Analysis of indoor CO2 concentration using split ventilation systems as an indicator of COVID-19 transmission
Loading...
Date
2023-07-23
Authors
Batista, ManuelBulgim, OscarMatus, ErickaEstrella, JaimeGittens, RolandoMolino, Jay
Asesor
Journal Title
Journal ISSN
Volume Title
Publisher
American Journal of Applied Sciences
Abstract
We measured the indoor CO2 concentration in occupied areas with
ventilation systems that recirculate air without an external air supply. The
average time required to achieve the highest probability of contagion was
also measured based on the number of participants in the group. Three
different experimental groups were evaluated: Group One (G1), which
included 5 participants; Group Two (G2), with 10 participants; and Group
Three (G3), with 15 participants. Before the measurements, the CO2
concentration was measured to be homogeneous and its sampled value was
given by the difference between the indoor and outdoor CO2 measurements
(>5000 ppm or 0.5% CO2 in air) averaged over an 8-h work day Time Weighted Average (TWA.). G1 and G3 group participants performed low intensity daily office activities, such as reading and talking. In contrast,
Group Two (G2) was asked to perform moderate intensity activities, such
as frequently lifting 10 kg items and walking quickly. The CO2 concentration
was measured with two instruments to compare the outdoor and indoor
measurements. Both devices were configured to take one reading every
second for 30 min. A mathematical model was developed from the CO2
concentrations measured, the group size, and the retention factor of the mask
being worn to determine the probability of inhaled air contaminated with an
aerosol of SARS-CoV-2. We concluded that the likelihood of contagion in
enclosed areas such as study areas, offices, and meeting rooms, among
others, which use ventilation without a circulation of fresh air, is high.
Despite proper distancing and masking, there is a 99% chance of contagion
in one of the modeled extreme case scenarios in less than 10 min of exposure.
The study took place in Albrook, Republic of Panama, which is a tropical
developing coastal geographic location where split air conditioning units are
widely used and, like many other countries in Latin America, where indoor
air quality has only recently started being discussed publicly and enforced.
Description
Keywords
air quality monitoringCO2 concentrationinstrument accuracy,pathogensenvironmental monitoringventilationmathematical modelCOVID-19
Cómo citar
Manuel, B. et al. (2023). Analysis of indoor CO2 concentration using split ventilation systems as an indicator of COVID-19 transmission. American Journal of Applied Sciences. http://repositorio2.udelas.ac.pa/handle/123456789/1246