WAT E R - S O U R C E H E AT P U M P S
JRC-Series
R e v. : D e c e m b e r 8 , 2 0 2 1
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
14
Ground-Water Heat Pump Applications
Open Loop - Ground Water Systems -
Shut off valves
should be included for ease of servicing. Boiler drains or
other valves should be “tee’d” into the lines to allow acid
flushing of the heat exchanger. Shut off valves should be
positioned to allow flow through the coax via the boiler
drains without allowing flow into the piping system.
P/T plugs should be used so that pressure drop and
temperature can be measured. Supply and return water
piping materials should be limited to copper, PE, or similar
material. PVC or CPVC should never be used as they are
incompatible with the POE oils used in HFC-410A products
and piping system failure and property damage may result.
Water quantity should be plentiful and of good quality.
Consult table 3 for water quality guidelines. The unit can
be ordered with either a copper or cupro-nickel water
heat exchanger. Consult Table 3 for recommendations.
Copper is recommended for closed loop systems and open
loop ground water systems that are not high in mineral
content or corrosiveness. In conditions anticipating heavy
scale formation or in brackish water, a cupro-nickel heat
exchanger is recommended. In ground water situations
where scaling could be heavy or where biological growth
such as iron bacteria will be present, an open loop system
is not recommended. Heat exchanger coils may over time
lose heat exchange capabilities due to build up of mineral
deposits. Heat exchangers must only be serviced by a
qualified technician, as acid and special pumping equipment
is required. Desuperheater coils can likewise become scaled
and possibly plugged. In areas with extremely hard water,
the owner should be informed that the heat exchanger
may require occasional acid flushing. In some cases, the
desuperheater option should not be recommended due to
hard water conditions and additional maintenance required.
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
WARNING!
Polyolester Oil, commonly known as POE oil, is
a synthetic oil used in many refrigeration systems including
those with HFC-410A refrigerant. POE oil, if it ever comes
in contact with PVC or CPVC piping, may cause failure of
the PVC/CPVC. PVC/CPVC piping should never be used
as supply or return water piping with water source heat
pump products containing HFC-410A as system failures and
property damage may result.
⚠
WARNING!
⚠
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.
Expansion Tank and Pump -
Use a closed, bladder-type
expansion tank to minimize mineral formation due to air
exposure. The expansion tank should be sized to provide at
least one minute continuous run time of the pump using its
drawdown capacity rating to prevent pump short cycling.
Discharge water from the unit is not contaminated in any
manner and can be disposed of in various ways, depending
on local building codes (e.g. recharge well, storm sewer,
drain field, adjacent stream or pond, etc.). Most local codes
forbid the use of sanitary sewer for disposal. Consult your
local building and zoning department to assure compliance
in your area.
Water Control Valve -
Always maintain water pressure
in the heat exchanger by placing the water control valve(s)
on the discharge line to prevent mineral precipitation
during the off-cycle. Pilot operated slow closing valves are
recommended to reduce water hammer. If water hammer
persists, a mini-expansion tank can be mounted on the
piping to help absorb the excess hammer shock. Insure
that the total ‘VA’ draw of the valve can be supplied by
the unit transformer. For instance, a slow closing valve can
draw up to 35VA. This can overload smaller 40 or 50 VA
transformers depending on the other controls in the circuit.
A typical pilot operated solenoid valve draws approximately
15VA..
