Medical office buildings contain a labyrinth of doctors' offices, exam rooms, and special procedure rooms, with dressed and partly dressed patients. However, if each room had its own temperature controls, the comfort of patients and staff would be enhanced. Since medical office buildings usually are provided with reheat on interior as well as exterior zones, conventional VAV boxes with reheat would have been expensive.

During schematic design, Kaiser expressed interest VAV diffusers. A cost study was undertaken with the contractor, and it showed that that thermally powered VAV diffusers could be provided for the same cost as a conventional VAV reheat system.

After initial implementation, feedback from facilities staff was that the system had few teething problems and performed very well over the first year of operation. The chief engineer was pleasantly surprised and has already recommended the system to other medical facilities.

Highlights

• The DDC system modulates the supply air damper to maintain its associated duct static pressure at setpoint (adjustable).
• The DDC system closes the static pressure dampers that serve electrical rooms when the air-handling unit is in morning warm-up mode.