The building had a large central AHU that served the interior of the facility. This unit would get new controls and sensors and would be represented with graphics at the new DDC front end. The perimeter of the building was conditioned with console-style fancoil units. The controls for the fancoil units were not altered, but temperature sensors were installed at each of the four building exposures (north, south, east, and west) on several floors so that the building operators could anticipate changes that might have to be made to accommodate changes in weather. Fresh air was delivered to the perimeter zones through overhead diffusers fed from a 100% outside air ventilation unit located in the penthouse. This unit was in poor condition and would be replaced.

The site visit revealed that the existing chillers were not the ordinary variety. They were gas-engine driven centrifugal chillers original to the building. These two 400-ton chillers were enormous and were resting on 12-in. thick inertia bases for acoustical purposes. They were works of engineering art and were maintained in excellent working order by a mechanic that started at the facility shortly after it opened. It was evident that he took pride in the operation of this equipment. Remarkably, this man had faithfully preserved not only the construction drawings for the building, but the specifications as well, which proved invaluable during the design process. The engines were loud, and ear protection was required if any significant amount of time was to be spent in the mechanical room.