Ventilators Made in America

In 2016 Kurt Shafer proceeded to improve on the ECOpower design. This resulted in the Invisco Industrial Tornado model line with the same model numbers and the same form and fit with a few functionality enhancements. See them at http://inviscoindustrial.com/

THE CHALLENGE

Hybrid rooftop ventilators were invented by Edmonds in Australia and have been designed into buildings all over the world. The University of Washington in Seattle is an excellent example. But the engineers at AEI were forced to derate the Edmonds EcoPower EP900 from 5,885 CFM to just 2500 CFM due to the poor performance in the predicted static pressure. The challenge for Kurt was to duplicate the value of the hybrid concept while improving performance at higher static pressures.

PERFORMANCE ENHANCEMENTS

  • The Tornado has a high performance propeller with 8 blades at a 50 degree angle
  • The motor is an electronically commutated brushless DC motor and all models work with 0-10 VDC speed control common to most building control systems.
  • The EP500, a 20 inch throat, pulls 6,320 CFM at 505 watts power and this air flow drops just 10% when static pressure rises to 0.1 inches water.
  • The turbine is 20% taller for enhanced gravity air flow.


GRAPHIC EXAMPLE OF THE VALUE OF USING A PROPELLER

Below is a graph of the high performance blade in a 20 inch throat. It has significant air flow (over 50%) at 0.5 SP. Note that the air flow is over 6000 CFM in a throat that is much smaller than the 36 inch diameter Edmonds EP900 that pulls 5885 CFM.


THE PROBLEM WITH MOTORIZING THE TURBINE

Below is a graph of the performance of the Edmonds EcoPower EP900. The air flow at full speed is 5,885 CFM through the huge 36 inch diameter throat at zero static pressure. The air flow drops off fast when there is any static pressure. That is the result of using the turbine to move air.