W2W Series Heat Pump
Ecologix Heating Technologies Inc
Page
11
www.ecologix.ca
221 Holiday Inn Drive Cambridge ON
ph: 519-658-4330
Step 10:
Using a single water pressure gauge, measure the
pressure drop at the pressure/temperature plugs
across the heat pump heat exchanger. Compare
the measurement with the flow versus the
pressure drop information for your specific
model (found in the tables below) and determine
the actual flow rate. If the flow rate is low,
recheck the selection of the loop pump module
model for sufficient capacity. If the model is
correct, there is likely trapped air or a restriction
in the flow circuit. System pressure should
increase rapidly as the flush pump works to force
more water into the system. Additional flushing
of the loop is needed if the water level in the
loop falls. This shows that there is air in the
system. System operating pressures should be
between 10 to 40PSI.
Table 3: Source/Load Heat Exchanger Water-Side Flow Data
W2W-36
gpm
7
8
9
10
11
12
13
psi
2.7
3.3
4.0
4.8
5.7
6.7
7.7
W2W-52
gpm
5
7
9
11
13
15
17
psi
1.3
1.6
2.1
2.8
3.6
4.6
5.8
W2W-72
gpm
12
14
16
18
20
22
24
psi
2.4
3.1
3.9
4.7
5.7
6.8
8.3
Table 4: Desuperheater Water-Side Flow Data
W2W-36
gpm
0.0
0.5
1.0
1.5
2.0
psi
0.0
0.3
0.5
1.2
1.9
W2W-52,72
gpm
1.0
1.5
2.0
2.5
3.0
psi
0.8
1.6
2.7
4.0
5.5
Table 5: Antifreeze Percentages by Volume
Type
Minimum Temperature for Low Temperature Protection
10ºF [-12.2ºC]
15ºF [-9.4ºC]
20ºF [-6.7 ºC]
25ºF [-3.9 ºC]
100% USP Propylene Glycol
38%
25%
22%
15%
Ethanol*
29%
25%
20%
14%
*Must be denatured with any petroleum based product
Antifreeze may be added before, during, or after
the flushing procedure. However, depending
upon which time is chosen, antifreeze could be
wasted when emptying the flush cart tank. See
antifreeze section for more details. Loop static
pressure will fluctuate with the seasons.
Pressures will be higher in the winter months
than during the cooling season. This fluctuation
is normal and should be considered when
charging the system initially. Run the unit in
either heating or cooling for a number of minutes
to condition the loop to a homogenous
temperature. This is a good time for tool cleanup,
piping insulation etc. Then final flush and
pressurize the loop to a static pressure of 40-50
psi (winter) 15-20 psi (summer).
After pressurization, be sure to remove the plug
in the end of the loop pump motor(s) to allow
trapped air to be discharged and to ensure the
motor housing has been flooded. This is step is
only required for Grundfos wet rotor circulators
with end plugs. Ensure the loop flow center
provides adequate flow through the unit by
checking pressure drop across the heat exchanger
and comparing it to the figures shown in the
performance table.
Antifreeze
In areas where minimum entering loop
temperatures drop below 40°F or where piping
will be routed through areas subject to freezing,
antifreeze is needed. Alcohols and glycols are
commonly used as antifreeze. However, your
local territory manager should be consulted for
the antifreeze best suited to your area. Freeze
protection should be maintained to 15°F below
the lowest expected entering loop temperature.
For example, if 30°F is the minimum expected
