4
53D0419
1 + 2 + 3 + 4 = 270°
1
2
3
4
1
2
3
4
FP2058
max elbows
hORIZONTAL TERMINATION
CONFIGURATION
(Continued)
• If a 90° elbow is used in the
horizontal vent run, the horizontal
vent length is reduced by 36" (914
mm).
Figure 28.
This does not
apply if the 90° elbows are used to
increase or redirect a vertical rise.
Figure 29
Example: According to the vent
graph, Figure 27, the maximum hori-
zontal vent length in a system with a
7.5' vertical rise is 20’ (6 m) and if a
90° elbow is required in the horizontal
vent it must be reduced to 17' (5.2
m). Refer to Page 22 "How to Use
the Vent Graph".
In Figures 28 and 29,
Dimension A
plus B must not be greater than 17'
(5.2m).
• The maximum number of 45°
elbows permitted per side wall
installation is two (2). These elbows can be installed in either the vertical
or horizontal run.
• For each 45° elbow installed in the horizontal run, the length of the hori-
zontal run MUST be reduced by 18" (45 cm). This does not apply if the
45° elbows are installed on the vertical part of the vent system.
• The maximum number of elbow degrees in a system is 270°.
Figure
30
Figure 30 -
Maximum Elbow Usage
VENT INSTALLATION
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
2 4 6 8 10 12 14 16 18 20
FP2047
sidewall vent graph
Horizontal Dimension from the
Outside Face of the Wall to the
Center of the Fireplace Vent
Flange
Figure 27 -
Rear Wall Venting Graph
Figure 28 -
Horizontal Run Reduction
90°
7'6"
A
B
FP2056
Horizontal run reduc
FP2056
10'
7'6"
7'
A
B
FP2057
max vent run elbows
Figure 29 -
Maximum Vent Run with Elbows
A + B = 17' Maximum
90° Elbow = 3'
Example:
Elbow 1 = 90º
Elbow 2 = 45º
Elbow 3 = 45º
Elbow 4 = 90º
Total Angular Variation = 270º
FP2057
FP2058