915SB: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
35
A10497
Fig. 47 – Vent Terminations for Ventilated Combustion Air
A96128
Fig. 48 – Pipe Vent and Combustion
Ventilated Combustion Air
The vent pipe for a Ventilated Combustion Air System must terminate
outdoors. See
for references to vent clearances required by
National code authorities. Allowable vent terminations are shown in
. The combustion air pipe terminates in a well-ventilated attic or
crawl space. Follow the clearances as shown in
.
The combustion air pipe cannot terminate in attics or crawl spaces that
use ventilation fans designed to operate in the heating season. If
ventilation fans are present in these areas, the combustion air pipe must
terminate outdoors as a Direct Vent System.
A combustion air inlet pipe to the outdoors is not required for a
Non-Direct (single-pipe) Vent System. A 12-in. long section of pipe with
a tight radius 2-in. (51 mm) 90 degree elbow is required to be attached to
the furnace. See
. This short inlet air pipe helps to ensure stable
combustion, as well as allow for sound attenuation. To aid sound
attenuation, point the inlet air pipe away from occupants. An extra elbow
and/or five feet of pipe may be used to accomplish the sound attenuation
function.
The Provinces of Alberta and Saskatchewan require a minimum
unobstructed distance of 4 ft. (1.2 M) from the foundation to the property
line of the adjacent lot for vent termination of any appliance with an
input over 35,000 BTUh. If there is less than 4 ft. (1.2 M) of
unobstructed distance to the property line of the adjacent lot, no type of
vent termination is permitted for appliances with inputs greater than
35,000 BTUh.
There are no additional restrictions on unobstructed distances greater
than 8 ft. (2.4 M). All single, two-pipe and concentric vents may be used,
providing all other Code and manufacturer’s requirements in these
instructions are adhered to. Refer to the appropriate
Vent Termination
section above for locating the vent termination.
If the unobstructed distance from the foundation to the property line of
the adjacent lot is no less than 4 ft. (1.2 M) and no greater than 8 ft. (2.4
M), it will be necessary to re-direct the flue gas plume. In this situation, a
concentric vent kit cannot be used. A 2-pipe termination (or single pipe
termination when permitted) that re-directs the flue gas away by use of
an elbow or tee, certified to ULC S636 from the adjacent property line
The concentric vent kit currently cannot be modified to attach an elbow
to the vent portion of the rain cap. A tee attached to the rain cap could
potentially direct the flue gas plume toward the intake air stream and
contaminate the incoming combustion air for the furnace.
Refer to
for terminations approved for use in Alberta and
Saskatchewan.
3” (76 mm)
12” (305 mm)
Pipe hangar
Ventilated Combustion Air
intake termination in crawl
space
Ventilated Combustion
Air intake pipe
CRAWL SPACE
ATTIC
highest level of insulation
A
WARNING
!
CARBON MONOXIDE POISONING HAZARD
Failure to follow the instructions outlined below for each appliance
being placed into operation could result in carbon monoxide poisoning
or death.
For all venting configurations for this appliance and other gas
appliances placed into operation for the structure, provisions for
adequate combustion, ventilation, and dilution air must be provided in
accordance with:
U.S.A. Installations
: Current edition
of Section 9.3 N
FPA 54/ANSI
Z223.1 Air for Combustion and Ventilation and applicable provisions
of the local building codes.
Canadian Installations
: Current edition of Part 8 of
CAN/CSA-B149.1. Venting Systems and Air Supply for Appliances
and all authorities having jurisdiction.
Termination Requirements for the Provinces of Alberta and
Saskatchewan
