Greenheck Fan Outdoor Air Ventilator manual CURB MOUNTING NV-90 and NV-120, Assemble Roof Curb

Installation Instructions for:

CURB MOUNTING*

NV-90 and NV-120

*For installations using Greenheck's optional roof curb.

1. Assemble Roof Curb

Curbs are shipped knockdown and require assembly by others. Assembly instructions are also included with curb.

Assemble curb sections as shown using hex bolts and lock nuts supplied with curb.

Detail shown is typical for all four corners.

Roof Curb
	41/2
2. Locate and Cut Roof Opening	241/4
When locating unit, make sure there is room to access unit
from all sides. Make sure inlet of this unit is located well
away from exhaust fans.	Recommended
405/8
	Roof Opening
Roof Opening for NV-120 and NV-90 = (A) 36" x (B) 36"	(36"x36")
	1031/2
3. Install Curb
Located curb over roof opening with dimensions shown to
the right and fasten in place.
	431/4
Check that diagonal dimensions are within
± 1/8" of each other and adjust as necessary. Shim as
required to level.
A	813/16
B

4. Install Ductwork

DThe following chart shows the duct sizes and straight

Roof Opening		lengths recommended for optimal performance (AMCA
		Publication 201-90). Using duct sizes less than
Ductwork		recommended lengths will affect fan performance. Good
by Others	C	duct installation practices should be followed for the
Roof Curb		remaining ductwork.
		Duct Locations:
			A	B	C	D	Straight
							Duct Length
		NV-90	24	93/8	24	301/4	81
		NV-120	26	91/2	26	291/4	96

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