LG GEN2 Series Installation And Operation Manual page 71

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 wall (or floor) and provide 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 wall and provide the minimum
clearance of 2 inches between the combustion air intake
and the exterior surface of the outside wall.
Be sure to maintain the minimum clearance of
12 inches between the exhaust pipe termination and the
combustion air intake.
Install CVA Assembl
y
Place the CVA assembly through the wall and verify
that all minimum clearance requirements as specified in
these instructions are met. Secure the CVA assembly to
the wall with corrosion-resistant sheet metal screws
through the mounting brackets.
Attach CVA Assembly to Unit
Connect the unit's combustion exhaust to the exhaust
connection on the CVA. Connect the unit's combustion
air supply intake to the combustion air connection on
the CVA.
Install Combustion Air Inlet Guard and
Exhaust Vent Terminal
Slide the combustion air inlet guard over the exhaust
pipe and fasten it to the combustion air pipe. Attach
the exhaust vent terminal to the discharge end of the
exhaust piping.
Seal Opening
Seal the opening between the wall and the air intake
pipe using an appropriate method.
Concentric Venting – Vertical
Refer to the diagram below for venting on vertical
concentric systems. Maintain at least 12 inches
between the top of the combustion air inlet terminals
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.
A = 12 inch minimum, but size
according to expected snow depth
B = 12 inch minimum
C = 12 inch minimum
Roof Line
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 diameters.
Non-Concentric Side Vent
Connection Diameter
Furnace Size Exhaust Combustion Air
(MBH) (inches) (inches)
75-175 4
200-400 6
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 referenced in these instructions).
Attach Mounting Brackets
Attach field-supplied corrosion-resistant mounting
brackets to the CVA using corrosion resistant sheet
metal screws.
Exhaust Vent
Terminal
B
Combustion Air
Inlet Terminal
A
Mounting Mounting
Bracket Bracket
C
Tee with
drip leg and
clean-out cap
C
Concentric Side Vent
Connection Diameter
Exhaust Combustion Air
(inches) (inches)
4 4 6
6 6 8
Vertical Concentric Venting
Vent Minimum Maximum
Length (feet) (feet)
Vertical 10 70