Looking for opinions on my fan options.

[AndyBogard]

I am looking for opinions on what would be best with my setup. I have a Nzxt Lexa Case, it has a 120mm front intake, a 120mm side intake, a 120mm rear exhaust, and a top 80mm exhaust. Also my system is an SLI system using an ASUS A8N32 SLI, Athlon 3700+, 2 Gigs of Corsair XMS PC4000, and 2 EVGA 7900GT CO Superclocked. I am looking for the best in cooling potential, but also don't want it to be too noisy.

Fans I have:

3 x Yate Loon 120mm fans @ 47CFM
3 x Sunon 120mm fans @ 90CFM
1 x Panaflo 80mm @ 39CFM
1 x Panaflo 80mm @ 47CFM
1 x Vantec Tornado 80mm @ 85CFM
1 x Vantec Tornado 92mm @ 120CFM <---For XP90
1 x Panaflo 92mm H1A @ ? <--------For XP90, currently using this one
1 x Panaflo 92mm U1A @ ? <--------For XP90

I am currently using the 3 Yate Loon 120mms and the 80mm Panaflo @ 39CFM. I have some of these fans on the way to me, I will have them Wednesday along with a fan controller.

Thanks in advance for advice.

 

[996GT2]

I'd say 1 Yate Loon in front and 1 in the rear would do fine in your system, as long as everything isn't overclocked a lot. You can keep the Panaflo for the XP90. If you want additional cooling you could install the 3rd Yate Loon or a quiet 80mm in the top (i.e. AC Pro2TL or Pro2TC)

 

[Ping to the Pong]

i say use all three yate loons and the 80mm 39cfm panaflo. Slightly undervolt the yateloons (maybe 9volts at the most) and run the the panaflo at 7v. Should make a super quiet system with decent airflow.

 

[ClockerXP]

You don't really have that hot of a rig. I have dual 7800GTs but only have a couple Aerocool Turbine 120mm fans that only turn at 950rpm. They keep my system plenty cool. And you can't even hear'em. My HDDs are the loudest thing in my case...

CxP

 

[Howard]

Whatever you do, keep your hands non-firey when working inside the case.

 

[suszterpatt]

I wouldn't install a fan in the top exhaust. Hot air can leave through the slot anyway, and negative pressure will only cause dust problems.

 

[Luckyboy1]

Sunon fans are reliable and move tons of air, but they sound like a weed wacker running in your case while doing it. I know you are asking to get the mostest out of what you currently have and I deeply respect that. those who just buy their way out of problems lack the sense God gave chickens in most instances because the problem can often be solved with what you have now. Still, I'd rather see the Panaflo fans at all stations, but that's my slant on things. They move the mostest of air while still keeping it relative to the amount of air you are moving, quiet. They also last and last.

Remember you have yet another exhaust fan that you are not considering here and that's the one in your power supply. Air should in general move from front to bac and bottom to top and with the result being a slight, net positive pressure in the end. So, for your current deal, I'd go with the front blowing in and the side as well. The result unfortunately will be a net negative case pressure and that's far from ideal. The back one needs to blow out and so does the top one simply due to their placement and so my question at this point is...

Is there anyplace to hang a fan on that case that hasn't already been taken by what you've mentioned?

Can you double-back any of those fans? Remember, wood screws are ready when you are!

 

[suszterpatt]

Uh, more intake than exhaust would result in a positive pressure. I don't see how that's bad either, as it helps to keep dust out. But yes, keep in mind that your PSU is probably also moving a considerable amount of air out of the case.

 

[Luckyboy1]

Originally posted by: suszterpatt
Uh, more intake than exhaust would result in a positive pressure. I don't see how that's bad either, as it helps to keep dust out. But yes, keep in mind that your PSU is probably also moving a considerable amount of air out of the case.

In this situation, when you consider the air moved by the power supply, you end up with negative pressure and that's not desirable. Why? Yes, negative pressures result in lower read temps. However, that's not the whole story. Less air presure means less molecules per cubic feet to exchange heat with. As a result, the efficiency of the exchange goes down disproportionatley to any gain you might get in lower read temps.

