36
6 - COMBUSTION AIR AND VENT PIPING
Roof
Terminations
12" (305 mm) Min. horizontal separation
between combustion air intake and vent of
same appliance.
12" (305 mm) Min. 84" (2.2 m) Max.
vertical separation between combustion air
intake and vent of different appliances.
15" (381 mm) Max. horizontal length of
vent.
Min. vent/intake between different
appliances 12" (305 mm).
Max. allowable total vertical vent length
with outside exposure is 10 ft.(3.05 m).
Abandoned unused masonry chimney may
be used as chaseway for combustion air
and vent. Both combustion air and vent
pipe must exit above top of chimney with
clearances same as shown in Figure 6-12.
FIGURE 6-13 -TWIN PIPE SIDE WALL VENT (S-TYPE
TERMINATION)
Vent
3" (76 mm) Min.
24" (610 mm) Max.
Separation
12"(305 mm) Min.
From Overhang
12" (305 mm) Min.
24" (610 mm) Max.
Separation Between
Bottom Of
Combustion Air Intake
And Bottom Of Vent
Combustion Air
Opening
Separation 24"
Min.
Grade, Snow
& Ice
Maintain 12"(305 mm) US, 18"(457 mm)
Canada clearance above highest anticipated
snow level, 24" (610 mm) above roof.
Avoid locations where snow may drift and
block vent and combustion air. Ice or snow
may cause boiler to shut down if vent or
combustion air becomes obstructed.
See Grade,
Snow & Ice
FIGURE 6-14 -TWIN PIPE SIDE WALL WITH 45° VENT
Vent
45° Elbow
Upward
3" (76 mm) Min.
24" (610 mm) Max.
Separation
Combustion Air, 90°
Elbow Downward
12" (305 mm) Min.
24" (610 mm) Max.
Separation
Opening
Separation 24"
Min.
See Grade,
Snow & Ice
FIGURE 6-15- SINGLE WALL EXHAUST KIT AND AIR
INTAKE MINIMUM DISTANCE CENTER TO CENTER WITH
45° ON COMBUSTION AIR
4
3/4"
[
120
mm]
FIGURE 6-16 -TWIN PIPE SIDE WALL VENT (MULTIPLE
APPLIANCES)
Vent
12" (305 mm) Min.
Separation
Manufacturer Recommends
Greater Separation
Combustion Air
See Grade,
Snow & Ice
12" (305 mm) Min.
24" (610 mm) Max.
Separation
PN 240012363 REV. B [03/29/2019]
