venting requirements
EN
2.9
top and rear exit vertical termination
Simple venting configurations.
For vent configurations requiring one or more 90° elbows (top exit) or one or more 90° elbows
(rear exit), the following formulas apply:
Formula 1: H
< V
T
T
Formula 2: H
+ V
T
T
Example:
V
= 5 FT (1.5m)
1
V
= 6 FT (1.8m)
2
V
= 10 FT (3.1m)
3
V
= V
+ V
+ V
= 5FT (1.5m) + 6FT (1.8m) + 10FT (3.1m) = 21 FT (6.4m)
T
1
2
3
H
= 8 FT (2.4m)
1
H
= 2.5 FT (0.8m)
2
H
= H
+ H
= 8FT (2.4m) + 2.5FT (0.8m) = 10.5FT (3.2m)
R
1
2
H
= .03 (four 90° elbows - 90°)
O
= .03 (360° - 90°) = 8.1 FT (2.5m)
H
= H
+ H
= 10.5FT (3.2m) + 8.1FT (2.5m) = 18.6FT (5.7m)
T
R
O
H
+ V
= 18.6FT (5.7m) + 21FT (6.4m) = 39.6FT (12.1m)
T
T
Formula 1:
H
18.6 FT (5.7m) < 21 FT (6.4m)
Formula 2:
H
39.6FT (12.1m) < 40 FT (12.2m)
Since both formulas are met, this vent configuration is acceptable.
22
W415-2881 / C / 03.07.22
< 40 feet (12.2m)
< 3.5V
T
T
+ V
< 40 FT (12.2m)
T
T
(H
) < (V
)
T
T
See graph to determine the required vertical rise V
required horizontal run H
40 (12.2)
30 (9.1)
REQUIRED
VERTICAL RISE
IN FEET
20 (6.1)
(METERS)V
T
10 (3.1)
3 (0.9)
0
HORIZONTAL VENT RUN PLUS OFFSET IN FEET
The shaded area within the lines represents acceptable
.
T
5
10
15
(1.5)
(3.1)
(4.6)
(METERS) H
T
values for H
and H
T
T
18.2A
for the
T
20
(6.1)