23
Flow Controller 3
R e v. : F e b u r a r y 9 , 2 0 1 6
Closed Loop Installation
home. Actual area can be 1500-3000 sq. ft. per ton [39.6 to
79.2 sq. meters per kW] of cooling. In the north, an ice cover
is required during the heating season to allow the pond
to reach an average 39°F [3.9°C] just below the ice cap.
Winter aeration or excessive wave action can lower the pond
temperature preventing ice caps from forming and freezing,
adversely affecting operation of the geothermal loop. Direct
use of pond, lake, or river water is discouraged because of
the potential problems of heat exchanger fouling and pump
suction lift. Heat exchanger may be constructed of either
multiple 300 ft. [92 meter] coils of pipe or slinky style loops
as shown in Figure 18. In northern applications the slinky or
matt style is recommended due to its superior performance
in heating. Due to pipe and antifreeze buoyancy, pond heat
exchangers will need weight added to the piping to prevent
floating. 300 foot [92 meter] coils require two 4” x 8” x 16”
[102 x 203 x 406 mm] blocks (19 lbs. [8.6 kg] each) or 8-10
bricks (4.5 lbs [2.1 kg] each) and every 20 ft [6 meters] of
1-1/4” supply/return piping requires 1 three-hole block.
Pond Coils should be supported off of the bottom by the
concrete blocks. The supply/return trenching should begin at
the structure and work toward the pond. Near the pond the
trench should be halted and back filled most of the way. A
new trench should be started from the pond back toward the
partially backfilled first trench to prevent pond from flooding
back to the structure.
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CAUTION!
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CAUTION!
This manual is not intended for commercial
loop design.
Figure 16: Typical Horizontal Loop Configurations
Seal and protect the entry point of all earth coupling
entry points into the building using conduit sleeves
hydraulic cement.
Slab on Grade Construction
New Construction: When possible, position the pipe in the
proper location prior to pouring the slab. To prevent wear as
the pipe expands and contracts protect the pipe as shown
in Figure 19. When the slab is poured prior to installation,
create a chase through the slab for the service lines with 4
inch [102 mm] PVC street elbows and sleeves.
Retrofit Construction: Trench as close as possible to the
footing. Bring the loop pipe up along the outside wall of
the footing until it is higher than the slab. Enter the building
as close to the slab as the construction allows. Shield and
insulate the pipe to protect it from damage and the elements
as shown in Figure 20.
Pier and Beam (Crawl Space)
New and Retrofit Construction: Bury the pipe beneath the
footing and between piers to the point that it is directly
below the point of entry into the building. Bring the pipe
up into the building. Shield and insulate piping as shown in
Figure 21 to protect it from damage.
Below Grade Entry
New and Retrofit Construction: Bring the pipe through the
wall as shown in Figure 22. For applications in which loop
temperature may fall below freezing, insulate pipes at least 4
feet [1.2 meters] into the trench to prevent ice forming near
the wall.
Pressure Testing
Upon completion of the ground loop piping, hydrostatic
pressure test the loop to assure a leak free system.
Horizontal Systems: Test individual loops as installed.
Test entire system when all loops are assembled before
backfilling and pipe burial.
Figure 17: Typical Vertical Loop Configurations
