Reznor RPBL Unit Installation Manual - Manual (Page 23)

Form I-SSCBL/RPBL, P/N 149159 R7, Page 23
FIGURE 20 - Brackets
for Attaching the
Concentric Adapter Box
to the Roof
5. Attach the concentric adapter box to the roof. On the inside, insert the
combustion air pipe up through the opening and attach brackets to the roof. (See
FIGURES 21 and 22.) On the outside, flash the combustion air pipe to the roof.
Flashing is field supplied .
6. Determine the length and install the double-wall vent pipe.
a) Determine the length. See FIGURE 21 to determine the required length of the
vent pipe. The vent pipe extending through the box and the inlet air pipe must be
one piece of double-wall vent pipe without joints.
FIGURE 21 - Assemble Concentric Adapter Box, Outdoor Combustion Air Pipe, and Double-Wall
Vent Pipe
Concentric Adapter Box
Mounting
Brackets
X = length of
combustion air pipe required
through and above the roof.
Height from box to top of inlet air
pipe must not exceed 48” (1219mm).
Minimum height above the roof is
18” (457mm) and must be higher
than anticipated snow depth.
First, attach Combustion Air Pipe and install the
Concentric Box
1) Determine length (X) of pipe (see requirements on the left).
2) Attach the pipe to the collar on the box.
3) Attach the brackets to the roof.
V
ent Flow
22” (559mm) minimum
Cold Climate NOTE:
In geographic areas where
the design ambient is -10°F
or lower, this minimum
height is 34” (864mm).
Collar for
the Indoor
Portion
of the
Combustion
Air Pipe
Double-Wall Vent Pipe -
Extend length of double-wall
vent pipe a maximum of 6”
(152mm) below the box.
After box is installed, install Concentric Vent Pipe -
One piece of continuous double-wall pipe must extend
from a minimum of 3” (76mm) above the outer com-
bustion air pipe to a maximum of 6” (152mm) below
the box. (NOTE: Vent pipe does not attach to the box;
it must be supported.)
1) Calculate height (see requirements on the left).
2) Be sure vent flow marking on pipe is in the right direction.
3) Slide pipe through the box and the outer inlet air pipe.
4) Attach to vent run no more than 6” (152mm) from the
adapter box. See instructions on page 18.
Vent pipe
extending
through the
box and the
combustion
air pipe
MUST be one
continuous
piece of double-
wall vent pipe.
A second section
of double-wall pipe
is permitted, joining
the long continuous
piece of vent pipe a
minimum of 3” (76mm)
above the top of the
combustion air pipe.
3” (76mm)
minimum
1) Attach the Brackets to the Box - The 6” (152mm)
portion of each bracket is designed with five
7/32” diameter holes so that attachment to the
box can be adjusted.
If the roof is combustible, position brackets to allow for
a 2” (51mm) clearance between the box and the roof.
After careful positioning, use sheetmetal screws to
attach the brackets. NOTE: If any holes are made in
the box in error, they must be sealed.
2) Attach the Box to the Roof (Step 5)
When the box is attached to the roof in Step 5, use the
2-1/2” (64mm) portion of the brackets. To adjust to
construction each bracket has three 7/32” diameter holes.
Outside View with concentric adapter
box attached to underside of roof. Install
field-supplied flashing at roof opening.
Snow Clearance
18” (457mm) minimum
(NOTE: Maximum
from concentric adapter
box is 48” (1219mm)
FIGURE 22 - Slide attached
Combustion Air Pipe up
through the Roof