29
Crawl Space and Attic combustion air
Ventilated combustion
air intake pipe
Pipe hangar
Ventilated combustion
air intake termination in
crawl space
3” (76 mm)
12” (305 mm)
CRAWL SPACE
ATTIC
Ventilated combustion
air intake pipe
Vent through roof flashing
12” (305 mm) min above
highest level of insulation
The Provinces of Alberta
and Saskatchewan require a
minimum unobstructed distance of 4ft. (1.2m) 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. (1.2m) 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 8ft. (2.4m). 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 4ft. (1.2m) and no greater
than 8ft. (2.4m), 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
with ventilated combustion air applications) that re-directs the
flue gas away by use of an elbow or tee, certified to ULC S636
from the adjacent property line must be used. See fig. beside.
The 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 boilers.
Refer to figure below for terminations approved for use in Alberta
and Saskatchewan.
Alberta and Saskatchewan Vent Terminations
CRAWL SPACE
For vent and combustion air pipe
length refer to the approved configu-
ration of horizontal and vertical vent
installation - Section 8.8, fig. 7 for 2”
and fig. 20 for 3”
9
WARNING: When using
a ventilated crawl space
for combustion air ensure
the make-up air opening
is adequately sized for
the boiler per National
Flue Gas Code, ANSI
Z223.1/NFPA 54as well
as applicable provisions
of the local building code,
in the United States
and CAN/CGA B149.1,
Installation Codes as well
as applicable provisions of
the local building code, in
Canada.
ATTIC
For vent and combustion air pipe
length refer to the approved con-
figuration of horizontal and ver-
tical vent installation - Secti
on
8.8, f
ig.
13-14 for 2” and fig. 18-
19 for 3”
9
WARNING: When using
a ventilated attic space
for combustion air ensure
the make-up air opening
is adequately sized for
the boiler per National
Flue Gas Code, ANSI
Z223.1/NFPA 54as well as
applicable provisions of the
local building code, in the
United States and CAN/
CGA B149.1, Installation
Codes as well as applicable
provisions of the local
building code, in Canada.
12 IN. (305 mm) MIN.
SEPARATION
BETWEEN BOTTOM OF
COMBUSTION AIR AND
OPTIONAL TERMINATION
BRACKET FOR 2-PIPE
TERMINATIONS
12 IN. (305 mm) MIN.
SEPARATION BETWEEN
BOTTOM OF COMBUSTION
AIR AND BOTTOM OF VENT.
12 IN. (305 mm)
ABOVE ANTICIPATED
SNOW LEVEL
OPTION
BRACKET
COUPLING
COMBUSTION-AIR
(ELBOW PARALLEL TO WALL)
MAINTAIN 12 IN. (305 mm)
CLEARANCE ABOVE
HIGHEST ANTICIPATED
SNOW LEVEL OR GRADE,
WHICHEVER IS GREATER.
12 IN. (305 mm) MIN.
SEPARATION
BETWEEN BOTTOM OF
COMBUSTION AIR AND
BOTTOM OF VENT.
Angle 22.5°
to 45° off wall
OVERHANG OR ROOF
VENT
EXHAUST
OVERHANG
CLEARANCE TO OVERHANG PER
CODE
12 IN. (305 mm) MIN. GROUND
LEVEL OR ANTICIPATED
SNOW LEVEL