Analysis of Air Ventilation Performance based on Aerodynamics Simulation

2001 ◽  
Author(s):  
Fuyuki Oshio ◽  
Kenichi Kurosaka ◽  
Kenji Okumura
Keyword(s):  
Air Ventilation ◽  
Ventilation Performance

scholarly journals Air Ventilation Performance of School Classrooms with Respect to the Installation Positions of Return Duct

2021 ◽  
Vol 13 (11) ◽  
pp. 6188
Author(s):  
Sungwan Son ◽  
Choon-Man Jang
Keyword(s):  
Air Quality ◽  
Numerical Analysis ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Three Dimensional ◽  
Cross Infection ◽  
School Students ◽  
Height Range ◽  
Air Ventilation ◽  
Ventilation Performance

For students, who spend most of their time in school classrooms, it is important to maintain indoor air quality (IAQ) to ensure a comfortable and healthy life. Recently, the ventilation performance for indoor air quality in elementary schools has emerged as an important social issue due to the increase in the number of days of continuous high concentrations of particulate matter. Three-dimensional numerical analysis has been introduced to evaluate the indoor airflow according to the installation location of return diffusers. Considering the possibility of the cross-infection of infectious diseases between students due to the direction of airflow in the classroom, the airflow angles of the average respiratory height range of elementary school students, between 1.0 and 1.5 m, are analyzed. Throughout the numerical analysis inside the classroom, it is found that the floor return system reduces the indoor horizontal airflow that causes cross-infection among students by 20% compared to the upper return systems. Air ventilation performance is also analyzed in detail using the results of numerical simulation, including streamlines, temperature and the age of air.

Development and trial of athletic T-shirt using spacer blocks to enhance ventilation

2017 ◽  
Vol 29 (5) ◽  
pp. 706-715
Author(s):  
Chu Po Ho ◽  
Jintu Fan ◽  
Edward Newton ◽  
Raymond Au
Keyword(s):  
Skin Surface ◽  
Air Gap ◽  
Comfort Level ◽  
Treadmill Running ◽  
Thermal Manikin ◽  
Design Development ◽  
Content Type ◽  
Air Ventilation ◽  
Ventilation Performance ◽  
Moisture Vapour

Purpose In previous studies, enlarging the air gap between fabric and the skin through the placement of spacer blocks has been proven to improve air ventilation, particularly when the pumping effect is activated during movement. These studies evaluated only the total thermal insulation (Rt) and moisture vapour resistance (Ret) by using a fabric thermal manikin. The purpose of this paper is to report the experience, perceived comfort level, and ventilation effect of two designed T-shirts in a wearer trial. Design/methodology/approach An athletic T-shirt (Vented Design) was designed by attaching spacer blocks to the underside of the fabric to enlarge the air gap. Eight subjects participated in the wearer trial, which comprised 30 min treadmill running, followed by 10 min of rest. At different points during the 40 min test period, subjects rated their body coolness, skin dryness, and overall comfort of the designed T-shirt. The testing was repeated with participants wearing the same T-shirt but without spacer blocks, which served as a control garment. The mean skin temperature of each subject was also measured to support survey findings. Findings The data were evaluated using independent t-tests. The T-shirt with spacer blocks provided higher ventilation than the control T-shirt after 10 min of running. Research limitations – because of limited resources, only eight subjects were recruited to this study. In addition, more T-shirt designs should be tested in the future to elucidate how T-shirt design affects ventilation performance. Originality/value This study investigated a T-shirt design wherein the air gap between the skin surface and fabric was increased. The results of the wearer trial showed that this design could be adopted as a design brief for further design development of related clothing. This study has implications for clothing designers developing functional clothing with improved ventilation.

Analysis of Natural Ventilation Efficiency of a Passive Solar Chimney in a Conference Hall of the Magic School of Green Technology

2013 ◽  
Vol 368-370 ◽  
pp. 603-606 ◽  
Author(s):  
Chun Han Chien ◽  
Hsien Te Lin
Keyword(s):  
Natural Ventilation ◽  
Ventilation Rate ◽  
Green Technology ◽  
Solar Chimney ◽  
Air Exchange Rate ◽  
Ventilation Efficiency ◽  
Air Ventilation ◽  
Passive Solar ◽  
Ventilation Performance ◽  
Air Exchange

