121932

S. Van Linden, M. Lacasse, N. Van Den Bossche

{"title":"Drainage of infiltrated rainwater in wall assemblies: Test method, experimental quantification, and recommendations","authors":"S. Van Linden, M. Lacasse, N. Van Den Bossche","doi":"10.1177/17442591221121932","DOIUrl":"https://doi.org/10.1177/17442591221121932","url":null,"abstract":"Drainage reduces the amount of water able to infiltrate toward the interior of wall assemblies. However, a portion of the infiltrated water remains in the assembly after drainage has occurred. The degree to which this retained portion of water affects the durability of the wall assembly can be evaluated by means of hygrothermal simulations. However, the number of studies reporting information on the retention percentage that can be applied as input for hygrothermal simulations and on the drainage performance of wall assemblies is, in general, quite limited. Therefore, an experimental study was developed, to assess governing test methods to evaluate drainage characteristics and to quantify retention of water in wall test specimens having various cavity widths and incorporating different drainage materials. It was concluded that apart from the absolute amount of retained water, the lateral spreading of water in the cavity and the overall wetted area, should also be considered, thereby resulting in reporting the retained amount relative to the wetted area. The latter values provide more detailed information on the behavior of water in the cavity. Additionally, it was concluded that a clear cavity of 1 mm can drain water more efficiently than a cavity of 10 mm. As well, the surface texture of drainage materials affected the spreading and retention of water within the cavity and the use of a drainage mat in the cavity resulted in an increased relative retention but a reduced lateral spreading of the water.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"43 1","pages":"1022 - 1056"},"PeriodicalIF":2.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77662761","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}

引用次数: 0

Hygrothermal performance of highly insulated external walls subjected to indoor air exfiltration 受室内空气泄漏影响的高绝热外墙的湿热性能

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2022-08-10 DOI: 10.1177/17442591221109956

Klaus Viljanen, J. Puttonen, Xiaoshu Lü

{"title":"Hygrothermal performance of highly insulated external walls subjected to indoor air exfiltration","authors":"Klaus Viljanen, J. Puttonen, Xiaoshu Lü","doi":"10.1177/17442591221109956","DOIUrl":"https://doi.org/10.1177/17442591221109956","url":null,"abstract":"The study comprises three laboratory tests in which typical Finnish highly insulated (HI) walls were exposed to concentrated leakages of indoor air under steady outdoor temperatures of 1–5°C. Airflows with a relative humidity of 50% and at rates of 1–3 L/min were directed close to the wooden frames inside the walls. The thermal resistance ratios between the exterior sheathing(s) and the whole wall (Γ) were 20%–22% and 1%–10% for the HI and baseline (BL) walls. The HI walls that presented Γ values of at least 20% were observed to be resistant to air exfiltration, and their durability was not affected by the addition of a gypsum sheathing outside the wooden frame or a more permeable vapor retarder. This is related to the negative linear correlation that exists between the moisture accumulation rate in wood-based material and the dew point depression (DPD) value. The developed approach, called the DPD method, shows that a significant degree of moisture accumulation does not occur even for DPD values of as low as −2°C if the exterior sheathing is vapor permeable. The airflow does not penetrate into the rigid mineral wool sheathing, which helps to avoid interstitial condensation. Regardless of thermal transmittance, the HI and BL walls with maximum Γ values of 1% were exposed to a high relative humidity and even interstitial condensation because the DPD values were often below −2°C. For these walls, the mold index analysis and visual observations confirmed the local risk for mold growth on the opposite side of the leakage point. In practice, long-term mold growth may be limited if the seasonal periods during which the outdoor temperature is 1–5°C last for a maximum of about 1 month every year.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"9 1","pages":"967 - 1021"},"PeriodicalIF":2.0,"publicationDate":"2022-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84221839","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}

引用次数: 0

Didactic device for teaching the importance of the time-dependent model for heat transfer calculations in constructive systems of buildings 用于讲授建筑构造系统中传热计算时相关模型重要性的教学装置

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2022-05-15 DOI: 10.1177/17442591221093057

G. Ramírez-Zúñiga, Guillermo Barrios, Guadalupe Huelsz Lesbros, Vanessa Sattele

引用次数: 0

On the potential of clustering approaches for hygrothermal material properties based on three degradation risks in solid masonry constructions 基于固体砌体结构中三种退化风险的湿热材料性能聚类方法的潜力

