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6 - COMBUSTION AIR AND VENT PIPING
FIGURE 6-2 Side Wall Coaxial Venting
WARNING
•
Covering non-metallic vent pipe and fittings with
thermal insulation shall be prohibited.
•
Use of cellular core PVC for venting flue gas could
result in death, or serious injury.
• Coaxial venting shall be fastened with screws.
Twin pipe venting is NOT fastened with screws.
!
FIGURE 6-3 Roof Mount Coaxial Venting
2” (50 mm)
X
Min. 8" (181 mm)
Max. 14" (356 mm)
Maximum Length = L
A B
21’ (6.4 m)
E F
21’ (6.4 m)
L1
L2
L = L1 + L2
Maintain 12"(305mm)
US (18"(457mm)
Canada) clearance
above highest
anticipated snow level
24" (610mm) above
roof or ground
Ground
Anticipated
Snow Line
Ground
Anticipated
Snow Line
Maintain 12"(305mm)
US (18"(457mm)
Canada) clearance
above highest
anticipated snow level
24" (610mm) above
roof or ground
Anticipated
Snow Line
18" Vertical
Clearance to
ventilated soffit
Illustration shows examples of maximum equivalent lengths.
Coaxial Elbows - Equivalent length
Elbow
Total Length Reduction
45°
1' 8" (0.5 m)
90°
3' 4" (1.0 m)
B. Coaxial Flue Options
• Standard horizontal termination is suitable only for
horizontal applications.
• Maximum permissible equivalent vent length is 21 ft.
(6.4 m)
•
An "in line" elbows in flue system must be taken into
consideration
Elbow
Total Length Reduction
45°
1' 8" (0.5 m)
90°
3' 4" (1.0 m)
•
The first elbow in horizontal run is NOT included in any
equivalent length calculations
A. Venting Instructions
PN 240011662 Rev. H [04/30/2019]