Specifications

21
53D9026
outsIde coMbustIon aIr precautIons & recoMMendatIons
outsIde coMbustIon aIr recoMMendatIons (contInued)
1. Extremely long runs and numerous turns in the duct leading from the replace to the combustion air assembly
should be avoided. These conditions will increase the resistance to the free ow of air through the duct.
Refer to Figures 1, 21, and 22 for methods of installing the outside air for combustion assemblies.
2. The combustion air assembly should be located at an exterior location, which is not likely to be accidentally
blocked in any manner. The assembly should be located above the snow line to prevent blockage by snow
accumulation.
3. The combustion air inlet assembly should never be mounted in a garage or storage area where combustible
fumes such as gasoline might be drawn into the replace.
4. Combustion air can be drawn form the crawl space under a house when an adequate supply of air is
provided by open ventilation.
5. Do not take combustion air from attic space or garage space.
FIgure 22