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  Subjects -> ENGINEERING (Total: 2282 journals)
    - CHEMICAL ENGINEERING (192 journals)
    - CIVIL ENGINEERING (186 journals)
    - ELECTRICAL ENGINEERING (102 journals)
    - ENGINEERING (1204 journals)
    - ENGINEERING MECHANICS AND MATERIALS (385 journals)
    - HYDRAULIC ENGINEERING (55 journals)
    - INDUSTRIAL ENGINEERING (68 journals)
    - MECHANICAL ENGINEERING (90 journals)

CIVIL ENGINEERING (186 journals)                     

Showing 1 - 186 of 186 Journals sorted alphabetically
ACI Structural Journal     Full-text available via subscription   (Followers: 17)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 2)
Acta Structilia : Journal for the Physical and Development Sciences     Open Access   (Followers: 2)
Advances in Civil Engineering     Open Access   (Followers: 34)
Advances in Structural Engineering     Full-text available via subscription   (Followers: 27)
Ambiente Construído     Open Access   (Followers: 1)
American Journal of Civil Engineering and Architecture     Open Access   (Followers: 30)
Architectural Engineering     Open Access   (Followers: 4)
Archives of Civil and Mechanical Engineering     Full-text available via subscription   (Followers: 1)
Archives of Civil Engineering     Open Access   (Followers: 10)
Archives of Hydro-Engineering and Environmental Mechanics     Open Access   (Followers: 1)
ATBU Journal of Environmental Technology     Open Access   (Followers: 3)
Australian Journal of Structural Engineering     Full-text available via subscription   (Followers: 6)
Baltic Journal of Road and Bridge Engineering     Full-text available via subscription   (Followers: 1)
BER : Building and Construction : Full Survey     Full-text available via subscription   (Followers: 9)
BER : Building Contractors' Survey     Full-text available via subscription   (Followers: 4)
BER : Building Sub-Contractors' Survey     Full-text available via subscription   (Followers: 3)
BER : Survey of Business Conditions in Building and Construction : An Executive Summary     Full-text available via subscription   (Followers: 4)
Berkeley Planning Journal     Open Access   (Followers: 7)
Bioinspired Materials     Open Access   (Followers: 5)
Bridge Structures : Assessment, Design and Construction     Hybrid Journal   (Followers: 15)
Building and Environment     Hybrid Journal   (Followers: 15)
Building Women     Full-text available via subscription  
Built Environment Project and Asset Management     Hybrid Journal   (Followers: 15)
Bulletin of Pridniprovsk State Academy of Civil Engineering and Architecture     Open Access   (Followers: 6)
Canadian Journal of Civil Engineering     Hybrid Journal   (Followers: 11)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 8)
Case Studies in Nondestructive Testing and Evaluation     Open Access   (Followers: 10)
Case Studies in Structural Engineering     Open Access   (Followers: 9)
Cement and Concrete Composites     Hybrid Journal   (Followers: 17)
Challenge Journal of Concrete Research Letters     Open Access   (Followers: 2)
Challenge Journal of Structural Mechanics     Open Access   (Followers: 5)
Change Over Time     Full-text available via subscription   (Followers: 2)
Civil and Environmental Engineering     Open Access   (Followers: 7)
Civil And Environmental Engineering Reports     Open Access   (Followers: 5)
Civil and Environmental Research     Open Access   (Followers: 19)
Civil Engineering = Siviele Ingenieurswese     Full-text available via subscription   (Followers: 4)
Civil Engineering and Architecture     Open Access   (Followers: 17)
Civil Engineering and Environmental Systems     Hybrid Journal   (Followers: 3)
Civil Engineering and Technology     Open Access   (Followers: 9)
Civil Engineering Dimension     Open Access   (Followers: 8)
Cohesion and Structure     Full-text available via subscription   (Followers: 2)
Composite Structures     Hybrid Journal   (Followers: 258)
Computer-aided Civil and Infrastructure Engineering     Hybrid Journal   (Followers: 10)
Computers & Structures     Hybrid Journal   (Followers: 36)
Concrete Research Letters     Open Access   (Followers: 6)
Construction Economics and Building     Open Access   (Followers: 2)
Construction Engineering     Open Access   (Followers: 8)
Construction Management and Economics     Hybrid Journal   (Followers: 21)
Construction Science     Open Access   (Followers: 4)
Constructive Approximation     Hybrid Journal  
Curved and Layered Structures     Open Access   (Followers: 2)
DFI Journal : The Journal of the Deep Foundations Institute     Hybrid Journal   (Followers: 1)
Earthquake Engineering and Structural Dynamics     Hybrid Journal   (Followers: 16)
Enfoque UTE     Open Access   (Followers: 4)
Engineering Project Organization Journal     Hybrid Journal   (Followers: 7)
Engineering Structures     Hybrid Journal   (Followers: 13)
Engineering Structures and Technologies     Hybrid Journal   (Followers: 2)
Engineering, Construction and Architectural Management     Hybrid Journal   (Followers: 14)
Environmental Geotechnics     Hybrid Journal   (Followers: 5)
European Journal of Environmental and Civil Engineering     Hybrid Journal   (Followers: 8)
Fatigue & Fracture of Engineering Materials and Structures     Hybrid Journal   (Followers: 16)
Frattura ed Integrità Strutturale : Fracture and Structural Integrity     Open Access  
Frontiers in Built Environment     Open Access  
Frontiers of Structural and Civil Engineering     Hybrid Journal   (Followers: 6)
Geomaterials     Open Access   (Followers: 4)
Geosystem Engineering     Hybrid Journal   (Followers: 1)
Geotechnik     Hybrid Journal   (Followers: 3)
Géotechnique Letters     Hybrid Journal   (Followers: 6)
HBRC Journal     Open Access   (Followers: 2)
Hormigón y Acero     Full-text available via subscription  
HVAC&R Research     Hybrid Journal  
Indoor and Built Environment     Hybrid Journal   (Followers: 2)
Infrastructure Asset Management     Hybrid Journal   (Followers: 2)
Infrastructures     Open Access  
Ingenio Magno     Open Access   (Followers: 1)
Insight - Non-Destructive Testing and Condition Monitoring     Full-text available via subscription   (Followers: 22)
International Journal for Service Learning in Engineering     Open Access  
International Journal of 3-D Information Modeling     Full-text available via subscription   (Followers: 3)
International Journal of Advanced Structural Engineering     Open Access   (Followers: 16)
International Journal of Civil, Mechanical and Energy Science     Open Access   (Followers: 1)
International Journal of Concrete Structures and Materials     Open Access   (Followers: 13)
International Journal of Condition Monitoring     Full-text available via subscription   (Followers: 2)
International Journal of Construction Engineering and Management     Open Access   (Followers: 8)
International Journal of Geo-Engineering     Open Access   (Followers: 3)
International Journal of Geosynthetics and Ground Engineering     Full-text available via subscription   (Followers: 4)
International Journal of Masonry Research and Innovation     Hybrid Journal   (Followers: 1)
International Journal of Pavement Research and Technology     Open Access   (Followers: 4)
International Journal of Protective Structures     Hybrid Journal   (Followers: 6)
International Journal of Steel Structures     Hybrid Journal   (Followers: 2)
International Journal of Structural Engineering     Hybrid Journal   (Followers: 10)
International Journal of Structural Integrity     Hybrid Journal   (Followers: 2)
International Journal of Structural Stability and Dynamics     Hybrid Journal   (Followers: 7)
International Journal of Sustainable Built Environment     Open Access   (Followers: 4)
International Journal of Sustainable Construction Engineering and Technology     Open Access   (Followers: 8)
International Journal on Pavement Engineering & Asphalt Technology     Open Access   (Followers: 6)
International Journal Sustainable Construction & Design     Open Access  
Journal of Bridge Engineering     Full-text available via subscription   (Followers: 15)
Journal of Building Engineering     Hybrid Journal   (Followers: 1)
Journal of Building Materials and Structures     Open Access   (Followers: 2)
Journal of Building Performance Simulation     Hybrid Journal   (Followers: 6)
Journal of Civil Engineering and Construction Technology     Open Access   (Followers: 11)
Journal of Civil Engineering and Management     Hybrid Journal   (Followers: 7)
Journal of Civil Engineering and Science     Open Access   (Followers: 7)
Journal of Civil Engineering Research     Open Access   (Followers: 6)
Journal of Civil Society     Hybrid Journal   (Followers: 3)
Journal of Civil Structural Health Monitoring     Hybrid Journal   (Followers: 4)
Journal of Composites for Construction     Full-text available via subscription   (Followers: 13)
Journal of Computing in Civil Engineering     Full-text available via subscription   (Followers: 24)
Journal of Construction Engineering     Open Access   (Followers: 7)
Journal of Construction Engineering and Management     Full-text available via subscription   (Followers: 19)
Journal of Construction Engineering, Technology & Management     Full-text available via subscription   (Followers: 4)
Journal of Constructional Steel Research     Hybrid Journal   (Followers: 8)
Journal of Earth Sciences and Geotechnical Engineering     Open Access   (Followers: 4)
Journal of Fluids and Structures     Hybrid Journal   (Followers: 6)
Journal of Frontiers in Construction Engineering     Open Access   (Followers: 2)
Journal of Green Building     Full-text available via subscription   (Followers: 11)
Journal of Highway and Transportation Research and Development (English Edition)     Full-text available via subscription   (Followers: 12)
Journal of Infrastructure Systems     Full-text available via subscription   (Followers: 21)
Journal of Legal Affairs and Dispute Resolution in Engineering and Construction     Full-text available via subscription   (Followers: 5)
Journal of Marine Science and Engineering     Open Access   (Followers: 1)
Journal of Materials and Engineering Structures     Open Access   (Followers: 4)
Journal of Materials in Civil Engineering     Full-text available via subscription   (Followers: 10)
Journal of Nondestructive Evaluation     Hybrid Journal   (Followers: 11)
Journal of Offshore Structure and Technology     Full-text available via subscription  
Journal of Performance of Constructed Facilities     Full-text available via subscription   (Followers: 4)
Journal of Pipeline Systems Engineering and Practice     Full-text available via subscription   (Followers: 7)
Journal of Rehabilitation in Civil Engineering     Open Access   (Followers: 3)
Journal of Solid Waste Technology and Management     Full-text available via subscription   (Followers: 1)
Journal of Structural Engineering     Full-text available via subscription   (Followers: 39)
Journal of Structural Fire Engineering     Full-text available via subscription   (Followers: 6)
Journal of Sustainable Architecture and Civil Engineering     Open Access   (Followers: 3)
Journal of Sustainable Design and Applied Research in Innovative Engineering of the Built Environment     Open Access   (Followers: 1)
Journal of the South African Institution of Civil Engineering     Open Access   (Followers: 4)
Jurnal Spektran     Open Access   (Followers: 1)
Jurnal Teknik Sipil dan Perencanaan     Open Access  
Konstruksia     Open Access  
KSCE Journal of Civil Engineering     Hybrid Journal   (Followers: 2)
Latin American Journal of Solids and Structures     Open Access   (Followers: 4)
Materiales de Construcción     Open Access  
Mathematical Modelling in Civil Engineering     Open Access   (Followers: 3)
Nondestructive Testing And Evaluation     Hybrid Journal   (Followers: 17)
Obras y Proyectos     Open Access   (Followers: 1)
Open Journal of Civil Engineering     Open Access   (Followers: 6)
Photonics and Nanostructures - Fundamentals and Applications     Hybrid Journal   (Followers: 2)
Practice Periodical on Structural Design and Construction     Full-text available via subscription   (Followers: 4)
Proceedings of the Institution of Civil Engineers - Bridge Engineering     Hybrid Journal   (Followers: 7)
Proceedings of the Institution of Civil Engineers - Civil Engineering     Hybrid Journal   (Followers: 11)
Proceedings of the Institution of Civil Engineers - Management, Procurement and Law     Hybrid Journal   (Followers: 8)
Proceedings of the Institution of Civil Engineers - Municipal Engineer     Hybrid Journal   (Followers: 3)
Proceedings of the Institution of Civil Engineers - Structures and Buildings     Hybrid Journal   (Followers: 4)
Random Structures and Algorithms     Hybrid Journal   (Followers: 5)
Recent Trends In Civil Engineering & Technology     Full-text available via subscription   (Followers: 4)
Research in Nondestructive Evaluation     Hybrid Journal   (Followers: 7)
Revista IBRACON de Estruturas e Materiais     Open Access   (Followers: 1)
Road Materials and Pavement Design     Hybrid Journal   (Followers: 9)
Russian Journal of Nondestructive Testing     Hybrid Journal   (Followers: 6)
Science and Engineering of Composite Materials     Hybrid Journal   (Followers: 61)
Selected Scientific Papers - Journal of Civil Engineering     Open Access   (Followers: 3)
Slovak Journal of Civil Engineering     Open Access   (Followers: 2)
Soils and foundations     Full-text available via subscription   (Followers: 4)
Steel Construction - Design and Research     Hybrid Journal   (Followers: 3)
Structural and Multidisciplinary Optimization     Hybrid Journal   (Followers: 9)
Structural Concrete     Hybrid Journal   (Followers: 11)
Structural Control and Health Monitoring     Hybrid Journal   (Followers: 9)
Structural Engineering International     Full-text available via subscription   (Followers: 11)
Structural Safety     Hybrid Journal   (Followers: 7)
Structural Survey     Hybrid Journal  
Structure     Full-text available via subscription   (Followers: 23)
Structure and Infrastructure Engineering: Maintenance, Management, Life-Cycle Design and Performance     Hybrid Journal   (Followers: 12)
Structures     Hybrid Journal   (Followers: 1)
Study of Civil Engineering and Architecture     Open Access   (Followers: 8)
Superlattices and Microstructures     Hybrid Journal   (Followers: 2)
Surface Innovations     Hybrid Journal  
Technical Report Civil and Architectural Engineering     Open Access  
Teknik     Open Access  
The IES Journal Part A: Civil & Structural Engineering     Hybrid Journal   (Followers: 6)
The Structural Design of Tall and Special Buildings     Hybrid Journal   (Followers: 6)
Thin Films and Nanostructures     Full-text available via subscription   (Followers: 2)
Thin-Walled Structures     Hybrid Journal   (Followers: 4)
Transactions of the VŠB - Technical University of Ostrava. Construction Series     Open Access   (Followers: 1)
Transportation Geotechnics     Full-text available via subscription   (Followers: 1)
Transportation Infrastructure Geotechnology     Hybrid Journal   (Followers: 8)
Underground Space     Open Access  
Water Science & Technology     Partially Free   (Followers: 25)
Water Science and Technology : Water Supply     Partially Free   (Followers: 22)

