Napoleon BGD36PTR Installation And Operation Instructions Manual page 9

DEFINITIONS
for the following symbols used in the venting calcula-
tions 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 )
Simple venting configuration (only one 90° elbow)
FIGURE 6
See graph to determine the required vertical rise V for the
required horizontal run H .
VERTICAL
R I S E I N
FEET
HORIZONTAL VENT RUN PLUS OFFSET IN FEET
The shaded area within the lines represents acceptable
values for H and V
T T
) and offsets
R
.
ELBOW VENT LENGTH VALUES
feet
1° 0.03
15° 0.45
30° 0.9
45° 1.35
90°* 2.7
* the first 90° offset has a zero value and is shown in
the formula as -90°
For vent configurations requiring more than one 90° el-
bow, the following formulas apply:
Formula 1: H < V
T T
Formula 2: H + V
T T
Example 1:
FIGURE 7
V
= 3 ft
1
V
= 8 ft
2
V = V + V
= 3 + 8 = 11 ft
T 1 2
H
= 2.5 ft
1
H
= 2 ft
2
H = H + H
= 2.5 + 2 = 4.5 ft
R 1 2
H
= .03(three 90° elbows - 90°) = .03(270° - 90°) = 5.4 ft
O
H = H + H
= 4.5 + 5.4 = 9.9 ft
T R O
H + V
= 9.9 + 11 = 20.9 ft
T T
H < V
Formula 1:
T T
9.9 < 11
H + V < 40 feet
Formula 2:
T T
20.9 < 40
Since both formulas are met, this vent configuration is ac-
ceptable.
inches
0.5
6.0
11.0
16.0
32.0
< 40 feet
W415-0210 / E / 06.25.03
9