Numerical Study on the Impact of Large Air Purifiers, Physical Distancing, and Mask Wearing in Classrooms

Atmosphere, Journal Year: 2023, Volume and Issue: 14(4), P. 716 - 716

Published: April 14, 2023

The risk of COVID-19 infection from virulent aerosols is particularly high indoors. This especially true for classrooms, which often do not have pre-installed ventilation and are occupied by a large number students at the same time. It has been found that precautionary measures, such as use air purifiers (AP), physical distancing, wearing masks, can reduce infection. To quantify actual effect precautions, it possible in experimental studies to expose subjects aerosols. Therefore, this study, we develop computational fluid dynamics (CFD) model evaluate impact applying aforementioned precautions classrooms on reducing aerosol concentration potential exposure presence index or infected patients. A CFD-coupled Wells–Riley used probability (IP) Different cases simulated varying occupancy room (half/full), volumetric flow rate AP, two different locations masks. results suggest using an AP reduces spread thereby However, person sitting adjacent patient only marginally reduced be avoided with half capacity class (physical distancing method) face masks efficiencies.

Language: Английский

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Using mobile air cleaners in school classrooms for aerosol removal: Which, where and how

Indoor and Built Environment, Journal Year: 2024, Volume and Issue: unknown

Published: July 25, 2024

Mobile air cleaners (MACs) have been proposed as a supplementary solution to combat the spread of respiratory aerosols in school classrooms. To determine which, where and how use MACs, seven small- medium-sized MACs were selected assessed for different settings configurations by 1) decay test determining clean delivery rate (CADR), 2) perception with panel subjects, together physical measurements, noise movement. The findings show that achieve desired CADR (appr. 1000 m 3 /h 30 students per classroom), key factors are induced airflow pattern location MACs. an upward supply toward occupied zone showed much higher (max. 775–1332 /h) than those horizontal 219–333 /h). Moreover, using multiple devices simultaneously was crucial when room size increased, combining mechanical ventilation could improve aerosol removal. Achieving sufficient would always lead level above limit 35 dB(A), yet sometimes rating more 50% acceptable. velocities mostly fulfilled requirement (<0.2 m/s), which aligned positive assessment. Hence, evaluation subjects can help optimize classroom.

Language: Английский

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A High-Performance Multi-Scale Modular-based Green Design Studio Platform for Building and Urban Environmental Quality and Energy Simulations

Sustainable Cities and Society, Journal Year: 2024, Volume and Issue: unknown, P. 106078 - 106078

Published: Dec. 1, 2024

Language: Английский

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Volatile organic compounds and cancer risk assessment in an intensive care unit

International Journal of Biometeorology, Journal Year: 2024, Volume and Issue: 68(9), P. 1731 - 1739

Published: July 18, 2024

Changes caused by air-cleaning devices in the amounts of volatile organic compounds an intensive care unit were monitored study. The cancer risk and hazard index calculated. measurements made for one month at isolated room two different points times unit. According to sampling program, turned off weeks 1 4 on 2 3. Volatile collected active sampling. Samples analyzed a thermal desorber coupled gas chromatography-mass spectrometry instrument with selective ion monitoring. results showed that concentrations benzene, toluene, o-xylene decreased about 70% after installed. assessment naphthalene was recorded highest level (Class A). value harmful when not benzene (p = 0.01), toluene 0.02), ethylbenzene styrene m, p-xylene 0.04) before installed significantly from those on.

Language: Английский

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A scoping review of indoor air quality assessment in refurbished buildings

Smart and Sustainable Built Environment, Journal Year: 2023, Volume and Issue: unknown

Published: April 18, 2023

Purpose Exposure to poor indoor air in refurbished buildings is a matter of health concern due the growing concentrations various contaminants as result building airtightness without amendment ventilation, or use materials such glue, paint, thinner and varnishes. Recent studies have been conducted measure pollutants assess risks affecting quality life, productivity well-being human beings. However, limited review recently provide an overview state knowledge. This study aims conduct scoping (IAQ) context energy-retrofitted buildings. Design/methodology/approach A systematic screening process based on PRISMA protocol was followed extract relevant articles. Web Science, Scopus, Google Scholar PubMed were searched using customised search formulas. Among 276 potentially records, 38 included final covering period from 2015 2022. Findings Researchers mapped out measured compounds selected found that carbon dioxide (CO 2 ) (11%) total volatile organic among most commonly contaminants. Two trends research including (1) impact ventilative properties IAQ (2) introducing IAQ. Originality/value The contribution this lies summarising evidence measurements buildings, discussing recent advancements, revealing significant gaps limitations, identifying drawing conclusions regarding future directions topic.

Language: Английский

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