Ruck Air Movement Prime Evo EC Mixed Flow FanGreater Efficiency. Higher Performance Ruck Air Movement develops highly efficient solutions for ventilation applications. Together with an outstanding aero efficiency, the use of brushless DC motors ensures the highest overall efficiencies, which show their strength especially in the partial load range. EC motors are permanent magnet motors in which the unit is electronically commutated. This commutation electronics uses a rectifier to convert the AC