Dual fans

[De Joker]

Will it make a big difference in airflow if i put 2 identical fans on top of each other, and if so how much gain can i expect as compared to only one fan (maybe 1.5x).

[Szech]

There's a good article here:
http://www.overclockers.com/tips336/

Essentially, you don't get a lot from stacking the fans. You get optimal results from stacking fans that spin in opposite directions, but even then, the gain is minimal.

[djurom]

I've tried that and I got ~2 deg but the noise was horrible. When I turned on the switch it was like I'm firing up F-15.

[Mykex]

I did alot of fooling around with that idea and the best flow came whan I spaced the fans apart from one anouther in a sealed duct. The space was about equal to the width of the fans and it wasn't as loud but did increase the volume.

[De Joker]

Thanks for the replys guys, i think i will try it with some space between the 2 fans. Also i am not gonna use it on a heatsink but as an exhaust fan for my case.