| 摘要 |
A vent assembly for mounting in a passageway extending through an exterior wall to provide ventilation to the space bounded by the exterior wall includes an apertured panel exteriorly juxtaposed with a security grate to prevent unauthorized intrusion through the exterior wall. Carriage bolts extend through the apertured panel and security grate into engagement with an anchoring element, such as brackets disposed in the passageway. In addition or in the alternative screws penetrably engaging the security grate may be attached directly to the exterior wall laterally of the passageway. The smooth surfaced head of the carriage bolts, coupled with the square cross-section of the shank adjacent the head mating with square apertures in the apertured panel and in the security grate prevent turning of the carriage bolts from a location external to the exterior wall. For further security, the louvered vent may be configured to overlap and shield the heads of the screws, if used. To further define the boundary of the passageway, a shroud disposed within the passageway may be employed. The interior end of the passageway may be left opened or covered with a vented panel whereby the vent assembly provides combustion air to a gas fired heater or other oxygen consuming device within the space bounded in part by the exterior wall.
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