32 ELECTRICALCONTRACTOR | FEB. 16 | WWW.ECMAG.COM
> FOCUS COMMISSIONING AND RETROCOMMISSIONING
“The value proposition is simple. Does the owner want to
fully realize all the functionality, energy savings and intended
lifespan of the system? To use an analogy, think of retrocommissioning as changing the oil in your car. If you do not change
your oil regularly, the car may run in a less-than-optimal state
and may break down earlier than expected. The electrical contractor has many opportunities to engage building owners in
the recommendation of retrocommissioning services,” he said.
Two major studies suggest retrocommissioning can produce
significant operating cost savings.
In 2009, the Lawrence Berkeley National Laboratory
(LBNL) published a study of commissioning in new and existing buildings. In this study, commissioning was applied to
the whole building. It found that commissioning generated
median 13 percent and 16 percent total energy savings in new
and existing buildings, respectively. More than 35 percent of
the existing buildings were found to have lighting deficiencies.
As an isolated measure, addressing such deficiencies was found
to generate a 1.4-year payback.
In 2013, the Energy Center of Wisconsin published a study that involved retrocommissioning
daylight-harvesting controls installed in 20
office buildings. Major problems reflected a lack
of defined light level targets, design document
review, functional testing and owner training.
Specific problems included improper calibration, zoning and
relay connections. In each space, the researchers tuned, calibrated and reoriented sensors; connected components that
were disconnected; changed time settings; and made other
adjustments, spending about 1–2 hours per space. As a result,
median energy savings more than doubled.
The study found the greatest increase in control effectiveness was in buildings in which commissioning had not
occurred during construction.
“There are many reasons why retrocommissioning an exist-
ing system is a good idea,” Knuffke said. “First off, changes may
have been made to the lighting control system for perfectly
understandable reasons—a schedule may have been extended
far past the normal shutoff time for a floor for accountants dur-
ing tax season, but then never put back on the normal schedule.
By scheduling a review of the system, a retrocommissioning
agent may identify these issues or provide information about
other changes that could be made to increase the efficiency of
Additionally, it could be possible that some control-system
features weren’t implemented initially because they may have
been regarded as too complex. Alternatively, the manufacturer
may have updated features without the owner’s knowledge.
“It’s always a good idea to have someone who’s familiar
with the system look it over to see if there are opportunities
for improved efficiency,” Knuffke said.
He advised electrical contractors to go beyond installation
and basic control systems programming and become proficient
in advanced control systems, which offer high-end features.
Simple retrocommissioning involves several major steps. Under-
stand the installed system to optimize programming and take
advantage of the latest available features. Conduct functional
testing to ensure installed equipment operates optimally given
available energy savings, site conditions and occupant prefer-
ences. Typically, this starts with a sampling and can be expanded
if needed. Assign deficiencies to a punch list. Reorient, repro-
gram, recalibrate and reconnect any devices as needed.
Based on customer demand, the current generation of light-
ing controls is designed with an emphasis on ease of use and
startup. Legacy lighting controls, however, can present chal-
lenges, such as an uncertain level of manufacturer support.
Doing the work comprehensively and efficiently requires an
understanding of the existing system. With these systems, it can
take time to gather documentation on the design and the system itself. However, doing this homework can be important in
developing an estimate for service and replacement hardware
that is less likely to present unpleasant surprises.
Many resources provide detailed information about commissioning, including IES-DG- 29, ASHRAE Guideline 0,
Lighting Controls Association Education Express free online
course, and the latest energy codes based on ASHRAE/IES 90. 1
and IECC. Standard 90. 1 2010, for example, requires all lighting
controls and associated hardware to be calibrated, adjusted,
programmed and ensured to operate in accordance with construction documents and manufacturer instructions. Specific
requirements are identified for occupancy sensors, program-mable-schedule controls and photosensors.
At a minimum, regarding occupancy sensors, the tester must
confirm that the placement, sensitivity and time-out settings
provide acceptable performance—e.g., the lights turn off only
when the space is vacated, and turn on only when occupied.
The installed base of lighting controls is growing, and many
of these systems may be ripe for tuning. Retrocommissioning can
provide the owner a way to retune their systems and optimize
performance and energy cost savings. Electrical contractors that
are knowledgeable about lighting controls and functional testing
may find opportunity by providing these services.
DILOUIE, L.C., a lighting industry journalist, analyst and
marketing consultant, is principal of ZING Communications. He can
be reached at www.zinginc.com.
Go beyond installation and basic control
systems programming, and become proficient
in various advanced control systems.