I done removed my hard drive bay. Thing is huge with three slots. Looked like it was blocking air flow so figure why not.Has much as you want. Just make sure to a well balanced airflow - look into this. You want some fans pulling air in and a fan(s) pulling air out.
The loudest fan will be the cpu fan, I suggest you go aio if you want quieter sound.
That gap next to the fan on the right is where it was at.