slk 900-fan blowing up or down?-can i mount a 120mm on it?

aowen512 · Post by **aowen512** » Wed Jun 29, 2005 5:09 pm

i read that its best to suck air up but i wanted to get a confirmation from you guys before i resit the heatsink etc to find out

i currently have it sucking air up, but what if i turned it to blow air down? would i lose performance, gain, or stay about the same

i have a 92mm TT fan on it(loud) but it blows about 47 cfms

slk900 w/ as5 on a tbred 2600+ @ 2.4ghz
temps = idle 37-47 load

my second question was is there a way to mount a 120mm fan straight to it without getting one of those conversion kit things (either a diy kind of thing or bending the braces or something like that) if there is not i guess ill just buy a conversion kit

just let me know if you need to know more or you can check my sig to help as well

D235hadow · Post by **D235hadow** » Wed Jun 29, 2005 5:25 pm

It's been a while since I read anything about the slk's but everything I saw indicated better performance with the fan blowing down. This would also add airflow over your nb and mosfets. My fan blows down. I tried it briefly sucking air off the heatsink and found that there was a slight increase in cpu temps, a large increase in mb temps, and an increase in fan rpm (it's a fixed speed fan).

To answer your second question, yes, as long as it's a 25mm thick fan. Use the mounting clip holes just above the set you are using for your 92mm fan and you'll find that the clips fit over the sides of a 120mm fan nicely. However, you'll definitely want the fan blowing down since otherwise there will be nothing holding the fan blades away from the heatsink.

Shadowknight · Post by **Shadowknight** » Wed Jun 29, 2005 6:44 pm

I've tried a Nexus 120mm on it, and I saw no advantage over a 92mm.

frostedflakes · Post by **frostedflakes** » Wed Jun 29, 2005 7:22 pm

I also saw the best results on an SLK-900A with the fan blowing down.

Flo-Job · Post by **Flo-Job** » Wed Jun 29, 2005 7:49 pm

The advantage of a bigger fan is, that the same amount of air is moved with lower rpm, and therefore lower noise. The frequency of a bigger fan's noise is usually lower, which makes a more pleasant noise to humans.

Flo

frostedflakes · Post by **frostedflakes** » Wed Jun 29, 2005 7:57 pm

But wouldn't the larger deadspot (caused by motor hub on the 120mm) negate any possible advantage to the higher CFM/dBA ratio.

Shadowknight · Post by **Shadowknight** » Wed Jun 29, 2005 8:02 pm

frostedflakes: yeah, that was my experience. Most of the bigger fan blades were blowing AROUND the heatsink. The XP-120 is made so that it "catches" the air from all sides of the fan, the XP-90/900U/etc. miss the extra air, and have a bigger deadspot accordingly. Thus, it works out to not provide any benefit vs. a 92mm. Actually, it may have increased temps vs. a 92mm, but it's been a couple of months and I can't remember if that's true or not. Definetly no advantage over the smaller fan though.

aowen512 · Post by **aowen512** » Wed Jun 29, 2005 9:35 pm

well with a 80-120 or 92-120 air duct converter... wouldnt that center the airflow better?

i will try reversing the fan prob tomorrow and post my results. i havent ordered the medium speed yate loons yet so i cant try with 120 nor do i have a converter duct so that will be for the future

thx for the replies keepum coming!!

~ARO

frostedflakes · Post by **frostedflakes** » Wed Jun 29, 2005 9:39 pm

Yes, with a converter/extender it should work much better.

aowen512 · Post by **aowen512** » Thu Jun 30, 2005 10:21 pm

after reading reviews on other forums on the slk900 it was about half and half on fan direction, but most people suggest using it blowing down as long as there are no hot components creating hot air around it.. which i do not so when my aerogate 3 comes in im going to put the therm on the cpu and while resitting the hs ill switch the fan and post

thx guys

aowen512 · Post by **aowen512** » Sun Jul 10, 2005 9:02 pm

ok ive got my medium speed yate loons in

i took off the 90mm on my slk900 on put the 120 yl on it blowing down first. the temps would get up to 56C and that is where i have my alarm sets so i would stop playing some cs source and temps would drop

i then tried it with air sucking up and it hasnt gone past 50C now

with the case i have and the room i have a conversion kit from like 80-120 will not work so i just bent the clips and what not a lil bit and just kind of made it work.. im thinking about going back to the 90mm though because i had alot better performance

the way i have the 120yl mounted is not centered because of space issues

|----------------|
|[~~~~~~~]|
|[~~~~~~~]|
|[~~~()~~~]|
|----------------|
|----------------|

above is a very bad drawing but basically |--| denotes fan hanging over the hs, [~~] denotes the hs itself, and () is center of fan

im guessing becasue it is not centered that prob lowers performance, i cannot center it because i cannot move the fan higher up because it hits the psu