Information on fans? (physics)

[The Greek]

Hey I'm looking for some information on the physical properties of how fans work. I'm building a small grow box, not necessarily for weed even, for serious I might grow some citrus bonsais or something. But anyways I want info on how the pressure works, and the most efficient way to move air, and math formulas and general principles and shit. I don't need much info to complete my box but now I'm curious so I want to get an in-depth understanding that can be applied to small and large scale.

For instance, what would happen if your incline fan was less efficient then your output fan, and vise versa.

[Banned]

On a grow box air pressure isnt too critical so long as the input can compete with output of air, this is more important with a grow tent with flexible sides, so long as air is flowing and extracting surplus heat the rest is not critical.

[The Greek]

What happens with conflicting pressure rates in an enclosed environment? Does it cause extra tension on the fans?

[zombo.com]

Best case scenario, with a sealed room, you want negative pressure inside, so that all scent is definitely being pushed through your exhaust/filters. Normally this is accomplished with passive intake, and active exhaust. Or at least much stronger exhaust than you're intake pusher fans.

Sory i can't help you with the math, i'm more a trial and error type.

So far so good, no trial. :)

[Jerk.]

http://en.wikipedia.org/wiki/Fan_death

[Mantikore]

fluid flow can be pretty complex.

what do you mean by moving air efficiently? is that like, moving the most air with the least electricity or time or what? Assuming your box is sealed, the hole sizes you should leave for venting is determined by size and shape.