Econar GeoSource 2000 GV Series Installation And Operating Instructions Manual page 7

Table
3
-
Side
Flow
Rates
Pressure/Temperature
(P/T)
ports should be installed
in
the entering and leaving water lines
of
the heat
pump on
a
closed
loop
system (see
Figure 1). A
thermometer
can be
inserted
into
the
P/T
ports to
check
entering
and
leaving
water temperatures. A pressure gauge can also be
inserted
into
these
P/T ports to determine
the pressure
differential between
the
entering
and
leaving water. This
pressure differential
can then be compared to
the
specification
data on each
particular
heat
pump to
determine the
flow
rate
of
the system.
A
PumpPAKrM that is
individually
sized
for
each
application
can
supply pumping requirements for
the
earth loop
fluid.
The PumpPAKrM
can also be used
to
purge
the
loop system.
The PumpPAKrM is wired directly
to
the contactor and operates
whenever
the compressor
runs (see
Electrical
Diagram
-
Figure
5). If
a
PumpPAKrM
is
not
used, a separate
pump
can be used
which is energized with
a
pump relay (note: electrical
code
will
require
a
fused disconnect
for pumps other than
PumpPAKsrM).
Filling
and
purging
a
closed
loop
system are
very
important
steps
to
assure
proper
heat
pump operation.
Each loop
must be
purged
with
enough
water
flow
to
assure a
two feet per
second
flow
rate
in
each
circuit in
the
loop.
This normally requires a
lYz
to
3 HP high head
pump to circulate
fluid
through the loop to remove
all
the
air out of
the
loop
and
into
a
purging tank. Allow
the
pump
to
run
10
to l5
minutes after
the
last air bubbles
have been
removed.
Enough antifreeze must
be added
to
give a
l0"F
to l5oF
freeze
protection to
the earth loop
system.
This
amount should
be
calculated
and added
to
the
loop after purging is
complete.
After
antifreeze
has
been
installed
it
should be measured
with
a
hydrometer,
refractometer or
any other device to determine
the
actual
freezing
point of
the solution. Remember that
a
low
antifreeze level
will
lock
the heat
pump out
on
low
pressure during wintertime
operation.
The purge
pump
can be used to
pressurize the system
to
an
initial
static pressure of 30-40
psi.
Make
sure the
system
is
at
this pressure
after the
loop pipe
has had
enough time
to stretch. In
order to
achieve the 30
to 40
psi initial
pressure, the loop may need to be
pressurized to
60 to
65
psi.
This static pressure
will
fluctuate
from
heating to
cooling
season,
but the pressure should always
remain
above
zero
so
circulation pumps
do
not cavitate
and air
cannot be
pulled into
the system.
SFor
information regarding
earth
loop
installations contact
your
local
installer, distributor or factory
representative.
B.
Open Loop Applications
An
open system gets its name
from
the open discharge
of
water after
it
has been used
by
the heat
pump. A
well
must
be
available that can supply all of
the
water
requirements
(see Table 3)
of
the heat
pump along with
any
other water requirements drawing
off
that
same
well.
The well
must be capable
of supplying
the heat
pump's
required
flow
rate for
up
to
24
hours per day on
the
coldest
winter
day.
Fi_gure
2 shows the necessary
components
for
water
piping of
an
open
system. First,
a
bladder type pressure
tank
with
a
"draw down" of
at
least
lVz
times
the
well
pump capacity must
be
installed
on the
supply
side
of
the
heat
pump.
Shut
off
valves and boiler drains on the
entering and
leaving water lines
are necessary
for future
maintenance issues.
A
screen strainer is
placed on
the
supply
line with
a
mesh size
of
40 or 60 and enough
surface area
to
allow for particle buildup
between
cleanings.
Pressure/Temperature (P/T) ports
are
placed in
the supply
and
discharge lines
so
that thermometers or pressure
gauges can be
inserted into the water stream.
On the
well
water discharge
side
of
the heat
pump,
a
flow control
valve
must be
mounted next to
the heat
pump to regulate
the
maximum water flow through the
unit. A
solenoid
valve is
then
installed
and
wired
to the accessory
plug on
the
controller. This
valve
will
open when the
unit
is
running
and
close when
the
unit stops.
A
visual
flow
meter is
then installed to
allow visual inspection of
the
flow
requirements.
The
flow
meter is useful
in
determining when maintenance is
required.
(If
you can't
read the
flow,
cleaning is required.)
Schedule
40 PVC
piping, copper tubing, polyethylene or
rubber
hose can be used
for supply
and
discharge water
lines.
Make
sure
line
sizes are
large
enough to supply the
required flow with
a
reasonable pressure
drop (generally
l"
diameter
minimum). NOTE:
Do not
use
plastic
female
fittings with
metal
male
fittings, or fractures may
result in
the female
fittings.
Always
use
plastic male into
steel female
!
Water
discharge is
_eenerally
made to
a
drain field,
stream,
pond,
surface
discharge, tile line, or
storm sewer.
VCAUTION:
Using
a
drain field requires soil
conditions
and adequate
sizing to
assure
rapid percolation,
or
the
required
flow
rates
will
not
be
achieved. Consult
local codes and ordinances to
assure
compliance. DO
pf
discharge water to
a
septic
system.
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