Open Loop (Well System Applications); Water Connections - Bard Q-TEC Series Literature Assembly

OPEN LOOP
(Well System Applications)
NOTE It is highly recommended on ground water
systems (pump & dump) that a cupronickel
coaxial coil is utilized on the source side of the
system. Not doing so may void the product
warranty due to aggressive/corrosive/highly
oxygenated water attacking a copper coaxial
water coil.

WATER CONNECTIONS

It is very important that an adequate supply of clean,
noncorrosive water at the proper pressure be provided
before the installation is made. Insufficient water,
in the heating mode for example, will cause the low
pressure switch to trip, shutting down the heat pump.
In assessing the capacity of the water system, it is
advisable that the complete water system be evaluated
to prevent possible lack of water or water pressure
at various household fixtures whenever the heat
pump turns on. All plumbing to and from the unit
is to be installed in accordance with local plumbing
codes. The use of plastic pipe, where permissible,
is recommended to prevent electrolytic corrosion
of the water pipe. Because of the relatively cold
temperatures encountered with well water, it is strongly
recommended that the water lines connecting the unit
be insulated to prevent water droplets form condensing
on the pipe surface.
Refer to Figure 33. Slow closing Solenoid Valve (6)
with a 24V coil provides on/off control of the water flow
to the unit. Refer to the wiring diagram for correct
hookup of the valve solenoid coil.
Constant Flow Valve (7) provides correct flow of water
to the unit regardless of variations in water pressure.
Observe the water flow direction indicated by the
arrow on the side of the valve body. Table 7 shows the
flow rate of each valve. Two constant flow rate valves
may be installed in parallel to increase the flow. For
example, when a 8603-007 (6 GPM) and 8603-011
(5 GPM) are installed in parallel the total flow will be
11 GPM.
Strainer (5) installed upstream of constant flow valve
(7) to collect foreign material which would clog the flow
valve orifice.
Figure 33 shows the use of shutoff valves (9 and 11),
on the in and out water lines to permit isolation of the
unit from the plumbing system should future service
work require this. Globe valves should not be used as
shutoff valves because of the excessive pressure drop
inherent in the valve design. Instead use gate or ball
valves as shut-offs so as to minimize pressure drop.
Manual 2100-738A
Page 54 of 71
Drain cocks (8 and 10) and tees have been included to
permit acid cleaning the refrigerant-to-water coil should
such cleaning be required. See WATER CORROSION
section.
Drain cock (12) provides access to the system to check
water flow through the constant flow valve to ensure
adequate water flow through the unit. A water meter is
used to check the water flow rate.
Figure 33
Piping Diagram
10
11
6
TABLE 12
Constant Flow Valves
Min. Available
Part No.
Pressure PSIG
CFV-5 15 
CFV-6 15 
CFV-7 15 
CFV-9
15 

The pressure drop through the constant flow valve will
vary depending on the available pressure ahead of the
valve. Unless minimum of 15 psig is available
immediately ahead of the valve, no water will flow.
8
9
7
12
MIS-2749
Flow Rate GPM
5
6
7
9