1. Remove CFC chillers. The easiest,
most straightforward approach is to
replace, or retrofit, all existing CFC
machines with new machines using
non-CFC refrigerants before the LEED
application is submitted. The problem
is that this is often far from feasible.
First, where do you get the capital for
the replacement or retrofit? Also, in the
case of a retrofit, you may be sacrificing
both capacity and efficiency. As a result,
this is often not a desirable approach.
2. Set up a plan to remove them.
The USGBC actually gives systems
the option to defer the replacement
or retrofit of CFC chillers. You can
publish a plan by a ranking officer of
your institution that a designer can
use to satisfy the USGBC requirement.
The plan must include removing CFCs
from the system within five years from
substantial completion date of the
project that is applying for LEED. In
addition, during this phaseout period
you must reduce the annual leakage
of CFC-based refrigerants to 5 percent
or less using the U.S. Environmental
Protection Agency (EPA) Clean Air Act,
Title VI, Rule 608 procedures governing
refrigerant management and reporting.
Juan Ontiveros, with the University
of Texas at Austin, has issued just such
a letter for his campus (posted on the
facility’s Web site – see http://tinyurl.
com/2c2smh7) stating the university’s
plan to phase out all its chillers containing CFC-based refrigerant within five
years and to maintain leakage rates
below 5 percent.
The USGBC does expect you to stick
to your plan. How, you might ask, will
it be able to verify that you do so?
Based on the EPA’s Rule 608 reporting
procedures, all owners of equipment
containing CFC-based refrigerants are
already required to report their leakage
rates annually to the EPA. This gives the
USGBC a public record that can be used
to verify compliance in the future.
3. Or do all the following:
• Task 1. Demonstrate the investment
required to replace or retrofit the chill-
ers would have greater than a 10-year
simple payback. Our experience in
working with clients has shown this to
be relatively easy to achieve. Even when
considering the cost of a replacement
chiller alone – independent of demolition, electrical, piping, accessories, etc.
– the simple payback period can often
exceed 100 years based on the minimal
run time these machines normally see.
In addition, even when higher run times
are assumed based on better efficiencies, as would likely be the case, more
often than not the replacement economic payback period will still exceed
10 years.
• Task 2. Reduce annual refrigerant
leakage to 5 percent or less using
EPA Clean Air Act, Title VI, Rule 608
procedures governing refrigerant
management and reporting. This can
be a tougher issue. On average, well-maintained chillers with CFC-based
refrigerants will approach around
4 percent annual leakage rates. We
have seen some as low as 2 percent
but some as high as 8 percent. However,
it is the aggregate percentage loss that
matters. If your mix of machines has an
aggregate loss of more than 5 percent
annually, you will have an issue not only
with this approach but the previous one
as well. The only options are to figure
out how to reduce the leakage rate or
go with approach 1.
• Task 3. Reduce the total leakage
over the remaining life of the unit to
less than 30 percent of its refrigerant
charge. Now this is a tough one. At
first glance, approach 3 seems to give
CFCs a free ride. However, task 3 puts
an expiration date on your ticket. It’s
all dependent on your leakage rates.
If you can achieve an average annual
aggregate leakage rate of 3 percent,
you can extend your phaseout date for
10 years; but if you are at 5 percent,
you are back to the five-year limit in
approach 2.
Be Prepared
Recently we received a call from the
University of North Carolina at Chapel
Hill’s chilled-water manager: “We’re
building a new research facility, and per
the chancellor’s direction, all new buildings
on campus will achieve a minimum LEED
Silver rating. My designer has informed me
to do so we need to first verify there are
no CFCs in the district energy plants.”
The problem is that the university
still has six machines totaling 5,000 tons
of capacity in the system that use R- 11.
It rarely runs these machines – only a
few hundred hours during peak cooling
periods, which represents only 10 percent
of the total system capacity. The school
has no capital allocated to replace them
and many other opportunities already in
line competing for limited future capital
upgrades that would improve overall
system efficiency.
Tim Griffin, PE, LEED,
AP,;is;IDEA’s;liaison;with
the;U.S.;Green;Building
Council;and;serves;on
IDEA’s;board;of;directors.
He;is;a;principal;and
branch;manager;with
RMF;Engineering;Inc.,;a;firm;specializing;in
district;energy;system;planning,;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;may;be;reached;at
tgriffin@rmf.com.
