16
W415-0680 / 04.10.08
FIGURE 31
MAXIMUM
VERTICAL
R I S E I N
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 two 90° elbows (top exit) or one 90° elbow (rear exit), the following
formulas apply:
Formula 1: H
T
< 3V
T
Formula 2: H
T
+ V
T
< 40 feet
Example 7:
V
1
= 2 ft
V
2
= 1 ft
V
3
= 1.5 ft
V
T
=
V
1
+
V
2
+
V
3
= 2 + 1 + 1.5 = 4.5 ft
H
1
= 6 ft
H
2
= 2 ft
H
R
=
H
1
+
H
2
= 6 + 2 = 8 ft
H
O
= .03 (four 90° elbows - 90°)
= .03(90 + 90 + 90 + 90 - 90) = 8.1 ft
H
T
=
H
R
+
H
O
= 8 + 8.1 = 16.1 ft
H
T
+ V
T
= 16.1 + 4.5 = 20.6 ft
Formula 1:
H
T
< 3V
T
3V
T
= 3 x 4.5 = 13.5 ft
Since this formula is not met, this vent confi guration is unacceptable.
H
1
H
2
V
3
V
1
90°
90°
90°
V
2
90°
when
(H
T
)
>
(V
T
)
Simple venting confi gurations
See graph to determine the required vertical rise
V
T
for the required horizontal run
H
T
.
FIGURE 32
Since only formula 2 is met, this vent confi guration is unacceptable and a new fi replace location or vent confi guration will
need to be established to satisfy both formulas.
V
1
= 1.5 ft
V
2
= 5 ft
V
T
=
V
1
+
V
2
= 1.5 + 5 = 6.5 ft
H
1
= 1 ft
H
2
= 1 ft
H
3
= 10.75 ft
H
R
=
H
1
+
H
2
+
H
3
= 1 + 1 + 10.75 = 12.75 ft
H
O
= .03 (three 90° one 45° elbow - 90°)
= .03(90 + 90 + 90 + 45 - 90) = 6.75 ft
H
T
=
H
R
+
H
O
= 12.75 + 6.75 = 19.5 ft
H
T
+ V
T
= 19.5 + 6.5 = 26 ft
Formula 1:
H
T
< 3V
T
3V
T
= 3 x 6.5 = 19.5 ft
19.5 < 19.5
Since both formulas are met, this vent confi guration is acceptable.
H
2
H
3
V
1
V
2
90°
45°
90°
H
1
90°
FIGURE 33
Example 8:
Formula 2:
H
T
+ V
T
< 40 feet
20.6
<
40
Formula 2:
H
T
+ V
T
< 40 feet
26
<
40
Summary of Contents for BCDV2CFN
Page 1: ...1 W415 0680 04 10 08 10 00 W415 0680 04 10 08...
Page 7: ...7 W415 0680 04 10 08 FIGURE 8...
Page 46: ...46 W415 0680 04 10 08...
Page 51: ...51 W415 0680 04 10 08 NOTES...
Page 52: ...52 W415 0680 04 10 08 NOTES...