21
climatemaster.com
THE SMART SOLUTION FOR ENERGY EFFICIENCY
Packaged Units
Rev.: 1/06/09B
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
The typical closed loop ground source system is shown
in Figure 13. All earth loop piping materials should be
limited to polyethylene fusion only for in-ground sections
of the loop. Galvanized or steel fi ttings should not be
used at any time due to their tendency to corrode. All
plastic to metal threaded fi ttings should be avoided due
to their potential to leak in earth coupled applications.
A fl anged fi tting should be substituted. P/T plugs
should be used so that fl ow can be measured using the
pressure drop of the unit heat exchanger.
Earth loop temperatures can range between 25 and
110°F [-4 to 43°C]. Flow rates between 2.25 and 3 gpm
per ton [2.41 to 3.23 l/m per kW] of cooling capacity is
recommended in these applications.
Test individual horizontal loop circuits before backfi lling.
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, fl ush
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 manager should be consulted
for 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
25 to 22°F [-4 to -6°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 fl uid 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 specifi c 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
CXM or DXM Control
When antifreeze is selected, the FP1 jumper (JW3) should
be clipped to select the low temperature (antifreeze 13°F
[-10.6°C]) set point and avoid nuisance faults (see “Low
Water Temperature Cutout Selection” in this manual). NOTE:
Low water temperature operation requires extended range
equipment.
CAUTION!
CAUTION!
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%
* Must not be denatured with any petroleum based product
CAUTION! Ground loop applications require extended
range equipment and optional refrigerant/water circuit
insulation.
To Next Page
Loading...
Need help?
General
