Abstract: A controlled environment room encompassing a room space is provided with air supply structure which includes a room ceiling surmounting the room space, a top closure disposed above the ceiling and spaced apart from the ceiling to form a plenum chamber therewith, and an array of steel joists extending between and constructed and arranged to support the ceiling and the closure, the joists each including a pair of spaced apart chords which are components of the ceiling and are constructed and arranged to support the ceiling, the chords defining between them elongate slots extending through the ceiling, the slots providing air passageways extending from the plenum chamber to the room space for conducting pressurized air from the plenum chamber to the room space.

Abstract: Energy conservation structure is provided for a controlled environment room having an opening in a wall thereof through which work is passed and through which room air under pressure may be discharged from the room, thereby to prevent contamination of the room air by contaminants in outside air entering the room through such opening, the energy conservation structure including structure providing suction adjacent to the wall opening to induce the flow of room discharge air thereto, the latter structure being constructed and arranged for communication with structure and apparatus for recycling the discharge air of such induced flow to the controlled environment room.

Abstract: A universally mountable humidifier which can be mounted such that the outlet extends upwardly, downwardly or from a selected sidewall. The humidifier can be mounted in many different orientations and locations. The versatility of the manner of installing it allows it to be adaptable to nearly all environments.