Performance Evaluation of Particulate Matter and Indoor Microclimate Monitors in University Classrooms under COVID-19 Restrictions

Abstract

Optical monitors have proven their versatility into the studies of air quality in the workplace and indoor environments. The current study aimed to perform a screening of the indoor environment regarding the presence of various fractions of particulate matter (PM) and the specific thermal microclimate in a classroom occupied with students in March 2019 (before COVID-19 pandemic) and in March 2021 (during pandemic) at Valahia University Campus, Targoviste, Romania. The objectives were to assess the potential exposure of students and academic personnel to PM and to observe the performances of various sensors and monitors (particle counter, PM monitors, and indoor microclimate sensors). PM1 ranged between 29 and 41 μg m−3 and PM10 ranged between 30 and 42 μg m−3. It was observed that the particles belonged mostly to fine and submicrometric fractions in acceptable thermal environments according to the PPD and PMV indices. The particle counter recorded preponderantly 0.3, 0.5, and 1.0 micron categories. The average acute dose rate was estimated as 6.58 × 10−4 mg/kg-day (CV = 14.3%) for the 20–40 years range. Wearing masks may influence the indoor microclimate and PM levels but additional experiments should be performed at a finer scale.

Practical Impact of the COVID-19 Pandemic on Indoor Air Quality and Thermal Comfort in Kindergartens. A Case Study of Slovenia

“…With the COVID-19 outbreak, humanity has been facing challenges, which have had an impact on every aspect of society, health, economy, culture, etc. Changes due to COVID-19 have also had environmental impacts on air quality and pollution [ 1 , 2 , 3 ], indoor air quality in schools [ 4 , 5 ], energy consumption [ 6 ] and on the built environment [ 7 , 8 , 9 ].…”

Role of Fluid Dynamics in Infectious Disease Transmission: Insights from COVID-19 and Other Pathogens

“…The minimal momentum required for the air curtain to reach the other side of the doorway with and without wind was calculated by Sirén, who studied the thermal properties of the air curtain by developing an equation for thermal loss and comparing it with real-world data [232]. Numerical simulations, semi-analytical models, and laboratory-scale investigations in water align well with full-scale tests conducted on an air curtain within a completely sealed structure [233]. Frank and Linden researched how adding another ventilation route, such as an open window, impacted the efficiency of an air curtain, as well as how the air curtain's performance changed due to the shift in the neutral level [234].…”

Assessment of Thermal Comfort and Indoor Air Quality in Library Group Study Rooms

“…In a study by Sarbu et al [16], the thermal comfort and indoor air quality were assessed based on PMV and PPD indices as well as CO 2 concentration using subjective and experimental measurements in two air-conditioned classrooms at a university. These indices were also used by other research teams [17][18][19] to evaluate the thermal comfort of students in classrooms.…”