Navien NHB Series, Installation & Operation Manual

Page: 60 / 135

60 Venting the Boiler
Indoor Boiler Installation Venting Examples (continued)
Ɣ
3 in or 4 in Two-pipe Vertical Venting – Intake and exhaust pipes
do not have to terminate in the same area.
12" (300 mm) min
From any
obstruction
(above, below,
left, or right)
Exhaust Gas
Intake Air
12”
(300 mm) min.
12”
(300 mm) min.
36” (900 mm) min.
Ɣ
Concentric Roof Venting
Maintain 12” (300mm) min.
clearance above highest
anticipated snow level or grade,
whichever is greater (maximum
of 24” above roof )
Vent
Vent
Combustion Air
Combustion Air
Indoor Boiler Installation Venting Examples (continued)
Ɣ
Non-Concentric Sidewall Venting - Air is drawn from a different
location that is at least 12 in (300 mm) away from the exhaust
termination. The exhaust termination can be located either on
the sidewall or roof. Try to minimize the length of the intake air
pipe when installing the vent.
12”
(300mm) min.*
* 12” (300mm) above the highest anticipated snow level, or as
required by local codes, whichever is greater.
Ɣ
Concentric Sidewall Venting
Combustion Air
Combustion Air
Maintain 12”
(300 mm)
min. clearance
above highest
anticipated snow
level or grade,
whichever is
greater.
1” (25 mm) min.
Vent
Vent