MHSC DIRECT VENT MLDV500 Installation And Operating Instructions Manual page 23

VENTING INSTALLATION
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
40' Max. Height
8' Min. Height
Figure 30 -
Support Straps for Horizontal Runs
•
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
FP1183
18" (450 mm).
max height
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).
75D0004
10'
Maximum
Support Straps
Every 3'
40' Max. Height
8' Min. Height
1
2
3
4
Example: Elbow 1
Elbow 
Elbow 3
Elbow 4
Total Angular Variation
Figure 31 -
Maximum Elbow Usage
FP1179
max bends
MLDV Series Gas Fireplace
10'
Maximum
Support Straps
Every 3'
FP1183
1
2
3
= 90°
4
= 45°
= 45°
= 90°
= 70°
3