           

Journal Cover Building and Environment
  [SJR: 2.121]   [H-I: 86]   [15 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0360-1323
   Published by Elsevier Homepage  [3044 journals]
  • Application of shape-stabilized phase-change material sheets as thermal
           energy storage to reduce heating load in Japanese climate
    • Authors: Hyun Bae Kim; Masayuki Mae; Youngjin Choi
      Pages: 1 - 14
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Hyun Bae Kim, Masayuki Mae, Youngjin Choi
      A shape-stabilized phase-change material (SSPCM) was installed on the floor, walls, and ceiling of various buildings, and its effects on indoor room temperature stabilization and heating load reduction were examined using experiments and simulations. The PCM model was developed based on the specific heat capacity of the SSPCM sheets measured using a thermostatic chamber and simulations results were obtained using EnergyPlus. The validity of the PCM model was examined by comparing the simulation and experimental results, which showed similar temperature tendency. The model was then examined to determine the applicability of PCM to the various climates in Japan through annual heating load simulations. The target buildings were classified as Type A (no PCM, reference), Type B (only the floor contained PCM), and Type C (the floor, walls, and ceiling contained PCM) using a standard Japanese house. Types B and C had the same amount of PCM. The simulation was run for 21 cases, with one being run for each type of building in seven Japanese climates. In addition, if the installation area of the PCM was expanded, the absorption area of solar radiation also increased; thus, the melting and solidification times of the PCM decreased and its heat storage increased. Thereby, diurnal temperature swing decreased and the efficiency of the PCM increased. The heat-storage performance changed depending on the installation area and position, even when the same amount of PCM was installed in the building. Therefore, when using PCMs in buildings, the installation area and position should be considered alongside the amount of PCMs.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.038
      Issue No: Vol. 125 (2017)
       
  • Simulating air distribution and occupants' thermal comfort of three
           ventilation schemes for subway platform
    • Authors: Changping Liu; Angui Li; Changqing Yang; Wenrong Zhang
      Pages: 15 - 25
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Changping Liu, Angui Li, Changqing Yang, Wenrong Zhang
      Excellent air distribution is an indispensable factor to acquire comfortable environment in high density occupant areas, such as subway stations. This study assesses the air distribution by adopting three different air supply schemes (mixing ventilation, stratified air ventilation and air curtain ventilation) for a subway platform. The simulation results are discussed in detail by considering air velocity, air temperature, age of air and Relative Warmth Index (RWI). It was demonstrated that air curtain ventilation presented an appropriate velocity and temperature distribution, which provides a healthy and comfortable environment. Focusing on the air curtain ventilation scheme, four cases were investigated to indicate the air velocity and temperature distribution in the occupied region. It is indicated that the highest velocities and the lowest temperatures were both achieved at the height of 0.2 m above the floor. Dimensionless velocity with different air supply velocity was proposed in this paper. This research is applicable for air curtain ventilation design appropriate for subway platform.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.036
      Issue No: Vol. 125 (2017)
       
  • Shading control strategy to avoid visual discomfort by using a low-cost
           camera: A field study of two cases
    • Authors: C. Goovaerts; F. Descamps; V.A. Jacobs
      Pages: 26 - 38
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): C. Goovaerts, F. Descamps, V.A. Jacobs
      Daylighting in offices creates a comfortable and healthy working environment for its users. However, maximizing the amount of daylight can cause visual hindrance. To improve the visual and thermal comfort for the users, designers implement shading systems, which control the transmitted solar and visual radiation. To ensure a comfortable indoor environment, designers need to choose an appropriate control strategy. Different control strategies exist, but the acceptance and satisfaction of the user regarding these strategies remains quite low. Therefore, we developed a control strategy that is based on the comfort requirements of the users. The control strategy aims at avoiding visual discomfort for the user, while optimizing for daylight availability and improving user satisfaction by providing the possibility to override the automated control of the shading system. This is the first study where a shading device is controlled by a controller system with a low-resolution camera. The controller system captures High Dynamic Range images and evaluates a visual comfort parameter, namely the ‘Daylight Glare Probability’. The system controls the actuator of the shading device based on the assessed level of comfort. This paper demonstrates two experimental case studies where the controller system and the control strategy are implemented. The controller system is able to keep the visual hindrance below a predefined limit, while sufficient daylight can still enter the office room.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.030
      Issue No: Vol. 125 (2017)
       
  • Study on moisture condensation on the interior surface of buildings in
           high humidity climate
    • Authors: Shijun You; Wenqingping Li; Tianzhen Ye; Fan Hu; Wandong Zheng
      Pages: 39 - 48
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Shijun You, Wenqingping Li, Tianzhen Ye, Fan Hu, Wandong Zheng
      Hot and humid air infiltration would lead to moisture condensation on the interior surface of buildings in high humidity climate, which has a negative influence on the indoor environment and building life. This study aims to expound the transient property of moisture condensation on the interior surface of buildings in high humidity climate, and find the typical places where moisture condensation often occurs by numerical and experimental methods. A numerical model of a test chamber is established, which is used to predict the distribution of heat and humidity due to air infiltration. Simulation results from the application of FLUENT software are compared with the experimental data, and a validation procedure is presented. The effect of outdoor air temperature, humidity ratio and wind speed on the moisture condensation state is investigated. The results prove that these parameters have a significant impact on the start time, duration and magnitude of moisture condensation. Two regression equations are developed from the experimental results, which describe the relationship between the indoor air temperature, humidity and the factors of infiltrated air. Meanwhile, two kinds of dew-proof solutions are proposed.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.041
      Issue No: Vol. 125 (2017)
       
  • An FMI-enabled methodology for modular building performance simulation
           based on Semantic Web Technologies
    • Authors: Matthias Mitterhofer; Georg Ferdinand Schneider; Sebastian Stratbücker; Klaus Sedlbauer
      Pages: 49 - 59
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Matthias Mitterhofer, Georg Ferdinand Schneider, Sebastian Stratbücker, Klaus Sedlbauer
      The concept of modular building performance simulation has been accredited with considerable potential to realize the vision of an integrated building simulation platform for several stakeholders. Current literature identifies missing technological advancement as the key obstacle for its realization. This work presents a methodology that incorporates the Functional Mock-up Interface, Semantic Web Technologies and Building Information Modeling to realize a modular building performance simulation. The approach is based on the specification of Functional Mock-up Units using a formal information model. This allows to set individual simulation modules in context with an overarching data framework in order to identify their role within a building performance simulation. Through the additional association to project-specific information in a digital representation of a building, an algorithm is able to automatically infer the simulation topology of an arbitrary number of contributing simulation modules by means of reasoning. An example demonstrates the feasibility and indicates the technological potential of the approach.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.021
      Issue No: Vol. 125 (2017)
       
