The predictions of infection risk of indoor airborne transmission of diseases in high-rise hospitals: Tracer gas simulation

Lim, Taesub; Cho, Jinkyun; Kim, Byungseon Sean

doi:10.1016/j.enbuild.2010.02.008

Cited by 45 publications

(26 citation statements)

References 11 publications

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“…The other disadvantage might be that the results in terms of ACH obtained following measurement conducted over a period of time are average values, and therefore do not allow one to draw any conclusions regarding characteristics of specific periods of time during the measurement period (such as night periods or when the building is not occupied). Our results indicated low specific airflow rates that possibly Downloaded by [Florida International University] at 07:13 28 December 2014 compromise IAQ and occupants comfort and, due to the low ventilation rate, potentiate airborne contaminant transmission (Lim et al, 2010;Sun et al, 2011). Kalema and Viot (2013) found that the use of transferred air between rooms created a flexible and energy-efficient ventilation alternative to maintain a low CO 2 concentration in educational buildings in situations where there is a constant air volume ventilation and where the use of the space is changed.…”

Section: Discussionmentioning

confidence: 90%

Environmental and Ventilation Assessment in Child Day Care Centers in Porto: The Envirh Project

Mendes

Aelenei

Papoila

et al. 2014

Journal of Toxicology and Environmental Health, Part A

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Children attending day care centers (CDCC) have been reported to be more prone to infectious diseases when compared with those cared for at home, and are exposed to conditions that may increase the risk of allergies and asthma. Several studies revealed that consequences of poor ventilation conditions include high levels of carbon dioxide (CO2) and many other indoor pollutants commonly detected in schools. Nine child day care centers were selected randomly to participate in this study. Fifty-two classrooms were assessed for chemical, biological, physical, and allergen parameters in spring and winter seasons in these nine CDCC located in Porto, Portugal. Outdoor measurements were also conducted for comparison. Our results indicated that (i) particulate matter (PM10) median levels were above the national reference levels, both by classroom type and by season; (ii) TVOC kindergarten peak values may raise some concern; (iii) CO2 was present at high median and maximum levels during spring and winter assessment in both nurseries and kindergartens classrooms; (iv) total bacteria concentrations were 57- and 52-fold higher in the nursery and kindergarten than outdoors, respectively, for the spring season; (v) winter and spring median predicted mean vote (PMV) indices were between "neutral" (0) and "slightly cool" (≤ -1) in the thermal sensation scale for comfort situations (-2 to 2) for both types of classrooms; (vi) there were significant differences for both PMV and predicted percentage of dissatisfied (PPD) indices by season; and (vii) CO2, total bacteria, and gram-negative bacteria were associated with low airflow rates. These data will help to evaluate the effectiveness of current building operation practices in child day care centers regarding indoor air quality and respiratory health.

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Section: Discussionmentioning

confidence: 90%

Environmental and Ventilation Assessment in Child Day Care Centers in Porto: The Envirh Project

Mendes

Aelenei

Papoila

et al. 2014

Journal of Toxicology and Environmental Health, Part A

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“…The two-way airflow through the window turned into one-way inflow, and thus re-entry risk was avoided. Lim et al [20,21] further confirmed the possibility of pollutant transmission from lower floors to upper floors through buoyancy-driven airflow by means of field measurement and numerical analysis in a hospital setting. Considering the variety of indoor pollutants, Gao et al [22] utilized Lagrangian and Eulerian models to simulate particulate (pollutant) transmission between adjacent floors.…”

Section: Introductionmentioning

confidence: 89%

Gaseous pollutant transmission through windows between vertical floors in a multistory building with natural ventilation

