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SSCBL-RPBL-IOM (10-22) 149159-C
2 . Install vent pipe and combustion air pipe runs:
a . Connect piping to heater in accordance with specifications listed in
Specific Venting Requirements: Piping
and
Specific Venting Requirements: Venter Outlet and Combustion Air Inlet Connections
sections .
b . Seal all joints in accordance with specifications listed in
Specific Venting Requirements: Joints and Sealing
section .
Due to high temperature considerations, do not enclose exhaust pipe or place pipe closer than 6
inches (152 mm) to combustible material .
c . Extend piping runs close to wall location selected in step 1 and support piping in accordance with specifications
listed in
Specific Venting Requirements: Support
section .
3 . Cut hole through outside wall for combustion air pipe .
a . Ensure that outside wall construction thickness is between 1 inch (25 mm) minimum and 48 inches (1,219
mm) maximum .
b . Ensure that hole accommodates 8-inch (203-mm) combustion air pipe . Thimble may be required depending
on building construction and/or local codes . Larger diameter combustion air pipe serves as clearance for vent
pipe on noncombustible construction .
c . When installing system with more than one furnace section, ensure that that there is minimum of 26-1/8 inches
(664 mm) between center lines of each terminal pipe . Prepare one hole per furnace with spacing as shown
.
4 . Secure longer angles on concentric adapter box brackets (see
) to concentric adapter box .
NOTE: The longer angle of the concentric adapter box bracket has five 7/32-inch holes that allow
the position of the bracket on the box to be adjusted. The shorter angle has three 7/32-inch holes
that allow adjustment to construction.
5 . Connect outside section of combustion air pipe to concentric adapter box (see
a . Determine length of combustion air pipe as follows:
(1) Bracket length from box to wall
(2) Plus wall thickness
(3) Plus 2 inches (51 mm) beyond wall
b . Secure inlet air pipe to collar of concentric adapter box using sheet metal screws . Seal joint and seam using
tape or sealant .
6 . Secure concentric adapter box to wall (see
):
⚠ CAUTION ⚠
• If the wall is combustible, ensure that brackets are positioned to allow a 2-inch (51 mm) clearance
between the concentric adapter box and the wall.
• If any holes are made in the concentric adapter box in error, ensure that they are sealed.
Table 20. Minimum Clearance Requirements for Horizontal Vent Terminal
Component/Structure
Minimum Clearance, All Directions Unless Specified (Feet (Meters))
Forced air inlet within 10 feet (3 .1 meters)
*
3 (0 .9) above
Combustion air inlet of another appliance
6 (1 .8)
Mechanical air supply inlet to any building
Canada: 6 (1 .8)
Any building opening (door, window, or gravity air inlet)
4 (1 .2) horizontal and below
1 (0 .3) above
Gas meter,
**
electric meter, and relief equipment
US: 4 (1 .2) horizontal
Canada: 6 (1 .8) horizontal
Gas regulator
**
US: 3 (0 .9) horizontal
Canada: 6 (1 .8) horizontal
Adjoining building or parapet
6 (1 .8)
Adjacent public walkway
7 (2 .1) above
Grade (ground level)
3 (0 .9) above
*
Does not apply to the inlet of a direct vent appliance .
**
Do not terminate the vent directly above a gas meter or service regulator .
