15
W415-1371 / 09.15.14
EN
(H
T
) > (V
T
)
Simple venting configurations.
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
For vent configurations requiring more than two 90° elbows the following formulas apply:
Formula 1: H
T
< 3V
T
Formula 2: H
T
+ V
T
< 40 feet (12.2m)
Example:
V
1
= 2 FT (0.6m)
V
2
= 1 FT (0.3m)
V
3
= 1.5 FT (0.5m)
V
T
=
V
1
+V
2
+V
3
= 2FT (0.6m) + 1FT (0.3m) + 1.5FT (0.5m) = 4.5FT (1.4m)
H
1
= 6 FT (1.8m)
H
2
= 2 FT (0.6m)
H
R
=
H
1
+ H
2
= 6FT (1.8m) + 2FT (0.6m) = 8 FT (2.4m)
H
O
= .03 (four 90° elbows - 90°)
= .03 (360° - 90°) = 8.1 FT (2.5m)
H
T
=
H
R
+ H
O
= 8FT (2.4m) + 8.1FT (2.5m) = 16.1FT (4.9m)
H
T
+ V
T
= 16.1FT (4.9m) + 4.5FT (1.4m) = 20.6 FT (6.3m)
Formula 1:
H
T
< 3V
T
3V
T
= 3FT (0.9m) x 4.5FT (1.4m) = 13.5FT (4.1m)
16.1FT (4.9m) > 13.5FT (4.1m)
Since this formula is not met, this vent configuration is
unacceptable.
Formula 2:
H
T
+ V
T
< 40 feet (12.2m)
20.6FT (6.3m) < 40 (12.2m)
Since only formula 2 is met, this vent configuration is unacceptable and a new appliance location or vent configuration will
need to be established to satisfy both formulas.
The shaded area within the lines represents acceptable
values for
H
T
and
V
T
0
5
(1.5)
10
(3.1)
15
(4.6)
20
(6.1)
10 (3.1)
20 (6.1)
3 (0.9)
25
(7.6)
30
(9.1)
19 (5.8)
90°
V
1
V
2
H
1
H
2
90°
90°
90°
V
3
18.1_2B
18
(5.5)
2 (0.6)
