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Table 7 — Heat Exchanger Pressure Drop
UNIT SIZES 036-120
UNIT SIZES 180,360
NOTE: Bold values indicate use of antifreeze is required.
Cleaning and Flushing — Cleaning and flushing of
the piping system is the single most important step to ensure
proper start-up and continued efficient operation of the system.
Follow the instructions below to properly clean and flush
the system:
1. Verify electrical power to the unit is disconnected and
lockout tag installed.
2. Install the system with the supply hose connected directly
to the return riser valve. Use a single length of flexible
hose.
3. Open all air vents. Fill the system with the water. DO
NOT allow system to overflow. Bleed all air from the
system. Pressurize and check the system for leaks and re-
pair appropriately.
4. Verify all strainers are in place. Start the pumps, and sys-
tematically check each vent to ensure all air is bled from
the system.
5. Verify make-up water is available. Adjust make-up water
appropriately to replace the air which was bled from the
system. Check and adjust the water/air level in the expan-
sion tank.
6. Raise the loop temperature to approximately 29.4 C.
Open the drain at the lowest point in the system. Adjust
the make-up water replacement rate to equal the rate of
bleed.
7. Refill the system and add trisodium phosphate in a pro-
portion of approximately 0.5 kg per 750 L of water (or
other equivalent approved cleaning agent).
Raise the loop temperature to 37.8 C. Circulate the solu-
tion for a minimum of 8 to 24 hours. At the end of this
period, shut off the circulating pump and drain the solu-
tion. Repeat system cleaning if desired.
8. When the cleaning process is complete, remove the short-
circuited hose. Reconnect the hoses to the proper supply,
and return the connections to each of the units. Refill the
system and bleed off all air.
9. Test the system pH with litmus paper. The system water
should be slightly alkaline (pH of 7.5 to 8.5). Add chemi-
cals, as appropriate, to maintain acidity levels.
10. When the system is successfully cleaned, flushed, refilled
and bled, restore power.
11. Check the main system panels, safety cutouts and alarms.
Set the controls to properly maintain loop temperatures.
Antifreeze — In areas where entering loop temperatures
drop below 4.4 C or where piping will be routed through areas
subject to freezing, antifreeze is needed.
Alcohols and glycols are commonly used as antifreeze
agents. Freeze protection should be maintained to 8.3° C below
the lowest expected entering loop temperature. For example, if
the lowest expected entering loop temperature is –1.1 C, the
leaving loop temperature would be –5.6 to –3.9 C. Therefore,
the freeze protection should be at –9.4 C (–1.1 C – 8.3 C =
–9.4 C).
Calculate the total volume of fluid in the piping system. See
Table 8. Use the percentage by volume in Table 9 to determine
the amount of antifreeze to use. Antifreeze concentration
should be checked from a well mixed sample using a hydrome-
ter to measure specific gravity.
FREEZE PROTECTION SELECTION — The –1.1 C FP1
factory setting (water) should be used to avoid freeze damage
to the unit.
Once antifreeze is selected, the JW3 jumper (FP1) should
be clipped on the control to select the low temperature (anti-
freeze –12.2 C) set point to avoid nuisance faults.
50PSW
UNIT SIZE
L/s
PRESSURE DROP (kPa)
–1 C 10 C 21 C 32 C
Source/Outdoor Coax
036
0.28
0.43
0.57
11.7
28.3
49.0
9.0
23.4
41.4
6.9
19.3
35.2
5.5
16.5
31.0
060
0.47
0.71
0.95
10.3
27.6
47.6
9.0
23.4
42.8
17.2
47.6
88.3
14.5
42.1
80.0
120
0.95
1.42
1.89
11.7
30.3
52.4
9.7
26.2
46.9
8.3
22.8
42.1
6.2
18.6
34.5
Load/Outdoor Coax
036
0.28
0.43
0.57
—
—
—
4.1
9.7
18.0
3.4
9.0
16.5
2.1
7.6
15.2
060
0.47
0.71
0.95
—
—
—
9.7
24.1
42.8
9.0
22.1
40.0
8.3
20.7
37.9
120
0.95
1.42
1.89
—
—
—
11.0
26.2
46.9
9.7
24.1
44.1
2.1
22.8
41.1
50PSW
UNIT SIZE
L/s
PRESSURE DROP (kPa)
0 C 10 C 20 C 30 C
Source/Outdoor Coax
180
1.10
1.67
2.21
4.82
17.92
32.40
2.76
11.72
22.75
1.72
11.38
21.37
0.88
9.47
19.30
360
2.21
3.34
4.42
11.03
26.88
48.95
8.27
24.82
44.82
7.22
23.10
41.36
6.29
21.29
38.47
WARNING
To avoid possible injury or death due to electrical shock,
open the power supply disconnect switch and secure it in
an open position before flushing system. Install lockout
tag.
CAUTION
To avoid possible damage to a plastic (PVC) piping sys-
tem, do not allow temperatures to exceed 43.3 C.
CAUTION
DO NOT use “Stop Leak” or any similar chemical agent in
this system. Addition of these chemicals to the loop water
will foul the system and inhibit unit operation.
IMPORTANT: All alcohols should be pre-mixed and
pumped from a reservoir outside of the building or
introduced under water level to prevent alcohols from
fuming.