Influence of ventilation strategies on dispersion and removal of fine particles: An experimental and simulation study

Çetin, Yunus Emre; Avcı, Mete; Aydın, Orhan

doi:10.1080/23744731.2019.1701332

Cited by 7 publications

(9 citation statements)

References 50 publications

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“…The velocity contours and vectors in the center plane of the y‐direction in Cases 1–3 are illustrated in Figure 5. The airflow distribution is mainly characterized by the air jet and eddies that appear within the flow domain 52 . As the ACH increases, circulation is enhanced.…”

Section: Resultsmentioning

confidence: 99%

“…All of the particles are instantaneously injected from the inlet into the indoor environment 51 . The total particle‐tracking time is 3600 s. The residuals for all variables are below 10 −4 for all equations 52 . Because the density differs depending on the pollen particle, to gain basic knowledge of the pollen particle tracks, the density is assumed to be the same as that of water (1.0 g/cm 3 ).…”

Section: Methodsmentioning

confidence: 99%

“…When the particle/wall interaction is set to rebound, particles are rebounded back into the air after touching the walls, and the StR value equals 0. Therefore, the RR values are affected by the ACH and AR values 52 . It is also necessary to eliminate the interference of the particle‐rebounding distance (critical line) on the statistics of the particles' SR and AR in the air, and the influence of the change of inlet/outlet locations and particle diameter on the particle‐rebounding distance.…”

Section: Methodsmentioning

confidence: 99%

“…51 The total particle-tracking time is 3600 s. The residuals for all variables are below 10 −4 for all equations. 52 Because the density differs depending on the pollen particle, to gain basic knowledge of the pollen particle tracks, the density is assumed to be the same as that of water (1.0 g/cm 3 ). The particle diameters considered for each case are 1, 5, 10, and 30 μm.…”

Section: Case Settingsmentioning

confidence: 99%

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A numerical study on the relationship between particle dispersion, accumulation, and indoor airflow in different ventilated rooms

Wang

Ooka

Kikumoto

et al. 2023

Japan Architectural Review

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This study serves as a basic study of the indoor dispersion of pollen particles, simulating the flow field and discussing the behavior of particles of different diameters in different rooms. By comparing the vertical velocity components of particles () and the mean flow velocity of z‐direction component () plus the terminal settling velocity in a gravitational field (), the differences between values and plus values are found to occur mainly at locations close to the opposite wall of the inlet. The location of the differences between values and plus values is important findings of this study, which facilitates the improvement of the simulation method at a later stage and the rational design of indoor ventilation patterns to easily remove particles from the room.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Case Settingsmentioning

confidence: 99%

See 2 more Smart Citations

A numerical study on the relationship between particle dispersion, accumulation, and indoor airflow in different ventilated rooms

Wang

Ooka

Kikumoto

et al. 2023

Japan Architectural Review

View full text Add to dashboard Cite

show abstract

“…Special attention has also been given to pathogen transmission using Reynolds-averaged Navier Stokes (RANS), unsteady Reynolds-averaged Navier Stokes (URANS) and Reynolds Stress (RS) models associated with ventilation strategies for particle removal and dispersion (Cetin et al 2020a ; He et al 2011 ; Katramiz et al 2020 ; Murga et al 2020 ; Park and Chang 2019 ; Shao et al 2020 ; Wang et al 2020 ), human movement (Li et al 2020 ; Tao et al 2020 ; Tao et al 2019 ), comparison of Eulerian-Eulerian and Eulerian–Lagrangian approaches for the pathogens transport and trajectory (Yan et al 2020 ) and human expiratory events (e.g. coughing, sneezing, speaking) (Chen and Zhao 2010 ; de Oliveira et al 2021 ; Kang et al 2015 ; Li et al 2018 ; Licina et al 2015 ; Liu et al 2016a , b ; Yan et al 2019 ; Zhang et al 2020a , b , c , d ; Zhu et al 2006 ), among others.…”

