Navien NHB Series User Manual

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

Navien NHB Series Specifications

General

Type	Condensing Boiler
Efficiency	Up to 95% AFUE
Fuel Type	Natural Gas or Propane
Vent Type	Direct Vent
Vent Diameter	2" or 3"
Heat Exchanger Material	Stainless Steel
Water Connections	3/4" NPT
Dimensions	Varies by model
Weight	Varies by model
Warranty	5-Year Parts