W2W Series Heat Pump
Ecologix Heating Technologies Inc
Page
9
www.ecologix.ca
221 Holiday Inn Drive Cambridge ON
ph: 519-658-4330
GROUND –LOOP HEAT PUMP APPLICATIONS
Closed Loop Applications
A closed loop system re-circulates the same
water/antifreeze solution through a closed system
of underground high-density polyethylene pipe.
As the solution passes through the pipe it collects
heat (in the heating mode) that is being
transferred from the relatively warm surrounding
soil through the pipe and into the relatively cold
solution. The solution is circulated back to the
heat pump that extracts its heat and then returns
to the ground to absorb more heat from the earth.
The W2W-Series heat pumps are designed to
operate on either
vertical or horizontal closed
loop applications
. Vertical loops are typically
installed with a well drilling rig up to 200 feet
deep or more. Horizontal systems are typically
installed with excavating or trenching equipment
approximately six to eight feet deep, depending
on geographic location and length of pipe used.
Earth loops must be sized properly for each
particular geographic area and individual
capacity requirements. Contact your local
installer for loop sizing requirements in your
area.
Loop Pump Selection
Select a loop circulation pump based upon the
gpm required and total system pressure drop.
Lake or Pond Loops
Closed loop systems may also be used in lakes or
rivers to supply a heat source to the heat pump.
Typically a loop consisting of geothermal pipe
can be designed and placed in an area not much
deeper than 15ft with some water currents
present. In any lake or pond, municipal and area
by-laws must be observed in regards to a lake or
pond loop. The use of an environmentally
friendly loop fluid like ethanol should be
considered if the loop was ever damaged.
Consult an IGSHPA or CGC certified installer
for proper lake or pond loop design.
Piping Installation
All earth-loop piping materials should meet
CSA-C448. P/T plugs should be used so that
flow can be measured using the pressure drop of
the unit heat exchanger in lieu of other flow
measurement means. Earth loop temperatures
can range between 25-110°F and 2.25 to 3gpm
of flow per ton of cooling capacity is
recommended in these applications. Upon
completion of the ground loop piping, 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. Vertical U-Bends and Pond Loop
Systems: test vertical U-bends and pond loop
assemblies with a test pressure of at least 100
psi. Either water or air may be used as the testing
medium.
Table 2: Approximate Fluid Volume
Fluid Volume (gal [liters] per 100’ [30 meters]
Pipe)
Pipe
Size
Volume (gal)
[liters]
Copper
1”
4.1 [15.3]
1.25”
6.4 [23.8]
2.5”
9.2 [34.3]
Rubber Hose
1”
3.9 [14.6]
Polyethylene
¾” IPS
SDR11
2.8 [10.4]
1” IPS
SDR11
4.5 [16.7]
1.25” IPS
SDR11
8.0 [29.8]
1.5” IPS
SDR11
10.9 [40.7]
2” IPS
SDR11
18.0 [67.0]
1.25” IPS
SCH40
8.3 [30.9]
1.5 “IPS
SCH40
10.9 [40.7]
2” IPS
SCH40
17.0 [63.4]
Unit Heat
Exchanger
Typical
1.0 [3.8]
Flush Cart Tank
10” Dia x 3ft
tall
[254mm x
91.4cm tall]
10 [37.9]
Flushing the Earth Loop
Once piping is completed between the unit, flow
center and the ground loop, final purging and
charging of the loop is needed. A flush cart (at
least a 1.5hp pump) is needed to achieve
adequate flow velocity in the loop to purge air