The space shuttle operates in the vaccum of space. It is cold out there. You can turn the bird around so the heat exchangers face the dark side and the cold of space. So, if the negative pressure thing applies, then they don't have much of a need for cooling. Wrong, their heat exchangers are gigantic when compared to the amount of heat they are dealing with!

 

[ClockerXP]

Do you honestly believe there is I big enough pressure drop to make any type of real difference in air density? My god, these are crappy little fans inside poorly sealed enclosures we are talking about! Even if our cases were completly and perfectly sealed, the exhaust fans we are using are not enough to create any noticeable drop in air pressure/density.

 

[suszterpatt]

Originally posted by: ClockerXP
Do you honestly believe there is I big enough pressure drop to make any type of real difference in air density? My god, these are crappy little fans inside poorly sealed enclosures we are talking about! Even if our cases were completly and perfectly sealed, the exhaust fans we are using are not enough to create any noticeable drop in air pressure.

The cases not being sealed is part of the problem, those little cracks and holes are where most of the dust comes in (if you have filters on your intake fans). I have about twice the exhaust CFM than intake, and I can actually feel the air moving in when putting my hand next to an opening. Needless to say, my comp gets dusted up pretty fast.

 

[Luckyboy1]

Not just a dust thing! Yes, the dust thing is important as well and being able to manage just where and how the air comes in is important as a result.

As far as pressure drops go... you betcha a few fans can drop pressure! Even a 1/8th of one atmosphere pressure drop is quite possible in a case and will yield dramatic results. If pressure didn't matter, they wouldn't include something as mundane as the difference between takeoff in a low pressure area vs. a high pressure area in airplane weight load tables, but let's keep it simpler than all that...

http://hypertextbook.com/physics/thermal/gas-laws/

Ok, ok, so it's not so simple and that's why you'll just have to take the word of my Father who had a Doctorate of Science degree in Mechanical Engineering and my Brother in-law who designs the next generation of satellite that they are going to smash into the next planet they aim it at due to some small mathmatical error!

In fact, reduce the pressure in the case even a little bit and the amount of molecules per cibic feet goes way down. this leads to people like a fellow flight simmer who said...

Ok, I've changed the fans around and while the pressure is now slightly positive, I get the same temperature readings. Of course I'm able to overclock farther now, but I don't understand that.

The answer is simple. it's called air density at any given temperature or the isothermic dynamics of a given situation. Physics is realy hard to escape!

 

[ClockerXP]

You go with that if you want but any difference is much more likely to be attributable to changes in air flow volume or the path of the air flow rather than changes in the density of the air. Changing fan configurations will change the path of air flow much more than the miniscule amount it will change the air pressure (which I doubt will be even measureable unless you have very sensitive equipment).

If you want to go with the air pressure theory, remember that when you compress air it gets warmer. So by that theory positive pressure makes the air in your case warmer. Not that I believe the pressure changes we are talking about here really make any difference but that's the physics of it. Work done in compressing air increases the air's internal energy and raises its temperature. <-- Involves the First Law of Thermodynamics.

 

[Luckyboy1]

Yes, it does raise temp. to raise pressure. Still, that's the way the big boys exchange heat... at pressure. Sure, we are dealing with less than high pressures here. That's why I say slightly positive is better than slightly negative. Take the difference between the two and yes, it is measurable and not even just with sensitive instrumentation. Take the difference from static and maybe a different story.

and here's an edit fer yah!

Even the Thermaltake rep came into a thread and said positive case pressure is the way to go and yes, is important!

 

[ClockerXP]

I'll agree that "+" pressure is in general good. It helps reduce dust buildup which, over time, reduces the effectiveness of cooling components. Also, with even or slightly positive pressure you're more likely to get better air movement in the case because you aren't starving your exhaust fans. This more to do with air movement & patters rather than air density.