Journal of Building Physics最新文献_第8页

Influence of variability in hygrothermal properties on analytical results of simultaneous heat and moisture transfer in porous materials 湿热特性变化对多孔材料热湿同步传递分析结果的影响

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2021-10-20 DOI: 10.1177/17442591211034194

Hiroaki Yamamoto, S. Takada

{"title":"Influence of variability in hygrothermal properties on analytical results of simultaneous heat and moisture transfer in porous materials","authors":"Hiroaki Yamamoto, S. Takada","doi":"10.1177/17442591211034194","DOIUrl":"https://doi.org/10.1177/17442591211034194","url":null,"abstract":"Depending on the data source used, the material hygrothermal properties that are used in the numerical analysis of simultaneous heat and moisture transfer will not be consistent. Differences in measurement methods and the individuality of specimens account for this. It is necessary to choose values from these different physical property sets to conduct a numerical calculation, which can cause the calculated results to differ. The subsequent range of variation in the calculated results should be quantitatively evaluated. In this study, the physical properties of several types of porous building materials were first gathered from four databases. The data were then categorized based on the kind of material and compared in terms of each physical property (density, porosity, specific heat, moisture capacity, thermal conductivity, and vapor permeability). The density, porosity, and specific heat varied by 10% on average, and the moisture capacity, thermal conductivity, and vapor permeability varied by 20% or more for all types of materials. In particular, the vapor permeability of plywood and moisture capacity of gypsum board differed by 50%. The influence that these physical property value variations had on hygrothermal calculation results was then quantitatively demonstrated for moisture and heat flow rate under a step change in the relative humidity or temperature of indoor air for a single layer wall. The moisture and heat flow rate into a single layer wall fluctuated by approximately 10%–40% due to differences in the vapor permeability and moisture capacity of the materials. For all types of materials, moisture was transferred more slowly than heat. Therefore, differences in moisture property values, such as vapor permeability and moisture capacity, influenced the results more significantly. Moreover, the moisture flow was accompanied by a phase change. The differences in moisture property values thus affected the heat flow.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"105 1","pages":"757 - 773"},"PeriodicalIF":2.0,"publicationDate":"2021-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80944954","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

Investigation into the hygrothermal behavior of fired clay materials during the freezing of supercooled water using experiments and numerical simulations 用实验和数值模拟研究了烧制粘土材料在过冷水冻结过程中的湿热行为

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2021-10-05 DOI: 10.1177/17442591211041144

Kazuma Fukui, C. Iba, M. Taniguchi, Kouichi Takahashi, D. Ogura

{"title":"Investigation into the hygrothermal behavior of fired clay materials during the freezing of supercooled water using experiments and numerical simulations","authors":"Kazuma Fukui, C. Iba, M. Taniguchi, Kouichi Takahashi, D. Ogura","doi":"10.1177/17442591211041144","DOIUrl":"https://doi.org/10.1177/17442591211041144","url":null,"abstract":"In this study, supercooling effects on the hygrothermal behavior of fired clay materials under various experimental conditions, such as water content, cooling rates, and size of specimens were investigated using experimental methods and hygrothermal simulations. We report results of the differential scanning calorimetry (DSC) and temperature distribution changes during a freeze–thaw (FT) experiment using unsaturated specimens. Also, we developed a numerical model of the freezing and thawing processes including the supercooling processes. The DSC results show the freezing of the supercooled water in a fired clay material is considerably faster than that in cement-based materials. It was also found that the dependency of the supercooling effects on the cooling rates seemed to be small. When the water saturation of a material decreases, the rate of the ice saturation increase during the freezing of the supercooled water is decreased while the freezing points of the supercooled water was not changed considerably. The comparison of the results of the FT experiment and hygrothermal simulations show that the combination of the existed hygrothermal model and a modified kinetic equation can reproduce the rapid temperature rise during the freezing of the supercooling water in the FT experiment. Finally, the size effects of specimens on the supercooling phenomenon was discussed based on the experimental and calculation results. The freezing points got higher when a specimen was larger. Due to differences in the ratio of the surface area to the volume, hygrothermal behavior in small specimens and relatively large specimens like that of the DSC and the FT experiment, respectively were markedly different. Water in a relatively large specimen with a small ratio of surface area to volume can achieve the thermodynamic equilibrium in a short period after the freezing starts.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"22 1","pages":"723 - 756"},"PeriodicalIF":2.0,"publicationDate":"2021-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81578764","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

