At the minimum, DDC systems control comfort in buildings. But a networked, programmable control system can do much more, according to Jim Coogan, P.E., Siemens Building Technologies.

Coogan will present an overview of DDC systems in Design and Specification of DDC Systems, a professional development seminar being offered this spring by ASHRAE. It will take place May 17-18 in Chicago.

"DDC offers a wide range of benefits to building owners and operators," he said. "A networked, programmable control system can optimize HVAC operation to save energy. It can log and report the conditions experienced by the building users, such as temperature, humidity, and IAQ. It can inform building operators of problems requiring immediate action or long-term attention."

Determining which functions are most valuable in a particular building depends on the use of the space and the interests of the operating staff, he said. "Turning this potential into useful reality depends on effective DDC design and specification," Coogan said.

The seminar will provide hands-on experience with control flow diagrams, system flowcharts, sequences of operations, DDC shop drawings, project specifications, point lists, writing diagrams, and acceptance test procedures.

Attendees will earn 1.3 continuing education units, 13 professional development hours or 13 American Institute of Architects learning units. In addition to the course manual, attendees will receive ASHRAE Guideline 13-2000, Specifying Direct Digital Control Systems.

For more information, visit the "ASHRAE Learning Institute" shortcut on To register online for the seminar, visit