Monessen Hearth BUF400 User Manual

16 

8'max.

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 fireplace.

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 fireplace to the combustion air 

assembly. These conditions increase the resistance to the free flow of air through the duct. See Figures 14
through 17 for methods of installing the outside air for combustion assemblies.

Above 

Snow

Level

Ground 

Level 

Basement 
Wall 

Inlet Grill in 

Soffit

(Overhang)

Inside Wall 

Outside

Wall

Duct Extended 

to Miss Joist 

To Outside Wall