  • Carbon nanotubes / activated carbon fiber based air filter media for
           simultaneous removal of particulate matter and ozone
    • Authors: Shen Yang; Zhenxing Zhu; Fei Wei; Xudong Yang
      Pages: 60 - 66
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Shen Yang, Zhenxing Zhu, Fei Wei, Xudong Yang
      Indoor environment is faced with complex pollution by particulate matter (PM) and ozone. In this study, we proposed to use carbon nanotubes/activated carbon fiber (CNTs/ACF) to remove both PM and ozone with high removal efficiencies, high quality factor and low pressure resistance. The CNTs/ACF filter media were fabricated through growth of CNTs upon pristine ACF using chemical vapor deposition method. The PM filtration efficiencies of the CNTs/ACF and pristine ACF were measured for different particle sizes. The quality factors of these two media were calculated and compared. The ozone removal efficiency of the CNTs/ACF and ACF were tested as well. Results indicate that growth of CNTs on ACF elevated the media for PM filtration, and increased the quality factor by 48%. The CNTs/ACF presented >99% ozone removal, as high as the ACF. Compared with other CNTs-based filter media that have been proposed in previous studies, the CNTs/ACF exhibited higher quality factor, much lower pressure resistance, higher ozone removal efficiency, and upper-middle PM filtration efficiency.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.040
      Issue No: Vol. 125 (2017)
       
  • Returning and net escape probabilities of contaminant at a local point in
           indoor environment
    • Authors: Juyeon Chung; Eunsu Lim; Mats Sandberg; Kazuhide Ito
      Pages: 67 - 76
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Juyeon Chung, Eunsu Lim, Mats Sandberg, Kazuhide Ito
      The quantified recirculation of a contaminant in a local domain is an essential property of the ventilation efficiency in a room. The returning probability of a contaminant (α) generated in a local domain and its net escape probability (NEP) are essential information for understanding the structure of the contaminant concentration distribution in a room and for controlling the indoor air quality. Here, we propose the fundamental definitions of α and NEP and discuss their potential relation with the net escape velocity (NEV) concept. NEP is defined at a local point and/or local domain as the probability that a contaminant is exhausted directly through an exhaust outlet and does not re-circulate to the target local point/domain again. In a computational fluid dynamics (CFD) simulation, the minimum local domain in a room corresponds to the control volume (C.V.) of discretization; hence, NEP in a C.V. is assumed as the probability in a point without volume. In this study, the calculation results of α, NEP, and NEV distributions in a simple two-dimensional model room and a three-dimensional room with push-pull type ventilation system are demonstrated and discussed.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.028
      Issue No: Vol. 125 (2017)
       
  • Application of artificial neural networks for determining energy-efficient
           operating set-points of the VRF cooling system
    • Authors: Min Hee Chung; Young Kwon Yang; Kwang Ho Lee; Je Hyeon Lee; Jin Woo Moon
      Pages: 77 - 87
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Min Hee Chung, Young Kwon Yang, Kwang Ho Lee, Je Hyeon Lee, Jin Woo Moon
      The aim of this study was to develop an Artificial Neural Network (ANN) model that can predict the amount of cooling energy consumption for the different settings of the variable refrigerant flow (VRF) cooling system's control variables. Matrix laboratory (MATLAB) and its neural network toolbox were used for the ANN model development and test performance. For the model training and performance evaluation, data sets were collected through the field measurement. Four steps were conducted in the development process: initial model development, input variable selection, model optimization, and performance evaluation. In the initial model development and input variable selection process, seven input variables were selected as input neurons: TEMPOUT, HUMIDOUT, TEMPIN, LOADCOOL, TEMPSA, TEMPCOND, and PRESCOND. In addition, the initial model was optimized to have 2 hidden layers, 15 hidden neurons in each hidden layer, a learning rate of 0.3, and a momentum of 0.3. The optimized model demonstrated its prediction accuracy within the recommended level, thus proved its potential for application in the control algorithm for creating a comfortable indoor thermal environment in an energy-efficient manner.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.044
      Issue No: Vol. 125 (2017)
       
  • How do urban buildings impact summer air temperature' The effects of
           building configurations in space and time
    • Authors: Yuliang Lan; Qingming Zhan
      Pages: 88 - 98
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Yuliang Lan, Qingming Zhan
      The urban building plays an important role that dominates the urban thermal environment by altering the heat exchange. In this study, we coupled GIS techniques with statistical methods to investigate the variance of Air Temperature (AT) and how it is influenced by urban buildings in Wuhan (China). The objectives of this study are to: 1) explore the dynamic relationships of building indicators and AT at varying geographic scales, so as to determine the calculation scale for spatial configuration; 2) examine how the relationships change with time; 3) investigate the combined and individual effects of these building indicators. The indicators were chosen from the perspective of urban planning, including Floor Area Ratio (FAR), Building Density (BD), the local Moran's I of Building (MB) and Building Height (BH). Results show that an area extent of 200 m is optimal for examining the AT-building relationships. The AT-building relationships are evidenced to be significant during nighttime but negligible during daytime, and reach the strongest level at different time depending on the day's temperature levels. Results of ridge regression analyses demonstrate that, for hot days, urban buildings can jointly explain as high as 48.9% of the AT variance during summer nighttime, and the explanatory level can reach 53.4% at 1:00 a.m. Spatial configuration was proved to effectively impact on AT, which is always neglected by urban planners and decision-makers. Our findings suggest that optimizing building patterns at an appropriate scale can achieve more significant effects on mitigating nighttime UHI. The insights gained from our study have significant implications for sustainable urban development.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.046
      Issue No: Vol. 125 (2017)
       
  • Near fields of gasper jet flows with wedged nozzle in aircraft cabin
           environment
    • Authors: Zhanqi Tang; Xujia Cui; Yong Guo; Nan Jiang; Shen Dai; Junjie Liu
      Pages: 99 - 110
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Zhanqi Tang, Xujia Cui, Yong Guo, Nan Jiang, Shen Dai, Junjie Liu
      The geometry of the outlet nozzle has a direct effect on the near fields of turbulent jets. An attempt is made to modify the gasper jet nozzle by adding wedges of different sizes. The near fields of the wedged gasper jets are measured by a hot-wire anemometer. For the with-wedges cases, the mean velocity exhibits a more rapid decay in the axial direction, and the turbulent intensity is attenuated after the “second potential core.” The higher-order statistics, such as skewness and kurtosis, indicate no obvious difference in the downstream region. As the turbulent structures are formed, the energy spectra indicate that their average energy increases under the wedges' perturbation. Then, the anti-axial-symmetry of the transition flows is observed in two characteristic planes. The mean velocity does not exhibit a significant difference between the two planes, but the turbulent intensity in the perturbed plane embodies the wedges' influence. The wedged nozzle affects the energy intensity and diffusion angle of the turbulent structures in the perturbed plane, and the difference from the unperturbed plane is confirmed by the discrepancy spectra. Furthermore, the anti-axial-symmetry is characterized by turbulent intermittency and entrainment. The turbulent intermittency in the perturbed plane performs with a lower value in the near-nozzle region, and evolves into axial-symmetry in the further downstream region. For turbulent entrainment, the entrainment ratio manifests that wedged nozzle reduces the flow mass in the entrainment of ambient air in the downstream region.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.047
      Issue No: Vol. 125 (2017)
       
  • Heat transfer analysis of an integrated double skin façade and phase
           change material blind system
    • Authors: Yilin Li; Jo Darkwa; Georgios Kokogiannakis
      Pages: 111 - 121
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Yilin Li, Jo Darkwa, Georgios Kokogiannakis
      In this study, the heat transfer in an integrated double skin facade (DSF) and phase change material (PCM) blind system has been theoretically analysed. Both heat transfer and airflow models with CFD methods have been developed for the integrated DSF and PCM blind system. Data from an existing typical DSF building have been obtained in order to define input parameters for the simulation exercise and validate the numerical models. The temperature and velocity fields in DSF with the PCM blind system has been predicted under overheating scenario using the ANSYS Workbench FLUENT software and been compared with case of conventional aluminium blind system. This study has shown that the integrated PCM blind system was able to reduce the average air temperature and outlet temperature of the DSF while improving the convective heat transfer between the cavity air and the blades. Compared with the aluminium blind, the PCM blind can absorb large amount of excessive heat in the cavity. Overall the integrated PCM blind system has the potential to be used as an effective thermal management device for minimising the overheating effect in DSFs.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.034
      Issue No: Vol. 125 (2017)
       
  • Uncertainty quantification of upstream wind effects on single-sided
           ventilation in a building using generalized polynomial chaos method
    • Authors: Xiang Sun; Jinsoo Park; Jung-Il Choi; Gwang Hoon Rhee
      Pages: 153 - 167
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Xiang Sun, Jinsoo Park, Jung-Il Choi, Gwang Hoon Rhee
      The single-sided ventilation rate in a building can be estimated using an empirical correlation that developed based on the results of deterministic experiments or numerical simulations. Owing to the complex flow patterns near a building, it is difficult to establish a robust correlation considering upstream wind uncertainties such as wind speed and direction. We perform RANS simulations and generalized polynomial chaos-based uncertainty quantification analysis to investigate the effects of the upstream uncertainties on the ventilation rate. It was found that the reference wind speed and the incident angle significantly affect the ventilation rate. Warren and Parkins' correlation shows a reasonable prediction of the average ventilation rate over the incident angle, while Larsen's correlation, in general, underestimates the ventilation rates. Further, the average ventilation rates in the side direction are lower than those in the windward and leeward directions, while larger variations of the ventilation rate in the leeward direction are found at high speeds, compared to those in the other directions. Owing to unresolved turbulent induced ventilation rates in the RANS model, the present ventilation rates may not accurately provide actual ventilation rates. Nevertheless, the present UQ analysis indicates that the existing correlation between the ventilation rate and the wind speed must account for the influence of the wind direction, especially at high wind speeds, in order to estimate the single-sided ventilation rate in a building with greater accuracy.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.037
      Issue No: Vol. 125 (2017)
       
