Air Circulation Fans

I try to build a personalized fan that will suck the hot air out of my laptop. I know there is a cooling block there but I just love to do a DYI so I try to do.

How can I change the normal fan (the one breath of air) to a fan airflow (one that sucks the air out)

just get a real fan who downwoods blows. and suddenly it was the left or right timber, it will block the heat, but you should do in the moring when theres not much heat becuse he could blow hot air at the