I know it's bad for the air flow but what if i only have 1 fan that is extracting air and nothing is pushing it in? tried to install the other 1 but my PSU is too big and it just won't fit in there, will it be a good idea to remove the side of the case?
if you only have 1 fan then you need the case closed. of you wont get air flow across the board. you will just pull air from directly in front of the fan and not through the case.
best you save up 40-50quid and buy a basic gaming case with at least 2 120mm fans...
coolermaster do some great basic cases that will work well with the setup you have.