Influence of Carbon Dioxide Fluctuation and Thermal Environment on Workability, Physiology and Psychology

Although carbon dioxide (CO2) is a gas not perceived by human, extremely high concentration of CO2 has an influence on the human’s health. High concentration of CO2 also leads to lowering concentration ability and promoting drowsiness. It may also have an influence on productivity and learning efficiency of human. We conducted experiments to measure the amount of workability and the physiological and psychological response of the subjects. In the experiment, the concentration of CO2 was set at the constant level at each case. And then, the concentration of CO2 was changed to examine the physiological and psychological response. In the result of the experiment, the CO2 concentration had the influence on productivity and working efficiency of human. Even if the CO2 concentration is not so high, physiological condition of the human would be also affected

Subject experiment on personal air-conditioning airflow using a vortex ring

A personal air conditioning system using vortex rings, which are characterized by their linearity and low diffusivity, is developed in this study. The authors have clarified the characteristics of the vortex ring airflow by LES (unsteady CFD) and full‐scale experiments. However, the airflow type and worker's comfort using vortex rings as an air conditioning system has not been clarified yet. As a result of the subject experiments, it became clear that air conditioning with vortex rings cooled the subjects better than conventional air conditioning and improved their sense of comfort with respect to the airflow. In addition, it was found that airflow to the neck was more effective since the subjects were less likely to feel the airflow at the top of the head due to the resistance of the hair on the head. The effectiveness of the vortex ring as a personal air conditioning system was clarified, enabling relaxation of the room temperature setting. The comfortability of the airflow sensation provided by the vortex ring was also examined when further airflow was given

Assessment of the impacts of window-to-wall ratio and overhangs on building energy performance – Kabul, Afghanistan

Windows have the potential to save energy in a significant way. Therefore, the analysis and optimization of the Window-to-Wall Ratio (WWR) play an important role in improving energy efficiency in buildings. Windows are always beneficial to utilize daylight and reduce lighting energy demand. However, solar heat gain is advantageous during cold days and disadvantageous on hot days. As the configuration of the window areas varies according to the geographical location, the objective of this study is to evaluate the impact of WWR on the energy performance of buildings in the cold semi-arid climate of Kabul, Afghanistan. In this study, various energy simulations were conducted for three types of building shapes (Square, Rectangle, and “L”-Shape) to determine the most energy-efficient proportion of windows and overhang sizes in different cardinal directions. Based on the simulation results, windows on south façades have notable energy-saving potential in Kabul's climatic conditions. However, increasing the window size on north, east, and west façade leads to an increase in the total heating and cooling energy consumption. The optimal WWR of the south façade window for square, rectangular, and “L”-Shaped is 0.7, 0.55, and 0.55, respectively. Additionally, the findings indicate that overhangs in all orientations slightly affect the total energy demand as they only reduce cooling load. The study concludes that optimizing the windows on the south façade reduces energy demand by up to 8.13% if no windows are provided in other directions, while the total energy consumption rises by up to 36% as the WWR on the north, east, and west façades increase from 0 to 0.8

Research on Differences Between Multiple Workspaces in ABW Offices on Productivity and Communication, Psychological and Physiological Quantities

In this study, we will investigate the effects of different work environments on intellectual productivity and communication in an Activity-Based-Working (ABW) oriented B-site office of Company A, which has multiple workspaces with different settings for the purpose of improving productivity and health. In this paper, we use a subject experiment and report on the effects of different work environments on the intellectual productivity and physiological and psychological quantities of the subjects in the ABW office, based on the outline of the building where the subject experiments were conducted and the results of objective and subjective evaluations of the subject experiments conducted in the middle and summer periods

A collaborative platform for sustainable building design based on model integration over the internet

Considerable potential exists for reducing life cycle environmental impacts of buildings in Japan. While energy consumption during the operation stage of a building's lifetime is usually dominant, indirect energy use and pollutant emissions associated with production and disposal of building materials during construction and demolition are significant. For sustainable building design, interactions between the performance and dynamics of the building structure and energy systems must be considered. A collaborative platform based on the distributed object-based modelling environment, DOME, and a set of component models for sustainable building design analysis is presented. Integration examples of the component models to study particular building designs are described

New k-ε Model including Damping Effect due to Buoyancy in Stratified Flowfield

暖房時，冷房時の室内空間等においては，流れ場が成層化し浮力に基づくダンピング効果により鉛直方向の乱流輸送が抑制され，流れ場の一部が層流化する現象が，しばしば観察される．この浮力ダンピングの効果をk-εEVMに組み込んだ新しい改良型モデルを提案し，このモデルの性能を検証した．また温度成層により流れが層流化する現象に対し，従来壁近傍でのみ適用されてきている低Re数型k-εモデルを，壁面の影響を直接受けない領域での層流化効果に対しても適用可能となるように改良して用いた．特集 乱流の数値シミュレーション（NST） その1

Numerial and Experimental Stuldy on Thermally Stratified Flowfield within Atrium Space

近年，アトリウムと称されるガラスで覆われた巨大吹抜空間が数多く建築されるようになった．アトリウム空間の特徴として一般に，① 天丼が高い，② 日射が差し込む，③ 鉛直方向の温度分布が生じやすい，④ 空調される居住域が空間の一部に限定される，などがある．このため良好な居住環境を実現するためには，設計に際し流れ場の熱輸送状態の正しい解析が必要とされる．本報では夏季のモデルアトリウム空間内の流れ場・温度場性状に関し，熱的成層を考慮したk-εモデルおよび模型実験により解析を行い，温度成層時の流れ場・熱輸送現象に関して考察を行った．特集 乱流の数値シミュレーション（NST） その