Operating instructions

18
W415-0680 / 04.10.08
For vent confi gurations requiring more than one 45º and one 90° elbow the following formulas apply:
Formula 1:
H
T
< 4.2 V
T
Formula 2: H
T
+ V
T
< 24.75 feet
Example 2:
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 (one 45° elbow + four 90° elbows - 135°)
= .03(405 - 135) = 8.1 ft
H
T
= H
R
+ H
O
= 5.5 + 8.1 = 13.6 ft
H
T
+ V
T
= 13.6 + 5.5 = 19.1 ft
Formula 1: H
T
< 4.2V
T
4.2V
T
= 4 .2 x 5.5 = 23.1 ft
13.6 < 16.8
Since both formulas are met, this vent confi guration is acceptable.
FIGURE 37
H
1
H
2
H
3
H
4
V
1
V
2
90°
45°
90°
90°
90°
BCDV42CF VERTICAL TERMINATION
when (H
T
) < (V
T
)
Simple venting confi gurations
45°
MAXIMUM VERTICAL
RISE IN FEET
V
T
HORIZONTAL VENT RUN PLUS
OFFSET IN FEET
H
T
The shaded area within the lines
represents acceptable values
for H
T
and V
T
.
For vent confi gurations requiring more than one 45º and
one 90° elbow the following formulas apply:
Formula 1:
H
T
< V
T
Formula 2: H
T
+ V
T
< 40 feet
See graph to determine the required vertical rise V
T
for the
required horizontal run H
T
.
FIGURE 38
Formula 2: H
T
+ V
T
< 24.75 feet
19.1 < 24.75
Example 3:
90°
90°
90°
H
1
V
1
V
2
45°
H
2
V
1
= 5 ft
V
2
= 10 ft
V
T
= V
1
+ V
2
= 5 + 10 = 15 ft
H
1
= 3 ft
H
2
= 2.5 ft
H
R
= H
1
+ H
2
= 3 + 2.5 = 5.5 ft
H
O
= .03 (one 45° elbow + three 90° elbows - 135°)
= .03 (45 + 90 + 90 +90 - 135) = 5.4 ft
H
T
= H
R
+ H
O
= 5.5 + 5.4 = 10.9 ft
H
T
+ V
T
= 10.9 + 15 = 25.9 ft
Formula 1: H
T
< V
T
10.9 < 15
Since both formulas are met, this vent confi guration is acceptable.
FIGURE 39
Formula 2: H
T
+ V
T
< 40 feet
25.9 < 40