Constructing The Appliance Chase; Clearances - Heatilator Direct Vent Gas Appliance CNXT4236IH Owner's Manual

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 out-
side walls of the home to prevent cold air drafting prob-
lems. 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.
Combustible flooring may be installed next
to the front of the appliance.
30 in.
(762 mm)
to ceiling
36 in.
(914 mm)
Figure 5.2 Clearances to Combustibles
18
1/2 in. (13 mm)
1/2 in.
(13 mm)
Drywall
0 in.
0 in. to level
of standoffs
0 in. to
floor
Heatilator • Caliber CNXT Series • 4047-132 Rev U • 11/08
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.
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.
B
C
A
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.
A
Rough
Opening
Model (Width)
CNXT4236 in. 42
mm 1067
CNXT4842 in. 48
mm 1219
D
B C D
Rough Rough Rough
Opening Opening Opening
(Height) (Depth) (DVP Pipe)
38 3/4 23 10
984 584 254
38 3/4 23 10
984 584 254