26D4750
12
MCUF Series Vent-Free Firebox
OpTIONAL Ak-4 OUTSIDE AIR kIT
COMBUSTION AIR
1. Locate combustion air assembly at an exterior location
which is not likely to be accidentally blocked in any man-
ner. 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 fireplace.
3. Combustion air can be drawn from the crawl space un-
der 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 ap-
pliance vent terminal.
6. Avoid extremely long runs and numerous turns in the
duct leading from the fireplace to the combustion air
assembly. These conditions increase the resistance to
the free flow of air through the duct.
Refer to Figures
12 through 15
for methods of installing the outside air
for combustion assemblies.
FP2843
OA basement
Above
Snow
Level
Ground
Level
FP2843
Figure 12 -
Basement Installation
8’ Max
FP2844
OA concrete slab
Inlet Grille
in Soffit
(Overhang)
FP2844
Figure 13 -
Concrete Slab Installation
(Optional Outside Air Runs)
FP2845
OA crawl space
Duct
Extended to
Miss Joist
To Outside Wall
FP2845
Figure 14 -
Installation Above Basement
or Crawl Space
FP2846
OA corner install
Outside
Wall
FP2846
Figure 15 -
45° Corner Installation on Slab Floor
