Fan Speed Adjustment - Bosch GWH 2400 ES NG Manual

Maintenance and service
6.7

Fan speed adjustment

Installation adjustment: Flue pipe length setting
for minimum power - P2.
After installing the GWH 2400 ES, the minimum power
fan speed must be selected to compensate for variation
in vent pipe length.
Total vent length calculation
B Determine the total length of all straight sections of
vent pipe and enter in table 19, line 1.
B Count the number of 90° elbows used and enter that
value in line 2. (Do not count terminals and first elbow
used on intake and exhaust).
B Count the number of 45° elbows used and enter that
value in line 3.
B Repeat steps 1 through 3 for air intake pipe and enter
those values in the intake section of table 19.
B Add line 4 from Exhaust to line 4 of Intake and enter
result in line 5.
This is the total equivalent vent length.
Exhaust
1 Straight section length
2 90° elbows (qty)
3 45° elbows (qty)
4
Intake
1 Straight section length
2 90° elbows (qty)
3 45° elbows (qty)
4
5 Total equivalent vent length =
Table 19Determining vent length combination (see
example in Table 20)
Example
Exhaust
• 7 - 3' straight sections
• 1 - 1' straight section
• 2 - 90° elbow.
Intake
• 5 - 3' straight sections
• 2 - 90° elbows.
36
__ x 1 =
____
__ x 2.5 =
____
__ x 1.25 =
____
Total:
____
__ x 1 =
____
__ x 2.5 =
____
__ x 1.25 =
____
Total:
____
____
Total length 22'
Total length 15'
Example
Exhaust
Straight section length
(feet)
90° elbows (qty)
45° elbows (qty)
Total:
Intake
Straight section length
(feet)
90° elbows (qty)
45° elbows (qty)
Total:
Total equivalent vent length =
Table 20Determining vent length combination example
Note: Do not count terminals and first elbow used on
intake and exhaust.
Total maximum length not to exceed
i
52ft.
22 x 1 = 22
1 x 2.5 = 2.5
0 x 1.25 = 0
24.5
15 x 1 = 15
1 x 2.5 = 2.5
0 x 1.25 = 0
17.5
42
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