Heatilator NNXT33-IFT Installation Manual page 13

Note: If the inside of the framed cavity is to be finished,
the framing dimensions must include the finished
surface. If drywall is to be attached to the rear wall,
the depth must be measured from the drywall surface.
NO COMBUSTIBLE MATERIALS
IN SHADED AREA.
CLEARANCES TO COMBUSTIBLES:
1 INCH - BOTTOM & SIDES OF VENT PIPE
3 INCHES- TOP OF VENT PIPE
NO COMBUSTIBLE MATERIALS ALLOWED
BELOW TOP OF STANDOFFS.
NNXT MODEL
(NG/PROPANE)
NNXT33-IFT
NNXT36-IFT
* Adjust framing dimensions for interior sheathing (such as sheetrock)
C** Add 11-1/2 inches for rear vented elbow vented directly off the rear of the appliance.
Figure 3.7 Clearances to Combustibles
Heatilator • NNXT33-IFT, NNXT33L-IFT, NNXT36-IFT, NNXT36L-IFT Installation Manual • 2628-980 Rev. C • 8/20
2 X 4 OR 2 X 6 FRAMING
FINISH WALL
COMBUSTIBLE
FOR MANTEL AND WALL
PROJECTIONS SEE SECTION 10.B
TOP OF FIREPLACE OPENING
*MINIMUM FRAMING DIMENSIONS
A
Rough
Opening
(Width)
in. 39
mm 991
in. 42
mm 1067
Combustible flooring may be installed next
to the front of the appliance.
COMBUSTIBLE
FRAMING
B C**
Rough Rough
Opening Opening
(Height) (Depth)
34-7/8 19-5/8
886 498
34-7/8 19-5/8
886 498
1/2 in.
(13 mm)
Clearance to Ceiling
30 in. (762 mm)
36 in.
(914 mm)
B
C
A
D D
Rough Rough
Opening Opening
(DVP Pipe) (SLP Pipe)
10 9
254 229
10 9
254 229
1/2 in.
(13 mm)
Drywall
0 in.
0 in. to level
of standoffs
0 in.
D
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