Operating instructions

14
W415-0680 / 04.10.08
Formula 1: H
T
< 3.5V
T
Formula 2: H
T
+ V
T
< 24.75 feet
Example 5:
V
1
=4 ft
V
2
=1.5 ft
V
T
= V
1
+ V
2
= 4 + 1.5 = 5.5 ft
H
1
=2 ft
H
2
=1 ft
H
3
=1 ft
H
4
=1.5 ft
H
R
=H
1
+ H
2
+ H
3
+ H
4
= 2 + 1 + 1 + 1.5 = 5.5 ft
H
O
=.03 (four 90° elbows + one 45° elbow - 90°)
=.03(90 + 90 + 90 + 90 + 45 - 90) = 9.45 ft
H
T
=H
R
+ H
O
= 5.5 + 9.45 = 14.95 ft
H
T
+ V
T
= 14.95 + 5.5 = 20.45 ft
Formula 1: H
T
< 3.5V
T
3.5V
T
= 3.5 x 5.5 = 19.25 ft
14.95 < 19.25
Since both formulas are met, this vent confi guration is acceptable.
For vent confi gurations requiring more than two 90° elbows the following formulas apply:
H
1
H
2
H
3
H
4
V
1
V
2
90°
90°
45°
90°
90°
FIGURE 28
Formula 2: H
T
+ V
T
< 24.75 feet
20.45 < 24.75
REQUIRED VERTICAL
RISE IN INCHES
V
T
HORIZONTAL VENT RUN PLUS
OFFSETS IN FEET
H
T
See graph to determine the required vertical rise V
T
for the required
horizontal run H
T
The shaded area within the lines represents acceptable values for H
T
and V
T
.
FIGURE 27
when (H
T
) > (V
T
)
Simple venting confi guration (only two 90° elbows)