Invisco is now making the best gravity rooftop turbine ventilator in history – the Tornado. And we are making it in America. Edmonds in Australia proved this concept with their Hurricane. They ship them all over the world.
Above is a closeup of the vanes. Air flowing through the Tornado can flow right out through the vanes. And the air flow causes the head to rotate and that action actually accelerates the air flow when the blades start to pull air up. And any breeze will accelerate air flow even more. Here is data from tests showing the effect that even a light breeze has on accelerating air flow:
|Model||Throat||CFM in a breeze|
|6.8 MPH (Tested)||15 MPH (Estimated)|
To put the data above into perspective, note that the 900 would take over 1/4 horsepower to move 3700 CFM with no breeze!
Here are the models introduced in 2017. Other sizes available upon request to HT@inviscoIndustrial.com
|Model/Throat||Vane Height||Top Diameter|
|H300T 12 inch throat||7 in||20 in|
|H600T 24 inch||10 in||32 in|
|H900T 36 inch||16 in||44 in|
Here is the sealed stainless steel bearing – two are used under the turbine head and allow the shaft to be removed easily for shipment.
Traditional rooftops like those from Greenheck, PennBarry and TwinCityFan have flat tops that force the air to go down before it can go up. They do not take advantage of breezes. Below is the LorenCook design – they are proud to show their radiused throat top edge that improved their free air flow slightly.