  • Detached eddy simulation of pedestrian-level wind and gust around an
           elevated building
    • Authors: Jianlin Liu; Jianlei Niu; Cheuk Ming Mak; Qian Xia
      Pages: 168 - 179
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Jianlin Liu, Jianlei Niu, Cheuk Ming Mak, Qian Xia
      Wind flow turbulence is known to have a major influence on the pedestrian-level wind (PLW) environments, particularly around a building. The elevated design of a building, as a special feature, proved to improve pedestrian-level weak wind conditions in high-density cities. The present study aims to assess three turbulence models, the detached eddy simulation (DES), the steady-state RANS (SRANS), and the unsteady-state RANS (URANS), in their simulation of the PLW flow turbulence concerning wind gust. The simulated mean wind velocities around isolated buildings with and without an elevated design were compared with those obtained from a wind tunnel experiment. The effects of mesh resolution and inflow fluctuating algorithm on the performance of the DES model were thoroughly evaluated. The DES model can better reproduce the mean flow fields than the other two models. Finally, the unsteady fluctuations of wind flow around the buildings with and without the elevated design are analyzed in terms of instantaneous wind velocity, lift coefficient, energy spectral density, and turbulence intensity. The predicted lift coefficient and Strouhal number are approximately 0.01 and 0.09, respectively, which is consistent with what are reported in the literature. Modifications of the frequency of vortex shedding, periodical wind flow pattern, and the normalized wind gust flow fields around the two types of buildings are compared in detail. The work reveals that transient turbulent flow pattern can be reasonably obtained with the DES model, indicating the potential of using the DES for PLW gust assessments in urban planning.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.031
      Issue No: Vol. 125 (2017)
       
  • PIV experimental study of the large-scale dynamic airflow structures in an
           aircraft cabin: Swing and oscillation
    • Authors: Jiayu Li; Junjie Liu; Congcong Wang; Mark Wesseling; Dirk Müller
      Pages: 180 - 191
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Jiayu Li, Junjie Liu, Congcong Wang, Mark Wesseling, Dirk Müller
      The dynamic behaviors of airflows, which are common in aircraft cabins with mixing ventilations, significantly influence the thermal sensation of passengers and contaminant transmissions. In this paper, to analyze the large-scale dynamic characteristics in aircraft cabins, a series of long-term large-scale particle image velocimetry (PIV) measurements were performed in an aircraft cabin mockup to provide necessary basic data. Two typical airflow fields, jet zones characterized as large-scale circulations and collision zones featured as interactions of two lateral jets, were selected as the research objects of the dynamic behaviors in the cabin. In collision zones, the temporal characteristics of the swing motions were presented via proper orthogonal decomposition (POD) method, and the swing periods were 25.2 s–29.8 s and 13.0 s–19.8 s under isothermal and cooling conditions, respectively. By analyzing the occurrence probability of swings, the swing-induced contaminant transmission regularity was presented. In jet zones, the dynamic behavior of large-scale circulation was revealed by identifying the circulation center of each instantaneous flow field. However, the center oscillated in a small range near the breath zone of the passenger seating in the middle of one side, and the plumes under cooling conditions further reduced the range, which explained the lock-up phenomenon founded in contaminant transmission studies in the cabin. Finally, several vortex identification methods with raw and reconstructed instantaneous airflow fields were compared, and their practicalities were discussed.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.07.043
      Issue No: Vol. 125 (2017)
       
  • The effects of ventilation and floor heating systems on the dispersion and
           deposition of fine particles in an enclosed environment
    • Authors: Yu Zhou; Yelin Deng; Peng Wu; Shi-Jie Cao
      Pages: 192 - 205
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Yu Zhou, Yelin Deng, Peng Wu, Shi-Jie Cao
      Recent years, most cities in China suffer from ambient particulate matter pollution, especially in winter. The absence of fresh air system in most northern heating buildings in winter results in the poor indoor air quality. This work aims to deal with the particle dispersion in a ventilated and floor-heated indoor environment by using experimental measurements and computational fluid dynamics (CFD) methods. Two ventilation systems were considered, i.e., top & down supply. Firstly, experiments were conducted to validate the velocity and particle concentrations by CFD simulation. Secondly, unsteady particles (with the diameter of 1 μm) dispersion was simulated with different inlet velocities (i.e., 0.3, 0.4 and 0.5 m/s) and floor temperatures (i.e., 293, 298, 303 and 308 K) in a ventilated and floor-heated chamber. Lagrangian method was employed for particles tracking. It is found that the higher the inlet velocity, the faster particle concentration decayed. For the same inlet velocity, particles in the chamber were removed faster with the increase of floor temperature. When the inlet velocity was 0.5 m/s and the floor temperatures were 293 and 308 K, it took 391s and 200s respectively for normalized concentration decreasing to 0.1. The number of particles deposited on the floor decreased with the increase of the inlet velocity and the floor temperature. This study also identifies that when the floor temperature was 308 K, the removing time is reduced by 15% for normalized particle concentration with the down-supply ventilation mode. These findings would be facilitating for the future design of ventilation and heating systems.

      PubDate: 2017-09-07T23:42:53Z
      DOI: 10.1016/j.buildenv.2017.08.049
      Issue No: Vol. 125 (2017)
       
  • Driving forces for green building technologies adoption in the
           construction industry: Ghanaian perspective
    • Authors: Amos Darko; Albert Ping Chuen Chan; Samuel Gyamfi; Ayokunle Olubunmi Olanipekun; Bao-Jie He; Yao Yu
      Pages: 206 - 215
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Amos Darko, Albert Ping Chuen Chan, Samuel Gyamfi, Ayokunle Olubunmi Olanipekun, Bao-Jie He, Yao Yu
      As a response to mitigate various negative environmental effects of the construction industry, recent years have witnessed a growing interest in green building technologies (GBTs) adoption and development. Consequently, many studies have been conducted on the forces driving the GBTs adoption in different countries. However, there have been few studies identifying the driving forces (DFs) for GBTs adoption in developing countries such as Ghana. This study aims to identify the major DFs for GBTs adoption within the developing country of Ghana. To achieve the objective, 21 DFs were identified from a comprehensive literature review. Through a questionnaire survey with 43 professionals with green building experience, the results first indicated that “setting a standard for future design and construction”, “greater energy efficiency”, “improved occupants' health and well-being”, “non-renewable resources conservation”, and “reduced whole lifecycle costs” were the top five forces driving the GBTs adoption. Further comparative analysis showed that the topmost rank of “setting a standard for future design and construction” is unique for GBTs adoption in only the developing country of Ghana, not in the developed country of the US. Additionally, factor analysis revealed that the underlying forces for the 16 significant DFs were environment-related, company-related, economy and health-related, cost and energy-related, and industry-related forces. This study improves understanding of the major DFs for GBTs adoption, providing a valuable reference for practitioners and policy makers to promote the wider adoption of GBTs. Future study will investigate the interrelationships between the significant DFs and their impacts on the GBTs adoption process. Future work is also required to employ a larger sample and investigate in greater detail the differences between the GBTs adoption DFs in Ghana and many other specific countries.

      PubDate: 2017-09-07T23:42:53Z
      DOI: 10.1016/j.buildenv.2017.08.053
      Issue No: Vol. 125 (2017)
       
  • Effect of airflow interaction in the breathing zone on exposure to
           bio-effluents
    • Authors: Mariya Bivolarova; Wojciech Kierat; Eva Zavrl; Zbigniew Popiolek; Arsen Melikov
      Pages: 216 - 226
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Mariya Bivolarova, Wojciech Kierat, Eva Zavrl, Zbigniew Popiolek, Arsen Melikov
      The influence of the complex interaction of three airflows - breathing flow, convective flow around the human body and ventilation flow directed against the face - on the exposure to dermally-emitted effluents from a person's own body was examined together with the effects of source location and control. A breathing thermal manikin was used to simulate a seated person in a full size climate chamber. Bio-effluents released at the armpits and groin were simulated with two tracer gases. It was found that the flow of exhalation substantially affected the exposure to dermally-emitted bio-effluents released close to the breathing flow, e.g. armpits. The exposure in the case of exhalation through the nose was higher than when exhalation took place through the mouth. Breathing did not influence the exposure to gaseous pollutants emitted from the lower part of the body, in this case, the groin. Local pollution source control by exhaust ventilation integrated into the seat reduced the exposure. Airflow imposed against the face can substantially reduce the exposure regardless of the pollution source location. However, when this flow is combined with local source control the exposure may paradoxically increase, depending on the airflow interaction at the breathing zone and the source location.

      PubDate: 2017-09-07T23:42:53Z
      DOI: 10.1016/j.buildenv.2017.08.043
      Issue No: Vol. 125 (2017)
       
  • Vertical greening systems – A review on recent technologies and
           research advancement
    • Authors: Alexandra Medl; Rosemarie Stangl; Florin Florineth
      Pages: 227 - 239
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Alexandra Medl, Rosemarie Stangl, Florin Florineth
      Vertical greening systems represent an emerging field in technology and research since they are traded as promising measure to encounter the negative impacts of climate change. Research and development in the field of green infrastructure are steadily progressing, determining aesthetic improvements as well as environmental, social and economic benefits. The purpose of this paper is to provide a systematic state-of-the-art in the field of vertical greening systems and identify significant gaps in research. Additionally, recent scientific studies are analysed to bundle existing knowledge on research in the specific field of green walls and to derive indications on set up practices to facilities and improvement of their post-comparability. The study is based on literature review using scientific literature such as peer-reviewed journals, conference papers and books as well as master and doctoral theses, research reports, research articles and recommendations. The study concludes that benefits of vertical greening systems in current literature often refer to general benefits of vegetation. Specific knowledge has been promoted on microclimatic effects, but complementary studies with focus on vertical greening systems are still lacking. Additionally, it was revealed that there is great potential for research on vertical greening systems in rural areas, especially taking into consideration the application of green walls on construction buildings like shotcrete walls, tunnel portals or highway bridges. For better comparability of future studies, single parameter-centered analyses under constant and comparable conditions are recommended.

