W415-3093 / B / 05.06.22
EN
20
venting requirements
Simple venting configuration
(only two 90° elbows)
See graph to determine the required vertical rise
V
T
for the
required horizontal run
H
T
.
REQUIRED
VERTICAL RISE IN
FEET
(METERS)
V
T
HORIZONTAL VENT RUN PLUS OFFSET IN FEET (METERS)
H
T
The shaded area within the lines represents acceptable
values for
H
T
and
H
T
90°
V
1
V
2
H
1
H
2
90°
90°
90°
H
3
(H
T
) > (V
T
)
4.2 (1.3)
8.3 (2.54)
12.5 (3.8)
0
2.5
(0.8)
5
(1.5)
7.5
(2.3)
10
(3.1)
12.5
(3.8)
15
(4.6)
17.5
(5.3)
20
(6.1)
12.25 (3.7)
1
(0.3)
5.5
(1.68)
1
(0.3)
3.5
(1.1)
19.25
(5.9)
16.3_2D
For vent configurations requiring more than two 90° elbows, the following formulas apply:
Formula 1: H
T
< 3.5V
T
Formula 2: H
T
+ V
T
< 24.75 feet (7.5m)
Example:
V
1
= 4 FT (1.2m)
V
2
= 1.5 FT (0.5m)
V
T
=
V
1
+ V
2
= 4FT (1.2m) + 1.5FT (0.5m) = 5.5 FT (1.7m)
H
1
= 2 FT (0.6m)
H
2
= 1 FT (0.3m)
H
3
= 1 FT (0.3m)
H
4
= 1.5 FT (0.5m)
H
R
=
H
1
+ H
2
+H
3
+H
4
= 2FT(0.6m) + 1FT(0.3m) + 1FT(0.3m) + 1.5FT(0.5m) = 5.5 FT(1.7m)
H
O
= .03 (four 90° one 45° elbow - 90°)
= .03 (90 + 90 + 90 + 90 + 45 - 90) = 9.45 FT (2.9m)
H
T
=
H
R
+ H
O
= 5.5FT (1.7m) + 9.45FT (2.9m) = 14.95FT (4.6m)
H
T
+ V
T
= 14.95FT (4.6m) + 5.5FT (1.7m) = 20.45FT (6.2m)
Formula 1:
H
T
< 3.5V
T
3.5V
T
= 3.5FT (1.1m) x 5.5FT (1.7m) = 19.25FT (5.9m)
14.95 FT (4.6m) < 19.25 FT (5.9m)
Formula 2:
H
T
+ V
T
< 24.75 FT (7.5m)
20.45 FT (6.2m) < 24.75 FT (7.5m)
Since both formulas are met, this vent configuration is acceptable.