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Aura Attic Fan | CFM: 3300 20″ Diameter 12″ Tall Collar AF-20-C12


  • Optional Fan Controls

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Brand: Active VentilationUPC(GTIN): 843951001463 SKU: AF-20-C12 Category:
Attic Fan - Aura Fan AF-20-C12-side

Drawings for Aura Attic Fan are available Here

Basic dimensions of the Aura 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:

20 in.
50.8 cm.

Outside Diameter:

25 in.
63.5 cm.

Square Flange (side length):

26 in.
66 cm.

Height of Head:

9 in.
22.9 cm.

Collar Height:

12 in.
30.5 cm.

Height of Flange:

0 in.
0 cm.

Total Height with Collar and Flange:

21 in.
53.3 cm.

Louvers are the vertical openings in the vent, which facilitates the flow of air, while keeping animals, insects, debris, and embers out.  The combination of inner and outer Louvers on our patented “Aura” series of vents and fans are shaped to create a positive vacuum effect which draws air out of the vent, utilizing a physical principle known as the Venturi effect.

Louver Height (inside):

6.25 in.
15.875 cm.

Louver Height (outside):

6.25 in.
15.875 cm.

Size of opening btwn blades (inside):

0.125 in.
0.3175 cm.

Size of opening btwn blades (outside):

0.25 in.
0.635 cm.

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:

314.2 sq. in.

Free Air Space:

2.182 sq. in.

1:150 Ventilation Rule:

654.5 sq. in.

1:300 Ventilation Rule:

1309 sq. in.

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:

436 CFM
Airflow in 6.4 KPH Wind: 12.35 CMM

5.2 MPH Wind:

462 CFM
Airflow in 8.4 KPH Wind: 13.08 CMM

7.4 MPH Wind:

685 CFM
Airflow in 11.9 KPH Wind: 19.4 CMM

9.8 MPH Wind:

771 CFM
Airflow in 15.8 KPH Wind8: 21.83 CMM

11 MPH Wind:

881 CFM
Airflow in 17.7 KPH Wind8: 24.95 CMM

AC Motor Horsepower:

3/4 hp

Max Amps:

10.5 A

Motor Type:

PSC - Open Ventilation

Airflow With Fan:

3300 CFM
93.4 CMM

Fan Blade Count:

4 Blades

Fan Blade Diameter:

18 in.
45.72 cm.

Installation Guides Under Development. Coming Soon.

Aura Fan, Roof Mounted Exhaust Fan 120 cfm, 20″ diameter Roof Vent with a 12″ Collar Height and 26″ x 26″ Square Flange

This attic fan / roof fan EXHAUSTS CONTINUOUSLY whether the electric motor is ON or OFF. When the fan is off, outside air moving against the Aura Ventilator causes the Venturi effect, thereby creating an exhaust. The exhaust is created without the use of electricity or moving parts. On the days when the fan is not needed, the Aura Vent will still operate passively; this increases the life of the motor since it is not in constant use. The Aura Fan Ventilator reduces energy consumption.

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.

Actual Package Weight 45 lbs
Dimensions 26 × 26 × 26 in
UPS Dimensional (Billable) Weight 127 lbs

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