      PubDate: 2017-09-07T23:42:53Z
      DOI: 10.1016/j.buildenv.2017.08.054
      Issue No: Vol. 125 (2017)
       
  • Effect of natural ventilation on indoor air quality and thermal comfort in
           dormitory during winter
    • Authors: Zhangping Lei; Chuanping Liu; Li Wang; Na Li
      Pages: 240 - 247
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Zhangping Lei, Chuanping Liu, Li Wang, Na Li
      This study is to prove that natural ventilation is necessary for students' sleeping even in Beijing's −9 °C winter and explain that opening windows at proper width will decrease the indoor temperature slightly, but obviously reduce the CO2 concentration. The indoor air quality in dormitories was monitored experimentally at different ventilation areas (from 0.011 m2 to 0.11 m2), and the thermal comfort and mental state of the students after 7 h of sleep were analyzed through a questionnaire survey. Results showed that indoor air quality generally improved with the increase in natural ventilation area, whereas the thermal comfort level gradually declined. Approximately 0.055 m2 is the appropriate natural ventilation area (corresponding to 0.036 m3/s natural ventilation rate) for dormitories with 10–12.5 m3 per capita space during Beijing's winter. In addition, a model was proposed for window opening to predict indoor air quality and temperature in different natural ventilation areas during winter nights. With increasing the student number in dormitory, it is necessary to increasing the windows open area, and once the per capita space is less than 6.5 m3, the indoor air quality cannot meet the comfortableness only by windows opening.
      Graphical abstract image

      PubDate: 2017-09-07T23:42:53Z
      DOI: 10.1016/j.buildenv.2017.08.051
      Issue No: Vol. 125 (2017)
       
  • On the influence of sensible heat release on displacement ventilation in a
           train compartment
    • Authors: Daniel Schmeling; Johannes Bosbach
      Pages: 248 - 260
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Daniel Schmeling, Johannes Bosbach
      The aim of this study is to quantify the influence of heat release on ventilation efficiency and thermal comfort parameters of displacement ventilation in a generic train compartment. A series of human subject studies was conducted for various mean room temperatures. Complementary, measurements using thermal manikins with variable sensible heat release were performed for the same mean room temperatures. Three main findings were achieved: First, values of latent and sensible heat release of human subjects in displacement ventilation are in very good agreement with the standard using T c h e s t as mean room temperature. Second, the heat removal efficiency (HRE) decreases with increasing mean cabin temperature, that is decreasing sensible heat release, during human subject tests. However, the HRE remains stable during the test with thermal manikins at a constant sensible heat release. Third, we found that variation of the sensible heat has a negligible impact on the flow velocities near the passenger dummies. This indicates that the cooling performance is limited by the rate of fresh air available through the fresh air lake.

      PubDate: 2017-09-07T23:42:53Z
      DOI: 10.1016/j.buildenv.2017.08.039
      Issue No: Vol. 125 (2017)
       
  • Towards an integrated method to assess effects of lift-up design on
           outdoor thermal comfort in Hong Kong
    • Authors: Yaxing Du; Cheuk Ming Mak; Taiyang Huang; Jianlei Niu
      Pages: 261 - 272
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Yaxing Du, Cheuk Ming Mak, Taiyang Huang, Jianlei Niu
      City residents wish to have pleasant experience in outdoor space, which are often impeded by thermally uncomfortable conditions, particularly in hot and humid summer. Lift-up design can provide comfortable microclimate in summer but the effects of lift-up design on thermal comfort in a built-up environment have not been systematically studied. This paper aims to investigate the effects of lift-up design on outdoor thermal comfort comprehensively, as well as the effects on pedestrian level wind environment. The thermal comfort assessments are carried out by using a proposed integrated method, which combines wind tunnel tests and on-site monitoring to calculate Physiologically Equivalent Temperature (PET) values. The Hong Kong Polytechnic University (HKPolyU) campus is selected as study area. The investigation mainly focuses on summer and winter seasons. Four typical days in a year were chosen to carry out on-site monitoring for obtaining environmental parameters. This study demonstrates that the proposed integrated method can be used to predict outdoor thermal comfort. Results also show that lift-up design can effectively improve pedestrian level wind environment and thermal comfort. Moreover, lift-up design can provide a comfortable microclimate in summer while not cause strong cold stress in winter. These findings provide solid evidence bases to city planners and architects of available options for creating pleasant outdoor microclimate in precinct planning.

      PubDate: 2017-09-07T23:42:53Z
      DOI: 10.1016/j.buildenv.2017.09.001
      Issue No: Vol. 125 (2017)
       
  • Modelling urban airflow and natural ventilation using a GPU-based
           lattice-Boltzmann method
    • Authors: Marco-Felipe King; Amirul Khan; Nicolas Delbosc; Hannah L. Gough; Christos Halios; Janet F. Barlow; Catherine J. Noakes
      Pages: 273 - 284
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Marco-Felipe King, Amirul Khan, Nicolas Delbosc, Hannah L. Gough, Christos Halios, Janet F. Barlow, Catherine J. Noakes
      Simulation of urban airflow and ventilation potential is desirable for building design, however the complex and transient nature of flows in urban environments makes this a challenging task. This study aims to evaluate the capability of a lattice-Boltzmann method (LBM) code deployed on a graphical processing unit (GPU) using a large eddy sub-grid turbulence model for cross-flow ventilation of an idealised cubical building at wind-tunnel scale. ANSYS Fluent is used as a numerical comparison. Façade pressure and ventilation of the cube are investigated for parallel and perpendicular wind directions with the building in isolation and regular array format. Pressures, velocities and ventilation rates are compared to experimental data from wind tunnel and full-scale experiments of the Silsoe cube. Simulations compare favourably with experimental values and between each other. When the cube was surrounded by other cubes, simulations suggest that vortex shedding from up-wind buildings provides pulsating ventilation, improving airflow ingress in the parallel wind cases. A parametric study showed that doubling surrounding building height had a small negative effect on ventilation but was mitigated by high levels of downdraft and flow fluctuations in the vertical plane. Comparatively, doubling the central building height had a net positive effect but caused high internal airspeeds for both angles. The LBM code running on one GPU was several orders of magnitude faster than Fluent with similar accuracy. Simulation time using the LBM approach was several orders of magnitude lower than Fluent.

      PubDate: 2017-09-14T04:07:55Z
      DOI: 10.1016/j.buildenv.2017.08.048
      Issue No: Vol. 125 (2017)
       
  • Hygrothermal modeling and evaluation of freeze-thaw damage risk of masonry
           walls retrofitted with internal insulation
    • Authors: Xiaohai Zhou; Dominique Derome; Jan Carmeliet
      Pages: 285 - 298
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Xiaohai Zhou, Dominique Derome, Jan Carmeliet
      For historical buildings with a worth-preserving appearance, internal wall insulation can be the only possible solution to improve the building energy efficiency. However, the application of an internal insulation layer changes significantly the hygrothermal performance of the building envelope. For masonry walls, such intervention may lead to freeze-thaw damage of the brickwork. In this study, a hygrothermal model is developed. The model takes into account moisture and heat transport in porous medium and tracks the occurrence of freezing and thawing in function of pore size distribution and as well as the ice content. Freezing and melting of water in porous medium is implemented based on the theory of freezing point depression, as freezing temperature of water in porous medium depends on pore size, i.e. water in the smaller pores freezes at temperatures lower than 0 °C. The numerical model results are compared with a porous medium freezing experiment and good agreement is found. Traditional hygrothermal assessment uses the number of zero crossings on a Celsius scale as the number of freeze-thaw cycles. We propose a method that uses the number of actual ice growth and melt cycles as an indicator more accurately accounting for the freeze-thaw process. In addition, we develop an index, called FTDR Index, to assess freeze-thaw damage risk. We perform simulations of uninsulated and internally retrofitted masonry walls using two Swiss climatic conditions. The study clearly shows increase of freeze-thaw cycles and ice content after internal retrofitting in both climates. Thus, FTDR Index increases after internal retrofitting.

      PubDate: 2017-09-14T04:07:55Z
      DOI: 10.1016/j.buildenv.2017.08.001
      Issue No: Vol. 125 (2017)
       
  • Do the plants in functional green walls contribute to their ability to
           filter particulate matter'
    • Authors: T. Pettit; P.J. Irga; P. Abdo; F.R. Torpy
      Pages: 299 - 307
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): T. Pettit, P.J. Irga, P. Abdo, F.R. Torpy
      Indoor air quality has become a growing concern as people are spending more time indoors, combined with the construction of highly sealed buildings that promote thermal efficiency. Particulate matter (PM) is a common indoor air pollutant, with exposure to high concentrations associated with several detrimental health outcomes. Active botanical biofilters or functional green walls are becoming increasingly efficient and have the potential to mitigate high suspended PM concentrations. These systems, however, require further development before they become competitive with industry standard in-room air filters. Whilst the plant growth substrate in active biofilters can act as a filter medium, it was previously not known whether the plant component of these systems played a function in PM filtration. This study thus examines the influence of the botanical component on active green wall PM single pass removal efficiency (SPRE), with a focus on evaluating the air filtration features of different plant species in green wall modules. All tested botanical biofilters outperformed biofilters that consisted only of substrate. Green walls using different plant species had different single pass removal efficiencies, with fern species recording the highest removal efficiencies across all measured particle sizes (Nephrolepis exaltata bostoniensis SPRE for PM0.3-0.5 and PM5-10 = 45.78% and 92.46% respectively). Higher removal efficiencies were associated with increased pressure drop across the biofilter. An assessment of plant morphological data suggested that the root structure of the plants strongly influenced removal efficiency. These findings demonstrate the potential to enhance active botanical biofiltration technology with appropriate plant species selection.

      PubDate: 2017-09-14T04:07:55Z
      DOI: 10.1016/j.buildenv.2017.09.004
      Issue No: Vol. 125 (2017)
       
  • Steady flows in a naturally-ventilated enclosure containing both a
           distributed and a localised source of buoyancy
    • Authors: J.L. Partridge; P.F. Linden
      Pages: 308 - 318
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): J.L. Partridge, P.F. Linden
      We consider the flows and stratification established in a naturally-ventilated enclosure containing both localised and distributed sources of buoyancy. In this study, both the localised and distributed sources originate from the same horizontal plane, with both adding buoyancy to the enclosure, i.e. representing a point source of heat and a horizontally distributed source of heat at the base of a room. An important parameter controlling the transient and steady states of the enclosure is the ratio of the source buoyancy fluxes ψ = B D B L , with B D and B L the source buoyancy flux of the distributed and localised source, respectively. We examine the role of entrainment between the layers, due to turbulent mixing, and construct a mathematical model to predict the stratification within the room for a range of ψ. We also show that for large ψ and opening areas the two-layer nature of the flow breaks down and there is a short circuit that allows the incoming air to escape through the upper opening without interacting with the full volume of the space. The validity of this model and its break down as predicted by a critical Richardson number are verified against small-scale experiments and the consequences for real-world buildings are discussed.

      PubDate: 2017-09-14T04:07:55Z
      DOI: 10.1016/j.buildenv.2017.08.023
      Issue No: Vol. 125 (2017)
       
  • Experimental implementation of whole building MPC with zone based thermal
           comfort adjustments
    • Authors: Trent Hilliard; Lukas Swan; Zheng Qin
      Pages: 326 - 338
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Trent Hilliard, Lukas Swan, Zheng Qin
      This paper presents an experimental implementation of a whole building model predictive control (MPC) approach for a LEED gold certified academic building. The MPC is divided into portions for morning start and daytime optimization, to allow for specialized models to be used for the varying tasks. The MPC consists of a whole building optimization for energy that is supplemented with a zone operative temperature (ZOT) comfort metric. A ZOT based metric was used to evaluate thermal comfort, as traditional air temperature metrics neglect radiative impacts on comfort. The comfort metric is employed after the energy optimization to ensure comfort is the highest priority and maintained in each zone. A final layer of occupant feedback is incorporated to allow for users to provide feedback as to their comfort level and allow for changes in the comfort temperature range for their space. A four-month experimental test period shows a 29% HVAC electric energy reduction and a 63% thermal energy reduction compared to previous years for the same time period.

