Horizontal - LG GEN2 Series Installation And Operation Manual

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 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 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.
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. Be sure to include the required tee's with drip legs
and clean-outs.
Install Combustion Air Inlet Guard and Exhaust
Vent Terminal
Slide the combustion air terminal over the vent 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 roof and the air intake
pipe using an appropriate method.
Installation of Two Pipe Venting –

Horizontal

Refer to the diagram for venting on horizontal two pipe
systems. Maintain at least 12 inches of clearance
between the exhaust pipe termination and the exterior
surface of the exterior wall.
The combustion air pipe must be a minimum of
12 inches from the exhaust pipe and 2 inches from the
exterior surface of the outside wall.
A maximum of 48 inches of building wall thickness is
required for separated combustion vent pipe.
Vent Connection Diameter
Vent terminals must be used. The vent kit includes two
terminals per furnace.
Construct the vent
system as shown
Furnace Size
in the drawings
and refer to the
table for the correct
vent connection
diameters.
Vent Length
Refer to table for
minimum and maximum
vent lengths. The
minimum vent length is
5 feet and the maximum
vent length is 50 feet.
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.
Install Exhaust Pipe
Run an exhaust pipe from the unit's combustion exhaust
through the exterior wall to the outdoors. The exhaust
pipe must terminate at least 12 inches from the outside
surface of the outside wall. Attach exhaust vent terminal
to the end of the exhaust pipe. Using field-supplied
mounting brackets, support the exhaust pipe as needed.
Install Combustion Air Pipe
Run a combustion air pipe from the unit's combustion
air intake through the exterior wall to the outdoors.
The combustion air pipe must terminate at least 12
inches from the exhaust vent pipe and 2 inches
from the exterior surface of the outside wall. Attach the
combustion air inlet guard to the end of the combustion
air pipe. Using field-supplied mounting brackets, support
the combustion air pipe as needed.
Seal Wall Openings
Using an appropriate method, seal the wall openings
around the piping.
EXHAUS
T
COMBUSTION AIR
Horizontal Two Pipe Venting
Vent Connection Diameter
Exhaust Combustion
(MBH) (inches) (inches)
75-175 4 4
200-400 6 6
Horizontal Two Pipe Venting
Vent Length
Vent Minimum Maximum
Length (feet) (feet)
Horizontal 5 50