Development of supply ventilation strategy to reduce pm_2.5 in school classrooms

The purpose of this study is to propose a novel method to pressurize a room using a ventilation system to block outdoor PM_2.5 through infiltration. We made various cases according to the building airtightness performance, pressurization ratio, and filter level, and evaluated the performance of the proposed method using simulation. As the simulation method, CONTAM, mass balance equation, simple thermal load equation, and regression equation were used. As a result, first, using the proposed method, the indoor PM_2.5 concentration could be reduced to a maximum of 30% even on a day when the outdoor PM_2.5 concentration is high. Second, in the case of airtight buildings, it showed excellent performance even with less pressure. Third, improving the filter level of the ventilation system was a good way to further reduce indoor PM_2.5. Finally, a moderate level of pressurization strategy was found to be thermally beneficial.