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c l i m a t e m a s t e r. c o m
T H E S M A R T S O L U T I O N F O R E N E R G Y E F F I C I E N C Y
Tr a n q u i l i t y
®
2 2 ( T Y ) S e r i e s
R e v. : 1 2 / 1 7 / 1 4
Ground-Water Heat Pump Applications
Open Loop - Ground Water Systems
- Typical open
loop piping is shown in accompanying illustration. 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 fl ushing of the heat exchanger. Shut off valves
should be positioned to allow fl ow through the coax via the
boiler drains without allowing fl ow into the piping system.
P/T plugs should be used so that flow can be measured
using the pressure drop of the unit heat exchanger. Water
temperature may be viewed on the iGate communicating
thermostat.
Supply and return water piping materials
should be limited to copper, HPDE, or other acceptable
high temperature material. Note that PVC or CPVC
material is not recommended as they are not compatible
with the polyolester oil used in HFC-410A products.
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); 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 fi eld, 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. Ensure 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. Note
the special wiring diagrams for slow closing valves (shown
later in this manual).
Open Loop - Ground Water Systems
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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!
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 qualifi ed 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 fl ushing.
In some cases, the desuperheater option should not be
recommended due to hard water conditions and additional
maintenance required.
