7
SUSTAINABLE CHICAGO Spring 2014
sence of a mechanical penthouse. “The project was
actually rejected for a federal grant,” stated STR
Partners, “as it cost less than the conventional sys-
tem.” The cost saved by reducing construction
helped to offset the geothermal system, while the
ground-source heat pumps lower the overall HVAC
energy operations by an estimated 20%.
Energy generation is only one prong in the two-
part offense on energy consumption. Energy effi-
ciency is the other and Goode Academy is replete
with energy-saving technologies, especially when it
comes to lighting. Most lights in the school, for ex-
ample, are controlled by occupancy sensors; class-
rooms go further with automatic dimming controls
when daylight enters the space.
The school also has several water-saving tech-
nologies in place. Low flow fixtures are attached to
showers, toilets and urinals, for example, but the
profoundest technology is the filtration system on
the pool. The most widely used filters (and not co-
incidentally, those with the cheapest upfront cost)
use sand to clean the water. One key process in fil-
tering pool water is “backwashing,” which in a pool
the size of Goode Academy’s would mean discharg-
ing between 3,000 and 4,000 gallons of water per
week. This is a waste not just of water, but of the
heat and treatment chemicals that went into it.
The school opted for a regenerative media filter
that cost twice as much at installation. But the sig-
nificant water and energy savings will pay back the
extra cost quickly. Instead of sand, these filters gen-
erally use either perlite or diatomaceous earth, and
each weekly backwash results in between 300 and
400
gallons—an order of magnitude lower than the
alternative.
The most visible water-saving feature of the school
is the cistern in the community garden. Non-potable
rainwater diverts from the roof over cascading stain-