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Frequently asked Questions about geothermal
Jump to a question:
1. Why use a geothermal
heat pump system at the high school?
2.
How does it work?
3.
Is the system really geothermal?
4.
Will the geothermal heat
pump system reduce noise in the classroom?
5.
Is a
geothermal heat pump system more costly to
install than other systems?
6.
How much energy can be
saved by using a geothermal heat pump system?
7.
What are the long-term
operations and maintenance costs for geothermal
heat pump systems?
8. Have such systems been
used successfully in New York state?
9.
What does the New
York State Energy Research and Development
Authority (NYSERDA) say about geothermal heat
pump sytems?
10.
What does the U.S.
Department of energy say about these systems?
11.
Do the wells built for
geothermal heat pump systems have any impact on
the surrounding ground?
12.
Won't it be
wasteful to cool the high school during summer?
13.
Why are we ripping
out the current heating systems?
14. Where else can I get
information about geothermal heat pump systems?
1. Why use a geothermal heat pump system
at the high school?
The current heating and cooling systems are
inefficient, provide inconsistent heating and in
some cases can no longer be repaired. The
district considered many different options for
upgrading or replacing the systems in the
schools. After much discussion and engineering
assistance from the district's architects and
construction managers, a geothermal heat pump
system was agreed on for the high school primarily because it would
provide significant energy savings. Geothermal
heat pump systems are quieter and require less
maintenance than conventional air-ventilation
systems, and are environmentally friendly.
Geothermal heat pump systems have been in use
for more than 20 years with thousands of
installations nationwide, including in many
different school and business locations. [See
question #8 below for specific locations that
use geothermal.]
2. How does it
work?
Geothermal heat pump systems transfer heat from
the earth to buildings. The ground remains at a
constant temperature year-round (about 50
degrees Fahrenheit), providing a source of heat
in the winter and a means to cool air in the
summer.
The type of geothermal heat pump system being
considered for the district would circulate
water in a closed loop through vertical wells in
the ground. The water is then circulated through
the school building, where highly efficient heat
pumps extract heat from the loop or reject heat
to the loop, as needed, to heat or cool the air.
A geothermal heat pump system is sustainable,
meaning no heating or cooling of the earth is
ever required.
An added benefit of this type of system is its
flexibility in keeping learning spaces
comfortable, since heat can be moved from warm
areas that need cooling to cool areas in need of
heating. In other words, one room can be cooled
while another is heated, ensuring all students
are comfortable.
3. Is the
system really geothermal?
Technically the system is a ground
source, closed loop, heat pump system. Industry
experts commonly refer to this type of system as
a "geothermal heat pump" system. It is also
referred to as a "geoexchange" system.
4. Will the geothermal heat pump system
reduce noise in classrooms?
Yes. The heating units will be above the
corridor ceilings or within mechanical rooms
(instead of within the classrooms like in the
current system), reducing noise.
5. Is a
geothermal heat pump system more costly to
install than other systems?
Yes. However, their substantially lower energy
costs pay back the cost of installation in two
to eight years.
Lower maintenance costs also result in such
systems having the lowest overall cost of any
heating and cooling system. One study examining
various heating and cooling options for schools
found that geothermal systems had a 15 percent
lower life-cycle cost (meaning the cost of
installation, operating and maintenance over the
life of the system) than the next most
attractive option.
Moreover, installation costs have declined
substantially in recent years, and are expected
to continue falling, as more builders and
contractors offer such systems. The industry is
also developing innovative ways to install the
systems faster and more efficiently.
6. How much energy
can be saved by using a geothermal heat pump
system?
The U.S. Department of Energy estimates that
geothermal heat pump systems reduce consumption
of electricity from 25 to 50 percent when
compared to traditional heating and cooling
systems.
In Lincoln, Nebraska, four elementary schools
have been using geothermal heat pumps since
1995. When compared to other new schools with
similar heating and cooling needs, these schools
use approximately 26% less source energy per
square foot of floor area. Over a 20-year
period, these savings are expected to reach
about $3.8 million for the four buildings.
Administrators in four New York school districts
(Webster, East Irondequoit, Unadilla and
Cobleskill-Richmondville) said their geothermal
heat pump systems have shown energy savings. To
further reduce energy costs, these
administrators all suggested having back-up
boilers, which is included in Niskayuna's plans.
All said that switching to a geothermal system
was a wise decision.
