LG AR-DR12-05A Installation And Operation Manual page 77

INDIRECT GAS FIRED FURNACES
Concentric Venting Installation
Concentric Venting – Vertical
Refer to the diagram for venting on vertical concentric systems. Maintain at least 12 inches between the top of the combustion air inlet termi-
nals and the bottom of the exhaust terminal. (Dim. B).
The bottom of the combustion air intake pipe must terminate above the snow line or at least 12 inches above the roof, whichever is greater.
A tee with a drip leg and a clean-out cap must be provided on the combustion air and exhaust pipe to prevent debris from entering the heat
exchanger.
Figure 39: Concentric Venting - Vertical
Vent Connection Diameter
Vent terminals must be used (one vent terminal and inlet terminal
included with each furnace). Construct the vent system as shown in the
drawings and refer to the table for the correct vent connection diame-
ters.
Vent Length
Refer to table. The total equivalent vent length must include elbows.
The equivalent length of a 4 inch elbow is 6 feet and the equivalent
length of a 6 inch elbow is 10 feet.
Determine Venting Location
Determine the location of the concentric venting adapter (CVA) based on any clearances that must be maintained (follow all codes refer-
enced in these instructions).
Attach Mounting Brackets
Attach field-supplied corrosion-resistant mounting brackets to the CVA using corrosion resistant sheet metal screws.
Install Exhaust Pipe
Attach a field-supplied exhaust air pipe to the concentric side of the CVA. Provide enough exhaust piping to pass through the roof and pro-
vide the minimum clearance of 12 inches between the exhaust pipe termination and the combustion air intake. With all required clearances
satisfied, attach the exhaust pipe to the CVA.
Install Combustion Air Pipe
Attach a field-supplied combustion air pipe to the concentric side of the CVA. Be sure to provide enough combustion air piping to pass
through the roof and provide the minimum clearance of 12 inches between the combustion air intake and the exterior surface of the roof. This
clearance may need to be increased to allow for snow accumulation.
Be sure to maintain the minimum clearance of 12 inches between the exhaust pipe termination and the combustion air intake.
Install CVA Assembly
Place the CVA assembly through the roof and verify that all minimum clearance requirements as specified in these instructions are met.
Secure the CVA assembly to the ceiling with corrosion-resistant sheet metal screws through the mounting brackets.
Due to our policy of continuous product innovation, some specifications may change without notification.
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