Owner's Manual
71D0530
1
GCUF Vent-Free Fireboxes
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 1" above the snow line
to prevent blockage by snow accumulation.
. Never mount the combustion air inlet assembly in a
garage or storage area where combustible fumes such
as gasoline might be drawn into the replace.
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.
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 replace to the combustion air
assembly. These conditions increase the resistance to
the free ow of air through the duct. Refer to Figures
12 through 15 for methods of installing the outside air
for combustion assemblies.
FP2459
OA basement install
Above
Snow
Level
Ground
Level
FP459
Figure 12 -
Basement Installation
8' Max.
FP2460
OA slab install
Inlet Grille
in Soft
(Overhang)
FP460
Figure 13 -
Concrete Slab Installation
(Optional Outside Air Runs)
FP2461
above basement
Duct
Extended
to Miss
Joist
FP461
Figure 14 -
Installation Above Basement or
Crawl Space
To Outside Wall
FP2462
OA corner install
Outside
Wall
Inside Wall
FP46
Figure 15 -
45° Corner Installation
on Slab Floor










