Basic HTML Version
HOW IT’S DONE
INNOVATION BUSINESS GADGETS
1
2
3
DIGGING DEEP FOR A GREENER CAMPUS
You’ll never see it in the recruiting brochures, but a coal boiler belching
soot across an otherwise idyllic ivy-covered quad is almost as common
a sight on college campuses as undergraduates and oak trees. That
is, unless the college is Indiana’s Ball State University, which is in the
process of installing the largest geothermal district-heating system in
the U.S. By its completion in 2014, the environmentally friendly system
will both heat and air-condition every building on campus using plain
water that’s been pumped through some 3,600 underground bore-
holes, cu ing the university’s carbon output by 85,000 tons and saving
$2 million a year. Here’s how they’ll do it.
BY JACQUELINE DETWILER
3
The reverse happens in the
winter. Coldwater, around
42 degrees, is heated to 55
degrees by the earth’s energy
while it travels through the
boreholes. The heat it picks
up is amplified by the heat
pump chillers and sent out to
warmup shivering students.
2
During summer months,
the heat pump chillers
reroute some of the hot
water into boreholes that
reach 400 to 500 feet into
the earth. On its journey,
the water cools, returning
to the surface at 55 degrees.
It can then be used to cool
classrooms.
1
The system’s main
elements are several
“large-capacity heat pump
chillers,” which use the same
technology as a refrigerator
tomake hot water hotter and
cold water colder. The heat
pump chillers then move
the water around campus,
transferring energy (heat)
fromplaces where it is no
longer needed (the cafeteria
kitchen) to places where it is
(residence halls).
HEMISPHERESMAGAZINE.COM
•
JUNE 2012
•
ILLUSTRATION BY JAMES PROVOST
67