A detailed study of energy use was made for a high-rise building complex in San Francisco, Callfornia. The complex includes a mix of four high-rise office buildings and retail shops. It was built over the last decade and a half and has a rich variety of HVAC systems reflecting the mechanical design trends of the times.

Energy-conserving equipment and controls designed and installed during the period 1984-1987 included a direct digital control system covering all major systems and more than 70 variable-speed control devices. Many of the existing pneumatic controls were retained, and new sampling devices were added. The uniqueness of the project stems from the application of global optimization techniques to determine control and operation strategies in real time and on a large scale.

This paper discusses the design scenarios considered; the criteria for the selection of energy management and control systems and the high-speed computer used for optimization; the magnitude of the optimization problem and model complexity; user interface requirements for unconventional control methods; the difficulty of calibrating a system with 5000 points and maintaining energy balances in interacting flow streams within acceptable bounds.