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88 Installing a Common Vent System
Intake
Maximum
length 20’
(6 m)
Minimum
length 36”
(91 cm)
Exhaust
Note
●
The illustration is intended for
reference purposes only.
●
Direct the exhaust away from any
building openings.
●
During cold weather situations, the
temperature of the exhaust will be
much warmer than the ambient air.
Therefore, you will see water vapor
being produced at the termination.
9.6.3 Direct Vent Application –
Horizontal Installation
12" (300 mm) min.
12" (3
00 mm
) min.
Exhaust Gas
Intake Air
In cases where a 12” horizontal clearance is not
possible, provide a vertical clearance of at least
36” with the exhaust above the intake but do not
exceed 20’.
Summary of Contents for NFB-175H
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