Vermont Casting 43LDVT - Manual (Page 13)

13
LDVT Series Direct Vent GaS Fireplace
10007852
FP1012
Top vent max run
1/25/00 djt
20' (6m)
7.5' (2.3m)
Pipe Straps
Every 3’ (914mm)
Firestop/Zero
Clearance Sleeve
Pipe
Straps Every
3’ (914mm)
FP1012
Fig. 14 Support straps for horizontal runs.
• If a 90° elbow is used in the horizontal vent run
(level height maintained) the maximum horizontal
vent length is reduced by 36” (914mm). This does
not apply if the 90° elbows are used to increase or
redirect a vertical rise.
Example: According to the chart the maximum
horizontal vent length in a system with a 7.5’ (2.3 m)
vertical rise is 20’ (6m) and if a 90° is required in the
horizontal vent it must be reduced to 17’ (5.2 m).
In Figure 16, Dimension A plus B must not be
greater than 17’ (5.2 m).
Horizontal plane means no vertical rise exists on this
portion of the vent assembly.
• The maximum number of 90° elbows per side wall
installations is three (3).
• If a 90° elbow is fitted directly onto the fireplace
flange the maximum horizontal vent run before the
termination or a vertical rise is 36” (914mm).
3'
(914mm)
FP1237
horizontal plane
12/02
FP1237
Fig. 15 Maximum horizontal vent run.
7.5'
(2.3m)
A
B
A + B = 17' (5.2m) Max.
1 x 90° elbow in horizontal plane = 3’ (914mm)
FP1238
Fig. 16 Maximum vent run with elbows.
• 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. 17)
Example:
Elbow 1 = 90°
Elbow 2 = 45°
Elbow 3 = 45°
Elbow 4 = 90°
Total angular variation = 270°
1 + 2 + 3 + 4 = 270°
FP1239
Fig. 17 Maximum number of elbow degrees.
1
2
3
4