A backdraft damper assembly is shown and described herein. In one embodiment, a damper assembly comprises: a main body, the main body having an inner surface defining throat, the throat defining an axial fluid flow path; a first door, the first door being hingedly connected within the main body; and a second door, the second door being hingedly connected within the main body, the damper assembly being transitionable between an open configuration and a closed configuration, at least a portion of each of the first door and the second door being received within a portion of the inner surface of the main body when the damper assembly is in the open configuration, such that the first door and the second door are not within the axial fluid flow path.

A fire damper for a ventilating fan includes a shutter and a frame provided with a flange. An opening is provided on the frame. The frame is further provided with a movable component for covering or uncovering the opening.

A fire damper for a ventilating fan includes a shutter and a frame provided with a flange. An opening is provided on the frame. The frame is further provided with a movable component for covering or uncovering the opening.

A fireproof shutter includes a frame having an opening through which a transport rail for movement of a transport vehicle passes, the opening being divided into an upper opening and a lower opening based on the transport rail, an upper door mounted on the frame and configured to open and close the upper opening, and a lower door mounted on the frame and configured to open and close the lower opening.