3.6
horizontal termination
Simple venting configuration (only one 90° elbow)
For vent configurations requiring more than one 90° elbow, the following formulas apply:
Formula 1: H
< V
T
T
Formula 2: H
+ V
< 40 feet (12.2m)
T
T
Example:
V
= 3 ft (0.9m)
1
V
= 8 ft (2.4m)
2
V
= V
+ V
= 3 ft (0.9m) + 8 ft (2.4m) = 11 ft (3.4m)
T
1
2
H
= 2.5 ft (0.8m)
1
H
= 2 ft (0.6m)
2
H
= H
+ H
= 2.5ft (0.8m) + 2 ft (0.6m) = 4.5 ft (1.4m)
R
1
2
H
= .03 (two 90° elbows - 90°) = .03 (180° - 90°) = 5.4 ft (1.7m)
O
H
= H
+ H
= 4.5 ft (1.4m) + 5.4 ft (1.6m) = 9.9 ft (3m)
T
R
O
H
+ V
= 9.9 ft (3m) + 11 ft (3.4m) = 20.9 ft (6.4m)
T
T
Formula 1: H
< V
T
T
9.9 ft (3m) < 11 ft (3.4m)
Formula 2: H
+ V
< 40 ft (12.2m)
T
T
20.9 ft (6.4m) < 40 ft (12.2m)
Since both formulas are met, this vent configuration is acceptable.
(H
) ≤ (V
)
T
T
See graph to determine the required vertical rise V
40 (12.2)
39 (11.9)
Required vertical
30 (9.1)
rise in feet
(meters) V
T
20 (6.1)
10 (3.1)
0
Horizontal vent run plus offset in feet (meters) H
The shaded area within the lines represents acceptable
venting requirements
the required horizontal run H
2.5
5
7.5
10
12.5
(0.8)
(1.5)
(2.3)
(3.1)
(3.8)
values for H
and V
T
T
90°
V
2
90°
H
90°
V
1
13.1
EN
for
T
.
T
15
17.5
20
(4.6)
(5.3)
(6.1)
T
H
2
1
19
W415-3091 / B / 03.22.22