Direct digital control (DDC) systems provide savings in energy conservation, maintenance and labor, as well as allowing better control over buildings. The benefits of DDC systems and recommendations for specifications of such systems in hvac control applications are included in a newly published guideline from the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) (Atlanta).

ASHRAE Guideline 13-2000, Specifying Direct Digital Control (DDC) Systems, addresses DDC for hvac control, monitoring and management functions, specifying hardware, performance and training. It covers system architecture, input/output structures, communications, program configuration, system testing and documentation.

The guideline represents a standardized approach to the design, documentation and specification of DDC systems for hvac control and energy management applications,” Ofer Pittel, chair of the committee that wrote the standard, said. “This standardization should improve the quality and value of DDC systems for building owners and users.

The guideline includes a general introduction of the principles of DDC system design and documentation; an article-by-article discussion of the content of a written specification for a DDC system; information about the DDC system that will be important to other subcontractors; additional information on valves and dampers; and annexes providing an outline of example specification, BACnet® discussion and interoperability case studies.