Feature
Story
The Campus
Geothermal Revolution:
Applying geothermal systems
in a new way
Michael Luster, PE, LEED AP, Project Manager/Senior Mechanical Engineer, MEP Associates LLC
Geothermal heat pump systems have been in use to provide heating and cooling for individual buildings for many years and
have become common in certain areas
of the United States. The application of
geothermal technology to U.S. district
energy systems is not new but has been
very limited until recent years. Today,
the engineering industry is transforming how the technology is applied. The
next step in the development and implementation of geothermal heat pump
systems (also called ground source heat
pumps) is their use in large campus
district energy networks, at colleges,
universities, government facilities, residential and commercial developments
or other groups of buildings.
While it has taken many years to lay
the groundwork for this, the transition
on campuses to geothermal heat pump
systems – the fastest-growing geother-
mal technology – has come quickly.
Three critical factors are mainly respon-
sible for this transformation: Over time,
geothermal heat pump systems have
become a mainstream energy source for
building systems; campuses are aggres-
sively exploring options to save energy;
and they are seeking new opportunities
to reduce or eliminate their use of fos-
sil fuels. Those institutions willing to
apply proven systems in new ways are
the agents of change for this geothermal
revolution.
Those institutions willing to
apply proven systems in new
ways are the agents of change
for this geothermal revolution.
Is Geothermal Right for
Your Campus?
While campus geothermal heating and cooling systems have gained
momentum, it is important to note that
no two such systems are the same. The
approach to evaluating and designing
each system, however, is similar and
includes the following three key steps
early in the process: accurately identifying the campus thermal profile, sizing
the well field and evaluating building
HVAC systems. Once this information is
established, the next step is to decide if
a geothermal heat pump system is right
for your campus.
1. Accurately identifying the campus thermal profile
The first and one of the most
important steps in the geothermal
design process – as in designing any
type of district system – is accurately
assessing the campus thermal profile.
The two components of the campus
thermal profile that must be analyzed
are the following:
• Monthly heating and cooling peaks
(Btu/hr) – The heating and cooling
peaks dictate the size of the heating
and cooling equipment needed to
transfer the peak Btus per hour from
the campus to well field (during cooling) and from the well field to the
campus (during heating).
• Monthly heating and cooling energy
consumption (Btu) – The total heating and cooling energy consumed
dictates the size of the well field (the
ground loop heat exchanger) needed
to store the Btus in the cooling season that will be used later during the
heating season.
The analogy could be made that
if the well field (the ground loop heat
exchanger) is viewed as a storage bucket,
the heating and cooling peaks are the
rate or flow out of or into the bucket,
