45
At
least
3
6
in.
18
in.
maximum
Vertical
separation
between
combustion
air
and
vent
8
3/4
in.
(222mm)for
3
in.
(7
6
mm)
k
i t
6
3/4
in.
(172mm)for
2
in.
(51mm)
k
i t
Roof
Te rmination
(Preferred)
Abandoned
masonry
used
as
raceway
(per
code)
At
least
3
6
in.
A
Maintain
12
in.
min.
clearance
above
highest
anticipated
snow
level,
maximum
of
24
in.
above
roof
Concentric
Vent
and
Combustion
Air
Roof
Termination
(preferred)
1
in.
(25mm)
maximum
(typ)
from
wall
to
inlet
12
in.
(3
0
5mm)
minimum
from
overhang
or
roof
Maintain
12
in.
min.
clearance
above
highest
anticipated
snow
level
or
grade
whichever
is
greater
A
At
lea
st
3
6
in.
Concentric
Vent
and
Combustion
-
Air
Side
Te rmination
A
At
least
3
6
in.
Side
wall
termination
of
less
than
12
in.
(3
0
5mm)
above
highest
snow
level
12
in.
min
from
overhang
or
roof
12
in.
(3
0
5mm)
separation
between
bottom
ofcombustion
air
and
bottom
of
vent
(typ)
Maintain
12
in.
min.
clearance
above
highest
anticipated
snow
level
or
grade
whichever
is
greater
(typ)
A
At
least
3
6
in.
A
Maintain
12
in.
(3
0
5mm)min
.
clearance
above
highest
anticipated
snow
level
Maximum
of
24
in.(
6
14mm)
above
roof
9
0
°
N
ote
:
"A"
denotes
0
to
<
2
in.
Between
the
first
2
vents
Third
vent
must
be
>
3
6
in.
away
(typ)
(914m
m)
(3
0
5mm)
(914mm)
(3
0
5mm)
(3
0
5mm)
(914mm)
(914mm)
(457mm)
(51mm)
(914mm)
A05090
Fig. 44 -- Combustion Air and Vent Pipe Termination for Direct Vent (2--pipe) System
Abandoned
masonry
used
as
raceway
(per
code)
12
in.
(3
0
5
mm)
min.
from
overhang
or
roof
Maintain
12
in.
(3
0
5mm)
minimum
clearance
above
highest
anticipated
snow
level
or
grade
whichever
is
greater.
Side
wall
termination
with
2
elbows
(preferred)
12
in.
min.
(3
0
5
mm)from
overhang
or
roof
Maintain
12
in.
(3
0
5mm)
minimum
clearance
above
highest
anticipated
snow
level
or
grade
whichever
is
greater
6
in.
(152mm)
minimum
clearance
between
wall
and
end
of
vent
pipe.
1
0
in.
(254mm)
maximum
pipe
length
Sidewall
Termination
with
Straight
Pipe
(preferred)
Roof
Termination
(Preferred)
Vent
Maintain
12
in
.
minimum
clearance
above
highest
anticipated
snow
level
maximum
of
24
in.
(
6
1
0
mm)
above
roof
.
9
0
°
(3
0
5mm)
A05091
Fig. 45 -- Vent Pipe Termination for Non-Direct Vent (1-pipe) System
58MEC
