A modular air-handling plenum for capable of supporting surgical apparatus or other objects is disclosed. The plenum is usually rectangular, may be formed of sheet metal, and features a truss spanning the width of the plenum to carry the weight of the apparatus. The plenum itself is attached to the ceiling of a room. An air handling component may be included to provide filtered and/or conditioned air in the vicinity of the suspended apparatus, or the plenum may be used strictly as an apparatus support, with no air-conditioning function. An ordinary suspended ceiling may also be mounted in the plenum for continuity with the remainder of the room.