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Heatilator • GNTC50 • 4002-095 Rev H • 06/07
23
3 in. (76 mm)
Top Clearance
1 in. (25 mm) Side
and Bottom Clearance
1 in. (25 mm)
Clearance Around
Vertical Sections
B. Wall Penetration Framing
• Frame a hole in a combustible wall for an interior wall
shield
fi
restop (Figures 6.1 through 6.3) whenever a wall
is penetrated. Use same size framing materials as those
used in the wall construction. The wall shield
fi
restop
maintains minimum clearances and prevents cold air
in
fi
ltration.
• If the hole being penetrated is surrounded by non-
combustible materials such as concrete, a hole with
diameter 1 in. greater than the pipe is acceptable.
A. Pipe Clearances to Combustibles
Fire Risk
Explosion Risk
Maintain vent clearance to combustibles as
speci
fi
ed.
• Do not pack air space with insulation or
other materials.
Failure to keep insulation or other materials
away from vent pipe may cause
fi
re.
WARNING
Figure 6.1 Pipe Clearances
3 in. (76 mm)
top clearance
1 in. (25 mm)
clearance
bottom & sides
Heat
Shield
Wall
Shield
Firestop
Heat
Shield
WALL
Note: Heat shields MUST overlap by a minimum of 1-1/2 in.
(38 mm).
The heat shield is designed to be used on a wall
4 in. to 7-1/4 in. (102 mm to 184 mm) thick.
If wall thickness
is less than 4 in. (102 mm) the existing heat shields must be
field trimmed. If wall thickness is greater than 7-1/4 in. (184
mm) a DVP-HSM-B will be required.
Figure 6.2 Horizontal Venting Clearances to Combustible Materials
E*
Framing should be
constructed of 2 X 4
lumber or heavier.
The center of the
framing hole is
1 in. (25mm) above
the center of the
horizontal vent pipe.
D*
D
Top Vent
E
Rear Vent
inches
37-3/4
21-7/8
mm
959
556
Model
GNTC50
6ENTFRAMINGHOLE
$/./40!#+7)4(
).35,!4)/./2/4(%2
-!4%2)!,
* Center of pipe
12 in.
10 in.
Figure 6.3 Exterior Wall Hole
6
6
Vent Clearances and Framing