2x120mm fans necessary?

Gerrok · Post by **Gerrok** » Mon Oct 13, 2003 1:04 pm

This article on the AMD website says that it's not necessary to have a fan on the front and back of your case:

http://www.amd.com/us-en/assets/content ... _guide.pdf

The physics I remember support this, but it's been a while and I was never very good with fluids. What do you all think? Should I be looking for a case that has a 120mm fan in the back, along with a ATX power source?

On a seperate note, does the Antec P160 have space for 2x120 mm fans? I don't know why, but for some reason the way it's said it sounds like it only has room for one fan (kinda like the 'you get one pizza, and one box' routine)

http://www.antec-inc.com/pro_details_en ... odID=81600#

Thank you in advance.

Jan Kivar · Post by **Jan Kivar** » Mon Oct 13, 2003 2:05 pm

Gerrok wrote:This article on the AMD website says that it's not necessary to have a fan on the front and back of your case:

http://www.amd.com/us-en/assets/content ... _guide.pdf

The physics I remember support this, but it's been a while and I was never very good with fluids. What do you all think? Should I be looking for a case that has a 120mm fan in the back, along with a ATX power source?

Nowadays all new cases have mount for one "extra" fan in the back, usually for 80 mm fan. This is mainly because the .PDF from AMD's site. The .PDF says that the rear cooling fan is needed for "proper cooling".

More expensive cases (Chieftec, Antec, Enermax... basically every brand case) have better cooling options: two 80 mm/two 92 mm/one 120 mm in back and front also; depending on the model.

There is no easy way to say which configuration is better. The current trend is 120 mm fans.

Gerrok wrote:On a seperate note, does the Antec P160 have space for 2x120 mm fans? I don't know why, but for some reason the way it's said it sounds like it only has room for one fan (kinda like the 'you get one pizza, and one box' routine)

It's said like that because the case is sold with only one fan (the rear one). There is mount for a second fan in the front, but it's not supplied by default, so You'd have to buy it separately. In most cases (no pun intended

) the front fan is unnecessary.

Cheers,

Jan

CoolColJ · Post by **CoolColJ** » Mon Oct 13, 2003 2:42 pm

I think it's a waste of time myself.

I run a single 120mm fan on my heavily overclocked system in my Sonata, and have no cooling problems. but I have an exceptional cool running system/CPU

This single 120mm moves a ton of air as is.

Katana Man · Post by **Katana Man** » Mon Oct 13, 2003 5:59 pm

Gerrok, a single 120mm can move plenty of air. But us noise conscious people would prefer multiple slow running 120mm's so you can can't hear them.

An analogy might be 1 person yelling, "FIRE!! Everybody out" vs some authority personel calmly directing people to the exits.

GamingGod · Post by **GamingGod** » Mon Oct 13, 2003 6:12 pm

damn i havent seen katana around in a while

Katana Man · Post by **Katana Man** » Mon Oct 13, 2003 6:15 pm

I'm always here. Everyday. Looking for new items with the word "120mm" in it

. I just haven't posted a ton recently.

pangit · Post by **pangit** » Tue Oct 14, 2003 12:44 am

Katana Man wrote:An analogy might be 1 person yelling, "FIRE!! Everybody out" vs some authority personel calmly directing people to the exits.

Brilliantly bizzare analogy! I can just picture lots of little people running around inside my case trying to get out of the fan exhaust!

frosty · Post by **frosty** » Tue Oct 14, 2003 8:10 am

Ok then is a 120 mm panaflo fairly silent as an exhaust fan or is a silent conscience person better off with a 92 or 80 mm at reduced voltage?

Metaluna · Post by **Metaluna** » Tue Oct 14, 2003 9:05 am

One thing that hasn't been mentioned yet is that adding a front fan helps reduce the negative pressure in the case, which in turn reduces the amount of air (and dust) sucked in through cracks and crevices in the case (getting dust sucked into optical drives is not a good thing). If anything you want the front fan to have greater airflow than the rear one to account for the additional exhaust fan in the PSU, and also to overcome the restance of any air filters or HD's that might be positioned at the front air intake. If you aren't in a dusty environment then I'd still have a very low speed front fan just to move a little extra air over the HD rack.

bdunosk · Post by **bdunosk** » Sun Oct 19, 2003 4:55 pm

Metaluna wrote:... which in turn reduces the amount of air (and dust) sucked in through cracks and crevices in the case (getting dust sucked into optical drives is not a good thing).

Not to thread (er post?) crap, but I would think a case would have to be pretty air-tight to pull air through your optical drives. But I think you're right about neg / pos pressures. I would think balancing your in / out would reduce the amount of pressure needed to move a given amount of air. Less pressure = quieter fan, right?

Metaluna · Post by **Metaluna** » Mon Oct 20, 2003 12:34 pm

bdunosk wrote:Not to thread (er post?) crap, but I would think a case would have to be pretty air-tight to pull air through your optical drives.

I wouldn't have thought so either but I used to have a Yamaha CRW-F1 CD Writer which doesn't have an especially well-sealed tray. One day after several months of operation in my PC, I noticed that the blackish-grey tray seemed a little greyer than I remembered. I ran my finger over it, and sure enough there was a grey patch on my fingertip and a little trail left on the tray where the micro-fine dust layer had been wiped away. Shortly after that the drive developed power calibration errors and had to be sent in for service. I'm not sure if the problems were related but it's suspicious. It's also possible the deposits came from something inside the drive like a failing component.

I also have seen Liteon drives where if you open the tray door, you can see a ring of dust around the area where the front tray bezel comes to rest against the plastic faceplate. I assume that these are the larger dust particles that got trapped while air was being pulled into the drive around the tray.

