Ventamatic CX36BD2SPD - Manual (Page 2)

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INSTALLATION INSTRUCTIONS
VERY IMPORTANT
Please read before attempting installation
The wooden fan frame is installed on top of the joists, and the shutters open up between the joists, so
the rough opening will be smaller than the fan frame size
Veins run lengthwise in 24-in and 30-in shutters, and width-wise in 36-in shutters
Center vein is stationary to allow no-cut joist installation
*For model CX36BD2SPD – The joist-in method may be used only if the joists are 24-in on center, or
greater, and if there is enough space between the involved joist(s) and any walls.
24-in FANS: DO NOT INSTALL IN AN ATTIC SMALLER THAN 1200 sq ft. This fan requires 8-10 sq ft of
NET FREE EXHAUST AREA, obtainable with (40) 4 x 16, or (15) 8 x 16 soffit or undereave vents, or
equivalent.*
30-in FANS: DO NOT INSTALL IN AN ATTIC SMALLER THAN 1800 sq ft. This fan requires 10-12 sq ft
of NET FREE EXHAUST AREA, obtainable with (66) 4 x 16, or (24) 8 x 16 soffit or undereave vents, or
equivalent.*
36-in FANS: DO NOT INSTALL IN AN ATTIC SMALLER THAN 3000 sq ft. This fan requires at least 14
sq ft of NET FREE EXHAUST AREA, obtainable with (85) 4 x 16, or (31) 8 x 16 soffit or undereave vents,
or equivalent.*
*When measuring vents for NFA, remember that louvers and screens cut down considerably on the
available free air – this can be factored in by measuring the length by the width of the open vent area
and dividing the resulting surface size in half.
DO NOT OVERSIZE YOUR FAN! Additional installation of exterior vents may be required to
provide sufficient Exhaust Area (NFA) for your fan to operate safely and effectively.
Remember – bigger is not better with Whole House Fans. A smaller fan that operates
efficiently will always be preferable to a fan that is too big for its application.
24-in 28 3/8 x 28 3/8
30-in 35 x 35
36-in 42 1/8 x 42 1/8
FINISHED OUTSIDE WOODEN FRAME
DIMENSIONS
24-in 27 3/4 x 28 3/8
30-in 31 1/2 x 33 7/8
36-in 39 1/4 x 35 5/8
OUTSIDE SHUTTER DIMENSIONS
24-in 28 x 26
30-in 32 1/4 x 29 1/2
36-in 34 x 37 1/2
SHUTTER ROUGH OPENING (L x W)