20
240012994 Rev. B [08/31/2020]
5 - COMBUSTION AIR AND VENT PIPING
FIGURE 5-14 - (2"/ 60 mm & 3" / 80 mm) Twin Pipe
Roof Vent CAN BE USED ON ALL SIZES
15"
(381 mm)
Max.
Vent Combustion
Air
12" (305 mm) US,
18" (458 mm) Canada Min.
Above
Anticipated Snow Line
Roof Line
12" (305 mm) Min.
FIGURE 5-16 - Horizontal Twin Pipe, Exhaust and
Intake
12" (305 mm)
Minimum Separation
Manufacturer
Recommends
Greater Separation
4
3/4"
[120 mm]
Combustion Air
12" (305 mm)
Anticipated Snow Line
Vent - T Terminal
See Grade,
Snow & Ice
See Grade,
Snow & Ice
FIGURE 5-15 - (3" / 80 mm ONLY) Single Wall
Exhaust Kit and Air Intake Minimum Distance Center
to Center
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 chase-way for combustion air and
vent. Both combustion air and vent pipe must
exit above top of chimney with clearances as
shown in Figure 5-14.
Vent Terminal
Combustion Air
Ground
Level
FIGURE 5-12 - Twin Pipe on Roof Combustion Air On
Sidewall CAN BE USED ON ALL SIZES
FIGURE 5-13 - Twin Pipe Flue On Sidewall,
Combustion Air On Roof CAN BE USED ON ALL SIZES
This Termination
can be used on:
2" / 60 mm ON
205
3" / 80 mm
ON ALL SIZES
vent only
This Termination
can be used on:
3" / 80 mm
ALL SIZES
vent pipe only
This Termination
can be used on:
2" / 60 mm ON
205
3" / 80 mm
ON ALL SIZES
vent only
