Napoleon Fireplaces GD82NT-T - Manual (Page 9)

9
W415-0666 / 01.28.08
REQUIRED VERTICAL
RISE IN FEET
V
T
HORIZONTAL VENT RUN PLUS OFFSET IN FEET H
T
when (H
T
) < (V
T
)
FIGURE 10
For vent confi gurations requiring more than zero 90° elbow
(top exit) or one 90° elbow (rear exit), 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
.
VERTICAL TERMINATION
The shaded area within the lines represents acceptable
values for H
T
and V
T
.
V
1
= 5 ft
V
2
= 6 ft
V
3
= 10 ft
V
T
= V
1
+ V
2
+ V
3
= 5 + 6 + 10 = 21 ft
H
1
= 8 ft
H
2
= 2.5 ft
H
R
= H
1
+ H
2
= 8 + 2.5 = 10.5 ft
H
O
= .03 (four 90° elbows - 90°)
= .03 (90 + 90 + 90 + 90 - 90) = 8.1 ft
H
T
= H
R
+ H
O
= 10.5 + 8.1 = 18.6 ft
H
T
+ V
T
= 18.6 + 21 = 39.6 ft
Formula 1: H
T
< V
T
18.6 < 21
Formula 2: H
T
+ V
T
< 40 feet
39.6 < 40
Since both formulas are met, this vent confi guration is
acceptable.
Example 4:
90°
90°
90°
H
2
V
2
V
1
90°
FIGURE 11
H
1
V
3