I have a fractal design arc mini which has 3 fans, 120mm in front and rear, and a 140mm top fan. I was wondering if I should add a side fan in the case, if so I can do either 120 or 140mm. I don't overclock and have a i7-3770. I don't have a separate graphics card yet but will be adding one soon.
More aboutshould side case
If your temps indicate that you need another fan, then add one. If not, then you're better off without the additional noise.