Vent Diagrams - Heatilator NNXT4236IF-B Installation Manual

F. Vent Diagrams
General Rules:
• Additional elbows: SUBTRACT 3 ft. from the total H
measurement for each 90º elbow installed horizontally.
• Additional elbows: SUBTRACT 1-1/2 ft. from the total H
measurement for each 45º elbow installed horizontally.
• A maximum of three 90º elbows (or six 45º elbows) may
be used in any vent configuration. Some elbows may be
installed horizontally.
• Elbows may be placed back to back anywhere in the
system.
•
Any 90º elbow may be replaced with two back to back
45º elbows.
• When penetrating a combustible wall, a wall shield
firestop must be installed.
• When penetrating a combustible ceiling, a ceiling firestop
must be installed.
• Horizontal runs of vent do not require vertical rise;
horizontal runs may be level.
• When the horizontal termination cap is exposed to high
precipitation, the cap should have a 1/4 inch downward
slant to allow any moisture in cap to be released. See
Figure 4.8.
W
A
L
L
1/4 in. max.
(6 mm)
Figure 4.8 Water Infiltration Prevention Tip
Heatilator • NNXT4236IF-B, NNXT4236ILF-B, NNXT3933IF-B, NNXT3933ILF-B Installation Manual • 2384-980 Rev. J • 6/17 19