Attaching the CPU Fan

[ThunderBoyDavid]

i would say that this is a simple question... BUT... And let me say.. i am a Technician.. have been for the past 25 years. My question is about attaching a CPU Fan. Right now my main system is water cooled. i am wanting to build an ITX system... which would require a CPU fan.

It seems throughout all my years of building PCs... that every time i install a CPU fan.. i am always told that it's installed backwards. i don't get it.. i thought the fan only went on one way. Of course i haven't installed a fan in 6 or 7 years now...

What is the correct way to install a CPU fan? Please?
Thanks, David, ThunderBoyDavid

 

[CountMike]

Computer fans are brushless DC fans and can work only with correct +/- connections. In essence, they are poly-phase AC motors with a DC>AC electronic converter inside.
That's from electrical side. From mechanical side, it's best to position them so "go with the flow" of air inside the case that's most usually front intake and rear or top exhaust fans. On CPU cooler body, it's best to set them so they blow thru cooler fins and toward exhaust side of the case. All of that is for tower coolers of course, with coolers parallel to CPU you don't have a choice, they have to blow toward CPU and MB.

 

[smorizio]

thunder if you look at a cpu fan off the cooler or a case fan the vendor mark one side to show airlfow. if they dont then us tech have to power on the fan one time and see which way the air flows through the fan. flip a case fan one way and it sucking air into the case...flip it the other way then it blowing air out.

 

[CountMike]

Most fans have flow direction from free side to the side where it's motor mount is, in addition most also have an arrow to show flow direction.