The Aura Gravity Roof Ventilator removes heat from the attic in the summer and in the winter. This allows for year-round ventilation. It functions like a spinning roof turbine but without any moving parts. Aura Gravity Ventilators rely on the Venturi Effect when wind blows against the outer louvers. As a result, this creates an upward draft allowing air to freely flow in and out of the vent. 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).
The Aura Gravity Ventilator also ventilates the roof through “The Stack Effect”. This is when hot air naturally rises out through the roof vents.
The Collar Height is the height of the neck of the vent.
Net Free Area
in Sq. In.
The 1/8 inch louvers are designed to prevent rain, snow, insects and animals from entering inside the vent.
The Aura Gravity Ventilator comes in an array of diameters and collar heights allowing for installation in any climate zone. See the Climate Zone Chart to determine the proper collar height for installation in your area. In other words, this vent can be used for both flat and steep sloped roofs. It has been engineered to be used for both residential and commercial buildings. However, if you are looking to ventilate a duct, we offer vents with a tailpipe adapter. On the other hand we also have Static Vents with curb mount flanges to be installed on roof curbs.
As you know by now the Aura Gravity Ventilator uses wind to help exhaust out hot attic air with no moving parts. Here is a deeper explanation on how this gravity ventilator accomplishes this function. To start, when wind enters the outer row of louvers, the angle of the louvers causes the wind to spin around the circumference of the gravity vent. Spinning air creates suction towards the center of the vent. This suction creates the necessary vacuum to extract out the heat and moisture from the attic. This function is demonstrated by the animation above. Air flow ratings were documented by Georgia Tech.
Aura Gravity Ventilators are made up of aluminum, making them durable, lightweight and will not rust. Gravity ventilators can be painted by our durable powder coating system, see our color options powder coat colors.
The diameter size of all roof vents determines the Net Free Area, also known as the "NFA". NFA is the measured amount of opening each vent offers at each specific size. to be available for venting air through a specific vent size. The calculator below will find the overall number of vents needed to effectively ventilate the targeted attic space.
Once you have the area, pulldown to select the specific vent diameter to show the number of vents of that size which would ventilate the specified area with both 1/300 and 1/150 rule.
The roof vent calculation values shown above are for the exhaust portion of the roof. The same amount of net free air inches is needed for air intake as well. Proper roof ventilation consists of 50% air exhaust and 50% air intake.