Industrial Rooftop Ventilation

Here is the highest performance rooftop ventilator in history – the Tornado – a HYBRID that offers both the highest performance free gravity air flow and optional powered air flow in one unit using the modern EC motor with infinitely variable speeds. 

Here is a comparison between the Tornado and the top 2 competitors in America, Greenheck and LorenCook.  You can see that the Invisco Tornado turbine rain top is better than any other design in the world. Air flows up and out without ANY restriction.

Here is the heart of the Invisco Tornado. You can see the 6 bladed propeller on the 1/2 horsepower EC motor – capable of pulling air in high static pressure applications. 

Here is a most important case study – the Los Angeles suburb Studio City – where 8  hybrids are used and Invisco is the only source.

The purpose of this page is to describe Australian rooftop technology that was used by Affiliated Engineers in Seattle to design a new 4 story engineering building for the University of Washington in 2012. AEI went to Edmonds in Australia because none of the companies listed above had the excellent free gravity air flow that Edmonds has.


This is the best example of the value of this Australian hybrid design- Affiliated Engineers working with ZimmerGunsulFrasca in Seattle chose Edmonds for passive draw in their stack – and since they could not quite meet the ideal draw they made use of the optional motorized air flow.