How should I set up my case fans?

[thepowerofdonuts]

Hi. I have a crappy old computer that I'm fixing up for my mom. I just have no idea how to set up the fans. I have room for 4 fans, all 80mm. There is one front fan at the bottom, 2 side fans, also pretty low, and a rear fan right below the power supply (the psu goes at the top in this case). Which fans should be intake and which should be exhaust?

 

[jpbg]

id say 1 back exhaust 1 side exhaust and 1 front intake(faster then the other two

 

[ausch30]

The front and side should be intake and the back exhausting along with the PSU. Having the side exhaust will make the air go from the front fan (in) to the side fan (out) without ever really cooling anything.

 

[royalcrown]

Don't really bother with the sides, ausch30 is right on the direction of airflows.

 

[Onus]

+1 @ausch30