Feature
Story
Beauty Secrets:
How USC added TES,
preserved campus aesthetics
David Bain, Business Development, DYK Incorporated
District cooling systems throughout the world have realized the
benefits of incorporating thermal
energy storage (TES). Many university
systems, for example, are taking advantage
of the ability of TES to reduce energy costs
by shifting cooling loads to off-peak hours
as well as to serve as a ‘virtual’ chiller
expansion. But for universities and other
campuses with limited space and strict
aesthetic guidelines, installation of a
large TES tank may not appear to be
an option; regardless of the type of TES
system used, the tank may be viewed
and rejected by some stakeholders as
unsightly. By taking measures to hide or
disguise the tank, however – by burying
or aesthetically enhancing it – a campus
is more likely to be able to bring the
benefits of adding TES to fruition with
less community resistance.
The University of Southern California
(USC) is a case in point. In recent years,
USC has managed to install a 30,000-
ton-hr stratified chilled-water TES tank
on its 155-acre University Park Campus,
located 3 miles south of Los Angeles,
while maintaining campus aesthetics. By
proposing to construct this tank below
ground, USC facilities management was
to able to gain the support it needed to
expand its district cooling system, adding
6,000 tons of cooling capacity.
Weighing Options
A renowned private research university with more than 33,000 enrolled
students and 11,000 faculty and staff, USC
was founded in 1880 and is the oldest
institution of its kind in the West. The
university first installed a small district
cooling loop on the University Park Campus
in 1998; it has since been enlarged to a
6,000-ton system. On a peak day, this
system provides more than 90,000 ton-hr
of cooling – 15 equivalent full-load hours.
Chillers located throughout several campus
buildings are interconnected.
As USC grew over the years and more
buildings were connected to the district
cooling system, the need for increased
cooling capacity arose as well. There was,
however, simply no land available for an
expanded system. John Welsh, USC’s
associate vice president of facilities
management services, recognized that
he could use his existing cooling system
to charge a TES tank at night and have
this serve as a ‘virtual’ chiller during
daytime peaks while incorporating this
tank into the campus by burying it.
Although a TES tank would be much
larger than a basic chiller, Welsh had
also considered that installing a chiller
would require the use of limited above-grade space for cooling towers and
other equipment. Another incentive for
choosing a TES system came from the
university’s energy provider, the Los
Angeles Department of Water and Power,
which offered a rebate to customers who
were willing to shift peak loads to off-peak power.
Although a TES tank would be
much larger than a basic chiller,
installing a chiller would require
the use of limited above-grade
space for cooling towers and
other equipment.
Planning Phase
Initial planning for the TES project,
including choosing the system type and
location, began during spring 2001. Welsh
spearheaded the project and continues
to oversee its operation today. In addition,
Richard Snouffer, USC’s director of energy
services, and Craig Drown, associate
director of energy services, as well as
others, collaborated in a team effort to
bring this project to reality.
As the addition of a chiller was ruled
out due to space limitations, initial consideration was given only to chilled-water
TES and ice TES. However, the USC facilities
