6 720 644 930
12
Installation instructions
Calculation example for 3" venting:
Exhaust
Combustion air
Calculation example for 4" venting:
Exhaust
Combustion air
System used
Concentric
Number of 90° elbows needed:
1
Number of 45° elbows needed:
2
Table 8
Calculation of example
Max. length
28.5’
90° elbow reduction
- 2.5’
sub-total =
26’
45° elbow reduction
- 2.5’
Total =
23.5’
Table 9
i
For this example, the maximum allowable
exhaust pipe length is 23.5 feet.
System used
Concentric
Number of 90° elbows needed:
2
Number of 45° elbows needed:
1
Table 10
Calculation of example
Max. length
28.5’
90° elbow reduction
- 5’
sub-total =
23.5’
45° elbow reduction
- 1.25’
Total =
22.25’
Table 11
i
For this example, the maximum allowable
combustion air pipe length is 22.25 feet.
System used
Twin pipe
Number of 90° elbows needed:
2
Number of 45° elbows needed:
2
Table 12
Calculation of example
Max. length
61.25’
90° elbow reduction
- 2.5’
sub-total =
58.75’
45° elbow reduction
- 1.5’
Total =
57.25’
Table 13
i
For this example, the maximum allowable
exhaust pipe length is 57.25 feet.
System used
Twin pipe
Number of 90° elbows needed:
1
Number of 45° elbows needed:
2
Table 14
Calculation of example
Max. length
61.25’
90° elbow reduction
- 1.25’
sub-total =
60’
45° elbow reduction
- 1.5’
Total =
58.5’
Table 15
i
For this example, the maximum allowable
combustion air pipe length is 58.5 feet.
