Monessen Hearth Magnum Unvented Vent-Free Fireboxes MCUF42D SERIES - Manual (Page 16)

16
26D4720
USING OPTIONAL AK-4 OUTSIDE AIR KIT
8'max.
COMBUSTION AIR
1. Locate combustion air assembly at an exterior location which is not likely to be accidentally blocked in any manner.
Locate assembly a min. of 12" above the snow line to prevent blockage by snow accumulation.
2. Never mount the combustion air inlet assembly in a garage or storage area where combustible fumes such as gasoline
might be drawn into the fi replace.
3. Combustion air can be drawn from the crawl space under a house when an adequate supply of air is provided by open
ventilation.
4. CAUTION: Do not take combustion air from attic space or garage space.
5. Locate air supply inlet at least 3' away from any appliance vent terminal.
6. Avoid extremely long runs and numerous turns in the duct leading from the fi replace to the combustion air assembly.
These conditions increase the resistance to the free fl ow of air through the duct. See Figures 17 through 20 for methods
of installing the outside air for combustion assemblies.
Figure 17 - Basement Installation
Figure 18 - Concrete Slab Installation
(Optional Outside Air Runs)
Above
Snow
Level
Ground
Level
Basement
Wall
Firestop Spacer
Inlet Grill in
Soffi t
(Overhang)
Figure 20 - 45° Corner Installation on
Slab Floor
Figure 19 - Installation Above Basement or
Crawl Space
Inside Wall
Outside
Wall
Duct Extended
to Miss Joist
To Outside Wall
Note: Fireplace model in illustrations may not be representative of your appliance.