20
Venting
Co-Axial
4 x 90º ELBOWS MAXIMUM
(or equivalent)
Allowable Co-Axial Vent Con
fi
gurations
with restrictor positions
V2
V1
V3
H2
H1
Minimum 12”
pipe section
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
How to Read the Venting Chart
The chart below applies to co-axial roof or wall
termination.
1. Minimum 12 inch vertical pipe section required right
at unit.
2. The total length of the vent pipe cannot exceed
40 feet.
3. The minimum vertical height with roof termination
is 6 feet.
4. Any combination of rise and run can be used as long
as they are within the allowable limits shown on the
chart below.
5. A maximum of 4 x 90 degrees elbows—or equiva-
lent (2 x 45 degrees = 90 degrees)—can be used.
Excludes the 45 degrees take-o
ff
elbow shipped
with the appliance.
6. Each 90 degrees elbow installed on the horizon-
tal 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.)
7. 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.
8. A restrictor adjustment is required for most installa-
tions having a vertical rise—see next section.
Note:
The restrictor is shipped installed at the ex-
haust exit of the
fi
rebox.
Venting Chart
Example 1
V Value = V1 (3’) + V2 (2’) + V3 (1’)= 6’
H Value = H1 (0’) + H2 (3’) = 3’
Restrictor position # 1 required
2
4
6
8
10
12
14
16
18
20
VERTICAL
RISE (ft)
HORIZONTAL RUN (ft)
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
Position #5
Example 1
NO INSTALLATION
Position #4
Position #2/3
Position #1
12” minimum
vert pipe rise
1
NO INSTALLATION
