24
WARNING
Vent extending through exterior wall shall not
terminate adjacent to wall or below building
extensions such as eaves, balconies, parapets or
decks. Failure to comply could result in death or
serious injury.
!
6.4
Vent
Pipe Installation
• Minimum and maximum combustion air and vent pipe
lengths listed in Table 5. Pipe length counted from
combustion air connector to termination.
•
Install field-sourced 2" to 3", or 3" to 4" transitions, if used,
in vertical section.
• 90° elbows equivalent to 5.0 ft (1.6 m). 45° elbows
equivalent to 3.5 ft (1.1 m). 2" to 3" , or 3" to 4"
transitions have no equivalent length. See Table 6.
•
Use flexible Polyproplyene piping (PP) in a vertical position
only. Check PP pipe manufacturer for details. Each foot of
PP flexible pipe is equivalent to 2
⅝
feet of smooth pipe of
same diameter.
• Slope vent pipes minimum 1/4" per foot (21 mm/m) back
toward boiler. Support horizontal sections to prevent sags
capable of accumulating condensate.
• Support piping in accordance with pipe manufacturer's
instruction and authority having jurisdiction. In absence
of manufacturer's instruction use pipe hooks, pipe straps,
brackets, or hangers of adequate and strength located
at intervals of 4 ft (1.2m) or less. Allow for expansion/
contraction of pipe.
• Combustion air and vent piping must be air tight and water
tight.
•
Certified vent system components must NOT be
interchanged with other vent systems or unlisted pipe/
fittings.
•
6.5
Vent
Termination
•
Terminate combustion air and vent pipes with fittings or
concentric vent kit.
A. See "Parts, Kits and Optional Accessories" manual for
concentric vent kit part numbers.
B. Use horizontal pipe for vent and 90° elbow for
combustion air termination when using fittings.
• Separate vent terminal from air inlet terminal to prevent
flue gas recirculation. If T-Terminal is used on flue pipe
at sidewall, air inlet terminal shall be at least 36" or more
away from vent terminal.
• Locate combustion air termination as far as possible from
swimming pool, swimming pool pump house, and other
sources of airborne chlorine.
• Locate combustion air and vent terminals as required by
authority having jurisdiction.
Minimum/Maximum Vent Lengths
2” Pipe
3” Pipe
4” Pipe
Model
050/075/100
075/100
150/200
299
299
Min.
6 ft.
(1.8 m)
6 ft.
(1.8 m)
6 ft.
(1.8 m)
6 ft.
(1.8 m)
6 ft.
(1.8 m)
Max.
50ft.
(15.2 m)
100 ft.
(30.5 m)
100 ft.
(30.5 m)
25 ft.
(7.7 m)
100 ft.
(30.5 m)
Table 5 - Combustion Air and Vent Piping Length
For Example: Boiler can be installed on outside wall and vented with one 90° elbow and 1 ft (0.30 m) of vent pipe.
Table 6 -Equivalent Length of Venting Components
Equivalent Length of Venting Components
Component
Feet
Meters
90° Elbow
5
1.6
45° Elbow
3 1/2
1.1
2" x 3" Adapter
0
0
3" x 4" Adapter
0
0
Concentric Vent Kit
5
1.6
Polypropylene Flexible Pipe per Foot
2 5/8
0.8
6 - COMBUSTION AIR AND VENT PIPING
PN 240011320 Rev. G 10/01/2021]