A surface mounted device includes a hollowed base body mounted on a building or vehicle exterior, and a hollowed raised body supported and secured on the base body with hollowed elongated members. A free space is formed between the base body and the raised body. An opening or openings are facilitated on, and near the center of, the lower surface of the raised body, to connect the free space with the internal space of the base body through the hollowed raised body and hollowed elongated support members. The base body and the raised body are configured in such a way that the free space between them is narrower at the center than along the perimeter. This forms an airflow path that is first contracting towards the center and then expanding afterwards for any approaching wind direction, providing a venturi mechanism. The device thus creates a low air pressure in the free space near the center and hence suction effect at said opening, and communicates the suction effect to any space that is connected to the internal space of the base body.