11
If concentric vent termination is being used, refer to
Figure 10 for proper setup.
5 - COMBUSTION AIR/ VENT REQUIREMENTS
- Roof Vent / Intake Terminations
Figure 8
- Sidewall Vent/Intake Terminations
Figure 9
- Concentric Vent Terminations
Figure 10
Combustion Air/Vent Pipe Requirements
Boiler requires dedicated direct vent system. Direct vent
system, all air for combustion is taken directly from outside
atmosphere, and all fl ue products are discharged to outside
atmosphere.
Combustion air and vent pipe connections must terminate
together in same atmospheric pressure zone, either
through roof or sidewall (roof termination preferred). See
Figures 8 and 9 for required clearances.
12" (30 cm)
Minimum
8" (21 cm)
Minimum
15" (38 cm)
Maximum
3" (8 cm)
Maximum
Vent
Combustion
Air
12" (30 cm)
Minimum above
anticipated snow line
Vent
3" (8 cm)
Minimum
separation
12" (30 cm)
Minimum from
overhang
12" (30 cm) Separation
between bottom of
combustion air intake and
bottom of vent
See snow & ice
page 23
Combustion Air
Vent
12" (30cm)
Minimum
separation
Combustion Air
Combustion
Air
Vent
1" (2.54cm)
Maximum
Maintain 12"
clearance above
highest anticipated
snow level or grade
* See Note
Below
Vent
Combustion
Air
36"(0.9m) Minimum
Maintain 12"(30cm)
clearance above highest
anticipated snow level or
grade
12" (30cm) Minimum
*Must be less than 4" or greater than 24" Horizontal
distance between end bells of each air intake to prevent
fl ue gas recirculation.
1" (2.54cm)
Maximum
Overhang
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.