Heatilator • RBV4236/RBV4842 • 4048-210 • Rev S • 6/10
17
C
B
A
Per Vent Manufacturer’s
Specifications
30 in.
(762 mm)
to ceiling
0 in.
Drywall
0 in.
1/2 in.
(13 mm)
1/2 in.
(13 mm)
Combustible Object
0 in.to level
of standoffs
Combustible flooring may be installed
next to the front of the appliance.
36 in.
(914 mm)
A
Rough Opening
(Width)
B
Rough Opening
(Height)
C
Rough Opening
(Depth)
in.
42
39-3/4
22
mm
1067
1010
559
in.
48
39-3/4
22
mm
1219
1010
559
Model #
RBV4236
RBV4842
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 firestops and wall shield
firestops 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 floor of the chase
should be insulated. Vapor and air infiltration barriers
should be installed in the chase as per regional codes for
the rest of the home. Additionally, in regions where cold
air infiltration may be an issue, the inside surfaces may
be sheetrocked and taped for maximum air tightness. To
further prevent drafts, the wall shield and ceiling fire-
stops should be caulked with high temperature caulk to
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 specified air space
clearances to appliance and vent pipe:
• Insulation and other materials must be secured to
prevent accidental contact.
• The chase must be properly blocked to prevent blown
insulation or other combustibles from entering and
making contact with fireplace or chimney.
• Failure to maintain airspace may cause overheating and
a fire.
seal gaps. Gas line holes and other openings should
be caulked with high temp caulk or stuffed with unfaced
insulation. 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 finished,
the framing dimensions must include the finished surface.
Example: If drywall is to be attached to the rear wall, the
depth must be measured from the drywall surface.
