Maritime Geothermal WH-Series, Installation And Service Manual

Page: 14 / 77

Page 14 002028MAN-01 1-Oct-2015
Ground Water System Information
move the jumper plug from the Valve Connector and connect
the harness in its place.
Ideally there will be water flow available in excess of the
requirement of the heat pump. In such a situation the proper
pump can be selected to maintain a pressure of 30 to 40 psig.
on the lines when the heat pump is operating. However in some
cases a well can supply a heat pump only if the minimum
requirement for water is used.
Water flow to the heat pump can be controlled very
accurately by the installation of a reverse action refrigeration
pressure valve in the discharge line of the unit.
Another more common method of regulating the flow is by
the use of a DOLE Valve. This valve will automatically control
the amount of water flowing through it by varying the diameter of
a flexible rubber orifice through which the water passes. This
minimizes the water usage of the unit and also prevents a re-
versing unit from running excessively low discharge pressure
when in cooling mode. Dole valves can be noisy, it is recom-
mended that they be installed outside if possible.
Optionally a water flow meter can be installed in the dis-
charge line so that the exact amount of water flowing can be
determined at a glance. It should be placed between the Out-
door OUT (Supply OUT) pipe of the heat pump and the water
valve.
With proper flow, there should be
5-7°F (3-4°C) delta T
between the IN and OUT water temperatures of the heat pump
when operating in the heating mode.
All water line valves on both the supply and discharge lines
should be either BALL or GATE valves. GLOBE valves have a
higher pressure drop, meaning more pumping power to maintain
the required flow to the heat pump.
PIPE INSULATION
All ground water piping to and from the Outdoor Loop
ports on the heat pump should be insulated with 3/8” closed cell
pipe insulation, to prevent condensation and dripping onto floors
or walls.
WATER DISCHARGE METHODS
Water disposal methods vary from area to area. However,
some consideration should be made to prevent the cooled
discharge water from immediately coming in contact with the
supply source. Attempting to return the water to the source well
will eventually cool the water so much that the heat pump will
shut off on its low pressure safety control.
Acceptable methods for disposing of the waste water are
listed below. The waste water is clean, the heat pump has no
other effect than reducing the temperature of the water.
Refer
to drawing 000619INF for typical disposal method diagrams.

Second well (return well)

Percolation (Drain, ditch, leaching field)

Pond, river or stream.
ENSURE SELECTED METHOD CONFORMS TO LOCAL CODES.
GENERAL REQUIREMENTS
1. The temperature of the well water should be a minimum
of 50°F (10°C), and should normally be 55+°F (13°C)
2. The well system must be able to supply the required
water flow as listed under the Total Flow column in
TABLE 6 .
PLUMBING THE HEAT PUMP
Plumbing lines, both supply and discharge, must be of
adequate size to handle the water flow necessary for the heat
pump. A 1” copper or plastic line should be run to the Outdoor
IN (Supply IN) pipe of the heat pump. Similarly, a 1”' line should
be run from the Outdoor OUT (Supply Out) pipe to the method
of disposal. P/T plugs should be installed at each port. See
DIAGRAM A in the Ground Loop section for a description of P/
T plugs. The water valve should be installed in the discharge
line. Refer to drawing 000529CDG at the end of this section
for the recommended setup. Placing the water valve in the
discharge line ensures that the heat exchanger inside the heat
pump remains full of water when the unit is not running. Unions
or some other form of disconnect should be used so that the
coaxial heat exchanger may be accessed should it required
cleaning.
The heat pump has an electrical connector for the water
valve just inside the case. After the water valve is installed, run
the valve harness into the case through the hole provided. Re-
TABLE 6 - Required Flow and Air Tank Sizing
Heat
Pump
Model
Size
Heat
Pump
Flow*
USGPM
(L/s)
Home
Flow
USGPM
(L/s)
Total
Flow
USGPM
(L/s)
Minimum Air
Bladder
Tank**
USgal
(L)
25 8.0 (0.50) 4 (0.25) 12 (0.76) 24 (91)
45 10.0 (0.63) 4 (0.25) 14(0.88) 28 (106)
55 12.0 (0.76) 4 (0.25) 16(1.01) 32 (121)
65 14.0 (0.88) 4 (0.25) 18(1.14) 36 (136)
75 16.0 (1.01) 4 (0.25) 20 (1.26) 40 (151)
80 17.0 (1.07) 4 (0.25) 21(1.32) 42 (159)
* These are minimum water requirements based on an
entering water temperature of 55° F.
**Based on two-minute well pump run time. Use next size
larger tank if there is not a match for the value indicated.
A larger tank may be used if a longer run time is desired.
IMPORTANT NOTE: The R134a WH-series absolutely
requires a minimum source fluid temperature of 50
° F
or greater. This is different from standard geother-
mal heat pumps which use R410a refrigerant.
!
IMPORTANT NOTE: The 50
° F temperature require-
ment means the WH-series may use a water well
source only in suitably warm climates.
!