      PubDate: 2017-09-14T04:07:55Z
      DOI: 10.1016/j.buildenv.2017.09.003
      Issue No: Vol. 125 (2017)
       
  • Time dependence of characteristic parameter for semi-volatile organic
           compounds (SVOCs) emitted from indoor materials
    • Authors: Jingjing Pei; Yihui Yin; Jianping Cao; Yahong Sun; Junjie Liu; Yinping Zhang
      Pages: 339 - 347
      Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Jingjing Pei, Yihui Yin, Jianping Cao, Yahong Sun, Junjie Liu, Yinping Zhang
      Semi-volatile organic compounds (SVOCs) are widely used in various indoor materials and their adverse health effects have been increasingly recognized. The gas-phase SVOC concentration in equilibrium with the source material (y 0), as a characteristic parameter for SVOC sources, is mostly assumed to be constant in previous studies. However, decreases in y 0 with time have been observed in some studies. As a first step to reveal the mechanism behind the phenomenon, this study quantitatively investigated the variation of y 0 over time under two conditions: natural exposure to outdoor ambient (Case 1), and storage in a controlled ventilated chamber (Case 2). Three phthalates (Di-iso-butyl Phthalate (DiBP), Di-n-butyl Phthalate (DnBP), and di-(2-ethylhexyl) phthalate (DEHP)) emitted from polyvinyl chloride (PVC) floorings and one flame retardant (tris(2-chloroisopropyl) phosphate, TCPP) emitted from polyurethane foam (PUF) were targeted. Experimental results indicated that, for SVOCs with higher volatility, i.e., DiBP, DnBP, and TCPP, y 0 decreased 16%–49% after 60 days' exposure for Case 1; and 16%–36% for Case 2. For SVOCs with lower volatility, i.e., DEHP, no significant decrease in y 0 was observed after 60 days in both cases; while if prolonging the time to about 1.5 years, a decrease of 38% was observed. Discussion about potential reasons for the decrease of y 0 was presented. The results obtained here provide a further understanding about SVOC source characteristics and therefore help providing source strength for estimating indoor SVOC health exposure.

      PubDate: 2017-09-14T04:07:55Z
      DOI: 10.1016/j.buildenv.2017.08.052
      Issue No: Vol. 125 (2017)
       
  • Sensitivity tests of biological safety cabinets' contaminant contention to
           variations on indoor flow parameters in biosafety level laboratories
    • Authors: Bruno Perazzo Pedroso Barbosa; Nisio de Carvalho Lobo Brum
      Pages: 1 - 13
      Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124
      Author(s): Bruno Perazzo Pedroso Barbosa, Nisio de Carvalho Lobo Brum
      Laboratory buildings demand from 4 to 6 times more energy use than conventional applications, and near 50% of this energy use is due to its ventilation system. Previous studies have demonstrated that the strategy of increasing ventilation rates, in mixing ventilation mode, has limited effectiveness on airborne infection control and that the local airflow patterns are more important than a global ventilation rate for that purpose. The primary objective of this research was to assess the sensitivity of contaminant contention to variations on indoor flow parameters, for biosafety level (BSL-Biosafety level) laboratories. Selected testing scenarios were modeled, and the only contaminant source was located inside the biological safety cabinet (BSC-Biological safety cabinets). Numerical modeling, using computational fluid dynamics was performed, in order to assess the sensitivity of BSC's contaminant contention to different values on: generation rate; room thermal load; downflow turbulence; inflow velocity; and room air change rate. Another objective of this research was to assess the time scale related to contaminant transport from the BSC interior to the operator respiration zone, after a concentration build up has taken place inside the BSC. The results showed that BSC's contaminant contention is dependent on room indoor flow pattern, room turbulence level and inflow velocity. The use of higher values of ventilation rates in biosafety level laboratories should be analyzed with caution, because increasing the ventilation rate, with mixed ventilation, decreases the BSC's contaminant contention, due to the enhanced turbulent level, and may increase personnel exposure to hazardous contaminants that leak from the BSC.

      PubDate: 2017-09-14T04:07:55Z
      DOI: 10.1016/j.buildenv.2017.07.034
      Issue No: Vol. 124 (2017)
       
  • Home dampness-related exposures increase the risk of common colds among
           preschool children in Shanghai, China: Modified by household ventilation
    • Authors: Chanjuan Sun; Chen Huang; Wei Liu; Zhijun Zou; Yu Hu; Li Shen
      Pages: 31 - 41
      Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124
      Author(s): Chanjuan Sun, Chen Huang, Wei Liu, Zhijun Zou, Yu Hu, Li Shen
      Few studies have estimated the effects of dampness-related exposures and its interaction effects with poor household ventilation on common colds of preschool children. During April 2011–April 2012, we conducted a cross-sectional survey on home environment and childhood health and collected 13,335 parents-reported questionnaires of 4–6 year-old children in Shanghai, China. In this paper, we investigated associations between the incidence and duration of common colds among these children during the past 12 months before the survey and frequency of opening windows, as well as household dampness-related exposures (indicated by six dampness indicators). Significantly higher incidence (≥3 times) and longer duration (≥2 weeks) of common cold were found among children with than without these dampness exposures (p-value <0.01 for mold spots and p-value <0.001 for all other indicators). The number of dampness-related indicators had a positive and strong dose-response relationship with common colds (p-trend <0.01). Low frequency of ventilation was also a risk factor for children common colds. After adjusted for the potential confounders in the multiple logistic regression analyses, all dampness-related indicators were significantly associated with the increased odds of common colds and the highest odds ratios was 1.21 (95% CI: 1.16–1.27). We also found that dampness-related exposures and household ventilation habits (p-value for interaction <0.001) had a strong interaction effect on the incidence and duration of common cold. The stratified analysis of ventilation condition displays that the influence of dampness-related exposures has been modified by ventilation. Therefore, good household ventilation habits may have an effect of modification for dampness-related exposures.

      PubDate: 2017-09-14T04:07:55Z
      DOI: 10.1016/j.buildenv.2017.07.033
      Issue No: Vol. 124 (2017)
       
  • Holistic study of a timber double skin façade: Whole life carbon
           emissions and structural optimisation
    • Authors: Francesco Pomponi; Bernardino D'Amico
      Pages: 42 - 56
      Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124
      Author(s): Francesco Pomponi, Bernardino D'Amico
      The upkeep of existing buildings has a great role to play in reducing the carbon emissions of the built environment. Façade upgrade represents one of the most effective interventions to improve both thermal efficiency and aesthetic appeal of existing buildings. Double Skin Façades (DSFs) have much to offer due to their use of solar and wind energy to passively heat and cool indoor spaces, whilst guaranteeing freedom and flexibility in the aesthetic design of the refurbished building. However, DSFs also bear an increase in the embodied energy and carbon due to the additional materials required for the extra skin throughout all life cycle stages. In this article, life cycle assessment (LCA) and dynamic energy modelling have been combined through a parametric approach to obtain figures for the whole-life cycle carbon assessment of 384 different configurations of an innovative, timber-made DSF for UK low-carbon refurbishments. Additionally, the structural design of the façade was also investigated through a structural optimisation procedure which takes into account all relevant loads and ensures minimal use of the structural material. Results show that operational savings outweigh the embodied impacts and therefore the proposed DSF is a viable and effective solution for net carbon-negative refurbishments. The operational energy modelling also contributes to the characterisation of DSFs thermal behaviour in temperate climates.

      PubDate: 2017-09-14T04:07:55Z
      DOI: 10.1016/j.buildenv.2017.07.046
      Issue No: Vol. 124 (2017)
       
  • Artificial skylight effects in a windowless office environment
    • Authors: Markus Canazei; Wilfried Pohl; Harald R. Bliem; Markus Martini; Elisabeth M. Weiss
      Pages: 69 - 77
      Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124
      Author(s): Markus Canazei, Wilfried Pohl, Harald R. Bliem, Markus Martini, Elisabeth M. Weiss
      Research on the effects of windows has clearly indicated that humans want and need daylight to perform and feel well in indoor environments. However, until now, beneficial skylight effects have rarely been investigated. The present laboratory study aimed to quantify temporary artificial skylight effects using a randomized controlled study design. One hundred healthy young subjects either stayed in a windowless office environment that was illuminated by fluorescent lamps or an artificial skylight system that provided a virtual view of a cloudless sky and sun. Subjects rated room atmosphere parameters and their mood states, and participated in two different decision-making tests. Our results indicated that study participants felt more connected to the nature and perceived the windowless test room as more “lively,” and less “tense” and “detached” under artificial skylight as compared to that under fluorescent illumination. Furthermore, under artificial skylight, subjects reported lower feelings of tension, anxiety, and claustrophobic symptoms, and a higher positive mood state. Finally, subjects made riskier as well as more selfish decisions under artificial skylight. Thus, daylight-substituting technologies may profoundly influence mood states and alter decision-making behavior in windowless environments.
      Graphical abstract image

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.07.045
      Issue No: Vol. 124 (2017)
       
  • The impact of indoor environmental quality on work productivity in
           university open-plan research offices
    • Authors: Shengxian Kang; Dayi Ou; Cheuk Ming Mak
      Pages: 78 - 89
      Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124
      Author(s): Shengxian Kang, Dayi Ou, Cheuk Ming Mak
      Indoor environmental quality (IEQ) has significant impacts on office occupants' productivity and these impacts differ according to the type of office. The present study focuses on a special type of open-plan offices, university open-plan research offices (UOROs), and aims to study how the IEQ of this type of offices affects the occupants' productivity. A four-part IEQ assessment framework for the University Open-plan Research Office (UORO) is first proposed. Then the investigation is conducted based on survey responses collected from 231 people who are working in UOROs from 19 universities in China. The analysis results show a clear picture of (1) how the office productivity is affected by the five key IEQ aspects (layout, air quality, thermal comfort, lighting and acoustic environment), (2) how these five key IEQ aspects are affected by their corresponding sub-factors, such as conversation noise, and (3) how occupants' perception of sub-factors are affected by individual factors, such as occupant demographics and work activity. The results also emphasize the quality of acoustic environment has the greatest influence on the occupants' productivity in UOROs and imply occupants working in UOROs have higher requirements for acoustic environment than in other common types of open-plan offices. Based on the analysis, a decision-making strategy is also presented for the evaluation and improvement of the IEQ of UOROs.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.07.003
      Issue No: Vol. 124 (2017)
       
