Monessen Hearth Direct Vent Gas Fireplace MDV500 - Manual (Page 25)

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Figure 32 - Maximum elbow Usage
• Up to two 45° elbows may be used within the
horizontal run. For each 45° elbow used on the
horizontal plane, the maximum horizontal length
must be reduced by 18" (450mm).
Example: Maximum horizontal length
No elbows = 10’ (3m)
1x45° elbows = 8.5’ (2.6m)
2x45° elbows = 7’ (2.1m)
• A minimum of an 8' (2.5m) vertical rise is
required.
• Two sets of 45°elbows offsets may be used within
the vertical sections. From 0 to a maximum of 8'
(2.5 m) of vent pipe can be used between elbows.
See Figure 32.
• Determine the roof pitch and use the appropriate
starter kit for offset installation.
• The maximum angular variation allowed in the
system is 270°. See Figure 32.
• The minimum height of the vent above the high-
est point of penetration through the roof is 1'
(305mm).
1
2
3
4
1
2
3
4
Example: Elbow 1 = 90°
Elbow 2 = 45°
Elbow 3 = 45°
Elbow 4 = 90°
Total Angular Variation = 270°
Figure 31 - Support Straps for Horizontal Runs
40' Maximum Height
8' Minimum Height
40' Maximum Height
8' Minimum Height
10'
Maximum
10'
Maximum
Support Straps
Every 3'
Support Straps
Every 3'
Support
Straps
Every
5'Vertical
This Gas Fireplace has been approved for,
• Vertical installations up to 40' (12m) in height. Up to a 10' (3m)
horizontal vent run can be installed within the vent system
using a maximum of two 90° elbows. See Figure 31.
VENT INSTALLATION
VERTICAL THROUGH-THE-ROOF APPLICATIONS (continued)