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Aura Gravity Ventilator | 20″ Diameter 6″ Tall Collar AV-20-C06


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Gravity Ventilator - Aura Ventilator AV-20-C6-angle
Gravity Ventilator - Aura Ventilator AV-20-C6-cut-away-measurements

Basic dimensions of the Aura Vent 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:

6 in.
15.2 cm.

Height of Flange:

0 in.
0 cm.

Total Height with Collar and Flange:

15 in.
38.1 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 signature “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.
15.9 cm.

Louver Height (outside):

6.25 in.
15.9 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:

0/12 - 0°

Maximum Pitch Capacity (Standard Vent):

5/12 - 22.6°

Maximum Pitch Capacity (Modified):

12/12 - 45°

Free Air Space:

314.2 sq. in.
2026.8 sq. cm.

Free Air Space:

2.1817 sq. ft.
0.2027 sq. m.

1:150 Ventilation Rule:

654.5 sq. ft.
60.805 sq. m.

1:300 Ventilation Rule:

1309 sq. ft.
121.61 sq. m.

The Venturi effect 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

Installation Guides Under Development. Coming Soon.

Our Aura Vents have UL Certification. Check out other details and specifics on

UL Product IQ™ (Note: UL now requires you to have a free account to access this page)
UL’s Online Certifications Directory.

Texas Department of Insurance - Letterhead

Link to TDI Approval Document, from their web site

Texas Department of Insurance - Evaluation Program

Texas Department of Insurance - Aura Vent Chart

Click the Logo to see the full documentation of Active Ventilation Products approvals on the Florida DBPR web site.
Florida Approval

Active Ventilation Products Aura Vent series has been tested and approved by the State of Florida

Actual Package Weight 24 lbs
Dimensions 26 × 26 × 16 in
UPS Dimensional (Billable) Weight 78 lbs

Active Ventilation Products

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This Aura Gravity Exhaust Ventilator has a 20 inch in diameter opening to the attic or plenum. It also has a 6 inch tall collar. Model number AV-20-C06 has 314 inches of net free area (NFA) and comes with a 26″ x 26″ square shaped flange.

Aura Gravity Ventilators of 16 inch in diameter or larger are considered commercial sized. For those who are looking to ventilate their homes, they are encouraged to view roof vents that are smaller in diameter. Typically vents that are 14 inch in diameter or smaller are recommended.

When exhaust vents have a 6 inch tall collar like this vent does, or greater, (8 inch, 12 inch) they are typically used for flat or low slope roofs. Most roofs have a pitch to them, even roofs that are considered flat. For this exhaust gravity vent to work efficiently, it should be installed on the upper portion of the low slope roof since warm air rises. This particular gravity vent can go on a 0/12 to 5/12 pitch roof. For roofs that are pitched at 6/12 or greater, please notify the sales department when ordering your vents. All vents can be modified to operate up to a 12/12 pitch, even though it would not recommend putting an exhaust vent of this height on such a steep pitch.

The Aura Gravity Ventilator works like a roof turbine but with no moving parts.

Aura Gravity ventilators rely on the Venturi Effect (the creation of an upward draft) when wind blows against the outer louvers.

Even the smallest breeze can create exhaust ventilation so that air is drawn out of the gravity vent. This movement of air is proportional to the wind speed, and is measured in cubic feet per minute (CFM). Wind speeds of 11 mph for a 20 inch Aura Gravity Ventilator, produces 881 cfm of air exhaust for attic ventilation.

Aura Gravity Vents are UL Listed and rated up to 50+ PSF or wind pressure above 200 MPH.  Certified by Texas Department of Insurance, Florida State Approved & Conforms to the Standards of CALFIRE.