•The maximum number of 90° elbows per side wall installation is three (3). (Fig. 28)
•If a 90° elbow is fitted directly on top of the fireplace flange, the maximum horizontal vent run before the termination or a vertical rise is 36” (914 mm). (Fig.
29)
3 x 90° | 3 x 90° |
Elbows | Elbows |
FP1176
Fig. 28 Maximum three (3) 90° elbows per installation.
36"
(914 mm)
Max. 36" 
(914 mm) Max.
FP1177
Fig. 29 Maximum horizontal run with no rise.
•If a 90° elbow is used in the horizontal vent run (level height maintained) the maximum horizontal vent length is reduced by 36” (914 mm). (Fig. 29) This does not apply if the 90° elbows are used to increase or redirect a vertical rise. (Fig. 30, 31)
Example: According to the vent graph (Page 15) the maximum horizontal vent length in a system with a 7.5’ (2.3 m) 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). In Figure 31 Dimension A plus B must not be greater than 17’ (5.2 m).
AB
A + B = 17' (Max.)
(5.2m)
7'6"
(2.3m)
FP1178
Fig. 30 Horizontal run reduction.
XDV Direct Vent Gas Fireplace
B 7’
(178 cm)
A 10’ (254 cm)
| A + B = 17’ |
8’ | (518 cm) Max. |
(244 cm)
Fig. 31 Maximum vent run with elbows.
In Figure 30 & 31, dimension A plus B must not be greater than 17’ (5.2 m).
•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” (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°. (Fig. 32)
Example:
Elbow 1 = 90°
Elbow 2 = 45°
Elbow 3 = 45°
Elbow 4 = 90°
Total angular variation = 270°
1 + 2 + 3 + 4 = 270°
11 
22
33
4 | 4 |
|
FP1180
Fig. 32 Maximum elbow usage.
10009383 | 17 |