18
DVB4136 Direct Vent Gas Fireplace
20012322
3 x 90°
Elbows
3 x 90°
Elbows
FP1176
Fig. 26
Maximum three (3) 90° elbows per installation.
• If a 90° elbow is used in the horizontal vent run
(level height maintained) the horizontal vent length
is reduced by 36” (914 mm). (Fig. 28, 29) This does
not apply if the 90° elbows are used to increase or
redirect a vertical rise. (Fig. 26)
Example: According to the vent graph (Page 14) the
maximum horizontal vent length in a system with a 7
¹⁄₂
’
(2.3 m) 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).
Max 20"
Max 20"
36"
(914mm)
Max.
36"
(914mm)
Max.
FP1177
Fig. 27
Maximum horizontal run with no rise.
7'6"
(2.3m)
A
B
A + B = 17' (Max.)
(5.2m)
FP1178
Fig. 28
Horizontal run reduction.
V584-201
Horizontal Run
2/99 djt
A
10’
(3 m)
7’
(2.1 m)
8’
(2.4 m)
V584-201
B
Fig. 29
Maximum vent run with elbows.
In Figures 28 & 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 horizontal run MUST be reduced by
18” (457 mm). 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°. (Fig. 30)
Example:
Elbow 1 = 90°
Elbow 2 = 45°
Elbow 3 = 45°
Elbow 4 = 90°
Total angular variation = 270°
1
2
3
4
1
2
3
4
1 + 2 + 3 + 4 = 270°
FP1180
Fig. 30
Maximum elbow usage.
