ClimateMaster Tranquility TCH 024 - Ground-Loop Heat Pump Applications

climatemaster.com
15
Tranquility
®
Compact (TC) Series
Rev.: July 7, 2020
THE SMART SOLUTION FOR ENERGY EFFICIENCY
Ground-Loop Heat Pump Applications
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.
CAUTION!
CAUTION!
CAUTION! Ground loop applications require extended range
equipment and optional refrigerant/water circuit insulation.
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 ttings should not be used at any
time due to their tendency to corrode. All plastic to metal
threaded ttings should be avoided due to their potential to
leak in earth coupled applications. A anged tting should
be substituted. P/T plugs should be used so that 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 [2.41 to
3.23 l/m per kW] of cooling capacity is recommended in
these applications.
Test individual horizontal loop circuits before back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, ush
the system to remove all foreign objects and purge to
remove all air.
Antifreeze
I n 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 ofce 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 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 specic
gravity.
Low Water Temperature Cutout Setting - CXM 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.
Table 2: Antifreeze Percentages by Volume
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