But none of the fans say on them which way the air will flow. So is there anyway to tell which way the air is going to go?
Usually the main sticker on the front indicates that it will be drawing/pulling air through the fan from the sticker side.
It's easy to check this by hooking one up and feeling the airflow for yourself.
Because this is a new build I was wary of putting any power through it until everyone was hooked up.