Effect of air change rate on particle dispersion from inlet opening under varying particle source strengths

2020 ◽  
pp. 1-18
Author(s):  
Yunus Emre Cetin ◽  
Mete Avci ◽  
Orhan Aydin
Keyword(s):  
Particle Dispersion ◽  
Change Rate ◽  
Particle Source ◽  
Air Change Rate ◽  
Inlet Opening

scholarly journals Influence of Ceiling Height on Airflow and Particle Distribution in an Operating Room

2019 ◽  
Vol 111 ◽  
pp. 01032
Author(s):  
Aleyna Agirman ◽  
Yunus Emre Cetin ◽  
Mete Avci ◽  
Orhan Aydin
Keyword(s):  
Operating Room ◽  
Particle Distribution ◽  
Numerical Study ◽  
Surgical Site Infections ◽  
Particle Dispersion ◽  
Ansys Fluent ◽  
Change Rate ◽  
Numerical Predictions ◽  
Air Change Rate ◽  
Ceiling Height

Bacteria-carrying particles released by surgical staff are the main factors leading to surgical site infections (SSI). Operating rooms must be designed to reduce risks of such infections. In this numerical study, the effect of different ceiling heights on particle dispersion and deposition are studied for an operating room with laminar airflow (LAF) system. Two different particle diameters (12 and 20 ìm) are tested under three different ceiling heights (2.43–2.8–3.0 m) at a constant air change rate (ACH=20). Numerical predictions are performed by using the commercial software ANSYS Fluent 16.0. The results reveal that decreasing of the ceiling height reduces the amount of particle deposited on the surgical table.

scholarly journals Effect of Zero Air Change Rate On Particle Dispersion in A Room with Floor Heating

2019 ◽  
Vol 111 ◽  
pp. 02037
Author(s):  
Mustafa Mutlu
Keyword(s):  
Particle Diameter ◽  
Heating System ◽  
Ambient Air ◽  
Particle Dispersion ◽  
Lagrangian Model ◽  
Residential Areas ◽  
Change Rate ◽  
Heating Systems ◽  
Air Change Rate ◽  
Floor Heating

Dispersion of airborne particles in the office and residential areas should be well known as these particles in an enclosed volume has a significant effect on human health. In this study, the effect of the floor heating system, which is often preferred by end users due to the energy efficiency of low heating systems, on particle distribution in a room was investigated numerically. It is essential to examine the floor heating having a significant place among low heating systems, concerning particle dispersion. In enclose volumes, ambient air should be replaced with fresh air that is supplied from outdoor in order to ensure indoor air quality. However, the ideal air change rates may not be met for daily use, even in some cases air change rates might be zero. Therefore, in this study absence of air change were assumed, and after temperature and velocity distributions were determined, five different sized particles were tracked by using Eulerian-Lagrangian model. Additionally, three heating capacities (35 W/m2 41.25 W/m2 and 47 W/m2) of the floor heating system were investigated. In this study, where computational fluid dynamics were used, the effect of drag, lift, thermophoretic and Brownian forces were considered. It was found that particles were settled on walls and ceiling due to zero air change rate, and particle concentration rises in the lower part of the wall as particle diameter increases.

scholarly journals Comparison of Downdraught and Up Draft Passive Air Conduction Systems (PACS) in a Winery Building

Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 259
Author(s):  
Ádám László Katona ◽  
István Ervin Háber ◽  
István Kistelegdi
Keyword(s):  
Air Conditioning ◽  
Natural Ventilation ◽  
Dynamics Simulation ◽  
Computational Fluid Dynamics Simulation ◽  
General Applicability ◽  
Change Rate ◽  
Air Change Rate ◽  
Simulation Based ◽  
Ventilation Performance ◽  
Air Conduction

A huge portion of energy consumption in buildings comes from heating, ventilation, and air conditioning. Numerous previous works assessed the potential of natural ventilation compared to mechanical ventilation and proved their justification on the field. Nevertheless, it is a major difficulty to collect enough information from the literature to make decisions between different natural ventilation solutions with a given situation and boundary conditions. The current study tests the passive air conduction system (PACS) variations in the design phase of a medium-sized new winery’s cellar and production hall in Villány, Hungary. A computational fluid dynamics simulation based comparative analysis enabled to determine the differences in updraft (UD) and downdraught (DD) PACS, whereby the latter was found to be more efficient. While the DD PACS performed an air change range of 1.02 h−1 to 5.98 h−1, the UD PACS delivered −0.25 h−1 to 12.82 h−1 air change rate. The ventilation performance of the DD version possessed lower amplitudes, but the distribution was more balanced under different wind incident angles, thus this version was chosen for construction. It could be concluded that the DD PACS provides a more general applicability for natural ventilation in moderate climates and in small to medium scale industry hall domains with one in- and one outlet.

scholarly journals Estimation of a room ventilation air change rate using a stochastic grey-box modelling approach

Measurement ◽  
2018 ◽  
Vol 124 ◽  
pp. 539-548 ◽  
Author(s):  
Marcel Macarulla ◽  
Miquel Casals ◽  
Núria Forcada ◽  
Marta Gangolells ◽  
Alberto Giretti
Keyword(s):  
Change Rate ◽  
Room Ventilation ◽  
Air Change Rate ◽  
Modelling Approach

scholarly journals Quality of life control by selected methods of air exchange in a typical apartment building

2021 ◽  
Author(s):  
Iveta Bullová ◽  
Peter Kapalo ◽  
Dušan Katunský
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Allergic Diseases ◽  
Well Being ◽  
Indoor Climate ◽  
Apartment Building ◽  
Change Rate ◽  
Air Change Rate ◽  
Negative Effect

Air change rate is an important parameter for quantification of ventilation heat losses and also affects the indoor climate of buildings. Indoor air quality is significantly associated with ventilation. If air change isn't sufficient, trapped allergens, pollutants and irritants can degrade the indoor air quality and affect the well-being of a building's occupants. Many studies on ventilation and health have concluded that lower air change rates can have a negative effect on people’s health and low ventilation may result in an increase in allergic diseases. Quantification of air change rate is complicated, since it is affected by a number of parameters, of which the one of the most variable is the air-wind flow. This study aims to determination and comparison of values of the air change rate in two methods - by quantifying of aerodynamic coefficient Cp = Cpe - Cpi – so called aerodynamic quantification of the building and the methodology based on experimental measurements of carbon dioxide in the selected reference room in apartment building.

scholarly journals Intra-Cage Air Change Rate on Forced-Air-Ventilated Micro-Isolation System-Environment within Cages: Carbon Dioxide and Oxygen Concentration.

1997 ◽  
Vol 46 (4) ◽  
pp. 251-257 ◽  
Author(s):  
Masakazu HASEGAWA ◽  
Yuzuru KURABAYASHI ◽  
Toshinori ISHII ◽  
Kazuya YOSHIDA ◽  
Nobukazu UEBAYASHI ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Concentration ◽  
Isolation System ◽  
Change Rate ◽  
System Environment ◽  
Air Change Rate ◽  
Forced Air
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