- Vermont Castings Direct Vent Homeowner's Manual 33XDV, 36XDV, 39XDV

10009383 17
XDV Direct Vent Gas Fireplace
• 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°
Elbows
3 x 90°
Elbows
FP1176
Fig. 28 Maximum three (3) 90° elbows per installation.
Max 20"
Max 20"
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).
7'6"
(2.3m)
A
B
A + B = 17' (Max.)
(5.2m)
FP1178
Fig. 30 Horizontal run reduction.
V584-201
Horizontal Run
2/99 djt
A 10’
(254 cm)
B 7’
(178 cm)
8’
(244 cm)
A + B = 17’
(518 cm) Max.
V584-201
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
1
2
3
4
1 + 2 + 3 + 4 = 270°
FP1180
Fig. 32 Maximum elbow usage.