Adaptive opaque façades and their potential to reduce thermal energy use in residential buildings: A simulation-based evaluation 自适应不透明外墙及其在住宅建筑中减少热能使用的潜力:基于模拟的评估

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2021-09-27 DOI: 10.1177/17442591211045418

M. Juaristi, F. Favoino, T. Gómez-Acebo, Aurora Monge-Barrio

{"title":"Adaptive opaque façades and their potential to reduce thermal energy use in residential buildings: A simulation-based evaluation","authors":"M. Juaristi, F. Favoino, T. Gómez-Acebo, Aurora Monge-Barrio","doi":"10.1177/17442591211045418","DOIUrl":"https://doi.org/10.1177/17442591211045418","url":null,"abstract":"Adaptive façades are a promising choice to achieve comfortable low-energy buildings. Their effective performance is highly dependent on the local boundary conditions of each application and on the way the dynamic properties are controlled. The evaluation of whole building performance through building performance simulation can be useful to understand the potential of different Adaptive opaque façades (AOF) in a specific context. This paper evaluates through dynamic simulations promising design solutions of AOF for a residential building use in six different climates. It quantifies the total delivered thermal energy of 15 typologies of AOFs which consist of alternative adaptation strategies: (i) variation of solar absorptance of the cladding, (ii) variation of the convective heat transfer of air cavities and (iii) adaptive insulation strategies. For the first time, it also quantifies the performance of AOF which combine more than one adaptation strategy. The results show that the variation of the heat transfer by means of Adaptive Insulation components has the most significant impact on the reduction of the thermal energy use. The variation of the solar absorptance has also a significant positive impact when reducing heating consumption, but only if this adaptation strategy is actively controlled and combined with Adaptive Insulation components.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"22 1","pages":"675 - 720"},"PeriodicalIF":2.0,"publicationDate":"2021-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77278443","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

Experimental comparison of summer thermal performance of green roof (GR), double skin roof (DSR) and cool roof (CR) in lightweight rooms in subtropical climate 亚热带气候下轻型房间绿色屋顶(GR)、双层屋面(DSR)和冷屋面(CR)夏季热性能的试验比较

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2021-09-19 DOI: 10.1177/17442591211040545

Erlin Meng, Jiawang Yang, Ruonan Cai, Bo Zhou, Junqi Wang

{"title":"Experimental comparison of summer thermal performance of green roof (GR), double skin roof (DSR) and cool roof (CR) in lightweight rooms in subtropical climate","authors":"Erlin Meng, Jiawang Yang, Ruonan Cai, Bo Zhou, Junqi Wang","doi":"10.1177/17442591211040545","DOIUrl":"https://doi.org/10.1177/17442591211040545","url":null,"abstract":"Subtropical climate is characterized by high solar altitude angle in summer which causes the roof get more heat through solar radiation. GR, DSR, and CR all can decrease solar radiation heat gain of the roof. However, few researches have been done to the comparison of the thermal performance of these three roofs, especially in subtropical climate. In this study, four rooms were built separately with GR, DSR, CR, and ordinary roof (OR). The experiment was done from July 23 to August 4. Results showed that stabilities of the indoor air temperature of the four rooms were: DSR room > GR room > CR room > OR room. The GR, CR, and DSR can reduce the external surface temperature by 13.7°C, 12.0°C, and 4.8°C during the day while bring a temperature rise of 2.3°C, 1.9°C, and 0.9°C at night. Correlation analysis results showed that the internal surface heat flux of GR and DSR were negative correlated with weather factors while internal surface heat flux of OR and CR were positive correlated with weather factors. This study can give support to the selection between GR, DSR, and CR.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"50 1","pages":"809 - 832"},"PeriodicalIF":2.0,"publicationDate":"2021-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74209681","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: 3

