2 fans stacked on top of each other blowing 1 direction?

[frldyz]

Has anyone tried putting 2 fans back to back. Both pushing air the same direction?

My case has an intake fan, but you cant see it from inside the case. The interior is red and black theme. Just wondering what would happen if I stacked another fan ( corsair AF 140mm red/black ) directly behind the non visable intake fan.

 

[inachu]

I've seen people do that just with the CPU in regular pc cases.

They stack fans like that in blade servers.