Section: Computer Modelling Of Particles and Biological Agents’ Airbo...mentioning

confidence: 99%

Airborne transmission of biological agents within the indoor built environment: a multidisciplinary review

Argyropoulos

Skoulou

Efthimiou

et al. 2022

Air Qual Atmos Health

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The nature and airborne dispersion of the underestimated biological agents, monitoring, analysis and transmission among the human occupants into building environment is a major challenge of today. Those agents play a crucial role in ensuring comfortable, healthy and risk-free conditions into indoor working and leaving spaces. It is known that ventilation systems influence strongly the transmission of indoor air pollutants, with scarce information although to have been reported for biological agents until 2019. The biological agents’ source release and the trajectory of airborne transmission are both important in terms of optimising the design of the heating, ventilation and air conditioning systems of the future. In addition, modelling via computational fluid dynamics (CFD) will become a more valuable tool in foreseeing risks and tackle hazards when pollutants and biological agents released into closed spaces. Promising results on the prediction of their dispersion routes and concentration levels, as well as the selection of the appropriate ventilation strategy, provide crucial information on risk minimisation of the airborne transmission among humans. Under this context, the present multidisciplinary review considers four interrelated aspects of the dispersion of biological agents in closed spaces, (a) the nature and airborne transmission route of the examined agents, (b) the biological origin and health effects of the major microbial pathogens on the human respiratory system, (c) the role of heating, ventilation and air-conditioning systems in the airborne transmission and (d) the associated computer modelling approaches. This adopted methodology allows the discussion of the existing findings, on-going research, identification of the main research gaps and future directions from a multidisciplinary point of view which will be helpful for substantial innovations in the field.

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Removal efficiency of restroom ventilation revisited for short-term evaluation

Chen,

Zhai,

Yuan

et al. 2024

City Built Enviro

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Ventilation efficiency or contaminant removal efficiency is often evaluated using the ratio between the concentrations in the exhaust air and the room air. This ratio does not truly represent the expectation of ventilation in restrooms, where dynamic airflow fields and sources are more typical. This study focuses on a short-term (10 min) pollutant removal percentage in a residential restroom featuring a dynamic airflow field, particularly with the onset of window-induced stack ventilation during toilet uses. Thirteen ventilation scenarios of a residential restroom were studied using the numerical method that was validated by a mock-up experiment. The scenarios differed in the operation of the exhaust fan and window. Results show that the 10-min pollutant removal percentage of a typical exhaust ventilation system at 10 h-1 air change rate (ACH) is only 68.5%. Under exhaust ventilation, opening the window can introduce both adverse short circuit and favorable stack ventilation depending on the difference between the indoor and outdoor temperatures. As the temperature difference increases from 0 to 12.5 °C, the removal percentage increases from below 50%, a drop due to short circuit, to above 98% thanks to a tripled ventilation rate. The human thermal plume has notable effect on the removal percentage, but its effect can be neglected with the presence of stack ventilation. The hybrid ventilation strategy has impact on perceived air quality and thermal comfort. When the outdoor air is colder, opening the window under exhaust ventilation may increase the current sitting user’s exposure to the self-produced pollutants but can reduce the exposure of the next immediate standing user. In addition, opening the window in cold days will make the toilet user thermally uncomfortable with reduced local temperatures and increased airflow velocities. The study highlights the importance of using the short-term removal percentage to evaluate the performance of restroom ventilation.

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Influence of ventilation strategies on dispersion and removal of fine particles: An experimental and simulation study

Cited by 7 publications

References 50 publications

A numerical study on the relationship between particle dispersion, accumulation, and indoor airflow in different ventilated rooms

A numerical study on the relationship between particle dispersion, accumulation, and indoor airflow in different ventilated rooms

Airborne transmission of biological agents within the indoor built environment: a multidisciplinary review

Removal efficiency of restroom ventilation revisited for short-term evaluation

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