  • A tracked field study of thermal adaptation during a short-term migration
           between cold and hot-summer and warm-winter areas of China
    • Authors: Yanfeng Liu; Yu Dong; Cong Song; Yingying Wang; Lulu Liu; Jiaping Liu
      Pages: 90 - 103
      Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124
      Author(s): Yanfeng Liu, Yu Dong, Cong Song, Yingying Wang, Lulu Liu, Jiaping Liu
      The thermal adaptation of migrants is a continuous dynamic process which involves the adaptation of migrants to new thermal environment with their natural heat acclimation in original residence; however, this process has rarely been systematically investigated. This study explored whether the thermal comfort of migrants was significantly different from that of the local people during a short-term migration. Furthermore, whether the evolution of migrants' acclimation was developmental or reversible was also discussed. The survey was conducted in summer and included an adaptive investigation in Qionghai for eight days and a de-adaptation research in Xi'an for four days. Seven migrants who grew up in the northern China without any experiences of the southern lifestyle were recruited in a tracking field survey. The natural adaptation of the indigenes in Qionghai was also investigated as the control group. Comparison of indoor physical parameters and thermal subjective evaluation between the migrants and indigenes aided in systematical investigation of the time dependent adaptive level and preferred environment. The results showed that although thermal responses of migrants were significantly different from those of natives in the first and second day of migration, which then followed a trend similar to that of natives. Migrants were more sensitive and adaptive to high humidity environment. This study indicates that consideration of the thermal adaptive trend is definitely required when an indoor thermal environment is attempted to be designed for migrants. The results can be the basis of indoor environment design for migrants.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.07.022
      Issue No: Vol. 124 (2017)
       
  • Energy saving effect of air circulation heat storage system using natural
           energy
    • Authors: Haksung Lee; Akihito Ozaki; Myonghyang Lee
      Pages: 104 - 117
      Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124
      Author(s): Haksung Lee, Akihito Ozaki, Myonghyang Lee
      A central air circulation system that uses a roof ventilation layer and a phase change material (PCM) unit is proposed as a possible means of controlling thermal load and peak load. The central air-conditioning air-circulation-type system enables reduction of sensible heat load and facilitates radiative cooling/forced heat exchange in summer, and solar heat collection in winter, via the roof ventilation layer; thereby improving efficiency. The PCM unit is incorporated into the air circulation route to store the cold energy of the cooled air by radiative cooling and the heat energy of the heated air by solar heat collection. The actual measurement results of an experimental house were analyzed and numerical simulations were performed to evaluate the effective sensible heat and peak load reductions. The quantitative simulation and experimental results indicate that significant sensible heat reduction can be achieved by employing the proposed system, which uses natural energy to reduce the energy consumption of indoor temperature control.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.007
      Issue No: Vol. 124 (2017)
       
  • Classroom ventilation with manual opening of windows: Findings from a
           two-year-long experimental study of a Portuguese secondary school
    • Authors: Rogério Duarte; Maria da Glória Gomes; António Moret Rodrigues
      Pages: 118 - 129
      Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124
      Author(s): Rogério Duarte, Maria da Glória Gomes, António Moret Rodrigues
      Classrooms in Southern Europe are traditionally ventilated with manual opening of windows. This is an energy-sparing and perfectly appropriate way of ventilating classrooms when weather conditions are warm, however, as outdoor air temperatures drop, teaching staff and students tend to leave windows closed and, as a consequence, ventilation rates fall leading to poor indoor air quality. To safeguard classrooms' indoor air quality and promote energy conservation, understanding the conditions for which manual window-airing is appropriate is of great relevance. Yet, given the stochastic nature of window-airing, it is difficult to get hold of this understanding. The main objective of this paper is to find out when manual window-airing of classrooms is appropriate. To achieve this objective, four free-running classrooms of a Portuguese public secondary school were monitored during a two-year period. Ventilation rates were determined and it is concluded that manual opening of windows provides appropriate ventilation for outdoor running mean temperatures larger than 19 °C. When outdoor running mean temperatures are lower than 16 °C, manual window-airing becomes inappropriate and, for outdoor running mean temperatures between 16 and 19 °C, appropriate manual window-airing depends on the indoor air temperature. For the studied classrooms, these results translate into appropriate ventilation for approximately a quarter of the academic year. Because of the significance of this finding, the paper concludes with a review of the ventilation strategy used in the studied classrooms.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.07.041
      Issue No: Vol. 124 (2017)
       
  • Modeling and predicting occupancy profile in office space with a Wi-Fi
           probe-based Dynamic Markov Time-Window Inference approach
    • Authors: Wei Wang; Jiayu Chen; Xinyi Song
      Pages: 130 - 142
      Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124
      Author(s): Wei Wang, Jiayu Chen, Xinyi Song
      Demand-based HVAC control methods in buildings show great energy saving potential when accurate occupancy information is available. Appropriate service based on actual occupant demand could prevent unnecessary energy waste caused by system overcooling or overheating. Therefore, various occupancy detection approaches had attracted increasing attentions in recent years. Among them, Wi-Fi based detection approaches have been thoroughly discussed since Wi-Fi access points (APs) and wireless devices are ubiquitously used in modern buildings. Compared with traditional request and response based occupancy assessment, the newly developed Wi-Fi probe technology can actively scan Wi-Fi enabled devices even if they are not connected to the network. However, Wi-Fi probe detection still subjects to significant errors due to unstable signal and unpredictable occupant behavior. This study stresses the time-series and stochastic characteristics of detected signals and proposes a novel Dynamic Markov Time-Window Inference (DMTWI) model to predict reliable occupancy. The conventional Auto-Regressive Moving Average (ARMA) model and Support Vector Regression (SVR) model are also examined and compared with the proposed approach. Also, an on-site experiment was conducted to validate the proposed model, and the results reveal that the prediction accuracy is over 80% when x-accuracy tolerance is less than 4 for weekdays, 3 for holidays, and 2 for weekend days.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.003
      Issue No: Vol. 124 (2017)
       
  • Spatial variation of temperature of surface soil layer adjacent to
           constructions: A theoretical framework for atmosphere-building-soil energy
           flow systems
    • Authors: Hongxuan Zhou; Jiang Chang; Jing Sun; Chenwei Shang; Fengsen Han; Dan Hu
      Pages: 143 - 152
      Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124
      Author(s): Hongxuan Zhou, Jiang Chang, Jing Sun, Chenwei Shang, Fengsen Han, Dan Hu
      Lack of concern for spatial variation of urban soil temperature does not reflect the importance of soil temperature in ecosystem service. The method of construction-soil micro gradient transects (CSMGT) and in situ observations were applied in this study to understand the mechanism of higher soil temperatures in urban areas and the spatial variation of the temperature of surface soil layer adjacent to constructions. Based on experimental data, a new theoretical framework for atmosphere-building-soil energy flow systems was established to analyse the changing rate of the temperature of surface soil layer (RS) adjacent to constructions. The results of redundancy analysis and hierarchical partitioning showed horizontal heat flux between building and soil (HHF0) played a very important role in driving RS along the CSMGT at night, whereas joint effects of multiple energy factors drove it during daytime or on the scale of an entire day. Moreover, a formula was fitted to express the temperature of surface soil layer (TS) along the CSMGT. Each parameter (a, b and c) of the equation was significant relative to energy or meteorological factors (P < 0.01), and the distribution of the P value of parameter b matched the results of the redundancy analysis and hierarchical partitioning.
      Graphical abstract image

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.002
      Issue No: Vol. 124 (2017)
       
  • Global sensitivity analysis of an urban microclimate system under
           uncertainty: Design and case study
    • Authors: Jiachen Mao; Joseph H. Yang; Afshin Afshari; Leslie K. Norford
      Pages: 153 - 170
      Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124
      Author(s): Jiachen Mao, Joseph H. Yang, Afshin Afshari, Leslie K. Norford
      Over the last decade, significant efforts have been made to develop sophisticated physics-based urban simulators, given the undeniable need for sustainable-city initiatives to consider the potential impacts of climate change and massive urban growth. Nevertheless, even as a growing number of researchers have expanded their scope to the urban realm, there remain many problems resulting from the complexity of the urban microclimate, such as the Urban Heat Island (UHI) effect. This study is initiated with the intention to account for uncertainty in developing more coherent and integrated strategies concerning the energy and environmental issues in an urban system. The analysis builds upon the previously reported and updated Urban Weather Generator (UWG) to present a deep look into an existing urban microclimate system in Abu Dhabi (UAE). The case-specific baseline information is generated for the UWG and a global regression-based sensitivity analysis using the Monte Carlo technique is performed. Based on 30 candidate inputs covering the meteorological factors, urban characteristics, vegetation variables, and building systems, the uncertainty analysis indicates that the UWG is a fairly robust simulator to approximate the urban thermal behavior in downtown Abu Dhabi for different seasons. The identified significant factors will be the subject of future research to gain a higher resolution of critical urban simulation inputs, thereby providing more informed domain knowledge of the underlying mechanisms driving the microclimatic effect on the energy and environmental performances.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.011
      Issue No: Vol. 124 (2017)
       
  • The influence of relative humidity on adaptive thermal comfort
    • Authors: Marika Vellei; Manuel Herrera; Daniel Fosas; Sukumar Natarajan
      Pages: 171 - 185
      Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124
      Author(s): Marika Vellei, Manuel Herrera, Daniel Fosas, Sukumar Natarajan
      Buildings generate nearly 30% of global carbon emissions, primarily due to the need to heat or cool them to meet acceptable indoor temperatures. In the last 20 years, the empirically derived adaptive model of thermal comfort has emerged as a powerful alternative to fixed set-point driven design. However, current adaptive standards offer a simple linear relationship between the outdoor temperature and the indoor comfort temperature, assumed to sufficiently explain the effect of all other variables, e.g. relative humidity (RH) and air velocity. The lack of a signal for RH is particularly surprising given its well-known impact on comfort. Attempts in the literature to either explain the lack of such a signal or demonstrate its existence, remain scattered, unsubstantiated and localised. In this paper we demonstrate, for the first time, that a humidity signal exists in adaptive thermal comfort using global data to form two separate lines of evidence: a meta-analysis of summary data from 63 field studies and detailed field data from 39 naturally ventilated buildings over 8 climate types. We implicate method selection in previous work as the likely cause of failure to detect this signal, by demonstrating that our chosen method has a 56% lower error rate. We derive a new designer-friendly RH-inclusive adaptive model that significantly extends the range of acceptable indoor conditions for designing low-energy naturally-conditioned buildings all over the world. This is demonstrated through parametric simulations in 13 global locations, which reveal that the current model overestimates overheating by 30% compared to the new one.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.005
      Issue No: Vol. 124 (2017)
       
