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.

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.

Computational Modeling of Particulate Pollutant Transport in a Ventilated Room in the Presence of Two Heated Breathing and Rotating Manikins

2017 ◽  
Author(s):  
Seyed Ali Keshavarz ◽  
Mazyar Salmanzadeh ◽  
Goodarz Ahmadi
Keyword(s):  
Air Quality ◽  
Computational Modeling ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Rotational Motion ◽  
Indoor Environment ◽  
Ventilation System ◽  
Thermal Plume ◽  
Displacement Ventilation ◽  
Simulation Results

Recently, attention has been given to indoor air quality due to its serious health concerns. Clearly the dispersion of pollutant is directly affected by the airflow patterns. The airflow in indoor environment is the results of a combination of several factors. In the present study, the effects of thermal plume and respiration on the indoor air quality in a ventilated cubicle were investigated using an unsteady computational modeling approach. The person-to-person contaminant transports in a ventilated room with mixing and displacement ventilation systems were studied. The effects of rotational motion of the heated manikins were also analyzed. Simulation results showed that in the cases which rotational motion was included, the human thermal plume and associated particle transport were significantly distorted. The distortion was more noticeable for the displacement ventilation system. Also it was found that the displacement ventilation system lowered the risk of person-to-person transmission in an office space in comparison with the mixing ventilation system. On the other hand the mixing system was shown to be more effective compared to the displacement ventilation in removing the particles and pollutant that entered the room through the inlet air diffuser.

Modeling the Applicability of a Displacement Ventilation System

2021 ◽  
Vol 11 (1) ◽  
pp. 63-89
Author(s):  
Edgar C. Ambos ◽  
Evan Neil V. Ambos ◽  
Lanndon A. Ocampo
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Heat Load ◽  
Ventilation System ◽  
Internal Heat ◽  
The Philippines ◽  
Airflow Rate ◽  
Displacement Ventilation ◽  
Tropical Country

Due to its significant role in improving indoor air quality, displacement ventilation system is widely adopted in current literature. This paper proposes a displacement ventilation system for room conditions with ceilings that are relatively low, internal heat load could be high, walls could be sunlit, and occupants doing the low physical activity. These conditions are prevalent in the Philippines, being a tropical country. Input parameters to the design process such as heat load, the height of the ceiling, comfort, and indoor air quality requirements were generated, and the main output parameters are the stratification height and ventilation airflow rate. To demonstrate the proposed displacement ventilation system, four cases were generated. Results show that the ventilation airflow rates obtained from the four cases were greater than the minimum outdoor air requirements for health in conference rooms and large assembly areas which are 17.5 and 3.5 liters/sec*person respectively, for smoking and no smoking rooms.

The Indoor Air Quality and Thermal Comfort Experimental Research on the Combined Cooling Ceiling and Displacement Ventilation System

2012 ◽  
Vol 193-194 ◽  
pp. 1048-1051
Author(s):  
Jiu Chen Ma ◽  
Zhi Gang Zhang
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Ventilation System ◽  
Displacement Ventilation ◽  
Air Velocity ◽  
Air Conditioning System ◽  
Combined Cooling ◽  
General Guidance

In this energy saving and environment protection society, as a new kind of air conditioning system, the combined cooling ceiling (CC) and displacement ventilation (DV) system has been attracting more and more attention both at home and abroad. This paper has done experiments with different supply air temperature, various supply air velocity and changeable temperature of supply water by simulating to cool a small office in summer. Based on similarity theories, some suggestions are given for the numerical area of cooling parameters under some laboratory conditions. According to PMV, it is also presented in general guidance for indoor air quality and thermal comfort with CC/DV system.

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.

scholarly journals Indoor Air Quality Real-Time Monitoring in Airport Terminal Areas: An Opportunity for Sustainable Management of Micro-Climatic Parameters

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3798 ◽  
Author(s):  
Sara Zanni ◽  
Francesco Lalli ◽  
Eleonora Foschi ◽  
Alessandra Bonoli ◽  
Luca Mantecchini
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Real Time ◽  
Indoor Air ◽  
Electronic Monitoring ◽  
Ventilation System ◽  
Real Time Monitoring ◽  
Airport Terminal ◽  
Air Ventilation ◽  
Gaseous Contaminants

Indoor air quality (IAQ) management in public spaces is assuming a remarkable importance. Busy environments, like airport terminals, are currently regarded as possible hotspots and IAQ is a crucial element for passengers and staff protection, as well as a key aspect of airport passenger experience. A one-month monitoring period has been performed on IAQ in the airport of Bologna (Italy), as prototypal example of large regional airport. Four strategic areas within the airport have been equipped with electronic monitoring platforms, including different contaminants and two microclimatic sensors. Data suggest that daily variation in IAQ parameters typically follow the activity pattern of the different environments under study (i.e., passengers’ flows) for gaseous contaminants, where particulate matter counts oscillate in a definite range, with a significant role played by ventilation system. Gaseous contaminants show a correlation between indoor and outdoor concentrations, mainly due to airside activities. Micro-climatic comfort parameters have been tested to match with standards for commercial environments. As results appears in line with typical households IAQ values, the current air ventilation system appears to be adequate. Nevertheless, an integrated air management system, based on real-time monitoring, would lead to optimization and improvement in environmental and economical sustainability.

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.

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