i bought a new 125mm fan to reaplace my old broken 120mm
so i bought a new door to my case (Chieftech), now i wonder whether i want to put a big square window and stick the fan inside the window, or make a smaller round window, and stick the fan inside the door next to the window...
thx, alex

id get the big win and put it in the middle of that but its your case do whatever you think would look good

you could make the window around the fan.
if you have a black fan it might not look so good to have it in the window. it you keep a piece it the case in front it might look good.
check the case gallery. there are always a lot of good ideas there.
see what you like.

i'd do it next to the window