Hollow core door apparatus for preventing the build up of pressure in a room includes an inside door skin and an outside door skin, and the door skins include openings through which air flows. A center panel is disposed between and spaced apart from the skins. The center panel has an outer perimeter defined by notches through which air flows. Tabs between the notches are used to secure the center panel to the inside and outside door skins. Air flow from the room is through the opening in the inside skin, around the outer perimeter of the panel, and outwardly from the door and room through the outside skin in a non-linear manner. The door alone with normal undercuts and margins, and with its notches and associated structural elements, achieves a Rater-measured pressure differential of equal to or less than 3 pascals with respect to the main body of the building when bedroom room doors are closed. For larger rooms with air flow greater than one hundred fifty cfm, the pressure is equal to or less than 5 pascals. Air flow is controlled by a plurality of movable panels disposed adjacent to the outer perimeter of the center panel. Sensor elements for sensing desired information and for providing output signals, including signals for actuating the movable panels, are included. The air flow outwardly through the door is at least as great as the air flow into the room, thus the door provides internal transfer of air through the door to eliminate air pressure build up in a room, and at the same time limits light, sight, and sound travel through the door.

Hollow core door apparatus for preventing the build up of pressure in a room having a register through which air flows into the room and the door includes an inside door skin and an outer door skin, and the door skins includes openings through which air flows into and out of the room and which openings have substantially the same area to provide for a non-linear flow of air through the door to prevent the build up of pressure in the room. An embodiment combining a noxious gas absorbent material with the pressure build up prevention capability is also illustrated.

A hidden-lock door panel for use in a container includes a door panel body, a covering lid, a first lock, and a second lock. The door panel body includes a hidden space. The covering lid is disposed corresponding to the hidden space and slidably connected to the door panel body. The first lock and the second lock are both disposed in the hidden space. The first lock is an electronic lock and is used to control whether the covering lid can be released to slide. The second lock is used to control the door panel body to be unlocked or locked with respect to the container. Accordingly, unknowing persons are prevented from opening or breaking the door lock.