# Bosch C 950 Installation Manual page 14

14 | Installation instructions
For this example, the maximum allowable exhaust pipe
length is 12 feet.
Combustion air
System used
Number of 90° elbows needed:
Number of 45° elbows needed:
Table 14
Calculation of example
Max. length
90° elbow reduction
sub-total =
45° elbow reduction
Total =
Table 15
For this example, the maximum allowable combustion
air pipe length is 10 feet.
Calculation example for 4" PP, PVC, CPVC, or ABS venting:
Exhaust
System used
Number of 90° elbows needed:
Number of 45° elbows needed:
Table 16
Calculation of example
Max. length
90° elbow reduction
sub-total =
45° elbow reduction
Total =
Table 17
For this example, the maximum allowable exhaust pipe
length is 58.5 feet.
Combustion air
System used
Number of 90° elbows needed:
Number of 45° elbows needed:
Table 18
6 720 805 440 (2014/11)
Calculation of example
Max. length
90° elbow reduction
sub-total =
45° elbow reduction
Total =
Concentric
Table 19
2
1
Calculation example for 2" PVC venting:
23'
Exhaust
- 10'
System used
13'
Number of 90° elbows needed:
Number of 45° elbows needed:
- 3'
Table 20
10'
Calculation of example
Max. length
90° elbow reduction
sub-total =
45° elbow reduction
Total =
Table 21
Twin pipe
1
2
Combustion air
System used
63'
Number of 90° elbows needed:
- 2.5'
Number of 45° elbows needed:
61.5'
Table 22
- 3'
58.5'
Calculation of example
Max. length
90° elbow reduction
sub-total =
45° elbow reduction
Total =
Table 23
Twin pipe
2
2
For this example, the maximum allowable combustion
air pipe length is 55 feet.
For this example, the maximum allowable exhaust pipe
length is 4.5 feet.
For this example, the maximum allowable combustion
air pipe length is 4.5 feet.
63'
- 5'
58'
- 3'
55'
Twin pipe
1
0
9.5'
- 5'
4.5'
- 0'
4.5'
Twin pipe
0
2
9.5'
- 0'
9.5'
- 5'
4.5'
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