Overhead structural, fire extinguishing and ventilating system

Claim 1

An overhead structural fire extinguisher and ventilating system for use in building construction and comprising in combination: a pair of spaced longitudinally extending girders, a plurality of longitudinally extending spaced parallel steel joists each spanning between the girders, each of the joists having an upper chord and a tubular lower chord with web members laced therebetween, a ceiling below and depending from the lower chord to form an upper enclosure for a room, means for circulating water through the tubular lower chord, fire sprinkler nozzles operatively connected to the lower chord and penetrating through the ceiling to the room, the fire sprinkler nozzles activated by heat, ventilating air ducts positioned between the joists and connected to a source of ventilating air, the ceiling provided with openings whereby the ventilating air passes from the ventilating air ducts in noncontact heat exchange relationship with the water in the lower chord and through the ceiling to the room, the web members comprising a tube with a generally serpentine configuration having upper bends welded to the upper chord and lower bends welded to the lower chord, the lower chords terminating in ports, pipes joining at least some of the ports in flow communication.