Kurt Shafer here, the founder of Invisco and this web site. My involvement with the Australian hybrid rooftop invention started in 2015 when CSR Edmonds selected me to be their United States distributor for their hybrid rooftop ventilators. 

I created a new web site – https://EdmondsUSA.com – and called LorenCook reps all over the US. About 12 LorenCook reps signed on to be reps for Edmonds. another 12 or so Greenheck reps signed on as well. However, none of the reps had much success selling Edmonds. It appears that the performance of the Edmonds design was the deterrent. Edmonds engineers had made the decision to sacrifice powered air flow for free gravity air flow by motorizing the turbine instead of inserting a propeller blade. That fit the AEI design goal best because the AEI engineers were looking for pure gravity flow as you will see below in the “Stack Assist” description. 

I was fortunate to meet Edmonds and learn of their turbine. I then asked the Export Sales Manager, Alan Ramsay, for a license to build the hat in America. He informed me that Edmonds had no patent nor any other reason why I could not just take it and use it. He did, however, request that I not call it a Hurricane.  
 AEI engineers worked with ZimmerGunsulFrasca Architects on a University of Washington Molecular Engineering building in Seattle in 2011. The engineers scoured the world for the best rooftop ventilator and chose the CSR Edmonds ECOPower EP900 hybrid rooftop ventilator (the first one ever built) to help them meet LEED Gold in the design. The reason was that the Edmonds hybrid design combines the best of free gravity air flow along with optional powered air flow hence the term hybrid. This enabled the AEI engineers to create a hot air chimney that is heated by the sun light through windows in the sides of the 4 story chimneys that ventilate all 4 stories of the new building. Here is their description of this hot air chimney. This picture is one piece of the huge 8 foot long PDF created by the architect, ZGF.  

The Australian louvred rain hat (the “wind driven turbine” above) is the heart of that design efficiency.

Below is a picture of the Edmonds design. You can see that air can move up and out with no restriction. The AEI engineers recognized that the Americans had never progressed beyond the boxy rain hats that force the air to go down before it can go out. You can also see the small motor under the top. That motor is a special EC motor that has no magnetic force impeding it from rotating in the slightest breeze. But the result is that the motor cannot turn the louvre faster than a speed that pulls air in static pressure of higher than 0.11. As a result the Edmonds design is useless for most designs.

Below is a look at the positive effect of the Cook radiused edge and the Australian louvred top. This is a comparison between one of the top American firms, Greenheck, and the LorenCook performance and the Invisco Tornado performance under power and with free gravity air flow.   You can see that the Cook design offers significantly better air flow per watt of power than Greenheck but nowhere near the flow of the hybrid rain hat. And to the right below is the incredible performance in free gravity air flow. You can see the wind acceleration that was the most important feature for the AEI engineers. 

Today is 8-23-23 and I am communicating with Loren Cook II – President of LorenCook Company and grandson of it founder – to ask if he would like to license my patent pending hybrid rooftop design. If you like the idea of LorenCook Company being a source for this hybrid, please send me an email to kurt@invisco.com