Navien NFB Series User Manual

57Venting the Boiler
●
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
●
Concentric Sidewall Venting
1" (25 mm) min.
Combustion Air
Combustion Air
Maintain 12"
(300 mm)
min. clearance
above highest
anticipated snow
level or grade,
whichever is
greater
Vent
Vent
●
Concentric Vertical Venting
Combustion Air
Maintain 12” (300mm) min.
clearance above highest
anticipated snow level or
grade, whichever is greater
(maximum of 24” above roof)
Vent
Indoor Boiler Installation Venting Examples
The following are some possible indoor venting options:
●
Two-Pipe Sidewall Venting
12" (300 mm) min.
12" (300 mm) min.
Exhaust Gas
Exhaust Gas
Interior View
Exterior View
Intake Air
Intake Air

Navien NFB Series Specifications

General

Type	Condensing Boiler
Fuel Type	Natural Gas or Propane
Heat Exchanger	Stainless Steel
Vent Type	Direct Vent
Vent Diameter	2" or 3"