Lochinvar 399 Installation And Service Manual page 25

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. 25). Remove the
filter/bracket assembly from the rear of the unit. Attach the
filter/bracket assembly and DV box adapter to the right side
opening using the pre-drilled screw holes. Make sure you
attach the metal panel to the rear combustion air opening of the
unit.
The DV box adapter has an air inlet pipe mounting ring.
Connect combustion air inlet piping to the direct vent box
mounting ring.
FIG. 25 Moving Air Filter Assembly and DV Box Adapter
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
roof top air inlet)
• Galvanized steel vent pipe with joints and seams sealed as
specified below
• Type-B double-wall vent 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.
Installation and
Service Manual
Sealing Type-B Double-Wall Vent Pipe or Galvanized
Vent Pipe
Follow the steps below to properly seal Type-B double-wall
vent pipe or galvanized vent pipe.
1. Seal all joints and seams of the air inlet pipe using either
aluminum foil duct tape meeting UL Standard 723 or 181
A-P or a high quality UL Listed silicon sealant such as
those manufactured by Dow Corning or General Electric.
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.
2. For PVC, CPVC, ABS, dryer vent, or flex duct air inlet
piping, use a silicone sealant to ensure a proper seal at the
unit inlet and the air inlet cap.
3. For Dryer vent or flex duct, also use a screw-type clamp to
attach the inlet vent material to the unit inlet and the air
inlet cap.
Properly sealing the air inlet pipe ensures that combustion air
will be free of contaminates and supplied in proper volume.
WARNING: Properly seal all joints and
seams in the inlet vent piping system. Failure to
do so may result in flue gas recirculation,
spillage of flue products, and carbon monoxide
emissions. Carbon monoxide poisoning can
cause severe personal injury or death.
Vertical and Sidewall Combustion Air Inlet
IMPORTANT: To prevent recirculation of flue
products into the combustion air inlet, follow all
instructions in this section.
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