Unfortunately, due to a combination of lack of rain in California
and some glitches with the start-up
of the rainwater system, the building realized none of the expected
364,000 gallons of reused rainwater.
The actual water use data from
October 2013 to September 2014
considered process water, it is not
included in the LEED calculations
for water savings.
The proposed design includes
savings from the low flow fixtures,
bay water heat exchange and the
rainwater system, resulting in an
overall expected savings of 83%.
results in 34% savings, or over 1. 3
million gallons of potable water
saved annually. The actual data
includes the small café, (the large
restaurant is excluded), lab process
fixtures, and hose bibs for exhibit
and outdoor washdown, which
are not separately submetered or
included in the LEED baseline and
This difference likely explains
some if not most of the discrep-
ancy between actual and proposed
water savings and argues for a more
complete study of water than cur-
rently required by LEED, especially
in a region like California where
water is such a precious resource.
With more typical rainfall and a
fully functioning rainwater system,
annual water savings could rise to
more than 1. 6 million gallons.
The new Exploratorium continues to
inspire families and educators, and
now its operation is offering insights
for building professionals into the
possibilities of adaptive reuse and
other sustainable design strategies.
The bay water heat exchanger, the
radiant system, the plentiful amount
of daylighting supplied and many
other innovative features contribute
to this building’s transformation from
a run-down warehouse on a pier to a
high performance building. •
ABOUT THE AUTHORS
Joseph Wenisch, P.E., Member ASHRAE,
LEED AP, is an associate principal at
Integral Group in Oakland, Calif.
Lindsey Gaunt, LEED AP BD&C, is an
energy analyst at Integral Group in
Allow Sufficient Time for Commissioning.
Make sure that complex systems like rainwater reuse, energy and water monitoring,
and lighting programming are included as
part of the commissioning scope and sufficient time is allowed in the construction
schedule for complete testing. Even though
these systems were commissioned, the
time allowed was insufficient to properly
test them and problems showed up later
that should have been addressed.
For example, the rainwater system commissioning was pushed out and shortened
because construction was completed late.
When the rainwater system was enabled,
the load side pressure in the pipes varied
widely. The system was returned to bypass
mode to protect the pipes. The system sat
idle after commissioning for more than six
months before it was discovered that there
was a problem when the system ran for
more than a few days continuously.
Multiple problems were discovered—
improper calibration of pressure relief valve
setpoints, pump scheduling, improper setup
of the booster pump controllers, and a malfunctioning pump. These problems have all
been resolved, but if more time had been
allowed for commissioning, the system
could have been saving water from day one.
Monitor PV Panel Electricity Production
Against Solar Insolation. This should be
done continuously after occupancy, and
periodic cleaning should be increased
In this case, the solar PV installer also
has a long term service contract to clean
and monitor the panels. The installer
produced a report at the end of the first
year of operation comparing actual production to expected production based on
measured insolation. This information led
to the recommendation to increase panel
cleanings, but this recommendation could
have been made earlier based on continuous monitoring.
Plug Loads Are a Stubborn Problem That
Deserve Special Attention. Given that plug
loads can account for 50% or more of a
building’s energy use, and that the energy
use comes from many varied sources, the
facility owner and design team need to
collaborate early in the design process to
realize significant plug load savings.
In this particular case, while several
improvements were made in design like
adding programmable circuit breakers,
the bulk of the plug load discussion was
pushed into the construction phase. The
owner did work hand-in-hand with the
design team to develop a plug load action
plan showing a path to a 50% plug load
However, many of the measures have
yet to be implemented because getting
the museum up and running in its new
home took priority over the additional
tasks needed to reduce plug loads. Had
this entire process taken place earlier in
design, more savings could have been
realized in the first year of operation.
Still, having this roadmap will help the
Exploratorium going forward to reach its
goal of net zero operation.
Innovative Solutions. Look for systems
that produce multiple benefits to achieve
maximum performance at minimal added
cost, i.e., using the structural pile cap for
rainwater storage. This innovative solution
actually came about because the design
team couldn’t find another place to add
an approximately 5,000 gallon tank in the
main exhibit space.
It was only because the design team collaborated across disciplines that a structural engineer recognized there was a cavity about that size already being designed
into the structural pile caps below pier that
could be waterproofed and also used for
rainwater storage. So a structural engineer
in this case played a key role in designing
the rainwater reuse system.