Monessen Hearth DIRECT VENT MLDV500 - Manual (Page 23)

75D0004 3
MLDV Series Gas Fireplace
FP1183
max height
VERTICAL (THROUGH-THE-ROOF) APPLICATIONS (continued)
This Gas Fireplace has been approved for,
• Vertical installations up to 40' (1 m) in height. Up to a 10' (3 m) horizontal vent run can be installed
within the vent system using a maximum of two 90° elbows. Figure 30
VENTING INSTALLATION
Figure 31 -
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" (450 mm).
Example: Maximum horizontal length
No elbows
= 10’ (3 m)
1 x 45° elbows = 8.5’ (.6 m)
 x 45° elbows = 7’ (.1 m)
• A minimum of an 8' (.5 m) vertical rise is required.
• Two sets of 45°elbows offsets may be used within the
vertical sections. From 0 to a maximum of 8' (.5 m)
of vent pipe can be used between elbows. Figure 31
• Determine the roof pitch and use the appropriate
starter kit for offset installation.
• The maximum angular variation allowed in the system
is 70°. Figure 31
• The minimum height of the vent above the highest
point of penetration through the roof is ' (610 mm).
Example: Elbow 1 = 90°
Elbow  = 45°
Elbow 3 = 45°
Elbow 4 = 90°
Total Angular Variation = 70°
10'
Maximum
10'
Maximum
40' Max. Height
8' Min. Height
Support Straps
Every 3'
Figure 30 -
Support Straps for Horizontal Runs
40' Max. Height
8' Min. Height
Support Straps
Every 3'
FP1183
1
2
3
4
1
2
3
4
FP1179
max bends