Navien NHB H Series Installation And Operation Manual page 65

Two-pipe Vertical Venting - Intake and exhaust
●
pipes do not have to terminate in the same area.
36" (900 mm) min.
Intake Air
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" (300 mm) above the highest anticipated snow
level, or as required by local codes, whichever is
greater
Exhaust Gas
12" (300 mm) min
From any
obstruction
(above, below,
left, or right)
Concentric Sidewall Venting
●
Combustion Air intake
Exhaust
Gas
Maintain 12" (300 mm) min. clearance above highest
anticipated snow level or grade, whichever is greater.
Concentric Vertical Venting
●
Exhaust Gas
Combustion
Air intake
For cascade applications, the required
Note
horizontal clearance between
terminations is 12" for both sidewall and
vertical venting installations.
CAUTION
Do not vertically stack concentric
terminations on sidewalls. The
circulation of exhaust gases will
cause improper operation of the
boiler.
Multiple Low-Profile Terminations on Sidewall
●
(Cascade Only)
12" (300 mm) min.
Multiple Low-Profile Terminations on Roof
●
(Cascade Only)
12" (300 mm) min.
Combustion
Air intake
Combustion
Air intake
Exhaust
Gas
Maintain 12" (300 mm) min.
clearance above highest
anticipated snow level or
grade, whichever is greater
(maximum of 24" above
roof).
Exhaust
Gas
Venting for Combustion Air 65