15
Horizontal Run (ft)
Ve
rt
ica
l R
ise (
ft
)
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
2 4 6 8 10 12 14 16
Top or Rear outlet
1
1
3
5
Example 1
NO INSTALLATION
NO INSTALLATION
How to Read the Venting Charts
The charts below apply to co-axial roof or wall termina-
tion in installations with vertical rise. See page 17 for
installations with no vertical rise.
1. The total length of the vent pipe cannot exceed
40 feet.
2. The minimum vertical height with roof termination is
8 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.
Venting
Venting Charts
Co-Axial
5. 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.)
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. Maximum co-linear venting is 40 feet.
8. A restrictor is required for all installations—see
Restrictors
page 17 for more information.
Allowable Co-Axial Vent Con
fi
gurations with Vertical Rise
Example 1
Value V = V1 (6’) + V2 (4’) = 10’
Value H = H1 (2’) + H2 (1’) = 3’
