Basic Questions Concerning Water Cooling...

The alternative to direct air cooling

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DJCoryMinto
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Basic Questions Concerning Water Cooling...

Post by DJCoryMinto » Tue Apr 18, 2006 12:24 am

Hey everyone!

I'm about to buy the Reservator 1, but before I do, I have a few basic questions... In my current noisy setup, I have four hard drives (two of which spin at 10,000 RPM, the other two at 7800) in my Antec case. Two of these hard drives have mini fans attached to the drives themselves (probably 40mm or so). The case has three fans, allowing cool air in and out of the back and front. Plus, of course, my power supply has a fan. And the CPU has a CoolerMaster 120mm fan.

In getting the Reservator 1, the need for the CPU fan will thus be eliminated.

My question, then, is ... Do these hard drive fans RELY on the case's three fans to attain cool air? In installing the Reservator, I would hope to eliminate the case's fans, keeping only the power supply's internal fan and the two tiny fans attached to the [two 10,000 RPM] hard drives. But again, do these four hard drives rely on the three case fans? Also, could I eliminate those two tiny fans that are attached to two [10,000 RPM] hard drives (I would assume not - plus they are probably not noisy anyway)?

I ask these questions because the Reservator 1 (and other water-cooling systems) apparently doesn't have the tubing go through the hard drives. I guess it's stupid of me to assume that hard drives need cooling, too. hahaha So then, again, if the hard drives don't need water-cooling, do they indeed rely on the noisy case fans whose noisiness I am trying to eliminate?

If need be, I can keep the entire side panel removed from my Antec case to abate heat from the hard drives, in lieu of keeping the three case fans. Although, in that case, the noises from the hard drives and power supply might become more prevalent with the side panel of the case being ajar. Whatever.... I'm babbling.... :)


I'm new here; I just registered. Thanks for the great info on this site; I've just spent 2+ hours reading and learning, and I appreciate all of the hard work that everyone contributes here.

paapaa
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Post by paapaa » Tue Apr 18, 2006 2:20 am

Could you specify the manufacturer and model of your hard drives?

mikellpp
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Post by mikellpp » Tue Apr 18, 2006 3:37 am

One of the advantages of water cooling is that most of the cpu heat is removed from the case. With a psu fan drawing some air thru the case you may be able to eliminate your case fans, but your hard drives should have some air circulating over them. A small fan at 5 volts blowing over the hard drives should do the job.

I have a Reserator on a X2-3800 @ 2.2Ghz and have a _total_ of 2 fans in the case: one 120mm at 5 volts and one 80mm at 5 volts to blow over two hard drives. Everything is nice and cool.

Butcher
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Post by Butcher » Tue Apr 18, 2006 12:09 pm

I'd advise dropping the 40mm fans if possible, and keeping larger case fans running at 7 or 5V. Reason is large fans tend to run quieter, and in particular 40mm fans tend to be very noisy relative to their airflow.

DJCoryMinto
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Post by DJCoryMinto » Wed Apr 19, 2006 6:49 pm

paapaa wrote:Could you specify the manufacturer and model of your hard drives?
Well, one of them is used exclusively for backup in the event of a hard drive crash, and I back it up once every three months. So, for that one, it would be wise to power it off via windows, and turn it on only when I need to re-back things up. This will cause obviously less heat and noise. DUH... hahaha

Three remaining:
Western Digital WD2500JD (250GB, 7,200 RPM)
Western Digital WD360GD (36GB, 10,000 RPM) [O.S. hard disk, facilitates Cubase SX3]
Western Digital WD740GD (78GB, 10,000 RPM) [used for accessing audio pieces while working in Cubase, facilitates all the samples, drums, sounds, etc.]

Both 10,000 RPM drives have tiny fans on them. They are seemingly inaudible, and if they are audible, then certainly not enough to notice (i say that now, haha). I don't know if the fans came with the hard drives or if my buddy put them in for me thereafter. I would think the latter.

