The Aura Gravity Exhaust Ventilator has a 30 inch in diameter opening (throat) to the attic or plenum, it also has an 8 inch tall collar that provides an 8 inch clearance between the roof and the gravity vents louvers. Model number AV-30-C08 has 706 inches of net free area (NFA) and comes with a 40″ x 40″ square shaped flange.

Aura Gravity Ventilators size of 30 inches is considered an industrial sized roof vent. For those who are looking to ventilate their residential home, they are encouraged to view roof vents that are smaller in diameter. Typically roof vents that are 14 inch, 12 inch, 10 inch and 8 inch in diameter are commonly used for residential attic ventilation.

When exhaust vents have an 8 inch tall collar or greater, they are typically used for flat or low slope roof applications. Exhaust gravity vents work best when installed on the upper portion of the low slope roof since warm air rises. The Aura Gravity Vent can go on a 0/12 to 5/12 pitch roof for zones 1 through 6. For roofs that are pitched at 6/12 or greater, please notify the sales department when ordering your roof vents. All Aura Vents can be modified to operate properly up to a 12/12 pitch, even though it would not be recommend putting such a tall exhaust vent on such a 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 30 inch Aura Gravity Ventilator, produces 1,692 cfm of air exhaust for attic ventilation.