Installation & Operation Manual
2 Venting
Length of air inlet pipe
The installed length of air inlet pipe from the unit to the outside air inlet cap must not exceed 50 equivalent feet (15.2 m). Subtract 5 feet (1.5 m) of equivalent length for each 90° elbow. Subtract 2.5 feet (0.7 m) of equivalent length for each 45° elbow.
Do not exceed the limits for the combustion air inlet piping lengths.
Connecting the air inlet pipe to the unit
Connect the air inlet piping directly to the unit by attaching it to the DV box adapter. The DV box adapter is included in the direct vent kits. The combustion air inlet area of the unit is located at the right rear corner of the unit. This unit uses a simple air filter to ensure clean air is used for the combustion process. Attach the DV box adapter over the air filter (see FIG.
For venting versatility, you can move the air filter assembly and DV box adapter to the right side of the unit. Remove the metal panel on the unit’s right side (see FIG.
The DV box adapter has an air inlet pipe mounting ring. Connect combustion air inlet piping to the direct vent box mounting ring.
VERTICAL DV BOX ADAPTER |
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HORIZONTAL DV BOX ADAPTER |
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Figure | Figure |
Air inlet piping materials
The air inlet pipe(s) must be sealed. Select air inlet pipe material from the following specified materials.
•PVC, CPVC, or ABS*
•Dryer vent or sealed flexible duct (not recommended for rooftop air inlet)
•Galvanized steel vent pipe with joints and seams sealed as specified below
•
*Plastic pipe may require an adapter (not provided) to transition between the air inlet connection on the unit and the plastic air inlet pipe.
WARNING
Use only vent or air intake materials specified in this manual. Follow vent pipe manufacturer’s instructions. Failure to do so can result in property damage, personal injury, or death. Mixing of venting materials will void the warranty and certification of this unit.
Sealing
Follow the steps below to properly seal
1.Seal all joints and seams of the air inlet pipe using either aluminum foil duct tape meeting UL Standard 723 or 181
2.On horizontal runs, do not install vent pipe with seams pointing down. Position vent pipe so that the seams are on the top side of the vent pipe.
3.Secure all joints with a minimum of three sheet metal screws or pop rivets. Apply aluminum foil duct tape or silicone sealant to all screws or rivets installed in the vent pipe.
4.Ensure that the air inlet pipes are properly supported.
Sealing PVC, CPVC, ABS, dryer vent, and flex duct vent pipe
1.Clean the PVC, CPVC, or ABS air inlet pipe using the pipe manufacturer’s recommended solvents. Seal the pipe joints using standard commercial pipe cement.
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