Where to put case fans for old case, exhaust or intake ?


Jan 9, 2018
Hello all, I made this beautiful image below using my great Photoshop skills and soul of an artist.
Issue is, I have old case (according to QC stamp it is from 2008, i think I may have gotten it 1 year later). I have changed insides completely 2 times already , currently below there is my current setup.

To explain in a bit of detail:
The picture in general is artistic representation of my case
Colored in green is my motherboard.
I have added approximate position of 3 of my main components CPU, PSU and GPU. Each of them have their dedicated fan in yellow color.
While inspecting case I have found 3 places to put fans in. (marked with beautiful sky blue)
If I put one in back of case it is directly in front of my cpu, maybe ~2cm from it with little shift.
There is also place for side fan, that is partially in front of my large cpu fan. I think originally it had some plastic tubing connecting it to CPU fan, when it was stock one.
I also noticed small fan place in front of case, but is directly next to my hard drives and in front of it just front of case, however below part of case seem to have opening, so as bottom part of front, so that could be used for intake of air and dirt from ground.

I have cannibalized 2 old PSUs and currently have one working PSU fan, I am thinking about adding it somewhere in case. I am planning to add it in side as exhaust fan, however I am also planning to possibly add some more fans to get most of my system.

Take note, this system never had any case fans !

Any ideas ? Comments ?