Montigo HR38DF Installation, Operation & Maintenance Manual page 11

Figure 17. Vertical venting with 2 offsets (1 offset= two 90° bends).
Reduced Vertical Installation
It is possible to reduce vertical vent runs from 5"/8" venting to 4"/7"
venting. Reduced vertical venting may only be used when the installation
exceeds 12 feet and terminates through the roof, and if the vertical vent
reducer is used with the following venting configuration.
Figure 18. Reducing Vertical Vent from 5/8" to 4/7".
Part No. XG0147 - 011410
Installation
Figure 18a. RHS8 Installation. (Install by sliding over vent pipe where
it passes through the combustible construction.
RHS101 Heat Shield,
Outer Section.
Termination
Figure 18b. RHS101 Installation. (Install by sliding over vent pipe where
it passes through the combustible construction.
H38DF Series Gas Fireplace
1 MIN
1 MIN. Both
sides Typical
RHS8 Heat
Shield
1 MIN
Drywall
RHS101 Heat Shield,
Inner Section.
Framing
Vent from fireplace
Page 11