Greenheck Fan 470656 Installation of Concentric Venting General, Concentric Venting – Horizontal

Installation of Concentric Venting (General)

Concentric venting allows the exhaust pipe and combustion air pipe to pass through a single hole in the roof or wall of the building. A concentric venting adapter (CVA) is required for concentric venting.

The concentric venting adapter is designed for indoor installations and should never be installed on the exterior of the building.

The exhaust pipe must terminate with the vent terminal. For horizontal venting, the combustion air pipe must terminate with the combustion air guard. For vertical venting, the combustion air pipe must terminate with the inlet terminal. Depending on what was ordered, one of these vent terminals will be provided in the optional venting kit along with the concentric venting adapter (CVA).

If venting vertically through the roof, refer to the vertical concentric venting instructions. If venting horizontally through the wall, refer to the horizontal concentric venting instructions.

note

Vent piping is supplied by others and not supplied by manufacturer.

CVA-4	CVA-6
4-inch Concentric	6-inch Concentric
Venting Adapter	Venting Adapter

Combustion Air Connection	Exhaust Connection
Concentric Side	Concentric Side

CVA

Combustion Air Connection	Exhaust Connection
Non-Concentric Side	Non-Concentric Side

Top View

10Model IG / IGX Make-Up Air

Concentric Venting – Horizontal

Refer to the diagram below for venting on horizontal concentric systems. Maintain at least 12 inches from the combustion air inlet guard to the exhaust vent terminal (Dim. B). To prevent water from running into the combustion air pipe and to allow for easy installation of the combustion air inlet guard, the combustion air pipe must terminate at least 2 inches from the exterior surface of the outside wall (Dim. A).

A = 2 inch minimum	Exterior
B = 12 inch minimum
		Wall

Mounting
Bracket
	A	B
EXHAUST
COMBUSTION AIR		Exhaust
		Vent
		Terminal
Mounting
Bracket	Combustion
Pitch vent pipe downward	Air Inlet Guard
from furnace 1/4 inch per foot

Vent Connection Diameter

Vent terminals must be used (one vent 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 Vent		Concentric Vent
	Connection Diameter		Connection Diameter
Furnace	Exhaust	Combustion Air	Exhaust	Combustion Air
Size (MBH)	(inches)	(inches)	(inches)	(inches)
75-175	4	4	4	6
200-400	6	6	6	8

Vent Length

Refer to table for minimum and maximum vent lengths. The total equivalent vent length must include elbows. The equivalent length of a 4 inch elbow is

6 feet and the	Vent	Minimum	Maximum
equivalent length
	Length	(feet)	(feet)
of a 6 inch elbow
	Horizontal	5	70
is 10 feet.

1. 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).

2. Attach Mounting Brackets

Attach field-supplied, corrosion resistant mounting brackets to the CVA using corrosion resistant sheet metal screws.

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