was connecting into a district energy plant
that itself might not be commissioned.
As a result, it clarified in 2008 that only
the components of a district energy system
within the LEED-applicant building itself
(i.e., the heat exchanger, building tertiary
pump, controls, etc.) have to be commissioned to meet the prerequisite requirements.
These, of course, represent systems and
equipment building owners can control
within their own facilities.
However, while keeping the guidelines
from penalizing projects connecting into
district energy, the USGBC also did not want
to ‘reward’ projects extra points unless they
took the district energy plant into consideration. Therefore, if a LEED-applicant building
wants to pursue additional points through
enhanced commissioning, the plant systems
associated with the utility-provided chilled
water, steam, hot water, etc., must also meet
the enhanced commissioning requirements.
The steps for satisfying LEED’s
enhanced plant commissioning
requirements are straightfor-
ward and relatively easy
to achieve.
So, back to our original question: “Does
the plant have to be commissioned in order
to allow the connecting building to gain LEED
certification?” The answer is no. However,
building owners often want to pursue
enhanced commissioning because it is a
high-value-added service to their project
that easily gains two points toward LEED
certification. In addition, the steps for satisfying LEED’s enhanced plant commissioning requirements are straightforward and
relatively easy to achieve. Often these points
are crucial in getting a project to its targeted rating level. As a result, enhanced commissioning is normally targeted by project
teams pursuing LEED certification.
Act Strategically
Let’s dig deeper into the requirement
for enhanced commissioning. There are
situations where even if the LEED-applicant
building is pursuing the two points associated with enhanced commissioning, the
district energy plant does not have to be
commissioned. Those situations include
whenever the building project is less than
50,000 gross sq ft and when the energy
supplied to the building represents less
than 20 percent of its total annual energy
use. However, for most district energy systems there is too much risk associated with
‘hoping’ a potential customer will fit these
narrowly defined exceptions or will not need
the additional two points for enhanced
commissioning.
Therefore, it is prudent to be prepared
in advance to answer your potential customer’s question affirmatively: “Yes, sir, if
you are pursuing LEED certification and
connecting into our plant’s distribution network, I can assure you there will be no
problems meeting the prerequisite and
enhanced commissioning goals for your
project because of our plant.” To be able
to make this statement with confidence,
you need to do the following:
; New Plants: If you are developing a new
district energy plant on your campus or in
a municipality, include enhanced commissioning as part of the planning, design
and construction process. Most important,
don’t think of commissioning as something
you only do to check it off your list to satisfy
future LEED requirements. Commissioning
is an investment. As such, there is a return
associated with this investment. Focus on
the value that you can get out of commissioning and not the cost. (For more on
commissioning’s benefits, see the article
“Commissioning: Delivering a central plant
that works” in this issue of District Energy.)
; Fairly New Plants (less than five years
old): The LEED district energy guidance
document requires plants or equipment in
plants that are less than five years old to be
commissioned through the same process as
a new plant. If your plant was not commissioned when built, bring in a commissioning team to do so now. Again, focus
on the value you will gain from commissioning activities. Ask the team what it is
going to do to improve plant operation as
a part of the commissioning process.
; Existing Plants: If your plant is more than
five years old, you now fall under the
retrocommissioning requirements described
in the 2009 LEED for Existing Buildings:
Operations & Maintenance Energy and
Atmosphere Credit 2. 2 or 2. 3. Basically,
the process of retrocommissioning involves
bringing your plant back to the level of
operation that was originally intended,
which includes incorporating the goals of
all plant upgrades and enhancements that
have occurred through the years. The goal
of retrocommissioning is the same as that
of traditional commissioning. A successful
retrocommissioning project should have a
solid payback. Some of the many studies
on retrocommissioning have shown paybacks of less than a year.
In all cases, new building commissioning
or retrocommissioning must have occurred
within five years of the date of an applicant
building project’s substantial completion in
order to meet the enhanced commissioning
requirements for LEED certification. As an
option to retrocommissioning, you can establish a continuous commissioning process in
your plant. This involves demonstrating that
preventive and continuous maintenance
plans and efficiency-monitoring programs
are in place to ensure ( 1) that ongoing
system efficiencies meet the original design
intent and ( 2) that energy efficiency performance has been tested and recorded
under these programs during the five years
before the applicant building project’s substantial completion.
No matter who your customer may
be – public, private, institutional or industrial – be prepared for their call when it
comes. Determine now what you need to
do to have the right answers and align
those answers with the best opportunities
to improve your plant’s energy performance in the process.
Tim Griffin, PE, is IDEA’s
liaison with the U.S. Green
Building Council. He is a
principal and branch manager with RMF Engineering
Inc., a firm specializing in
district energy system
design and commissioning.
A registered engineer and a LEED Accredited
Professional, Griffin has a bachelor of science
degree in mechanical engineering from North
Carolina State University and a master of
business administration degree from Colorado
State University. He authored the book Winning
With Millennials: How to Attract, Retain, and
Empower Today’s Generation of Design Professionals. He may be reached at tgriffin@
rmf.com.
