Operating instructions

24
Side Wall
Terminations
 3" (80mm) Minimum horizontal
separation between combustion air
intake and vent terminations.
 8" (203mm) Minimum vertical
separation between combustion air
intake and vent terminations.
 12" (305mm) Separation between
bottom of combustion air intake and
bottom of vent.
 Multiple terminations as shown
in 6-1, 6-2, and 6-3 must be
a minimum of 12” (305mm)
horizontally between vent of one
termination and air intake of next
appliance.
 Maximum allowable total outside
exposure vent length equals 10 ft.
(3.05m).
 Maintain a pitch of 1/2" per ft.
(42mm/m) outside exposure back to
boiler to ensure proper condensate
drainage for horizontal runs.
Roof
Terminations
 3" (80mm) Minimum horizontal
separation between combustion air
intake and vent of same appliance.
 8" (203mm) Minimum vertical
separation between combustion
air intake and vent of different
appliances.
 15" (381mm) Maximum horizontal
length of vent.
 Minimum vent/intake between
different appliances 12" (305mm).
 Maximum allowable total vertical
vent length with outside exposure is
10 ft.(3.05m).
 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 as shown in gure 6-1.
12" (305mm)
Minimum
8" (203mm)
Minimum
15" (381mm)
Maximum
3" (80mm)
Minimum
Vent Combustion
Air
12" (305mm) US,
18" (458mm) Canada
Minimum Above
Anticipated Snow Line
Vent
3" (80mm)
Minimum
Separation
12" (305mm)
Minimum From
Overhang
12" (305mm) Separation
Between Bottom Of
Combustion Air Intake And
Bottom Of Vent
See Snow & Ice
Page 22
Combustion Air
Vent
12" (305mm)
Minimum
Separation
See snow & ice
page 23
FIGURE 6-1 Two Pipe Roof Vent
FIGURE 6-2 Two Pipe Side Wall Vent
FIGURE 6-3 Two Pipe Side Wall Vent (Multiple Appliances.
Combustion Air
Roof Line
6 - COMBUSTION AIR AND VENT PIPING