Desuperheater - Econar GeoSource Invision 3 Q Series Installation And Operating Instructions Manual

XV.
DESUPERHEATER
(OPTIONAL)
A
GeoSource
Invision3
heat
pump equipped
with
a
desuperheater
(QxxkWxT-SUP)
can
provide
supplemental heating
of
a home's
domestic hot water.
This is
done
by stripping
heat
from
the superheated gas
leaving the compressor and transferring
it
to
a
hot water
tank. A
desuperheater
pump, manufactured into
the
unit,
circulates water
from
the domestic hot water tank, heats
it
using
a
double
walled
water-to-refrigerant heat
exchanger, and returns
it
to the
tank.
The desuperheater
provides supplemental heating
because
it
only heats water
when
the
flrst
stage
compressor is
already
running to
heat
or cool
the
conditioned space. Because the desuperheater
is stripping
some
of
the
energy from the heat
pump in
order to heat the
water,
the heat
pump's capacity in
the
winter
will
be
slightly
less
than
a
unit without
a
desuperheater. During extremely cold weather, or
if
the
heat
pump
cannot keep
up with heating the space, the
desuperheater
fuse may be
pulled in
order to get more
capacity out of
the
unit.
Insulated copper
tubilg
should be used
to run from
the
hot water tank to
the desuperheater connections on the
left
side
of
the
unit.
The
built in
desuperheater
pump
can
provide
the
proper flow
to
the desuperheater
if
the total
equivalent length of
straight pipe
and
connections is kept
to
a
maximum
of
90
feet
of ll2-inch
type
L
copper tubing.
This
tubing can be connected to
the
hot water tank
in two
ways:
METHOD
1
Using a desuperheater
tee
installed in
the
drain
at the
bottom of
the
water heater (See Figure
9).
This
is the
preferred method
for
ease
of installation, comfort
and
efficiency.
The
tee
eliminates
the need
to
tap
into
the
dornestic hot water lines
and
eliminates household water
supply temperature variations that could occur
from
connecting to
the
hot
water pipes.
METHOD
2
Taking hot
water
from
the
bottom drain
and
returning
it
to
the
cold water supply
line
(See
Figure
l0).
This
method maintains
the same
comfort
and
efficiency
levels
but
increases
installation
time
and
costs. This
method
requires
a
check valve
in
the return
line
to
the
cold
water
supply
to
prevent water
from flowing
backwards through
the desuperheater
when
the
tank is
filling.
Water
passing
through the
pump backwards
damages rhe
rotor's bearing,
which
reduces
pump life
and
causes
noise
problems in
the
pump. A
spring-type check valve
with
a
pressure
rating
of
1/2
psi or
less
is
recommended.
All
air must
be
purged
from
the desuperheater
plumbing
before the
pump is engaged. To purge small
amounts
of
air from
the
lines, loosen
the desuperheater
pump from its
housing
by
turning the brass
collar. Let
water
drip
out
of
the
housing until
flow
is
established and
re-tighten
the
brass
collar. Using 1/2-inch copper tubing from
the
tank
to
the desuperheater
inlet
is
recommended to keep water
velocities high, avoiding
air pockets
at the
pump inlet.
An air vent in
the
inlet line
can also
help systems where
air is
a
problem.
If
one is used
(we recommend
a
Watts
Regulator brand
FV-4 or
Spirovent) mount
it
near the
desuperheater
inlet roughly
2-l/2
inches above the
horizontal
pipe.
Shutoff valves allow
access
to
the
desuperheater
plumbing without
draining
the
hot water
tank. Keep valves
open
when pump
is
running.
V C.IUTION
:
Running desuperheater
pump without
water
flow
will
damage the
pump.
Poor water
quality
may restrict
the
effectiveness of using
the desuperheater
tee
by plugging
the entrance
with
scale
or
buildup from
the bottom
of
the tank,
restricting
water
flow.
Desuperheater maintenance includes
periodically
opening
the
drain on
the
hot water tank
to
remove
deposits.
Ifhard
water,
scale, or
buildup
causes
regular
problems in hot water
tanks
in your
area,
it
may result
in
a
loss
of
desuperheater
effectiveness. This
may require
periodic
cleaning
with Iron
Out
or similar
products.
The
desuperheater's
high temperature cutout switch is
located on the return
line from
the
water
heater.
The
switch is wired in
series
with
the desuperheater pump to
disable
the
pump from circulating
at
entering water
temperature above
140'F.
Ifthe
desuperheater
causes
tank
temperatures to
become
uncomfortably
hot, this
temperature switch
can be
moved to
the
leaving water line
which
will
reduce the
tank maximum
temperatures l0oF
to
15nF. Do
not
remove
the high temperature switch or
tank
temperatures could
become
dangerously
hi-eh.
A
fuse is attached to
the
fuseholder and must
be
inserted in
the fuseholder after
the desuperheater
is
operational.
Do not insert fuse until
water
flow
is
available or
the
pump may
be damaged. Remove
the fuse
to disable
the
pump if
the desuperheater isn,t in
operation.
23