Trane GEH 006 Manual page 29

Figure 39: Pond loop system
Figure 40: Slinky loop system
WSHP-PRC001-EN
Application
Considerations
Open-Loop Design
Ground water from a well can be used to exchange heat
1 Water quality must be acceptable, with minimal suspended solids
and proper pH. To help ensure clean water, a straining device may be
required.
2 An acceptable way to discharge the significant volume of used water from
the heat pump should be defined. It may be necessary to install a recharge
well to return the water to the aquifer.
Slinky Loop
With the slinky-loop system application Figure 40,
groups of water-coupling, pipe coils are submerged
several feet below the low water level or within a
horizontal ground trench. This system has all of the
2 Anti-freeze fluid of at least 20-percent by volume must
be used.
3 The loop should not be placed within a moving body of water that is subject
to flooding.
in an open-loop system Figure 39. The ground
water is pumped from the well into the geothermal
heat pump, where heat is extracted or rejected and
then returned to an aquifer. The only change to the
ground water is a slight temperature difference. The
rejected water is dumped into a surface well,
lake, or stream, continually removing
water from the aquifer. Alternatively,
a recharge well may be installed to
return the water into the ground.
Open-loop systems use a large
amount of water, and can only
be economically justified where
wells and disposal systems are
easy to install.
Operation and benefits are
similar to those for closed-loop
systems. There are, however, several
considerations that should be addressed
prior to installation.
advantages of a vertical bore, or horizontal trench
application, and can be very cost effective
when applied in the proper land region.
With the slinky-loop system design,
some special considerations should be
taken for the installation if a pond
application is used.
1 The body of water should be close
to the structure. If the distance
from the water to the building must
accommodate a horizontal field, the
submerged loop would offer no
advantage over a horizontal water-loop
design.
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