  • Indoor air quality of daycare centers in Seoul, Korea
    • Authors: Sung Ho Hwang; SungChul Seo; Young Yoo; Ki Yeon Kim; Ji Tae Choung; Wha Me Park
      Pages: 186 - 193
      Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124
      Author(s): Sung Ho Hwang, SungChul Seo, Young Yoo, Ki Yeon Kim, Ji Tae Choung, Wha Me Park
      We determined the relation between indoor pollutants and certain building and environmental factors. We gathered data on variables such as biological pollutants (mold and bacteria), and chemical pollutants (formaldehyde, CO2, CO, and total volatile organic compounds, also known as TVOCs) from 25 daycare centers. The level of bacteria exceeded the limit of 800 CFU m−3 as mandated by Korea's Indoor Air Quality (IAQ) standard. The level of these bacteria showed a significant positive association with the building age and area, and a negative link with the ventilation time. As determined through a thermal assessment (p = 0.035), the levels of mold were significantly higher in water-damaged facilities than in those without. The levels of the five VOCs (benzene, toluene, ethylbenzene, xylene, and styrene) were observed at the highest indoors at night, compared to indoors and outdoors during the day. Proper ventilation and management of water and/or relative humidity in daycare buildings can help reduce the exposure to certain biological and chemical pollutants. The findings are useful to ensure the well-being of children in daycare centers.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.07.042
      Issue No: Vol. 124 (2017)
       
  • Integrating 4D thermal information with BIM for building envelope thermal
           performance analysis and thermal comfort evaluation in naturally
           ventilated environments
    • Authors: Worawan Natephra; Ali Motamedi; Nobuyoshi Yabuki; Tomohiro Fukuda
      Pages: 194 - 208
      Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124
      Author(s): Worawan Natephra, Ali Motamedi, Nobuyoshi Yabuki, Tomohiro Fukuda
      Thermal performance of the building envelope exerts considerable influence on maintaining indoor environmental conditions. Acquisition of sensor data of a building is essential to ensure the improvement of the indoor thermal environment for the occupants. The environmental sensor technologies together with Building Information Modeling (BIM) are tools for assessing/analyzing the performance of a building. Although BIM has a potential to verify thermal performance by using a BIM database, integrating the surface-heat of building envelopes and sensing data has not been fully explored in the existing BIM. BIM requires tools to enable building professionals to effectively detect the location of thermal defects and analyze the thermal performance and indoor thermal comfort by accommodating environmental information to be used in the analysis process. Therefore, this research presents a novel method for integrating time-stamped 3D thermal data in the BIM. In the proposed method, the BIM model is integrated with spatio-temporal thermal and air temperature data. Visual scripting is used for extracting and then mapping spatio-temporal thermal data to a 3D BIM model. The proposed system converts the collected thermal images into numeric surface temperatures, integrates collected environmental data in the BIM, calculates thermal comfort variables, such as mean radiant temperature (MRT), and assesses the thermal comfort level for various locations inside the building. The applicability of the proposed method is validated in a real-world case study. The developed prototype system provides valuable visualization information and statistical data for analyzing thermal performance and assessing the thermal comfort level.

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.004
      Issue No: Vol. 124 (2017)
       
  • Development of a computational fluid dynamics model with tree drag
           parameterizations: Application to pedestrian wind comfort in an urban area
           
    • Authors: Geon Kang; Jae-Jin Kim; Dong-Ju Kim; Wonsik Choi; Soo-Jin Park
      Pages: 209 - 218
      Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124
      Author(s): Geon Kang, Jae-Jin Kim, Dong-Ju Kim, Wonsik Choi, Soo-Jin Park
      We implemented a tree-drag parameterization scheme in a computational fluid dynamics (CFD) model and validated the results against wind-tunnel measurement and large-eddy simulation data using several statistical measures. The CFD model underestimated (overestimated) the pollutant concentrations on the leeward (windward) walls inside the street canyon in the presence of trees, because the CFD model could not resolve the latticed cage or simulate the concentration changes caused by the latticed cage. However, the simulated pattern and magnitude of pollutant dispersion were similar to those in the wind-tunnel measurements. The CFD model generally satisfied the statistical validation indices (e.g., normalized root mean square error, geometric mean variance, correlation coefficient, and proportion of predictions within a factor of 2 of the observations) but failed to satisfy the fractional and geometric mean biases due to underestimation (overestimation) on the leeward (windward) wall. We evaluated the trees' effect on pedestrian wind comfort in an urban area, using wind comfort criteria based on the Beaufort wind-force scale (BWS) to investigate the sensory level with respect to human activities. In the tree-free scenario, BWS values of 4 and 5 (i.e., unpleasant conditions for sitting for long and short periods, respectively) appeared in narrow spaces between buildings, the upwind side of buildings, and unobstructed areas. In the tree scenario, the BWS values decreased by 1–3 grades on the Pukyong National University campus located in the target area, indicating that trees planted on the campus effectively improved pedestrian wind comfort.
      Graphical abstract image

      PubDate: 2017-09-02T04:49:10Z
      DOI: 10.1016/j.buildenv.2017.08.008
      Issue No: Vol. 124 (2017)
       
  • Assessing impacts of factors on carbonyl compounds emissions produced from
           several typical Chinese cooking
    • Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Zhiyuan Xiang, Hongli Wang, Svetlana Stevanovic, Shengao Jing, Shengrong Lou, Shikang Tao, Li Li, Jing Liu, Mingzhou Yu, Lina Wang
      Carbonyl compounds are important constituents of photochemical smog and important precursors of photochemical smog formation. In order to investigate concentrations and types of carbonyls generated during cooking process, the influence of cooking styles, food materials, oil types and purification facilities were investigated. Silica cartridge impregnated with 2,4-dinitrophenylhydrazine (2,4-DNPH) and high performance liquid chromatography (HPLC) were adopted for collecting and analyzing samples. Results showed that the emission factors (EFs) of carbonyls (C1-C8) produced from cooking emissions varied within the range of 0.669–1.596 μg/kg. In relation to cooking styles, Barbecue (1.596 μg/kg) > Frying (1.530 μg/kg) > Teppanyaki (1.229 μg/kg) > Stir-frying (0.699 μg/kg), while C1-C3 carbonyls accounted for over 85% for the carbonyls concentrations. Regarding the food materials, generally, carbonyl emissions from meat dishes were greater than for non-meat dishes. Among different oil types used, cooking with sunflower oil resulted in the highest carbonyl emissions. In addition, carbonyls produced from frying carried the highest health risk. The high-voltage electrostatic methodology applied to remove carbonyls did not show as efficient for this purpose. Formaldehyde was found to be the largest contributor to ozone formation potential (OFP).

      PubDate: 2017-09-19T12:57:10Z
       
  • Thermal comfort criteria for personal air supply in aircraft cabins in
           winter
    • Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Yuxin Wu, Hong Liu, Baizhan Li, Yong Cheng, Diyi Tan, Zhaosong Fang
      Personal air supply systems (PASSs) have shown great potential in buildings, but to date, the usefulness of PASSs in aircraft cabins in winter has not been examined. In this study, 40 subjects participated in experiments in a model aircraft cabin constructed at Chongqing University. The subjects were exposed to air from a personal air supply at flow rates of 0, 0.5, 1.0, and 1.5 L/s under eight different conditions: 28, 26, 24, and 22 °C while wearing winter clothing (≈1.23 clo); 24, 22, and 20 °C while wearing winter clothing with a jacket (≈1.55 clo); and 26 °C while wearing summer clothing (≈0.65 clo). The results indicate that the subjects were more thermally sensitive to the environment in the aircraft cabin than that in buildings. Because a higher draft rate (DR) at the face occurred under some conditions, a new DR model based on convective heat transfer at the face was constructed. The perceived air quality (PAQ) had a strong relationship with the airflow rate of the air supply and the standard effective temperature, implying that the PAQ is affected by the heat balance of the body. Thus, recommended adjusted thermal environment criteria for a personal air supply while wearing winter clothing that account for the thermal sensation, drafts, and PAQ are presented.
      Graphical abstract image

      PubDate: 2017-09-19T12:57:10Z
       
  • Investigating parameters affecting the indoor temperature drop after a
           power cut -In-situ measurements and simulations
    • Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Victor Fransson, Hans Bagge, Dennis Johansson
      When looking at energy supply on a larger scale than to a single building, such as to a neighbourhood or a city, the combined effects of peak power demands can be seen to cause problems on the production side. These can be both economic and environmental and lead to the emission of greenhouse gases when fossil fuels are used to meet these peaks. Encouraging the demand side to reduce their power demands at these time could be one way of dealing with this issue. This paper investigates the temperature drops after a power cut both through measurements in the field and comparisons of these results to simulations. A single-family dwelling in use and a multi-family dwelling about to be decommissioned were studied. The comparisons showed that the rates of the temperature drops in reality were slower than in the simulation models. A parametric study of the variables affecting the temperature drops, such as furniture, showed that they might explain these differences.

      PubDate: 2017-09-19T12:57:10Z
       
  • Turbulent Schmidt number for source term estimation using Bayesian
           inference
    • Abstract: Publication date: 15 November 2017
      Source:Building and Environment, Volume 125
      Author(s): Fei Xue, Xiaofeng Li, Ryozo Ooka, Hideki Kikumoto, Weirong Zhang
      Source term estimation (STE) addresses the retrieval of emission source information, including location and strength, based on available information. STE can be viewed as an assimilation process of the observed concentration data measured by a sensor network and the predicted concentration data provided by a dispersion model. When considering emissions in complex urban areas, computational fluid dynamics (CFD) approaches are generally used to provide building-resolving results; however, the value of a key parameter, the turbulent Schmidt number S c t , has remained an arbitrary choice. Therefore, it is important to investigate the role of S c t in STE problems and determine its optimum value for the purpose of obtaining better estimation results. In this paper, the impact of S c t on STE problems is examined, and Bayesian inference is used to improve estimation accuracy by treating S c t as an extra unknown parameter. A wind tunnel experiment with a constant point tracer source in an urban-like geometry is used for demonstration. The results show that S c t has a major impact on estimation. Larger S c t values shift the estimated location towards the upwind direction and decrease the estimated strength. Compared with a conventional estimation method performed by using a pre-assigned value of S c t = 0.7 , treating S c t as an unknown improves point estimates, while the uncertainty increases since the proposed method introduces an extra unknown parameter. For source strength, more improvement in point estimates and a larger increase in uncertainty are shown due to its greater sensitivity of S c t compared with the source location.

      PubDate: 2017-09-19T12:57:10Z
       
  • IFC - Ed. Board
    • Abstract: Publication date: 1 November 2017
      Source:Building and Environment, Volume 124


      PubDate: 2017-09-14T04:07:55Z
       
 
 
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