This study focuses on the efficiency of passive solar chimney in natural ventilation performance of the conference hall at the Magic School of Green Technology (MSGT) in Tainan, Taiwan. The air exchange rate in the conference hall was between 5.73 ACH and 9.11 ACH, which exceeded the minimum air ventilation rate required in Taiwan. This shows that a passive solar chimney can effectively applied to the conference hall to meet indoor ventilation and air exchange requirements without using air conditioning.

scholarly journals Experimental assessment of different mixing air ventilation systems on ventilation performance and exposure to exhaled contaminants in hospital rooms

2018 ◽  
Vol 177 ◽  
pp. 207-219 ◽  
Author(s):  
F.A. Berlanga ◽  
I. Olmedo ◽  
M. Ruiz de Adana ◽  
J.M. Villafruela ◽  
J.F. San José ◽  
...  
Keyword(s):  
Experimental Assessment ◽  
Air Ventilation ◽  
Ventilation Performance ◽  
Ventilation Systems

scholarly journals Proposal of a New Method for Controlling the Thaw of Permafrost around the China–Russia Crude Oil Pipeline and a Preliminary Study of Its Ventilation Capacity

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2908
Author(s):  
Yapeng Cao ◽  
Guoyu Li ◽  
Gang Wu ◽  
Dun Chen ◽  
Kai Gao ◽  
...  
Keyword(s):  
Crude Oil ◽  
Natural Ventilation ◽  
Control Method ◽  
Oil Pipeline ◽  
Novel Structure ◽  
Oil Pipelines ◽  
Air Ventilation ◽  
Resistance Loss ◽  
Ventilation Performance ◽  
The Relationship

The China–Russia crude oil pipeline (CRCOP) has been in operation for over ten years. Field observation results have shown that a thaw bulb has developed around the CRCOP which expands at a rate of more than 0.8 m∙a−1 in depth. In view of the deficits of existing measures in mitigating permafrost thaw, a new control method is proposed based on active cooling. According to the relationship between total pressure loss and the driving force of natural ventilation, the wind speed in a U-shaped air-ventilation pipe around the CRCOP is calculated. By analyzing the theoretical calculation and numerical analysis results, it is found that the influence of thermal pressure difference on the natural ventilation of the structure can be negligible, and the influences of resistance loss along the pipe and local resistance loss in the pipe are similarly negligible. Exhaust elbows greatly improve the ventilation performance of the U-shaped air-ventilated pipe. This study developed a novel structure around warm-oil pipelines in permafrost for mitigating thaw settlement along the CRCOP and other similar projects across the world.

Numerical and Experimental Modeling of Indoor Air Quality Inside a Conditioned Space with Mechanical Ventilation and DX-Air Conditioner

2020 ◽  
Vol 38 (9A) ◽  
pp. 1257-1275
Author(s):  
Wisam M. Mareed ◽  
Hasanen M. Hussen
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Ventilation System ◽  
Thermal Conditions ◽  
Airflow Rate ◽  
Air Conditioner ◽  
Breathing Zone ◽  
Lecture Room ◽  
Ventilation Performance

 Elevated CO2 rates in a building affect the health of the occupant. This paper deals with an experimental and numerical analysis conducted in a full-scale test room located in the Department of Mechanical Engineering at the University of Technology. The experiments and CFD were conducted for analyzing ventilation performance. It is a study on the effect of the discharge airflow rate of the ceiling type air-conditioner on ventilation performance in the lecture room with the mixing ventilation. Most obtained findings show that database and questionnaires analyzed prefer heights between 0.2 m to 1.2 m in the middle of an occupied zone and breathing zone height of between 0.75 m to 1.8 given in the literature surveyed. It is noticed the mismatch of internal conditions with thermal comfort, and indoor air quality recommended by [ASHRAE Standard 62, ANSI / ASHRAE Standard 55-2010]. CFD simulations have been carried to provide insights on the indoor air quality and comfort conditions throughout the classroom. Particle concentrations, thermal conditions, and modified ventilation system solutions are reported.

Long-term association between urban air ventilation and mortality in Hong Kong

2021 ◽  
Vol 197 ◽  
pp. 111000
Author(s):  
Pin Wang ◽  
William B. Goggins ◽  
Yuan Shi ◽  
Xuyi Zhang ◽  
Chao Ren ◽  
...  
Keyword(s):  
Hong Kong ◽  
Urban Air ◽  
Air Ventilation
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