Wang

Zhang

Wang

et al. 2017

Energy and Buildings

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a b s t r a c tNatural ventilation is an effective strategy to control thermal comfort in buildings, and can be enhanced depending on the window style. The combination of natural ventilation and window can also facilitate the removal or dilution of gaseous pollutants from indoor sources in newly decorated buildings. However, the windows on the same facade may cause gaseous pollutant cross-transmission during single-sided natural ventilation between households on different floors close to the source. Although some research has focused on the pollutant cross-transmission in buildings, the simplification of windows into rectangular openings often affects accurate knowledge of pollutant transmission characteristics. Therefore, this investigation explored gaseous pollutant cross-transmission through real windows during singlesided, buoyancy-driven ventilation in a multistory building. Six types of windows were modeled for the indoor pollutant of gaseous formaldehyde (HCHO). Computational fluid dynamics (CFD) was utilized to solve characteristics of pollutant transmission inside and outside the multistory building. The results indicated that the ventilation rates, thermal profiles and pollutant transmission inside and outside the building varied for each window type, although the open window areas were identical. The re-entry ratio of exhausted air entering upper floors and the infection risk of epidemic viruses caused by airborne cross-transmission was sensitive to ventilation rates and window configurations, while the sensitivities for window configurations varied case by case. The comparisons also revealed that the specification of ambient temperature and pollutant release rate ultimately did not affect the evaluation of pollutant cross-transmission using CFD.

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“…An effective ventilation is recognized as a very important factor in the control of infections, for human comfort and also for energy recovery and system reliability solutions in operating theatres and isolation rooms in hospitals (Galson and Guisbond 1995;Li et al 2007;Méndez et al 2008;Dascalaki et al 2009;Lim et al 2010). It has been shown that an efficient heating, ventilation and air-conditioning (HVAC) installations can control the air quality and aseptic conditions, safe and suitable indoor thermal conditions for medical staff and surgeons, and patients (Balaras et al 2007).…”

Section: Introductionmentioning

confidence: 98%

Hospital ventilation simulation for the study of potential exposure to contaminants

Balocco¹

2011

Build. Simul.

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Airflow and ventilation are particularly important in healthcare rooms for controlling thermohygrometric conditions, providing anaesthetic gas removal, diluting airborne bacterial contamination and minimizing bacteria transfer airborne. An actual hospitalization room was the investigate case study. Transient simulations with computational fluid dynamics (CFD), based on the finite element method (FEM) were performed to investigate the efficiency of the existing heating, ventilation and air-conditioning (HVAC) plant with a variable air volume (VAV) primary air system. Solid modelling of the room, taking into account thermo-physical properties of building materials, architectural features (e.g., window and wall orientation) and furnishing (e.g., beds, tables and lamps) arrangement of the room, inlet turbulence high induction air diffuser, the return air diffusers and two patients lying on two parallel beds was carried out. Multiphysics modelling was used: a thermo-fluidynamic model (convection-conduction and incompressible Navier-Stokes) was combined with a convectiondiffusion model. Three 3D models were elaborated considering different conditions/events of the patients (i.e., the first was considered coughing and/or the second breathing). A particle tracing and diffusion model, connected to cough events, was developed to simulate the dispersal of bacteria-carrying droplets in the isolation room equipped with the existing ventilation system. An analysis of the region of droplet fallout and the dilution time of bacteria diffusion of coughed gas in the isolation room was performed. The analysis of transient simulation results concerning particle path and distance, and then particle tracing combined with their concentration, provided evidence of the formation of zones that should be checked by microclimatic and contaminant control. The present study highlights the fact that the CFD-FEM application is useful for understanding the efficiency, adequacy and reliability of the ventilation system, but also provides important suggestions for controlling air quality, patients' comfort and energy consumption in a hospital.

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The predictions of infection risk of indoor airborne transmission of diseases in high-rise hospitals: Tracer gas simulation

Cited by 45 publications

References 11 publications

Environmental and Ventilation Assessment in Child Day Care Centers in Porto: The Envirh Project

Environmental and Ventilation Assessment in Child Day Care Centers in Porto: The Envirh Project

Gaseous pollutant transmission through windows between vertical floors in a multistory building with natural ventilation

Hospital ventilation simulation for the study of potential exposure to contaminants

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