20
4 x 90º ELBOWS MAXIMUM
(or equivalent)
V2
V1
V3
H2
H1
Max. 18” pipe if
no vertical rise
is used
45° elbow take-off
supplied with unit
1” min.
all around
vertical pipe
3” min.
above top of
horizontal pipe
1” min. around
bottom & sides
of horizontal pipe
VE
RTIC
A
L
RI
S
E
(
ft
)
HORIZONTAL RUN (ft)
0
2
4
6
8
10
12
14
16
18
20
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
0
Position #4
Positions #2/3
Position #1
Example 1
NO INSTALLATION
NO INSTALLATION
Allowable Co-Axial
Vent Confi gurations with
restrictor positions
How to Read the Venting Chart
The chart below applies to co-axial roof or wall
termination.
1. The total length of the vent pipe cannot exceed
40 feet.
2. The minimum vertical height with roof termination
is 6 feet.
3. Any combination of rise and run can be used as
long as they are within the allowable limits shown
on the chart below.
4. A maximum of 4 x 90 degrees elbows—or
equivalent (2 x 45 degrees = 90 degrees)—can
be used. Excludes the 45 degrees take-o
ff
elbow
shipped with the appliance.
5. Each 90 degrees elbow installed on the horizontal
plane is equivalent to a 3 feet horizontal pipe;
therefore, 3 feet must be subtracted from allowable
horizontal run. (45 degrees elbow is equivalent to
18 inches horizontal pipe.)
6. All horizontal pipe runs must be graded 1/4 inch per
foot upwards in the direction of the exhaust
fl
ow.
The
fi
nal pipe length, when terminating through the
wall may be graded downwards slightly to prevent
water migration.
7. A restrictor adjustment is required for most
installations having a vertical rise—see next
section.
Note:
The restrictor is shipped installed at the
exhaust exit of the
fi
rebox.
Venting Chart
Example 1
V Value = V1 (2’) + V2 (4’) + V3 (2’)= 8’
H Value = H1 (0’) + H2 (3’) = 3’
Restrictor position # 1 required
Venting
Co-Axial
