Montigo R320 - Manual (Page 16)

Figure 10. Straight Vertical, Top or Rear Vent, Roof mounted
power vent.
Figure 10a. Multi-Elbow, Top or Rear Vent, Roof mounted power vent.
Note: Images are shown without screens for clarity purposes.
However, your fireplace should not be operated without proper
installation of screens.
R320 & R420 Power Vent Indoor Gas Fireplace
Page 16
XG0770 - 150105.1
Installation
This section applies to installations where the most efficient vent run
is through the roof. Refer to Appendix A - Power Vent locations,
to ensure the planned Power vent location is acceptable. Refer to
the table below for vent run requirements.
Section 3-2: Installing a Roof Mounted Vent System
Vent Configuration Refer to Figure
Maximum Vent Run
(Horizontal + Vertical)
Maximum Elbows†
Straight Vertical Top or Rear Vent Figure 10
100 Feet
Six 90°
or
equivalent †
Multi-Elbow Top or Rear Vent Figure 10a
Multi-Elbow with 6' downward vent
run Top or Rear Vent
Figure 10b 70 Feet**
† One 90° elbow is equal to two 45° elbows.
** For every additional 1 foot downward vent run subtract 10 feet from the maximum vent run.