Characteristics of outdoor pollutants intrusion and ventilation control in sentry buildings with normal openings

Sentry buildings have windows that are often open to facilitate communication between personnel. It also provides the possibility for the intrusion of pollutants such as vehicle exhaust emissions. To prevent the intrusion of outdoor pollutants and create an excellent indoor environment, internal circulation with double-attached ventilation (IC-DAV) and external circulation with double-attached ventilation (EC-DAV) are proposed for such buildings, and the isolation effect of two attached ventilation modes on pollutants is compared with that of natural ventilation. A computational fluid dynamics (CFD) method was used to simulate the transportation process and indoor distribution of outdoor pollutants intruding into sentry buildings from the regular openings under different outdoor wind directions, wind velocities, and states of the doors and ventilation modes. The results indicate that the leeward airflow of the three wind directions caused the largest pollutants to invade the room. The amount of pollutants intrusion increased with increasing wind velocity. When the leeward airflow and the windward airflow blow through the building, opening the door increased the amount of pollutants intruding into the room by 3.34 times and 8.85 times, respectively, compared with closing the door. However, the IC-DAV can isolate 81.7% of the pollutants while the EC-DAV can isolate 99.92% of the pollutants as compared with natural ventilation. Applying double attached ventilation mode in buildings can effectively prevent the intrusion of outdoor pollutants into the room, reduce the harm of outdoor pollutants to the health of indoor personnel, and provide a new idea for buildings to improve the indoor air quality.