Direction of case fans on an SX830.

[GusS]

Are the front fans supposed to be intake fans and the rear ones exhaust?

 

[DoOLiE11]

the front ones are intakes

and the back ones are exhaust

 

[danii8]

Usually, unless you have special setting.
If you did not mod your case(someting like side-intake),
front-intake and rear-exhaust will be better.