"Sucker" fans have small grabbing blades on the back of a disk like a water pump. Pushers have a blade that we are used to seeing.
Soon enough we will see high efficiency 30 blade tubine fans that will be as quiet as a regular room fan that will pell from 100 to 500 cfm depending on the power. Only recently has the technology become cheap enough to mold these types of blades that we now see on commercial jet aircraft engines.
I can't wait