I n s t a l l a t i o n , O p e r a t i o n , M a i n t e n a n c e
18
W A T E R - S O U R C E H E A T P U M P S
JE-Series
I s s u e D a t e :
M a y 1 0 , 2 0 2 1
Ground-Loop Heat Pump Applications
Pre-Installation
Prior to installation, locate and mark all existing
underground utilities, piping, etc. Install loops for new
construction before sidewalks, patios, driveways, and other
construction has begun. During construction, accurately
mark all ground loop piping on the plot plan as an aid in
avoiding potential future damage to the installation.
Piping Installation
All earth loop piping materials should be limited to
polyethylene fusion only for in-ground sections of the
loop. Galvanized or steel fittings should not be used at any
time due to their tendency to corrode. All plastic to metal
threaded fittings should be avoided due to their potential
to leak. A flanged fitting should be substituted. P/T plugs
should be used with units that do not include variable water
flow so that flow can be measured using the pressure
drop of the unit heat exchanger. Units equipped with any
of the four variable water flow configurations have built in
Schrader ports. Water temperature may be viewed on the
intelligent controls communicating service tool.
Earth loop temperatures can range between 25 and 110°F
[-4 to 43°C]. Flow rates between 2.25 and 3 gpm [2.41 to
3.23 l/m per kW] of cooling capacity is recommended in
these applications.
Test individual horizontal loop circuits before backfilling.
Test vertical U-bends and pond loop assemblies prior to
installation. Pressures of at least 100 psi [689 kPa] should
be used when testing. Do not exceed the pipe pressure
rating. Test entire system when all loops are assembled.
Flushing the Earth Loop
Upon completion of system installation and testing, flush
the system to remove all foreign objects and purge to
remove all air.
Antifreeze
In areas where minimum entering loop temperatures
drop below 40°F [5°C] or where piping will be routed
through areas subject to freezing, antifreeze is required.
Alcohols and glycols are commonly used as antifreeze;
however your local sales office should be consulted to
determine the antifreeze best suited to your area. Freeze
protection should be maintained to 15°F [9°C] below the
lowest expected entering loop temperature. For example,
if 30°F [-1°C] is the minimum expected entering loop
temperature, the leaving loop temperature would be 22 to
25°F [-6 to -4°C] and freeze protection should be at 15°F
[-10°C]. Calculation is as follows:
30°F - 15°F = 15°F [-1°C - 9°C = -10°C].
All alcohols should be premixed and pumped from
a reservoir outside of the building when possible or
introduced under the water level to prevent fumes.
Calculate the total volume of fluid in the piping system.
Then use the percentage by volume shown in table 2 for
the amount of antifreeze needed. Antifreeze concentration
should be checked from a well mixed sample using a
hydrometer to measure specific gravity.
CAUTION!
The following instructions represent industry
accepted installation practices for closed loop earth coupled
heat pump systems. Instructions are provided to assist the
contractor in installing trouble free ground loops. These
instructions are recommendations only. State/provincial
and local codes MUST be followed and installation MUST
conform to ALL applicable codes. It is the responsibility of
the installing contractor to determine and comply with ALL
applicable codes and regulations.
Table 2: Antifreeze Percentages by Volume
Low Water Temperature Cutout Setting - DXM2
Control
When antifreeze is selected, the LT1 jumper (JW3) should
be clipped to select the low temperature (antifreeze
10.0°F [-12.2°C]) setpoint and avoid nuisance faults
(see “Low Water Temperature Cutout Selection” in this
manual).
Note: Low water temperature operation
requires extended range equipment.
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CAUTION!
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CAUTION!
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Type
Minimum Temperature for Low Temperature Protection
10°F [-12.2°C]
15°F [-9.4°C]
20°F [-6.7°C]
25°F [-3.9°C]
Methanol
100% USP food grade Propylene Glycol
Ethanol*
25%
38%
29%
21%
25%
25%
16%
22%
20%
10%
15%
14%
CAUTION!
Ground loop applications require extended range
equipment and optional refrigerant/water circuit insulation.
* Must not be denatured with any petroleum based product
