Much of our work involves energy studies and retrofits to commercial buildings. We find a variety of systems on these projects, from the original pneumatic systems installed years ago to the latest DDC systems that are part of an integrated system. Because of this, we are often in a position to advise owners about upgrading both pneumatic and older DDC systems. The cost to upgrade these systems is significant, and owners demand to know the benefits of upgrading in terms of reduced energy expense, improved comfort, and better tools for operations.
The challenge is that simply upgrading from pneumatic to DDC will not necessarily save energy; in fact, since DDC controls are more accurate, they can actually use more energy. The solution is to use the new control sequences for systems optimization that can readily result in significant energy efficiency. A few examples of these sequences include improved scheduling, economizer control, static pressure, and discharge air reset.