CFDV Series Gas Fireplace
20
20306739
Example:
According to the vent graph (Page 16) 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).
In
Figures 30 & 31
, dimension A plus B must not be great-
er than 17' (5.2 m)
• The maximum number of 45° elbows permitted per in-
stallation is six (6). 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°.
Figure 32
Example:
Elbow 1 = 90°
Elbow 2 = 45°
Elbow 3 = 45°
Elbow 4 = 90°
Total angular variation = 270°
3 x 90°
Elbows
3 x 90°
Elbows
FP1176
Figure 28 –
Maximum three (3) 90° elbows per installation
36"
(914mm)
Max.
36"
(914mm)
Max.
FP1177
Figure 29 –
Maximum horizontal run with no rise
VENTING INSTALLATION
7'6"
(2.3m)
A
B
A + B = 17' (Max.)
(5.2m)
FP1178
Figure 30 –
Horizontal Run Reduction
A
10'
(3 m)
7'
(2.1 m)
7'6"
(2.3 m)
V584-201
B
Figure 31 –
Maximum Vent Run with Elbows
1
2
3
4
1
2
3
4
1 + 2 + 3 + 4 = 270°
FP1180
Figure 32 –
Maximum Elbow Usage
