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RBF-06-C04 | Round Back Attic Fan | 6″ Diameter, 4″ Collar

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  • Optional Fan Controls

    • 20 $
    • 60 $
    • 100 $
  • All our aluminum products can be painted with a durable baked-on powder coating surface finish.

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    • 7 $
    • 14 $

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Brand: Active VentilationUPC(GTIN): SKU: RBF-06-C04 Category:

Installation Guides Under Development. Coming Soon.

Basic dimensions of the Round Back Attic Fan and it’s identifying attributes. Primary identifying dimensions of vents and fans are the inside diameter of the Head, which equals the diameter of the hole being vented, and the height of the Collar which is the solid tube between the Head of the vent and the Flange which attaches to the roof.

Inside Diameter:

Outside Diameter:

Square Flange (side length):

Height of Head:

Collar Height:

Height of Flange:

Total Height with Collar and Flange:

Expected snow and rain in your region and the pitch of the roof are the key consideration when choosing the height of the collar of your roof vents. Zones 1 and 2 are not expected to sustain significant snow packs, while zones 3-7 are likely to experience snow, possibly for weeks or months. Vent collars under 4 inches are inappropriate for flat (0/12 pitch) roofs because even heavy rain can splash water into a shorter vent.

Map of Climate Zones

Minimum Pitch Capacity:

Maximum Pitch Capacity (Standard Vent):

Maximum Pitch Capacity (Modified):

Free Air Space:

Free Air Space:

1:150 Ventilation Rule:

1:300 Ventilation Rule:

When the Fan is OFF, the Venturi effect is stimulated by even small breezes creates a positive movement of air out of the vent without the need of any part of the vent to move. This movement of air is proportional to the wind speed, and can be measured in Cubic Feet per Minute or Cubic Meters per Minute.

4 MPH Wind:

Airflow in 6.4 KPH Wind:

5.2 MPH Wind:

Airflow in 8.4 KPH Wind:

7.4 MPH Wind:

Airflow in 11.9 KPH Wind:

9.8 MPH Wind:

Airflow in 15.8 KPH Wind8:

11 MPH Wind:

Airflow in 17.7 KPH Wind8:

AC Motor Horsepower:

Max Amps:

Motor Type:

Airflow With Fan:

Fan Blade Count:

Fan Blade Diameter:


6″ Diameter Round Back Attic Fan, constructed of durable, rust-free aluminum with a 4″ Collar Height and 12″ x 12″ Square Flange. This attic fan / roof fan EXHAUSTS CONTINUOUSLY whether the electric motor is ON or OFF. On the days when the fan is not needed, the Round Back Attic Fan will still operate passively. The model RBF-06-C02 has 28 square inches of Net Free Air Space. It is best used for 3/12 up to 12/12 roof pitch. Powder-coating is available in a wide variety of colors. The Inner louvers prevent the entry of rain, snow, insects and birds, while allowing the air to flow with no resistance. The 1/8th inch opening between the louver blades and all aluminum (“noncombustible”) material meets the requirements of California building code 706A.2 Vents to resist the intrusion of burning embers and flame through ventilation openings.