Bosch C 950 - Page 19

Installation instructions
19
C 950/C 1050 (Pro TL 175 C/199 C) – 6 720 805 440 (2019/10)
Use of elbows
It is recommended to limit the amount of elbows used in the
exhaust and combustion air piping to reduce friction in the air
flow. The following lists the maximum amount of 90° elbows
allowed in either the exhaust or combustion air piping:
Table 11
Two 45° elbows are equal to one 90° elbow. Any
combination of 45° and 90° elbows may be used in the vent
system as long as the combination does not exceed the
maximum listed in table 11 above.
Calculation example for 3" PVC, CPVC, or ABS venting:
Exhaust
Table 12
Table 13
For this example, the maximum allowable exhaust pipe length is
12 feet.
Combustion air
Table 14
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
Table 16
Table 17
For this example, the maximum allowable exhaust pipe length is
58.5 feet.
Max. number of 90° elbows 2"
venting
3"
venting
4"
venting
Twin pipe with two
terminations
1
1)
or 2
2)
1) If using 90 ° short sweep elbow.
2) If using 90 ° long sweep elbow.
57
Twin pipe with concentric
termination
_ 4 7
System used Twin pipe with
Number of 90° elbows needed: 1
Number of 45° elbows needed: 2
Calculation of example
Max. length 23’
90° elbow reduction - 5’
sub-total = 18’
45° elbow reduction - 6’
Total = 12’
System used Concentric
Number of 90° elbows needed: 2
Number of 45° elbows needed: 1
Calculation of example
Max. length 23’
90° elbow reduction - 10’
sub-total = 13’
45° elbow reduction - 3’
Total = 10’
System used Twin pipe
Number of 90° elbows needed: 1
Number of 45° elbows needed: 2
Calculation of example
Max. length 63’
90° elbow reduction - 2.5’
sub-total = 61.5’
45° elbow reduction - 3’
Total = 58.5’