as much
as they should and some waste a lot of energy. Better design,
controls, installation, monitoring, and maintenance can help
economizers meet their potential.
An air-side economizer is an HVAC control system that can provide
significant cooling energy savings when properly specified,
installed, commissioned, and maintained. Unfortunately, the
economizer's collection of dampers, actuators, linkages, sensors,
and controllers rarely achieves its savings potential.
Estimates indicate that only about one in four economizers works
properly, with the remaining three providing sub-par performance
or, worse yet, wasting prodigious amounts of energy. Failures are a
result of maintenance deficiencies, improper control, or systemic
problems.
A healthy economizer begins life with a good design concept,
careful specification of its constituent components, and
performance testing of its operation under a variety of conditions.
As time passes, it is important to retest the system periodically.
Although advances in computer-based diagnostics can help identify
malfunctioning systems, the human element is still essential to
maintaining these systems.
The first edition of this design brief was prepared for Energy
Design Resources in 2003. In August of 2011, an engineering review
of this document was completed to update passages affected by
changes in the California Building Energy Efficiency Standards
(Title 24 2008). The original content creator was not actively
involved in this engineering review, and therefore is not
responsible for the updates to the affected passages.
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