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...