Napoleon Madison GD80NT, Installation & Operation Instructions, Page: 11 / 40

11
W415-0695 / 05.12.08
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
.
See graph to determine the required vertical rise
V
T
for the
required horizontal run
H
T
.
FIGURE 12
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
16.1 > 13.5
Since this formula is not met, this vent confi guration is
unacceptable .
Formula 2:
H
T
+ V
T
< 40 feet
20.6 < 40
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.
FIGURE 11
H
1
H
2
V
3
V
1
90°
90°
90°
V
2
90°
when
(H
T
) > (V
T
)
Simple venting confi gurations
VERTICAL TERMINATION
For vent confi gurations requiring more than two 90° elbow
(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 5: