No single air distribution system is ideally suited for the heating and cooling needs of every house. In each case, design and installation are affected by envelope construction details, climate, cost, building and energy codes, noise levels, and the need for zone control. All of these factors contribute to the location of supply outlets and return openings and to the duct geometry. Locating Supply Outlets The comfort afforded by a forced-air heating or cooling system depends, in part, on whether the supply outlets are located at the perimeter, on the ceiling, or on an inside wall. Perimeter supply outlets blanket portions of the exterior walls with supply air using floor, baseboard, or