Airwatts depend on the orifice size used,the standard is 2.85, however with diameter size changes,such as half in'' one inch'' one and a half '',etc,the air watt ratings,can change for the high side dramaticly,To put it into simpler terms,put a crevice tool at the machine end and see where these numbers go. 
   The dual cyclone set up works on the same principle 
 
       O.T.   
 It's just a big numbers game.[right Carmine]   
 150 cfm is not much airmovement. But will suffice in a vacuum cleaner..........