Opinion ID: 785846
Heading Depth: 2
Heading Rank: 2

Heading: The Final HVAC Design

Text: 15 The final HVAC design for the Kansas City building utilizes three water-cooled centrifugal chillers of 350 tons each. Each chiller is independently sufficient to service the building at the reduced levels of projected overtime loads. Two air-handling units, each consisting of two supply fans, deliver cooled air from the chillers into the building. The HVAC system delivers air into the individual areas of the building through the use of variable air volume (VAV) boxes, which, as their name suggests, vary the volume of air delivered into a space through the use of dampers that open and close in response to a computer-generated temperature signal. A building automated control (BAC) system generates the VAV-box control signal in response to inputs from a total of 366 thermostats (up from the 175 thermostats originally estimated by Wieger) throughout the building, and also controls the operation of the chillers and the air-handling units. Although the BAC controls each VAV box independently, if overtime heating or cooling is requested for any amount of space in the building, the BAC system must operate the chillers and air-handling units at a level sufficient to cool at least one-half of one floor (approximately 25,000 square feet).