Vent Diagrams - Heatilator NDV3630I-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 confi guration. Some elbows may be
installed horizontally. See Figure 4.14.
• A maximum of four 90º elbows (or eight 45º elbows)
may be used in a top vented, vertically terminated vent
confi guration. See Figure 4.19.
• 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
fi restop must be installed.
• When penetrating a combustible ceiling, a ceiling fi restop
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.
1/4 in. max.
(6 mm)
Figure 4.8 Water Infi ltration Prevention
Heatilator • NDV3630I-B, NDV3933I-B, NDV4236I-B, NDV4842I-B Installation Manual • 2382-980 Rev. G • 4/16
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