Numerical study of different ceiling-mounted air distribution systems for a virtual classroom environment

This paper presents a comparative numerical study of different ceiling-mounted-localized air distribution systems placed above students in a virtual classroom in summer conditions. The influence of four different ceiling-mounted-localized air distribution systems, using vertical descendent jets, on the thermal comfort, local thermal discomfort, and air quality levels was numerically evaluated. The air distribution index, developed previously, was used for non-uniform environment. This index considers the thermal comfort level, air quality level, effectiveness for heat removal, and effectiveness for contaminant removal. Numerical simulations were conducted for a virtual classroom equipped with one of four different ceiling-mounted-localized air distribution systems and with 6 desks, 6 or 12 students, and 2 upper airflow outlets. Inlet air supply temperature of 20 and 24? and an outdoor air temperature of 28? were used. The simulation results show that the air supply system having a vertical air jet placed at 1.8m above the floor level (Case III), and with an inlet area of 0.01m(2) and a supply air velocity of 3m/s would represent the best option in comparison with other air supply methods. In general, the air distribution index value decreases with an increase in inlet air temperature and the number of occupants. The air distribution index values are highest for Case III representing a classroom with 6 or 12 occupants with an inlet air temperature of 20 or 24?.info:eu-repo/semantics/publishedVersio

Prevalence of respiratory symptoms among children in rural Myanmar-disease burden assessment attributable to household biomass smoke

More than three billion people continue to rely on solid fuels as their primary source of domestic energy which is associated with elevated concentrations of indoor air pollutants and increased morbidity and mortality both in adults and children. In Myanmar, solid fuel including coal and biomass (such as dung, crop and charcoal) is the main source of energy used in households. A community-based pilot study was conducted in rural Myanmar with the aim to determine the prevalence of childhood respiratory symptoms in association with the use of biomass for cooking. A total of eighty households were recruited and monitored for exposure to particulate matter with size less than 2.5 µm in aerodynamic diameter (PM2.5) and carbon monoxide (CO). In addition, mothers were interviewed to understand their cooking habits, some house characteristics and children's respiratory health. The study found that PM2.5 and CO were significant contributors for the prevalence of acute respiratory infections and trouble breathing among young children. House characteristics including mosquito coil, associated with children's respiratory health. The study confirms that domestic environments in developing countries, like Myanmar, continue to have significant health impacts on children