But I think you're right about neg / pos pressures. I would think balancing your in / out would reduce the amount of pressure needed to move a given amount of air. Less pressure = quieter fan, right?

Yes that's a good point too...I don't know how noticeable the difference is though.

limee · Post by **limee** » Wed Oct 22, 2003 10:25 am

Metaluna, was your Yamaha CRW-F1 retail or oem? Have you ever thought of custom modding your drives with a thin gasket?

Frosty: Yes, IMO a Panaflo 120mm "low" at 5v is pretty quiet, I doubt you will notice it when your using your computer.

Metaluna · Post by **Metaluna** » Wed Oct 22, 2003 12:45 pm

limee, it is a retail drive. I have thought about adding a thin gasket however I couldn't find a gasket material thin enough so I never got very far with the idea, though I'm sure I could find something if I spent enough time on it. The closest I came was to locate some self-adhesive felt strips used as a light-sealing material for cameras, but I never tried it out.

CaptainSensible · Post by **CaptainSensible** » Wed Oct 22, 2003 2:38 pm

I have a 120mm fan on the side of my case which blows fresh air on the HSF/heatsink and stops it from recycling warm air; both fans run at reduced speeds and are relatively quiet. I don't use an exhaust fan because the 120mm creates enough pressure on its own to stop anything from being sucked in.

However, the 120mm fan does blow a lot of rubbish into the case! I don't consider dust a problem because the only things which would be affected by it (optical drives) are well away from any air movements. I strip down my PC and get rid of any dust (usu. on fan blades and trapped in heatsinks) every few months anyway. Dust is only a problem in things like printers etc; sealed components (HDDs) and PCBs aren't affected by the stuff.

bob670 · Post by **bob670** » Sat Oct 25, 2003 3:56 am

"also have seen Liteon drives where if you open the tray door, you can see a ring of dust around the area where the front tray bezel comes to rest against the plastic faceplate. I assume that these are the larger dust particles that got trapped while air was being pulled into the drive around the tray. "

I'll concur with that statement, I have owned several Lite Ons that exhibit this behavior. Far worse are the current Mitsumi/Matshitsa (sp?) opticals that Dell is shipping, it's as if they aren't sealed anywhere and just soak dust right out of the air. The service depot guys at my office are screaming about the drop in quality big time.

Post by **Ralf Hutter** » Sat Oct 25, 2003 4:26 am

bob670 wrote:"also have seen Liteon drives where if you open the tray door, you can see a ring of dust around the area where the front tray bezel comes to rest against the plastic faceplate. I assume that these are the larger dust particles that got trapped while air was being pulled into the drive around the tray. "

That's one of the nice touches of the Plextor drives: they have this nifty piece of thin felt-like gasket material around the drive tray door to seal off the insde of the drive when the tray is closed. A few of my Toshiba DVDrom drives have this too.

bob670 · Post by **bob670** » Sat Oct 25, 2003 2:13 pm

Yes, I had a Toshiba DVD drive that had that gasket, very nice touch.

Metaluna · Post by **Metaluna** » Mon Nov 03, 2003 8:02 am

Ralf Hutter wrote:That's one of the nice touches of the Plextor drives: they have this nifty piece of thin felt-like gasket material around the drive tray door to seal off the insde of the drive when the tray is closed. A few of my Toshiba DVDrom drives have this too.

I have an old Plextor 16x at work...it doesn't have the gasket, but it does have a raised ridge all the way around the tray opening, which seats in a groove in the tray door when it's closed. This seems to do the trick. I seem to remember that my ancient Ricoh MP-6200S 2X CDRW had one of those felt-like gaskets too.

energy · Post by **energy** » Fri Nov 07, 2003 12:48 pm

My LiteOn 40x buner has a gasket on the tray - keeps it nice and clean. My friend has the 24x version without a gasket and the tray itself where the CD rests has a grey coating all over it.

fractal · Post by **fractal** » Mon Nov 17, 2003 3:03 pm

bdunosk wrote:
Metaluna wrote:... which in turn reduces the amount of air (and dust) sucked in through cracks and crevices in the case (getting dust sucked into optical drives is not a good thing).
Not to thread (er post?) crap, but I would think a case would have to be pretty air-tight to pull air through your optical drives. But I think you're right about neg / pos pressures. I would think balancing your in / out would reduce the amount of pressure needed to move a given amount of air. Less pressure = quieter fan, right?

Yes and no.

Yes, you can if you can convince the right amount of air to follow the exact path you want it to go.

No, because you can't. Well, some people can, but they have advanced degrees in thermodynamics and have access to smoke chambers and infrared cameras and ...

The atx specification, dated as it may be, suggests that most cases are best cooled with exhaust fans and judicial placement of holes to allow fresh (hopefully cool) air to enter the case.

I have seen cases that cool well using the "all fans must be exhaust fans". I have seen cases that cool well using the "all fans must be input fans". I have seen no cases that work well using the "let's ballance input and output with cases in the front and the back". They just don't work.

I can not find the site that had the smoke chamber test on someones "ballanced" system that had the hot air from the video card "spinning in a vortex over the video card" and another very hot spot over the northbridge. It was at an european university where a professor got pissed off that his system kept crashing and decided to find out why. His solution was to remove the front fan. Processor temperatures went up a few degrees. northbridge temperatures dropped 30c. Crashes went away.

Honestly, if you are sucking dust into your cd drive, you don't have enough air intakes in your case. It really is that simple.

2x120mm fans necessary?

2x120mm fans necessary?

Re: 2x120mm fans necessary?