Reznor SCE Unit Installation Manual - Manual (Page 16)

Form RZ-NA I-SCE, Page 16
VERTICAL VENT
INSTRUCTIONS (cont’d)
Outside view with concentric
adapter box attached to under-
side of roof. Install field-supplied
flashing at roof opening.
Snow Clearance
18” (457mm) minimum
(NOTE: Maximum
from concentric adapter
box is 48” (1219mm)
FIGURE 16 - Slide attached
Combustion Air Pipe up
through 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 15 and 16.)
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 15 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.
Determine the length by adding the requirements. Starting at the top, the vent pipe must
extend a minimum of 22” (559mm) beyond the top of the inlet air pipe; plus the width of the
roof; plus length of brackets; plus 6” (152mm) through the box; plus 6” (152mm) extending
out of the box on the heater side.
b) Install the pipe. Being sure the pipe is in the proper flow direction, slide the end into the
box and out through the combustion air pipe. Position the vent pipe to the lengths deter-
mined above. NOTE: The double-wall vent pipe does not attach to the box. The installer
must provide support.
Follow the instructions in FIGURE 9 , page 9, for connecting the double-wall pipe to the
single-wall pipe or Category III vent pipe run. A taper-type reducer is required.
Seal the circumference of the pipe and the opening of the box with silicone sealant. Seal the
area around the pipe completely.
FIGURE 15 - Assemble
Concentric Adapter Box,
Outdoor Combustion Air
Pipe, and Double-Wall Vent
Pipe
b). Attach the outside portion of the combustion air pipe to the box. Determine the length of
the combustion air pipe so that dimension ”X” in FIGURE 15 is equal to the bracket length,
plus the roof thickness, plus anticipated snow depth, but does not exceed 48“ (1219mm) or
have less than 18” (457mm) of pipe above the roof. Attach the inlet air pipe to the collar of the
concentric adapter box with sheetmetal screws.
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.
Vent 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 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 9.
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