case fan direction

watermelon · Post by **watermelon** » Tue Apr 25, 2006 1:38 pm

today i was tinkering with my computer and i took the case fan out. unfortunatly i cant remeber which way round it goes

does its blow hot air out, or cool air in?

the fan is not my mobo heatsink fan, just a secondary fan attached to the case which faces towards the mobo processor.

Post by **marshallh** » Tue Apr 25, 2006 1:49 pm

Depends on where the fan is. If it's on the back (next to expansion cards) you want it blowing out.
If it's in the front, it should be blowing inwards. Otherwise, you would essentially creat a vaccum in the case (not good).

Post by **gannon** » Tue Apr 25, 2006 1:55 pm

Well, the proper way is to put a filter between the fan and the case and have it suck air into the case.

timmeh87 · Post by **timmeh87** » Tue Apr 25, 2006 2:32 pm

only if theres other fans blowing out, or no other fans.

watermelon · Post by **watermelon** » Tue Apr 25, 2006 6:58 pm

the fan is on the side of the case direcrtly oposit the processor. the processor also has a fan alough i dont nkow whever that sucks or blows down the heatsink.

the psu is blowing out of the case.

this means that ATM i have the psu blowing out, the sidefan blowing out and i presume the cpu heatsink blowing out (sucking throug the heatsink).

is this correct?

feels a little hot, not sure if thats paranoia though

timmeh87 · Post by **timmeh87** » Tue Apr 25, 2006 7:57 pm

the fan on the side should be blowing in then. right now the air is not really moving anywhere, the fans are working against each other.

elliott · Post by **elliott** » Tue Apr 25, 2006 9:12 pm

watermelon wrote: i presume the cpu heatsink blowing out (sucking throug the heatsink).

Most blow towards the heatsink. I have only seen a few slotted PIII Dells that have it sucking past the heatsink with some wierd ducting.

My rule is lower fans are intake and upper fans are exhaust, since of course heat rises. I have 2 intake in the lower front panel, one intake low on the side and three exhaust on the back including PSU. I will be adding some ducting soon to try to improve flow a little more. My case temps are 35C and the overclocked CPU is running a 51C at full load, I would like to see closer to 30C and 45C with the ducting.