Sorry, the reason I ask is because on most research I've done there seems to be two arguments. On one hand some say that two fans, in parallel, with the same capacity to move air will only move that amount of air. On the other hand some say that fans in parallel of the same capacity will increase their efficiency and create a sort of exponential growth in the capacity of air they can physically move, but by only a small amount.
I would appreciate if you could provide additional information, links to articles or anything like that.