Napoleon Vittoria GD19N Installation And Operation Instructions Manual page 9

for the following symbols used in the venting calculations
and examples are:
> - greater than
> - equal to or greater than
< - less than
< - equal to or less than
H
- total of both horizontal vent lengths (H
T
(H ) in feet
O
H
- combined horizontal vent lengths in feet
R
H
- offset factor: .03(total degrees of offset - 90°*) in
O
feet
V
- combined vertical vent lengths in feet
T
TOP EXIT / HORIZONTAL TERMINATION
when (H ) < (V )
T T
Simple venting confi guration (only one 90° elbow)
Simple venting confi guration
(only one 90° elbow)
See graph to determine the required vertical rise V
required horizontal run H
VERTICAL
R I S E I N
FEET
35
V
33.3
T
30
20
17.5
10
0
.5 2.5 5
HORIZONTAL VENT RUN PLUS OFFSET IN FEET
The shaded area within the lines represents acceptable
values for H and V
T
DEFINITIONS
) and offsets
R
FIGURE 7
.
T
7.5 10 12.5 15
.
T
ELBOW VENT LENGTH VALUES
1°
15°
30°
45°
90°*
* the fi rst 90° offset has a zero value and is shown in the
formula as -90°
For vent confi gurations requiring more than one 90° elbow,
the following formulas apply:
Formula 1: H
Formula 2: H
FIGURE 8
for the
T
Example 1:
V
= 3 ft
1
V
= 8 ft
2
V = V + V
T 1
H
= 2.5 ft
1
H
= 2 ft
2
H = H + H
R 1
H
= .03(three 90° elbows - 90°) = .03(270° - 90°) = 5.4
O
ft
H = H + H
17.5 20
T R
H
H + V
= 9.9 + 11 = 20.9 ft
T
T T
H
Formula 1:
H
Formula 2:
20.9 < 35
Since both formulas are met, this vent confi guration is
acceptable.
feet
0.03
0.45
0.9
1.35
2.7
< V
T T
+ V < 35 feet
T T
90°
V
90°
V
1
= 3 + 8 = 11 ft
2
= 2.5 + 2 = 4.5 ft
2
= 4.5 + 5.4 = 9.9 ft
O
< V
T T
9.9 < 11
+ V < 35 feet
T T
9
inches
0.5
6.0
11.0
16.0
32.0
H
2
2
90°
H
1
W415-0612 / A / 11.05.07