Right Way For installing Fans !

[Akash Sagar]

Hey guys
After searching alot i finally come to this place.
I m In confusion about installing fans.
ok so it is like that i have 3fans (80mm) two have molex output and one have 3pin output.
and my chasis dont have front and top option for installing fans, it has two on side and one on rear thats it.
now i want to know whether installing side ones as intake and rear one as exhaust will be a good idea or vice versa ?
or leaving rear vent empty ?i hope i found my answers here like always
thanks

 

[13thmonkey]

in at the side and out at the back. 80mm fans run off molex will be loud and not move a lot of air.

 

[Akash Sagar]

Another problem ...one of my psu molex is not working....now i left with one molex...should i use a connector ? i have pne which divide one molex into two...but will it be safe ?

 

[13thmonkey]

that will be safe, except for the fact that one of yours doesn't work and you really need to understand why.