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2022-04-20 DOI: 10.1177/17442591221085734

Bruno Vanderschelden, Klaas Calle, N. Van Den Bossche

{"title":"On the potential of clustering approaches for hygrothermal material properties based on three degradation risks in solid masonry constructions","authors":"Bruno Vanderschelden, Klaas Calle, N. Van Den Bossche","doi":"10.1177/17442591221085734","DOIUrl":"https://doi.org/10.1177/17442591221085734","url":null,"abstract":"Historic masonry has a rich and colorful history making it a treasured part in our society. To preserve and protect this heritage, adequate moisture control, retrofit, and restauration strategies are required. However, due to the large range of material properties inherent to historic brickwork, a single uniform renovation strategy appears impossible. To describe similarity in brickwork, the existing clustering approach developed by Zhao was evaluated. The idea is that different types of bricks with similar properties can be represented by a single representative brick for that cluster, for example, when conducting hygrothermal simulations. It could help improve existing retrofit practice by reducing characterization processes and minimizing time-consuming laboratory measuring tests. However, in this paper the approach presented by Zhao is questioned since the clustering is solely based on an equal impact of the material properties and the response behavior and associated degradation risks are neglected. The aim of this paper was twofold. Firstly, similarity in brickwork obtained by clustering according to Zhao was evaluated by means of hygrothermal simulations to see whether bricks in the same cluster show similar degradation risks. Zhao’s clustering provides homogenous clusters regarding physical material properties, but significant variation was found in degradation risks for different bricks within the same cluster. Secondly, a methodology is presented to translate similarities in degradation profiles toward similarities in material properties. Sensitivity analyses were used to study the response behavior based on three degradations risks: mold growth, wood rot, and frost damage. Finally, an overall clustering scheme was generated for brickwork, based on classification trees for different degradation phenomena.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"25 1","pages":"882 - 922"},"PeriodicalIF":2.0,"publicationDate":"2022-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77567116","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}

引用次数: 4

Analysis of condensation and ventilation phenomena for double skin façade units 双层幕墙空调冷凝通风现象分析

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2022-04-12 DOI: 10.1177/17442591221084351

Francesco Squadroni, Giuseppe De Michele, E. Mazzucchelli, I. Demanega, S. Mangialardo, S. Avesani

{"title":"Analysis of condensation and ventilation phenomena for double skin façade units","authors":"Francesco Squadroni, Giuseppe De Michele, E. Mazzucchelli, I. Demanega, S. Mangialardo, S. Avesani","doi":"10.1177/17442591221084351","DOIUrl":"https://doi.org/10.1177/17442591221084351","url":null,"abstract":"This paper presents a study of the thermo-hygrometric behaviour of a Double Skin Façade (DSF) unit. The study aims (i) at comparing currently used calculation procedures according to European and American standards (UNI EN ISO 10077, UNI EN ISO 12631:2018, ISO 15099:2003, ANSI/NFRC 100 for the thermal performance and ISO 13788:2012 (2012) for the condensation risk), and (ii) at assessing the 2D hygrothermal performance of a double skin module through a Finite Element Method (FEM)-based model. According to the current standards, a detailed characterization of thermal and fluid dynamic phenomena in closed and ventilated cavities is neglected and a simplified approach is proposed, which tends to overestimate the overall U-value of the curtain wall (UCW) due to an incremental thermal resistance that depends on the thickness of the air gap layer and the level of ventilation. The potential risk of this simplification is that the DSF estimated design performance, whilst complying with regulatory requirements, present inconsistencies respect to the real behaviour, impacting energy, comfort, material degradation, etc. Accurate assessments could be done already during design through detailed FEM multi-physic analyses. Nevertheless, those require a specific knowledge, are cost and time-consuming. As a first step, this study focuses on comparing the normed calculation approach for the design, against a detailed FEM-based multi-physics methodology. Specifically, this couples CFD, hygrothermal and Ray Tracing physics in a tool for the calculation of thermal transmittance, g-value and relative humidity of a DSF with a customizable geometry. As a second step, given a real DSF unit that showed unforeseen phenomena of surface condensation inside the cavity during several hours in spring and autumn, the multi-physic tool has been used to evaluate the condensation risk with the current and modified DSF design, under static and time-dependent boundary conditions. Graphical abstract","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"48 7 1","pages":"1057 - 1090"},"PeriodicalIF":2.0,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88418037","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}

引用次数: 0