Intake Fans on the bottom of case are VERY LOUD!

[Deanyo2k7]

Hi, I previously had 2 AF120's on the bottom of my "Element Gaming/Raidmax Hyperion mATX case", and I found that sleeved bearing fans shouldn't be horizontally mounted. So I went and purchased "Aerocool Dead Silence 120mm Blue LED Fan's" and they have a "Fluid Dynamic Bearing" so I thought they would be better. When I hold the fan about 1cm above where the fan goes, it is silent and there is a fair amount of airflow. But then when I rest it on the case, it is loud (Not vibration, it is the sound of air) and there is little to none airflow. Even without the dust filters on. Why is this, the case sits about 0.75" off the desk, so there is plenty of room underneath. Also, if I lift the case up so there is an open space under the case, it is the same

And no, the fans are not running at 100%. I'm using a NZXT Sentry 2 Controller, and even at 40% speed there isn't much difference.

I'm so confused right now. Please Help

 

[smorizio]

http://www.amazon.com/Cosmos-Pieces-Rubber-Mounting-Screws/dp/B00H9905KA
sometimes if you use metal screws you can squeeze the fan/scroud to much and the fans wont spin right or they hit the bottom of the case. sometime you have to use rubber or fan spacers to keep the fans off the bottom of the case.

 

[Deanyo2k7]

http://www.amazon.com/Cosmos-Pieces-Rubber-Mounting-Screws/dp/B00H9905KA
sometimes if you use metal screws you can squeeze the fan/scroud to much and the fans wont spin right or they hit the bottom of the case. sometime you have to use rubber or fan spacers to keep the fans off the bottom of the case.

Yes, I'm using the rubber screws that came with the aerocool. They are just like them. This is why I'm sooo confused.

 

[Deanyo2k7]

There is too much air pressure building up between the fan and the bottom of the case if you're using them as exhaust. If intake and still noisy, you'll need to cut some metal away to increase airflow even further to get rid of the noise, adding these:

http://www.performance-pcs.com/shakeproof-washer-for-120mm-case-fan-black.html

or flip them around and use them as intake (which would be a normal setup, as heat rises). The exhaust should be the top and back (even front and sides if needed), with the bottom just being intake.

The bottoms are intake (as stated in the title) this is why im so puzzled....

 

[Geekwad]

There is too much air pressure building up between the fan and the bottom of the case if you're using them as exhaust. If intake and still noisy, you'll need to cut some metal away to increase airflow even further to get rid of the noise, adding these:

http://www.performance-pcs.com/shakeproof-washer-for-120mm-case-fan-black.html

or flip them around and use them as intake (which would be a normal setup, as heat rises). The exhaust should be the top and back (even front and sides if needed), with the bottom just being intake.

The bottoms are intake (as stated in the title) this is why im so puzzled....

Yeah, sorry.....realized that after I finished writing it. Even still, same premise. Too much metal in the way. Need to open it up even further....you're probably hearing the air moving quickly through the holes.

 

[Deanyo2k7]

There is too much air pressure building up between the fan and the bottom of the case if you're using them as exhaust. If intake and still noisy, you'll need to cut some metal away to increase airflow even further to get rid of the noise, adding these:

http://www.performance-pcs.com/shakeproof-washer-for-120mm-case-fan-black.html

or flip them around and use them as intake (which would be a normal setup, as heat rises). The exhaust should be the top and back (even front and sides if needed), with the bottom just being intake.

The bottoms are intake (as stated in the title) this is why im so puzzled....

Yeah, sorry.....realized that after I finished writing it. Even still, same premise. Too much metal in the way. Need to open it up even further....you're probably hearing the air moving quickly through the holes.

That is exactly what it sound like, but there is barely any are moving through when i put my hand over the fan. And also, if i cut the metal and the clip the dust filters back on (they will still fit on with the metal cut) will the noise just go back up? They are like soft thin filters with almost microscopic holes

P.S - How would i cut the metal? 😀

 

[PsyKhiqZero]

If you weren't javing any issues with the old fans then i would just go back to those. I've never heard of sleeve bearing that needed to be installed vertically.

The AF fans are used in top mounted radiators and I have yet to have an issue with mine.

 

[Geekwad]

No, the noise shouldn't go back up. The much smaller holes won't produce near the level of turbulence (which is part of why you're not feeling the airflow you'd expect on the other side).

Cutting metal the fun way:

http://www.maxim.com/gear/pocket-blowtorch-cuts-through-steel-tec-torch-2015-11

But a keyhole saw with a fine metal blade would also work:

http://www.amazon.com/Stanley-15-275-4-WAY-Keyhole-Saw/dp/B00002X21R

But you may also want to have a coping saw blade on hand to get started:

http://www.amazon.com/Stanley-0-15-106-15-106A-Coping-Saw/dp/B00002X222/ref=pd_sim_469_2?ie=UTF8&dpID=31VpRCd5c2L&dpSrc=sims&preST=_AC_UL160_SR160%2C160_&refRID=01TZ3Y4BA0PM5TM97PNJ