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.

Indoor Air Quality in a Cardiac Care Unit (CCU) under Different Ventilations

2021 ◽  
Vol 21 (1) ◽  
pp. 1-7
Author(s):  
Abdulhadi Salman ◽  
Ali A. Monem ◽  
Emad A. Khazal
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Indoor Environment ◽  
Thermal Environment ◽  
Numerical Study ◽  
Cardiac Care ◽  
Displacement Ventilation ◽  
Set Up ◽  
Cardiac Care Unit

A proper ventilation offered warranty for a perfect indoor environment. Indoor air environment includes indoor thermal environment and indoor air quality (IAQ). In this paper a numerical investigation of the indoor environment in different ventilations was accomplished. The Cardiac Care Unit (CCU) in Al-Rifai hospital in Thi-Qar governorate was chosen to be investigated, and its thermal achievement and indoor air quality in the hot summer weather were simulated. For the numerical study, the fluent technique used to set up the physical and numerical model of CCU. An attention has been paid carefully to considerate the distributions of the temperature and the velocity fields, followed by an argument of two different ventilation patterns; up-in and up-out ventilation (UV) and displacement ventilation (DV). After making the comparison, it was noticed that the displacement ventilation (DV) is clearly super than that of the up-in and up-out ventilation (UV) due to improvement in the indoor air quality.

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.

scholarly journals Indoor air quality in natural-ventilated bedrooms in renovated Norwegian houses

2021 ◽  
Vol 246 ◽  
pp. 01001
Author(s):  
Vegard Heide ◽  
Silje Skyttern ◽  
Laurent Georges
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Indoor Environment ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Opening Angle ◽  
Single Family ◽  
Night Time ◽  
Window Opening

The objective of this work is to investigate the indoor environment in bedrooms ventilated by window opening during night-time. How window opening behaviour affects indoor air quality (IAQ), and how window opening behaviour and IAQ is influenced by external factors, are important questions. The context is renovation of detached wooden houses in Norway. To motivate building owners to renovate their ventilation system, it is important to know the typical indoor environment in bedrooms of existing buildings with natural ventilation. Ten bedrooms in six case houses were investigated by measuring temperature, relative humidity, CO2, particulate matter, formaldehyde and TVOC. The window opening angle was also logged with an accelerometer. The measurements were conducted over 2 to 3 weeks, during March and April. The dwellings were renovated single-family and terraced houses from 1950 – 80, in Trondheim. All the bedrooms had natural ventilation, and the occupants stated they used to open bedroom windows at night. Participants answered a questionnaire about motivations and habits regarding window opening. The most common reason given for not opening was low outdoor temperatures. The window opening behaviour was both predictable and continuous. Windows were open every night in most of the bedrooms, and most of the windows were opened to the same position every night. High CO2 levels during night were found in two bedrooms. In the other bedrooms, the CO2 concentration was satisfying during night-time, although higher concentrations were found in some bedrooms during daytime. Finally, indoor temperature measurements confirmed that many occupants prefer a low bedroom temperature.

scholarly journals Feasibility of a Passive Ventilation System with a Thermal Damper - Simulations and measurement results of an experimental house in a mild region of Japan -

2019 ◽  
Vol 111 ◽  
pp. 06047
Author(s):  
Motoya Hayashi ◽  
Hoon kim ◽  
Yoshinori Honma ◽  
Junichiro Matsunaga
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Ventilation System ◽  
Indoor Environments ◽  
Air Supply ◽  
Measurement Results ◽  
Simulation Results ◽  
Ventilation Rates ◽  
Ventilation Systems

In order to retain good indoor air quality through the year in detached houses with passive ventilation systems, the authors investigated a mechanical control air-supply method. Firstly, indoor environments in houses with passive ventilation systems with thermal dampers, were examined using a simulation program (Fresh). Secondly, a passive ventilation system with a thermal damper, an under-floorheating system with a heat pump and were installed in an airtight house at Maebashi in Japan and measurements on its ventilation characteristics and indoor air quality were made. The simulation results showed that if the thermal damper is well tuned, this mechanically controlled air-supply opening keeps ventilation rates adequate through the year especially in airtight houses. The measurement results showed that the ventilation rates were kept above the required level through the year and the TVOC concentration decreases from 3000 to 200 μg/m3 in 5 months after the construction.

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.

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 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.

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