Majestic 400DVBL Installation And Operating Instructions Manual page 20

DVBL Series Gas Fireplace
VERTICAL/HORIZONTAL TERMINATION
CONFIGURATIONS (continued)
• If a 90° elbow is used in the horizontal vent run
(level height maintained) the horizontal vent length is
reduced by 36". See Figures 16 and 17, page 19. This
does not apply if the 90° elbows are used to increase
or redirect a vertical rise. Figure 19
Example: According to the vent graph (page 16) the
maximum horizontal vent length in a system with a 10'
vertical rise is 20' (6m) and if a 90° elbow is required in
the horizontal vent it must be reduced to 17' (5.2 m).
In Figures 18 and 19 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 horizontal run MUST be reduced by
18" (45cm). 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 20
A
10'
10'
A + B = 17' Maximum
Figure 19 - Maximum Vent Run with Elbows
20
7'
90° Elbow = 3'
Figure 18 - Horizontal Run Reduction
Example:
Total Angular Variation =
B
12" Min.
Figure 20 - Maximum Elbow Usage
VENT INSTALLATION
90°
A
10'
Elbow 1 =
Elbow 2 =
Elbow 3 =
Elbow 4 =
1
2
3
4
1 + 2 + 3 + 4 = 270°
B
90°
45°
45°
90°
270°
74D0010