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Building Simulation 2011, 4(1): 5-20 https://doi.org/10.1007/s12273-011-0019-6
Research Article | Issue | Published: 04 December 2011

Hospital ventilation simulation for the study of potential exposure to contaminants

Show Author's Information Carla Balocco( )
Department of Energy Engineering "Sergio Stecco", via S. Marta 3, 50139 Firenze, Italy
Keywords:
transient simulation, CFD, ventilation, HVAC, VAV plant, virus diffusion, isolation rooms
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Balocco C. Hospital ventilation simulation for the study of potential exposure to contaminants. Building Simulation, 2011, 4(1): 5-20. https://doi.org/10.1007/s12273-011-0019-6
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Abstract Full text About this article

Airflow and ventilation are particularly important in healthcare rooms for controlling thermo- hygrometric 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 convection- diffusion 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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About this article

Hospital ventilation simulation for the study of potential exposure to contaminants

Show Author's information Carla Balocco( )
Department of Energy Engineering "Sergio Stecco", via S. Marta 3, 50139 Firenze, Italy

Abstract

Airflow and ventilation are particularly important in healthcare rooms for controlling thermo- hygrometric 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 convection- diffusion 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.

Keywords: transient simulation, CFD, ventilation, HVAC, VAV plant, virus diffusion, isolation rooms

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Publication history
Copyright

Publication history

Received: 14 October 2010
Revised: 02 January 2011
Accepted: 06 January 2011
Published: 04 December 2011
Issue date: March 2011

Copyright

© Tsinghua University Press and Springer-Verlag Berlin Heidelberg 2011
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