Robustness of point measurements of carbon dioxide concentration for the inference of ventilation rates in a wintertime classroom

Indoor air quality in schools and classrooms is paramount for the health and well-being of pupils and staff. Carbon dioxide sensors offer a cost-effective way to assess and manage ventilation provision. However, often only a single point measurement is available which might not be representative of...

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Main Authors: Carolanne V.M. Vouriot, Maarten van Reeuwijk, Henry C. Burridge
Format: Article
Language:English
Published: Elsevier 2024-03-01
Series:Indoor Environments
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Online Access:http://www.sciencedirect.com/science/article/pii/S2950362024000018
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author Carolanne V.M. Vouriot
Maarten van Reeuwijk
Henry C. Burridge
author_facet Carolanne V.M. Vouriot
Maarten van Reeuwijk
Henry C. Burridge
author_sort Carolanne V.M. Vouriot
collection DOAJ
description Indoor air quality in schools and classrooms is paramount for the health and well-being of pupils and staff. Carbon dioxide sensors offer a cost-effective way to assess and manage ventilation provision. However, often only a single point measurement is available which might not be representative of the CO₂ distribution within the room. A relatively generic UK classroom in wintertime is simulated using Computational Fluid Dynamics. The natural ventilation provision is driven by buoyancy through high- and low-level openings in both an opposite-ended or single-ended configuration, in which only the horizontal location of the high-level vent is modified. CO₂ is modelled as a passive scalar and is shown not to be ‘well-mixed’ within the space. Perhaps surprisingly, the single-ended configuration leads to a ‘more efficient’ ventilation, with lower average CO₂ concentration. Measurements taken near the walls, often the location of CO₂ sensors, are compared with those made throughout the classroom and found to be more representative of the ventilation rate if made above the breathing zone. These findings are robust with respect to ventilation flow rates and to the flow patterns observed, which were tested by varying the effective vent areas and the ratio of the vent areas.
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spelling doaj-art-3747e72ec66749d48b6936962fee88912025-08-20T02:50:14ZengElsevierIndoor Environments2950-36202024-03-011110000410.1016/j.indenv.2024.100004Robustness of point measurements of carbon dioxide concentration for the inference of ventilation rates in a wintertime classroomCarolanne V.M. Vouriot0Maarten van Reeuwijk1Henry C. Burridge2Department of Civil and Structural Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK; Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Rd, Cambridge CB3 0WA, UK; Corresponding author at: Department of Civil and Structural Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK.Department of Civil and Environmental Engineering, Imperial College London, Skempton Building, South Kensington Campus, London SW7 2AZ, UKDepartment of Civil and Environmental Engineering, Imperial College London, Skempton Building, South Kensington Campus, London SW7 2AZ, UKIndoor air quality in schools and classrooms is paramount for the health and well-being of pupils and staff. Carbon dioxide sensors offer a cost-effective way to assess and manage ventilation provision. However, often only a single point measurement is available which might not be representative of the CO₂ distribution within the room. A relatively generic UK classroom in wintertime is simulated using Computational Fluid Dynamics. The natural ventilation provision is driven by buoyancy through high- and low-level openings in both an opposite-ended or single-ended configuration, in which only the horizontal location of the high-level vent is modified. CO₂ is modelled as a passive scalar and is shown not to be ‘well-mixed’ within the space. Perhaps surprisingly, the single-ended configuration leads to a ‘more efficient’ ventilation, with lower average CO₂ concentration. Measurements taken near the walls, often the location of CO₂ sensors, are compared with those made throughout the classroom and found to be more representative of the ventilation rate if made above the breathing zone. These findings are robust with respect to ventilation flow rates and to the flow patterns observed, which were tested by varying the effective vent areas and the ratio of the vent areas.http://www.sciencedirect.com/science/article/pii/S2950362024000018CO₂ sensorsUK schoolsIndoor air qualityComputational fluid dynamicsNatural ventilation
spellingShingle Carolanne V.M. Vouriot
Maarten van Reeuwijk
Henry C. Burridge
Robustness of point measurements of carbon dioxide concentration for the inference of ventilation rates in a wintertime classroom
Indoor Environments
CO₂ sensors
UK schools
Indoor air quality
Computational fluid dynamics
Natural ventilation
title Robustness of point measurements of carbon dioxide concentration for the inference of ventilation rates in a wintertime classroom
title_full Robustness of point measurements of carbon dioxide concentration for the inference of ventilation rates in a wintertime classroom
title_fullStr Robustness of point measurements of carbon dioxide concentration for the inference of ventilation rates in a wintertime classroom
title_full_unstemmed Robustness of point measurements of carbon dioxide concentration for the inference of ventilation rates in a wintertime classroom
title_short Robustness of point measurements of carbon dioxide concentration for the inference of ventilation rates in a wintertime classroom
title_sort robustness of point measurements of carbon dioxide concentration for the inference of ventilation rates in a wintertime classroom
topic CO₂ sensors
UK schools
Indoor air quality
Computational fluid dynamics
Natural ventilation
url http://www.sciencedirect.com/science/article/pii/S2950362024000018
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AT maartenvanreeuwijk robustnessofpointmeasurementsofcarbondioxideconcentrationfortheinferenceofventilationratesinawintertimeclassroom
AT henrycburridge robustnessofpointmeasurementsofcarbondioxideconcentrationfortheinferenceofventilationratesinawintertimeclassroom