There's a paper published by sheerwind, detailing the principles of operation - http://sheerwind.com/wp-content/uploads/sheerwind/2012/10/Allaei-Andreopoulos_AS

There's a paper published by sheerwind, detailing the principles of operation - http://sheerwind.com/wp-content/uploads/sheerwind/2012/10/Allaei-Andreopoulos_ASME-ES-FuelCell2013-18311.pdf http://sheerwind.com/wp-content/uploads/sheerwind/2012/10/Al.... There's no mention of any valves, too. But there's a more interesting claim they make: "(...) INVELOX captures the wind kinetic energy and uses the pressure differentials to increase the kinetic energy available to a turbine". I wonder how they manage to increase the kinetic energy of air flow without any external energy source.