| Certified |
| Maximum | Combustion |
| Air Inlet Max. Length* |
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Model | Vent | Air |
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Venting | Equivalent |
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No. | Size | Intake Pipe |
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Material | Vent Length* | 6” |
| 8” | 10” |
| 12” | |||
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399B |
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| 100’ |
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| 6” |
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499B |
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| 75’ |
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649B |
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| 100’ |
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| 40’ |
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749B |
| 8” |
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899B |
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| 30’ |
| 80’ |
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| 70’Room Air | Galvanized |
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989B |
| 10” |
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Category III |
| Steel, |
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1259B |
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| 40’ Ducted | PVC, ABS, |
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| 75’ |
| 100’ |
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| Combustion Air | CPVC |
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| 12” |
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1529B |
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1799B |
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1999B |
| 14” |
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| 40’ |
| 75’ |
2069B |
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2339B |
| 16” |
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*Subtract 10 ft per elbow. Max. 3 elbows.
Maximum combustion air duct length terminated at 100 equivalent ft.
Table M: Category III Horizontal and Direct Venting
The vent must be installed to prevent flue gas leakage. Care must be taken during assembly to ensure that all joints are sealed properly and are airtight. The vent must be installed to prevent the potential accumulation of condensate in the vent pipes. It is required that:
1.The vent must be installed with a slight downward slope of not more than 1/4 inch per foot of hori- zontal run to the vent terminal.
2.The vent must be insulated through the length of the horizontal run.
For installations in extremely cold climate, it is re- quired that:
1.The vent must be installed with a slight upward slope of not more than 1/4 inch per foot of hori- zontal run to the vent terminal. In this case, an approved condensate trap must be installed per applicable codes.
2.The vent must be insulated through the length of the horizontal run.
Termination
The flue direct vent cap MUST be mounted on the ex- terior of the building. The direct vent cap cannot be installed in a well or below grade. The direct vent cap must be installed at least 1 ft above ground level and above normal snow levels. The
WARNING: No substitutions of flue pipe or vent cap material are allowed. Such substitutions would jeopardize the safety and health of inhabitants.
Use only the special gas vent pipes listed for use with Category III gas burning heaters, such as the
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