Dunkirk DKVLT-050 Installation, Operation & Maintenance Manual page 24

FIGURE 6-1 Two Pipe Roof Vent
12" (305mm)
Minimum
8" (203mm)
Minimum
Vent
12" (305mm) US,
18" (458mm) Canada
Minimum Above
Anticipated Snow Line
FIGURE 6-2 Two Pipe Side Wall Vent
12" (305mm)
Minimum From
Overhang
See Snow & Ice
Page 22
FIGURE 6-3 Two Pipe Side Wall Vent (Multiple Appliances.
See snow & ice
page 23
Combustion Air
6 - COMBUSTION AIR AND VENT PIPING
3" (80mm)
Minimum
15" (381mm)
Maximum
Combustion
Air
3" (80mm)
Minimum
Separation
12" (305mm) Separation
Between Bottom Of
Combustion Air Intake And
Bottom Of Vent
Vent
Combustion Air
12" (305mm)
Minimum
Separation
Vent
Roof Line
Roof
Terminations
Side Wall
Terminations
24
 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 figure 6-1.
 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.