C L I M AT E M A S T E R WAT E R - S O U R C E H E AT P U M P S
TSM/TSL Vertical Stack
R e v. : J a n u a r y 1 8 , 2 0 2 1
C l i m a t e M a s t e r Wa t e r-S o u rc e H e a t P u m p s
34
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!
Ground loop applications require extended range
equipment and optional refrigerant/water circuit insulation.
⚠
CAUTION!
⚠
⚠
CAUTION!
⚠
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 in earth coupled applications. A flanged
fitting should be substituted. P/T plugs should be used so
that flow can be measured using the pressure drop of the
unit heat exchanger. Units equipped with any of the two
vFlow configurations have built in Schrader ports. Water
temperature may be viewed on the iGate communicating
thermostat or service tool.
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 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.
Water Quality Standards -
Table 3 should be consulted
for water quality requirements. Scaling potential should
be assessed using the pH/Calcium hardness method. If
the pH <7.5 and the calcium hardness is less than 100
ppm, scaling potential is low. If this method yields numbers
out of range of those listed, the Ryznar Stability and
Langelier Saturation indecies should be calculated. Use the
appropriate scaling surface temperature for the application,
150°F [66°C] for direct use (well water/open loop) and
DHW (desuperheater); 90°F [32°F] for indirect use. A
monitoring plan should be implemented in these probable
scaling situations. Other water quality issues such as iron
fouling, corrosion prevention and erosion and clogging
should be referenced in Table 3.
Antifreeze -
If any liquid fluid or piping is exposed to
unconditioned ambient below 42°F (5.5 C), antifreeze
must be added. If the liquid fluid entering the heat pump
is 50°F (10°C) or below, calculate the leaving heat pump
temperature (shown in submittal on performance data
selection notes section). Using the lowest temperature
leaving the heat pump, must protect system 15°F (8°C)
lower. IE: if temperature leaving the heat pump is 35°F
subtract 15°F = 20°F protection required, if Methanol is used
the system would require 16% mix by volume. Antifreeze is
available in alcohol and glycols, contact local sales office for
the best type for your system and area. Following must be
considered safety, thermal performance, corrosiveness, local
codes, stability, convenience, and cost.
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.
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
Minimum temperature leaving the unit F (C)
25 (-4)
30 (-1)
35 (1.5)
42 (5.5)
Protect liquid fluid to
Type
10 (-12)
15 (-9)
20 (-6.5)
25 (-2.5)
Methanol
25%
21%
16%
10%
100% Food Grade PG
38%
25%
22%
15%
Ethanol*
29%
25%
20%
14%
*Ethanol must not be denatured with any petroleum based product
CXM/DXM2 - must clip LT1 jumper if antifreeze is used. DO NOT clip without antifreeze.
Check with hydrometer after pump has mixed fluid well, now and at beginning of each
heating season.