Which side is up with a case fan?

I have a couple of Logisys 120mm clear case fans. I am trying to
determine which side is "up", so to speak. On black case
fans there are arror markers to tell you which direction the fan
turns and the direction of the airflow. There is no morkings on the
clear fans. Am I just missing the obvious and I should just connect
them and feel which way the wind blows? I must caution that I did
try that and the temp inside the computer got up to 159F before there
was a flash nd a bang and the power supply blew. Luckily the
motherboard seems to be OK. I built the computer myself (it is the
10th one , I think) ,but this is the first time I built one for
myself. I built or modified computers for family and friends, but I
was building my ultimate computer, with the clear view side, cool
(literally) lights and as many fans as I could reasonably cram into
the case. Some of the fans were the lighted kind Hey, I should be
able to have a little bling bling in my computer if I want. Anyway, I
learned about positive case pressure and stuff like that after the
blow up. What I need to know is how to determine which side of the
fand to use.
Any help would be most appreciated !

no.RemoveThis@spam.invalid (DBMaster) wrote:

>
> I have a couple of Logisys 120mm clear case fans. I am trying to
> determine which side is "up", so to speak. On black case
> fans there are arror markers to tell you which direction the fan
> turns and the direction of the airflow. There is no morkings on
> the clear fans. Am I just missing the obvious and I should just
> connect them and feel which way the wind blows?

Unless your fan blades are flat, the scoop of the fan blade
indicates airflow direction.