Hydronic-Side Heat Exchangers; Temperature Limitations; Ground Source Design - Econar GeoSource Ultra GW Series Installation And Operating Instructions Manual

are
normally
sized
to
supply
a
wintertime
EWT to
the
heat
pump down to
25oF.
2.
Ground Water
Systems
(see Figure
3)
The design water
temperature
will
be the well
water
temperature
in
the
geographic region
for
ground
water
systems.
Typical well
water temperatures are
in
the 50oF
range
in
many cold climates.
If
well
water temperature is
lower than 500F (Canadian
well
water can be as
low
as
40"F), the
flow
rate must be
increased
to
avoid leaving
water
ternperatures
below
the
freezing
point.
If
well water
temperatures
are above
50oF
(Some southern
stat€s
are
above 70oF), the
flow
rates may need to be
increased
to
dump
energy
more efficiently during
the
cooling
mode.
Varying
well
water temperatures
will
have
little
effect
on
unit
capacity
in
the cooling mode (since the well
is
connected
to
the
heat
pump
condenser),
but
can
have
large effects on capacity
in
the heating mode
(since
the
well
is
connected
to
the
evaporator).
If
well
water
temperatures exceed 70oF, special considerations such
as
closed
loop
systems should be considered.
C.
Hydronic-Side Heat Exchangers
Hydronic-side
heat exchangers discussed
in
section
VI
are
designed
to
operate at a specific
fluid
supply temperature.
This
operating temperature
will
have to be supplied to the
selected space
conditioning heat
exchanger
by
the
hydronic
heat
pump.
The
manufacturers
or
suppliers
of
the hydronic-side heat
exchangers
publish
the capacity
of
their equipment at different operating
temperatures
and
fluid flow
rates, and
these capacities
and
operating
temperatures are required
to
select the heat
pump to
be
used
in
the system.
When
selecting
the heat pump,
choose
a unit that will
supply the necessary heating
or
cooling
capacity
at
the
minimum and maximum hydronic loop
temperature
conditions, respectively. Example;
if
a fan coil
system
requires 35000
Btu/hr
to
cool a
space
with
45oF water
temperature
entering the water-to-air fan coil,
a GW47x
GeoSource
Ultra
heat
pump is
required
to
handle
the
cooling load.
If
an
intermediate heat exchanger
is
used
between
the
storage
tanks as pictured
in
Figure 1,
expect
a
10oF
operating temperature difference between the two
tanks.
For
example,
if
the
direct-coupled storage
tank
is
at
110oF,
expect the maximum
operating temperature
of
the
indirect-coupled tank
connected
through
an intermediate
heat exchanger to be
100oF.
D. Temperature Limitations
Be
aware
of
the operating range
of
the geothermal
system
when sizing
the
particular
heat
pump to avoid prematwe
equipment
failure.
Operating outside
of
these
limitationsmay
cause severe damage
to
the equipment
and
may
void warranty.
VCAUTIONS;
r
The
acceptable
hydronic
LWT is 70'F to
l15oF for
heating
and 35iF
to
50oF
for
cooling. Hydronic EWT
should remain
above 50oF
to avoid low-pressure lockouts.
.
The acceptable Ground Loop EWT is 25iF
to
50oF
for
heating
and
50iF
to
I
00T
for
cooling.
.
The
acceptable
Ground Water EWT is
45T
minimum
in
heating and
100T
maximum in
cooling.
IV.
UNTT
LOCATION
/
MOUNTING
VCAUTION
- Units
must
be
kept
in
an
upright position
during
transportation
or
installation,
or
severe
internal
damage
may occur.
elmportant
- To
ensure easy
removal
and replacement
of
access
panels, leave panels secured
in
place until
the
unit
is
set
in place
and
leveled.
elmportant
-
Locate the
unit
in
an
indoor
area where
the ambient temperature
will
remain above 45oF. Service
is
done
primarily from
the front. Top
and rear
access is
desirable
and
should
be
provided when possible.
elmportant
-
A
field
installed drain pan
is
required
under the entire
unit
where accidental
water
discharge
could
damage surrounding
floors,
walls or ceilings.
VCAUTION - Do
not
use
this unit during
construction.
Dust and debris
may quickly
contaminate electrical
and
mechanical components; resulting in
damage.
VCAUTION
-
Before
driving
screws
into
the
cabinet,
check on the inside
of
the
unit
to ensure the screw
will
not
damage
electrical, water, or refrigeration lines.
elmportant
-
Units
must
be
mounted
on a
vibration-
absorbing
pad
slightly larger than the
base
to
provide
isolation between
the
unit
and
the floor.
Water
supply
pumps should
not be hard plumbed directly to
the unit
with
copper
pipe; this
could transfer vibration from
the
water pump
to
the
refrigeration circuit,
causing
a
resonating
sound.
Hard plumbing must be isolated from
building
structures that could transfer vibration from
the
unit
through the
piping
to
the
living
space.
@CAUTION
-
Always use plastic male fittings
into
plastic
female
or into
metal
female
fittings.
Never
use
metal male fittings into
plastic female
fittings.
On metal-
to-metal
fittings;
use
pipe
thread compound, do not
use
pipe
thread tape, hand tighten
frst,
and then only
tighten
an additional
Yz
tlurr,
with
a
tool
if
necessary. On plastic
fittings, always
use
2 to 3
wraps
of pipe
thread tape, do
not
use
pipe thread compound, hand tighten first,
and then
only tighten
an
additional
Vz
tum
with
a
tool
if
necessary.
Do not over-tighten, or damage may occur.
V.
GROUND SOURCE DESIGN
Since water
is
the
source
of
energy
in
the winter
and the
energy
sink
in
the
summer,
a
good water
supply
is
possibly the
most
important
requirement
of
a geothermal
heat
pump
system
installation.
5