In addition to its inherent cost savings, a
geothermal heat pump system would allow the
district to eliminate 52 inefficient electric
air conditioning units currently at the high
school.
7. What are the
long-term operations and maintenance costs for
geothermal heat pump systems?
Lower maintenance costs than with conventional
heating and cooling systems is a benefit of
geothermal heat pump systems. Before installing
geothermal heat pump systems in the four
Lincoln, Nebraska elementary schools, extensive
studies and simulation models were conducted to
determine their economic feasibility relative to
other options. These studies concluded that when
all costs were included (energy, maintenance,
installation), the geothermal heat pump system
had the lowest life cycle cost, about 15 percent
lower than the next most attractive option.
8. Have such systems been used successfully
in New York state?
There are many such systems operating in New
York state, including at the Holiday Inn Express
in Albany, the Sagamore Resort in Lake George,
LeMoyne College in DeWitt, the Saratoga Springs
racetrack, Sullivan County Community College in
Loch Sheldrake and public schools in Webster,
East Irondequoit, Cobleskill-Richmondville,
Brockport, Indian River and Putnam Valley.
9. What does the
New York State Energy Research and Development
Authority (NYSERDA) say about geothermal heat
pump systems?
NYSERDA, an independent energy research
organization dedicated to improving New York's
environment, has extensively researched the use
and benefits of geothermal heat pump systems.
Its research indicates that when compared to
other heating/air conditioning replacement
systems, geothermal heat pump systems realize
significant energy savings.
NYSERDA's Web site states: "Office buildings
and schools are particularly good applications
for geothermal heat pumps. These facilities have
relatively high occupancy, fluctuating usage
schedules, and widely varying heating and
cooling requirements within individual zones
(offices and classrooms) that are difficult to
meet efficiently with conventional systems.
Further, efforts to improve the efficiency of
conventional systems employ control strategies
that can add considerable cost and complexity to
the systems, increase maintenance requirements,
and often compromise occupant comfort."
10. What does
the U.S. Department of Energy say about these
systems?
According to the U.S. Department of Energy:
"The geothermal heat pump, also known as the
ground source heat pump, is a highly efficient
renewable energy technology that is gaining wide
acceptance for both residential and commercial
buildings. Its great advantage is that it works
by concentrating naturally existing heat, rather
than by producing heat through combustion of
fossil fuels."
11. Do the wells
built for geothermal heat pump systems have any
impact on the surrounding ground?
Any geothermal heat pump system design begins
with an analysis of the subsurface conditions in
the area where the wells are to be drilled, to
determine the best location for the wells. Part
of this analysis includes determining the
thermal conductance of the surrounding soil,
which is a function of the geologic conditions
and of the subsurface ground water. This data is
then used to determine the optimal well depth
and well spacing to ensure that the well fields
are able to dissipate the rejected heat to the
moving ground water at a sufficient rate to
prevent a gradual warming of the well field.
12. Won't it be
wasteful to cool the high school during summer?
It will not be necessary to cool any building
spaces in the summer that do not require it for
occupant comfort. One of the benefits of the
geothermal heat pump system is that individual
rooms can be cooled as desired without having to
cool the entire building.
Also, the high school is truly used year-round,
as it houses summer school in July and August.
13. Why are we
ripping out the current heating systems?
Engineers have investigated the schools'
existing heating and ventilating systems and
determined that they need to be replaced because
they have reached the end of their useful lives.
The current systems are expensive to maintain,
are not energy efficient, and provide uneven
temperature control and fresh air ventilation.
New heating and ventilating systems, (including
the geothermal heat pump system at the high
school and hot water systems in the elementary
schools and Van Antwerp) will greatly improve the climate
control and indoor air quality in Niskayuna
schools.
14. Where can I get more
information about geothermal heat pump systems?
Many government and industry sources can be
found online, including:
Consumer's Guide -- from the U.S. Department
of Energy's Energy Efficiency and Renewable
Energy Web site
FAQs -- from the Geothermal Heat Pump
Consortium Web site
"GeoExchange Heating and Cooling Systems:
Fascinating Facts" from the Geothermal Heat
Pump Consortium Web site (note this is a PDF)
"Geothermal Heat Pumps Score High Marks in
Schools," from the U.S. Department of
Energy/Office of Geothermal Technologies Web
site (note this is a PDF)
Reports on schools and businesses that use
geothermal -- from the Geothermal Heat Pump
Consortium Web site
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