So, I guess then, the question is, will these three drives (remember, no longer four, as mentioned above) rely on the three case fans in the tower to stay cool? The case fans are semi-noisy. And I was wrong... these three case fans appear to be 100-120mm, not 40mm as I mentioned in my previous post. Again, a possible option would be to keep the entire side panel of my tower open. It's a big tower. Plus, if I take these three case fans out, there will be the physical gaps in the rear and front of the tower to aid in air passage, which will be a factor. Plus, as Mikellpp asserted, the enitre inside of the case will be significantly cooler to begin with, with the Reserator 1 effectively cooling down the CPU and GPU.

Given all of the above, guys, what do you think?

Many thanks!

DJCoryMinto
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Post by DJCoryMinto » Wed Apr 19, 2006 9:09 pm

Also, do I need to purchase the socket-775 adaptor seperately or does it come WITH the Reserator 1? I can't, for the life of me, find this info anywhere online. Are there any accessories that I need, in addition?

mikellpp
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Post by mikellpp » Thu Apr 20, 2006 2:06 pm

I have the blue Reserator 1 and it does not come with the 775 adaptor, but the black Reserator 1 Plus does.

If you can keep your hard drives at the bottom of a standard case instead of the top they will be about 5C cooler. Also in my experience an 80mm fan at 5 volts blowing on 3 drives in one hard drive cage will keep your drives cool. The case fans will only have an indirect effect (maybe no change in hard drive temps) if they are running at reduced voltage, which you will do if you want a silent pc.

Also do not assume that leaving the side off the case will always give lower temps. If you have the proper air flow thru the case, then opening the side might just mess up the air flow and raise temps. You just have to experiment.

zds
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Re: Basic Questions Concerning Water Cooling...

Post by zds » Thu Apr 20, 2006 7:51 pm

DJCoryMinto wrote: My question, then, is ... Do these hard drive fans RELY on the case's three fans to attain cool air? In installing the Reservator, I would hope to eliminate the case's fans, keeping only the power supply's internal fan and the two tiny fans attached to the [two 10,000 RPM] hard drives. But again, do these four hard drives rely on the three case fans? Also, could I eliminate those two tiny fans that are attached to two [10,000 RPM] hard drives (I would assume not - plus they are probably not noisy anyway)?
As the others have suggested: suspend-mount your hard drives vertically to the bottom of the case, and place some heavily undervolted fan (some 80-120mm fan at 5-7V) to act as an front intake and blow through the drives.

EDIT: To give you some perspective: the silent Nexus 120mm fan moves 37CFM worth air *at 1000rpm*. And is inaudible inside most of the cases, even at 12V (23db(A)).

40mm fans need to run a t really high speeds to move any air - the fastest I could find was rated for 8CFM and 7000rpm. This means that a) to move any air, 40mm fan needs to spin high rpm, and thus make lots of whine and b) a single 80-120mm fan for all the drives should have no problems meeting or exceeding the cooling efficiency of the separate 40mm fans.

If you want to be double-sure, use some quiet 120mm fans, like the Nexus one, use temperature-based fan controller and tape the thermal probe to the 10kprm drive farther away from the middle of the fan.

Usually, the hard drives do not produce so much heat, for example per the manufacturer's spec, the 74Gb Raptor (WD740GD) emits 8.4W worth heat *at worst* and so *any* airflow near them should be enough to keep them cool.

The reason to prefer 80-120mm fans is that due to the nature of the electrical motors and bearings they emit less noise per CFM they produce, especially compared to 40-60mm fans. The another reason is psychoacoustic: Human ear is much more sensitive to high rpm (3000-7000rpm, 50-116Hz) noise than low rpm (700-1000rpm, 11-16Hz) one. Thus even at the equal absolute noise level (dB, not dB(A)) it's harder for human to hear the 15Hz'ish noise than the 90Hz'ish, and thus it's less obtrusive.

DJCoryMinto
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Post by DJCoryMinto » Tue May 09, 2006 6:56 am

Great replies guys. Although I am posting 2 weeks later, I have been busy experimenting with the above recommendations. So far so good!

Butcher
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Post by Butcher » Fri May 12, 2006 2:24 am

Don't forget HDDs are basically a big chunk of metal, so pretty good it dissipating heat. :p

NB: You can't actually hear a 15Hz noise, human hearing only extends down to 20Hz at best, but you get higher frequency harmonics from fan bearings, and these are proportional to the RPM. So lower speed fans have a lower pitched sound and are less intrusive.

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