Trane EXWA Installation Manual page 23

Water Pressure Drop
Tables 6 and 7 should be used to define feet of head/pressure drop. Note: To calculate feet of head, when using gauges that read in PSIG,
multiply PSI by 2.31.
Table 6: Cooling water pressure drops (WPD) in feet of head
Source
Unit Size
GPM EWT
F
3.8
024 7.0 80
8.9
4.6
036 8.5 80
10.8
5.2
042 9.5 80
12.1
6.0
048 11.0 80
14.0
7.6
060 14.0 80
17.8
8.7
072 16.0 80
20.4
30.0
240 55.0 80
70.0
Water Volume
Table 8 is provided for use in calculating glycol requirements for the unit.
Table 8: Water volume
Water Side Water Side
Unit Size
Volume
Cubic In.
024 55
036 105
042 105
048 259
060 259
072 259
240 1057
Flow Checks
For the operating temperature drop (heating) and rise (cooling), refer to Table OP1 and OP2 for the proper water tempera-
ture change. Depending on the unit size, entering water temperature and water flow rate, the cooling temperature rise is
from 8°F-16°F. Based on the same criteria for heating, the temperature drop is from 2°F-13°F.
Pressure
Using the P/T ports and one 0-60 psi pressure gauge with the P/T port adapter, measure the pressure difference between
the water-in and water-out connections. Compare the pressure differential to Table 6 to determine flow.
Start-up Checklist and Log
Use the form on page 24 to log system and unit temperatures during start-up.
WSHP-SVX02A-EN
Operating Pressures
Load
Ft. Head EWT Ft. Head
Pressure F Pressure
1.3 1.6
4.5 53.6 5.4
7.2 8.7
1.9 2.3
6.6 53.6 7.9
10.6 12.7
2.4 3.0
8.6 53.6 10.3
14.1 17.1
3.3 4.0
11.6 53.6 14.0
19.1 23.1
5.4 6.5
19.1 53.6 23.1
31.5 38.1
7.1 8.6
25.3 53.6 30.5
41.8 50.5
2.9 3.6
8.1 53.6 9.7
12.2 14.7
Water Side
Volume Volume
Cubic Ft. Gallons
0.032 0.238
0.061 0.455
0.061 0.455
0.150 1.121
0.150 1.121
0.150 1.121
Note: The EXWA 240 has two circuits.
0.615 4.576
Table 7: Heating water pressure drops (WPD) in feet of head
Source
Unit Size
GPM EWT
F
3.8
024 7.0 60
8.9
4.6
036 8.5 60
10.8
5.2
042 9.5 60
12.1
6.0
048 11.0 60
14.0
7.6
060 14.0 60
17.8
8.7
072 16.0 60
20.4
30.0
240 55.0 60
70.0
Load
Ft. Head EWT Ft. Head
Pressure F Pressure
1.5 1.3
5.1 80 4.5
8.3 7.2
2.2 1.9
7.6 80 6.6
12.2 10.6
2.8 2.4
9.8 80 8.6
16.2 14.1
3.8 3.3
13.3 80 11.6
21.9 19.1
6.2 5.4
21.9 80 19.1
36.1 31.5
8.2 7.1
28.9 80 25.3
47.9 41.8
3.4 2.9
9.2 80 8.1
13.9 12.2
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