Heatilator • Novus NDV Series • 4055-187 Rev F • 06/08 19
D
Clearance to Ceiling
30 in. (762 mm)
0 in.
0 in. TO LEVEL
OF STANDOFFS
Combustible Object
36 in.
(914 mm)
0 in.
Combustible flooring may be installed next
to the front of the appliance.
Drywall
1/2 in.
(13 mm)
1/2 in.
(13 mm)
C
A
B
B. Constructing the Appliance Chase
A chase is a vertical box-like structure built to enclose the
gas appliance and/or its vent system. In cooler climates the
vent should enclosed inside the chase.
NOTICE: Treatment of ceiling fi restops and wall shield
fi restops and construction of the chase may vary with the
type of building. These instructions are not substitutes for the
requirements of local building codes. Therefore, you MUST
check local building codes to determine the requirements
to these steps.
Chases should be constructed in the manner of all outside
walls of the home to prevent cold air drafting problems.
The chase should not break the outside building envelope
in any manner.
Walls, ceiling, base plate and cantilever fl oor of the chase
should be insulated. Vapor and air infi ltration barriers
should be installed in the chase as per regional codes for
the rest of the home. Additionally, in regions where cold
air infi ltration may be an issue, the inside surfaces may be
sheetrocked and taped for maximum air tightness.
Figure 5.2 Clearances to Combustibles
C. Clearances
NOTICE: Install appliance on hard metal or wood surfaces
extending full width and depth. DO NOT install directly on
carpeting, vinyl, tile or any combustible material other than
wood.
WARNING! Risk of Fire! Maintain specifi ed air space
clearances to appliance and vent pipe:
• Insulation and other materials must be secured to prevent
accidental contact.
• Failure to maintain airspace may cause overheating and
a fi re.
To further prevent drafts, the wall shield and ceiling fi re-
stops should be caulked with high temperature caulk to
seal gaps. Gas line holes and other openings should be
caulked with high temp caulk or stuffed with unfaced insu-
lation. If the appliance is being installed on a cement slab,
a layer of plywood may be placed underneath to prevent
conducting cold up into the room.
Note: If the inside of the framed cavity is to be fi nished,
the framing dimensions must include the fi nished surface.
If drywall is to be attached to the rear wall, the depth
must be measured from the drywall surface.
Model
A
Rough Opening
(Width)
B
Rough Opening
(Height)
C
Rough Opening
(Depth)
D
Rough Opening
(DVP Pipe)
NDV3630 36 in./914 mm 34-7/8 in./886 mm 19-5/8 in./498 mm 10 in./254 mm
NDV3933 39 in./991 mm 34-7/8 in./886 mm 19-5/8 in./498 mm 10 in./254 mm
NDV4236 42 in./1067 mm 34-7/8 in./886 mm 19-5/8 in./498 mm 10 in./254 mm
NDV4842 48 in./1219 mm 34-7/8 in./886 mm 19-5/8 in./498 mm 10 in./254 mm