Ventilation Performance and Indoor Air Quality in Workstations under Different Supply Air Systems: A Numerical Approach

1997 ◽  
Vol 6 (3) ◽  
pp. 160-167
Author(s):  
Z. Jiang ◽  
F. Haghighat ◽  
Q. Chen
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Numerical Approach ◽  
Ventilation Performance

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.

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.

The Potential of Natural Ventilation in Single-Sided Ventilated Apartment to Improve Indoor Thermal Comfort and Air Quality

2011 ◽  
Author(s):  
M. F. Mohamed ◽  
M. Behnia ◽  
S. King ◽  
D. Prasad
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Architectural Element ◽  
Flat Design ◽  
Effective Ventilation ◽  
Computational Fluid Dynamics Cfd ◽  
Ventilation Performance

Cross ventilation is a more effective ventilation strategy in comparison to single-sided ventilation. In the NSW Residential Flat Design Code1 (RFDC) the majority of apartments are required to adopt cross ventilation. However, in the case of studio and one-bedroom apartments, it is acknowledged that single-sided ventilation may prevail. Deep plan studio and one-bedroom apartments may achieve lower amenity of summer thermal comfort and indoor air quality where mechanical ventilation is not provided by air conditioning. Since compliance with the code may allow up to 40% of apartments in a development in Sydney to be single sided, it is important to understand the natural ventilation performance of such apartments. The objective of this paper is to investigate the natural ventilation potential in single-sided ventilated apartments to improve indoor air quality and thermal comfort. This investigation includes simulating various facade treatments involving multiple opening and balcony configurations. Balcony configurations are included in this study because, in Sydney, a balcony is a compulsory architectural element in any apartment building. The study uses computational fluid dynamics (CFD) software to simulate and predict the ventilation performance of each apartment configuration. This study suggests that properly configured balconies and openings can significantly improve indoor ventilation performance for enhanced indoor air quality and thermal comfort, by optimizing the available prevailing wind. However, it is important to note that inappropriately designed fac¸ade treatments also could diminish natural ventilation performance.

A Study on the Evaluation of Ventilation Performance According to the Location of the Return Diffusers of an Upward Displacement Ventilation System in a Dome-Shaped Small Concert Hall

2019 ◽  
Vol 27 (03) ◽  
pp. 1950028
Author(s):  
Yong-Il Kwon
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Ventilation System ◽  
Vertical Wall ◽  
High Energy ◽  
Displacement Ventilation ◽  
Concert Hall ◽  
Upward Displacement ◽  
Ventilation Performance

The modern people are active in various cultural facilities and enjoy the leisure life. The spectators and performers using a small concert hall generally use this space for about 2[Formula: see text]h in an enclosed state, and so the space should maintain a comfortable thermal environment and indoor air quality. The ventilation systems that can be applied to small concert hall are generally classified as the mixing ventilation system and the displacement ventilation system, but the upward displacement ventilation system is known to be able to maintain the clean indoor air quality with high energy efficiency. The upward displacement ventilation system installed in a dome-shaped small concert hall is not limited in the height of the vertical wall. Therefore, it is necessary to evaluate the optimal height of the return diffuser by utilizing the ventilation performance and the air diffusion performance index (ADPI). This study was carried out to evaluate the effect of the return diffuser position on the ventilation performance of an upward displacement ventilation system installed in a dome-shaped small concert hall. It was confirmed that as the height at which the return diffuser is installed on the vertical wall increases, the ventilation efficiency increases and the thermal stratification formed in the upper area is significantly reduced.

Modelling the impact of multizone airleakage on ventilation performance and indoor air quality in low-energy homes

2019 ◽  
Vol 12 (6) ◽  
pp. 1141-1159
Author(s):  
Gaëlle Guyot ◽  
Hugo Geoffroy ◽  
Michel Ondarts ◽  
Léna Migne ◽  
Mallory Bobee ◽  
...  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Low Energy ◽  
Ventilation Performance ◽  
The Impact

scholarly journals Application of Wind as a Renewable Energy Source for Passive Cooling through Windcatchers Integrated with Wing Walls

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2536 ◽  
Author(s):  
Payam Nejat ◽  
Fatemeh Jomehzadeh ◽  
Hasanen Hussen ◽  
John Calautit ◽  
Muhd Abd Majid
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Passive Cooling ◽  
Quality Factors ◽  
Ventilation Performance ◽  
Wing Walls ◽  
The Impact ◽  
Ventilation Systems

Generally, two-third of a building’s energy is consumed by heating, ventilation and air-conditioning systems. One green alternative for conventional air conditioner systems is the implementation of passive cooling. Wing walls and windcatchers are two prominent passive cooling techniques which use wind as a renewable resource for cooling. However, in low wind speed regions and climates, the utilization of natural ventilation systems is accompanied by serious uncertainties. The performance of ventilation systems can be potentially enhanced by integrating windcatchers with wing walls. Since previous studies have not considered this integration, in the first part of this research the effect of this integration on the ventilation performance was assessed and the optimum angle was revealed. However, there is still gap of this combination; thus, in the second part, the impact of wing wall length on the indoor air quality factors was evaluated. This research implemented a Computational Fluid Dynamics (CFD) method to address the gap. The CFD simulation was successfully validated with experimental data from wind tunnel tests related to the previous part. Ten different lengths from 10 cm to 100 cm were analyzed and it was found that the increase in wing wall length leads to a gradual reduction in ventilation performance. Hence, the length does not have a considerable influence on the indoor air quality factors. However, the best performance was seen in 10 cm, that could provide 0.8 m/s for supply air velocity, 790 L/s for air flow rate, 39.5 1/h for air change rate, 107 s for mean age of air and 92% for air change effectiveness.

Measurement and Simulation of Indoor Air Quality and CO2 Concentration in a Hotel Room

2010 ◽  
Author(s):  
Ehsan Asadi ◽  
Manuel Gameiro da Silva ◽  
Jose´ J. Costa
Keyword(s):  
Air Quality ◽  
Simulation Model ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Co2 Concentration ◽  
Simulation Software ◽  
Building Simulation ◽  
Airflow Rate ◽  
Air Exchange Rate ◽  
Ventilation Performance

Indoor air quality (IAQ) is nowadays universally recognized as an important issue that affects the comfort and health of people, as well as their productivity. This paper describes the relationship of indoor CO2 concentration to building air quality and ventilation, with a focus on how CO2 can be used to evaluate and predict air quality and ventilation performance, namely the infiltration airflow rate. Besides it shows the ability of ESP-r building simulation software for predicting the CO2 concentration and the air exchange rate in a building. For this purposes a room of a hotel located in the urban area of Coimbra was chosen. The developed simulation model was then validated against empirical results. It was shown that a fair degree of agreement between ESP-r results and the experimental observation exist for the zones. High accuracy of the simulation model showed that building simulation software, namely ESP-r can provide a better understanding of indoor environmental conditions and be a powerful tool in finding the best modification measures for improving the indoor air quality in a building.

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