Greenheck IG Installation, Operation And Maintenance Manual page 13

Installation of Two Pipe Venting –
Horizontal
Refer to the diagram below for venting on horizontal
concentric systems. Maintain at least 12 inches of
clearance between the exhaust pipe termination and
the exterior surface of the exterior wall (Dim. A).
The combustion air pipe must be a minimum of 12
inches from the exhaust pipe and 24 inches from the
exterior surface of the outside wall (Dim. B).
A minimum of 1 inch and a maximum of 48 inches
of building wall thickness is required for separated
combustion vent pipe.
A = 12 inch minimum
B = 24 inch minimum
C = 12 inch minimum
Pitch vent pipe
downward
from furnace
¼ inch per foot
Vent Connection Diameter
Vent terminals must be used. The optional vent kit
includes two terminals. Construct the vent system as
shown in the drawings and refer to the table for the
correct vent connection diameters.
Furnace Size Exhaust
(MBH) (inches)
75 - 175
200 - 400
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.
Vent Minimum
Length
Horizontal
1. 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.
®
Exterior
Wall
Exhaust
Vent
Terminal
B
A
EXHAUST
COMBUSTION AIR
Two (2) field-supplied
support brackets
Combustion
Air Inlet
Terminal
Combustion
(inches)
4 4
6 6
Maximum
(feet) (feet)
5 50
2. 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 combustion vent pipe and 24 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.
3. Seal Wall Openings
Using an appropriate method, seal the wall openings
around the piping.
INTAKE END
Exhaust Connection
(Model IGX)
C
Combustion Air Connection
(Model IGX)
Exhaust Connection
(Model IG)
DISCHARGE
END
Combustion Air Connection
(Model IG)
Model IG / IGX Make-Up Air
13