Structural concrete constitutes the major duct system for the heating and cooling installation in a new bowling lane in Tulsa, Oklahoma. The 27,000 square foot building consists of 9 thin shell concrete barrels, with the sides of the barrels forming two sides of a triangularly shaped duct. Thermo-board of one and nine-sixteenth inch thickness and four inch vermiculite, 1:6 mix, make up the duct roofs. All shells and ducts are covered by a 4 ply membrane roof. To prevent deflection, metal supports are set in the duct valley. The bowling lanes are located at each end of the building, so only the central area, containing bowler seating, grill and office, is heated and cooled. The concrete ducts flank two sides of the central area. Air is ejected from vents along one face of each duct. Air is returned to handling units through louvered doors.