安心・安全を目指した大型観光バスの換気設計とウイルスの高効率排除

抄録

Measures to prevent the spread of COVID-19 are critical across the globe. Although a tour bus can carry many people at once, the small closed space is crowded with many people for long periods. Therefore, there is an increased risk of infection on tour buses. The air outlet of an air conditioner is designed to prioritize heating and cooling over ventilation. The aim of this study was to improve the ventilation performance of tour buses. To this end, a large-scale ventilation simulation was carried out using a supercomputer. The results are as follows: (1) when the overall ventilation air flow rate was fixed, it was necessary to intensively install new outlets in the upper rear part of the tour bus for rapid ventilation and (2) the ventilation efficiency was higher when a small number of high-output outlets were installed in the stead of a large number of low-output outlets. The reason for more effective ventilation was to create a large airflow in the tour bus. We proposed the design of a highly efficient ventilation system in a current bus space and elucidated the appropriate layout of ventilation outlets and the optimal protocol for opening windows.