Temperature dependency of the long-term thermal conductivity of spray polyurethane foam 喷涂聚氨酯泡沫长期导热系数的温度依赖性

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2021-09-15 DOI: 10.1177/17442591211045415

N. Holcroft

{"title":"Temperature dependency of the long-term thermal conductivity of spray polyurethane foam","authors":"N. Holcroft","doi":"10.1177/17442591211045415","DOIUrl":"https://doi.org/10.1177/17442591211045415","url":null,"abstract":"The thermal properties of closed-cell foam insulation display a more complex behaviour than other construction materials due to the properties of the blowing agent captured in their cellular structure. Over time, blowing agent diffuses out from and air into the cellular structure resulting in an increase in thermal conductivity, a process that is temperature dependent. Some blowing agents also condense at temperatures within the in-service range of the insulation, resulting in non-linear temperature dependent relationships. Moreover, diffusion of moisture into the cellular structure increases thermal conductivity. Standards exist to quantify the effect of gas diffusion on thermal conductivity, however only at standard laboratory conditions. In this paper a new test procedure is described that includes calculation methods to determine Temperature Dependent Long-Term Thermal Conductivity (LTTC(T)) functions for closed-cell foam insulation using as a test material, a Medium-Density Spray Polyurethane Foam (MDSPF). Tests results are provided to show the validity of the method and to investigate the effects of both conditioning and mean test temperature on change in thermal conductivity. In addition, testing was conducted to produce a moisture dependent thermal conductivity function. The resulting functions were used in hygrothermal simulations to assess the effect of foam aging, in-service temperature and moisture content on the performance of a typical wall assembly incorporating MDSPF located in four Canadian climate zones. Results show that after 1 year, mean thermal conductivity increased 15%–16% and after 5 years 23%–24%, depending on climate zone. Furthermore, the use of the LTTC(T) function to calculate the wall assembly U-value improved accuracy between 3% and 5%.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"20 1","pages":"571 - 603"},"PeriodicalIF":2.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80400122","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

Evaluation of methods for prediction of evaporation from water pools 水池蒸发预报方法的评价

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2021-07-26 DOI: 10.1177/17442591211034193

M. Shah

引用次数: 5

Smart wetting of permeable pavements as an evaporative-cooling measure for improving the urban climate during heat waves 可渗透路面的智能润湿作为一种蒸发冷却措施，在热浪期间改善城市气候

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2021-07-01 DOI: 10.1177/1744259120968586

A. Kubilay, A. Ferrari, D. Derome, J. Carmeliet

{"title":"Smart wetting of permeable pavements as an evaporative-cooling measure for improving the urban climate during heat waves","authors":"A. Kubilay, A. Ferrari, D. Derome, J. Carmeliet","doi":"10.1177/1744259120968586","DOIUrl":"https://doi.org/10.1177/1744259120968586","url":null,"abstract":"An urban microclimate model is used to design a smart wetting protocol for multilayer street pavements in order to maximize the evaporative cooling effect as a mitigation measure for thermal discomfort during heat waves. The microclimate model is built upon a computational fluid dynamics (CFD) model for solving the turbulent air, heat and moisture flow in the air domain of a street canyon. The CFD model is coupled to a model for heat and moisture transport in porous urban materials and to a radiative exchange model, determining the net solar and thermal radiation on each urban surface. A two-layer pavement system, previously optimized for maximal evaporative cooling applying the principles of capillary pumping and capillary break, is considered to design a smart wetting protocol answering the questions “when,” “how much,” and “how long” a pavement should be artificially wetted. It was found for the current optimized pavement solutions that a daily amount of 6 mm wetting over 10 min in the morning, preferentially between 8:00 and 10:00, guarantees a maximal evaporative cooling for 24 h during a heat wave.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"190 1","pages":"36 - 66"},"PeriodicalIF":2.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79756799","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: 19

