Installation / Operation Instruction Manual

Installation instructions
RTG 199 HE – 6 720 811 617 (2016/01)
13
Combustion air
Calculation example for 4" PP, PVC, CPVC, or ABS venting:
Exhaust
Combustion air
Calculation example for 2" PVC venting:
Exhaust
Combustion air
For this example, the maximum allowable exhaust pipe
length is 13 feet.
System used Concentric
Number of 90° elbows needed: 2
Number of 45° elbows needed: 1
Table 14
Calculation of example
Max. length 23’
90° elbow reduction - 10’
sub-total = 13’
45° elbow reduction - 2.5’
Total = 11.5’
Table 15
For this example, the maximum allowable combustion
air pipe length is 11.5 feet.
System used Twin pipe
Number of 90° elbows needed: 1
Number of 45° elbows needed: 2
Table 16
Calculation of example
Max. length 63’
90° elbow reduction - 5’
sub-total = 58’
45° elbow reduction - 5’
Total = 53’
Table 17
For this example, the maximum allowable exhaust pipe
length is 53 feet.
System used Twin pipe
Number of 90° elbows needed: 2
Number of 45° elbows needed: 2
Table 18
Calculation of example
Max. length 63’
90° elbow reduction - 10’
sub-total = 53’
45° elbow reduction - 5’
Total = 48’
Table 19
For this example, the maximum allowable combustion
air pipe length is 48 feet.
System used Twin pipe
Number of 90° elbows needed: 1
Number of 45° elbows needed: 0
Table 20
Calculation of example
Max. length 9.5’
90° elbow reduction - 5’
sub-total = 4.5’
45° elbow reduction - 0’
Total = 4.5’
Table 21
For this example, the maximum allowable exhaust pipe
length is 4.5 feet.
System used Twin pipe
Number of 90° elbows needed: 0
Number of 45° elbows needed: 2
Table 22
Calculation of example
Max. length 9.5’
90° elbow reduction - 0’
sub-total = 9.5’
45° elbow reduction - 5’
Total = 4.5’
Table 23
For this example, the maximum allowable combustion
air pipe length is 4.5 feet.