ATLANTA - At a minimum, direct digital control (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 by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) scheduled for 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 indoor air quality. 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, and acceptance test procedures.

The cost is $995 ($855 ASHRAE members). 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 at

Publication date: 04/19/2004