Experiential learning in building physics: The icebox challenge 建筑物理中的体验式学习:冰箱挑战

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2021-05-26 DOI: 10.1177/17442591211017948

R. McLeod, C. Hopfe

引用次数: 2

Dependence of gas permeation and adsorption on temperature in vacuum insulation panels (VIPs) containing getter materials 含吸气剂真空绝热板中气体渗透和吸附对温度的依赖性

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2021-05-26 DOI: 10.1177/17442591211017154

Hideya Yamamoto, D. Ogura

{"title":"Dependence of gas permeation and adsorption on temperature in vacuum insulation panels (VIPs) containing getter materials","authors":"Hideya Yamamoto, D. Ogura","doi":"10.1177/17442591211017154","DOIUrl":"https://doi.org/10.1177/17442591211017154","url":null,"abstract":"Vacuum insulation panels (VIPs) with a glass-fiber core has been considered to be difficult to operate for a long period of time, such as for building applications, because the thermal conductivity rises rapidly as the pressure increases. However, glass-fiber-core VIPs contain a material called a getter that continuously adsorbs permeated gas, and a theoretical model that considers the properties of the getter has not yet been developed. In this paper, the gas-adsorption mechanism by getters was investigated and a long-term-performance prediction model that considers the temperature dependence was proposed. Some gases were not adsorbed by the getter in the VIPs; however, a model was proposed that takes into account the non-absorbed gases by applying partial pressure to the adsorption isotherm in advance. The long-term performance of VIPs with different areas and volumes was compared with the measured values, and the validity of the calculation results was confirmed. These results show that the long-term performance of VIPs of different sizes can be accurately predicted when the getter performance is well understood.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"106 1","pages":"604 - 628"},"PeriodicalIF":2.0,"publicationDate":"2021-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89169590","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: 6

Effect of north wall internal surface structure on heat storage-release performance and thermal environment of Chinese solar greenhouse 北墙内表面结构对中国日光温室蓄热释放性能及热环境的影响

IF 2 4区工程技术

Journal of Building Physics Pub Date : 2021-05-10 DOI: 10.1177/17442591211013449

Yiming Li, Xiang Yue, Lei Zhao, Huiyun Xu, Xingan Liu, T. Li

{"title":"Effect of north wall internal surface structure on heat storage-release performance and thermal environment of Chinese solar greenhouse","authors":"Yiming Li, Xiang Yue, Lei Zhao, Huiyun Xu, Xingan Liu, T. Li","doi":"10.1177/17442591211013449","DOIUrl":"https://doi.org/10.1177/17442591211013449","url":null,"abstract":"Chinese solar greenhouse (CSG) is an energy-saving agricultural building which is used to grow vegetables in winter. The north wall of CSG plays an crucial role in concerning the production yield and quality during the winter months. To improve the thermal performance of north wall, different internal surface structures (ISS) with same materials were compared. Based on the field experiment and the proposed valuation, the dynamic heat storage-release characteristics of the north walls have been analyzed and discussed. The results showed that compared with the flat wall and the striped wall, the alveolate wall has better properties of heat storage and thermal insulation. Moreover, relative humidity in this type of greenhouse is more suitable for growing crops. The alveolate wall can improve indoor thermal environment and reduce the sensitivity to external environment. The obtained results can provide a basis for the scientific construction of the CSG north wall. It has significant potential for the area in high latitude, high altitude and long winter.","PeriodicalId":50249,"journal":{"name":"Journal of Building Physics","volume":"30 1","pages":"507 - 527"},"PeriodicalIF":2.0,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84715099","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