Understanding liquid cooling

The alternative to direct air cooling

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canthearyou
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Understanding liquid cooling

Post by canthearyou » Thu Nov 27, 2003 9:16 am

When I look at watercooled or liquied cooled systems, I do not undestand how they can be any quieter than air cooled. You need a radiator to exchange the heat and that typically has fans blowing over the fins. Doesn't this just shift the noise from one location to another?

I can see with a very large radiator and a large slow moving fan quiet could be achieved. The watercooled case I have seen has three 80mm fans on top of the case.

Maybe if a radiator was 120mm square and had an undervolted 120mm fan attached, I could see the quiet. I wonder if that might be enough to cool one of the SFF computers quietly (the PSU would have to be replaced as well).

Steve

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Post by supastar » Thu Nov 27, 2003 10:16 am

I only handle Innovatek kits as they are the market leader. They use 120 mm fans and every kit has a 7 volt cable, so the fan runs barely half speed. The latest kits have Papst fans. This is the only fan in the system apart from the power supply. Use a 120 mm fanned power supply - Seasonic or Fortron - and you have the basis for a very quiet machine.

The best place to mount the fan is at the top of the case. And the standard rad will handle 450W of waste heat. The system also runs cooler than with air so there is less thermal cycling and component life is increased.

canthearyou
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Post by canthearyou » Thu Nov 27, 2003 11:04 am

Thanks for the explanation. I can see where the slow 120 would do a good job.

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Post by chylld » Thu Nov 27, 2003 12:36 pm

Yep. Imagine getting rid of a 60/80mm CPU fan, 40mm NB fan, 40mm GPU fan and a 80/120mm case fan, and replacing it with a single 120mm fan and getting better results at the same time. :)

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Post by silvervarg » Thu Nov 27, 2003 12:40 pm

There is a few major differences between clooing with water and a radiator versus cooling with a CPU heatsink+fan.
You can blow air through a radiator (not as much static pressure).
A radiator can be consideraby larger that a CPU heatsink (at least easier to make larger).
With water cooling you are also able to spread the heat more, and cooling more evenly spread out heat is easier.

The major drawbacks with water cooling are:
Added weight.
Need to add a pump (that vibrates etc).
Possibility of leakage
Pump can break without beeing able to notify motherboard
Added costs for the cooling

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Post by supastar » Thu Nov 27, 2003 2:32 pm

Since the purpose of a forum is healthy discussion, may I beg to differ.

Why should the weight of the system matter? The only problem lies with heavy heatsinks attached to the cpu that are in excess of AMD/Intel weight limits. You add a pump, yes, but with a quality product and flexible mounts, vibration should not be a problem. Leakages are possible but ask users how often this occurs. Given a superior compression connection and good workmanship, this is a minimal occurence.

Your next comment is quite wrong. An electronic flow sensor is available, and is bundled in some kits, that provides a signal to the motherboard header. If flow fails then you have the identical signal that a failed processor cooling fan would give.

Yes the cost is greater. But then so is any added expense in the pursuit of quietness. Why single out water cooling? Water cooling is an investment that gives a quiet system with low operating temperatures and longer component life. Use passive radiators and it's even quieter.

And Gainward have a graphics card that is only available with a waterblock. They've given up on air cooling this product. The shape of things to come?

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Post by chylld » Thu Nov 27, 2003 3:15 pm

those flow meters are really expensive aren't they?

i think the main problem with WC is the price. given how obsessed we are with silent computing, we've found ways to make silent, aircooled, overclockable setups. a good WC system provides little to no noise reduction compared to a good AC system.

but i do think that WC is the way of the future. the mainstream market is getting ready for WC solutions but it's not quite there yet. hopefully when the price comes down :)

canthearyou
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Post by canthearyou » Fri Nov 28, 2003 11:35 am

Well, eventually supercomputers had to be cooled by liquid nitrogen and I doubt our PC's are as far behind as we might imagine. We may all end up with some kind of liquid cooling system.

My interest is mainly should I want to try small factor case, where there is a lot of heat in a small space.

Seal
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Post by Seal » Fri Nov 28, 2003 3:13 pm

Ok heres my setup, i got a few of my mates round to help show how watercooling is quiet.

Image

As you can see, the processor instead of being cooled by a small copper heatsink is instead indirectly cooled by a huge radiator which has much more surface area, thus = more efficient because you can use less airflow to remove more heat! Also instead of having to use a small fan to cool the cpu (biggest cpu fan u can get is probably a 80-92mm - from the slk HS range) you can use a huge 120mm fan, of which mr red set to 5v, thus = quiet cpu cooling.

I love my setup, mr blue does too, as you can see he cant believe that my computer is actually on because its that quiet!

As for temps... atm with the fans at 5v, its sitting at 41 deg C full load, so in theory i could turn the fans down even more... however if i did that it wouldnt do much as the comps already inaudible and also it'd have problems with the fan spinning up on bootup. Being able to turn your cpu fan below 5v in an air cooled system is very rare.

Seal

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Post by wussboy » Fri Nov 28, 2003 10:42 pm

Funny, Seal!

I'm gonna watercool too (hopefully this month) and plan on having only the PSU fan (120mm) on. Radiator may have a fan, but will be in another room (with the pump). I dream about how quiet it's going to be.

Seal, can you ask Blue Man what he thinks of my machine. Also, does Red Man ever get worried about getting sucked into a fan? That is all.

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Post by Tobi-Wan Kenobi » Sat Nov 29, 2003 4:55 am

WC can certinaly be quiter than AC. If you have a large (read very heay) radiator for exampel a car radiator you wont need a fan on it. But then you wpould need a good pump.

With watercooling youwould even be able to use a Wcooled PSU. I dont know if they are good but there are some on the market..

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Post by Bat » Sat Nov 29, 2003 8:32 am

Why do people keep saying this?
A big car radiator will present less flow resistance than a small radiator, because it has many more pipes in parallel through which the water can flow. Car radiators are almost always single-pass, unlike many "PC" radiators and some heater-cores and oil-coolers, which have the water looping back and forth many times, increasing flow resistance due to the long tube and tight turns.

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Post by joesgarage11 » Sat Nov 29, 2003 12:20 pm

canthearyou writes:
When I look at watercooled or liquied cooled systems, I do not undestand how they can be any quieter than air cooled. You need a radiator to exchange the heat and that typically has fans blowing over the fins. Doesn't this just shift the noise from one location to another?
Yup, and you move the heat, too.

Radiator fan noise can be avoided by using a passive radiator. I'm running a watercooled system with one undervolted 120mm fan to cool the case and power supply. It's very quiet. My 7 year old nephew used it yesterday and turned it on and off three times because he couldn't hear it when it started. :lol:

Here's the full article.

Just like aircooling, when watercooling you have to make choices about noise, complexity, cost, and cooling potential and do what works for you.
silvervarg writes:
The major drawbacks with water cooling are:
Added weight.
Need to add a pump (that vibrates etc).
Possibility of leakage
Pump can break without beeing able to notify motherboard
Added costs for the cooling
Absolutely true, but there are ways to cut the risks.

You could mount that vibrating pump in some foam or hang it by small stretch cords. Use hose clamps on all the tubing connections to lessen the risk of leaks. Get a flow sensor or run a temperature monitoring application to give you some warning if the pump fails. Exercise more to carry the added weight. Hehe, nothing I can suggest will make it cheaper, though. :cry:

canthearyou
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Post by canthearyou » Sat Nov 29, 2003 1:06 pm

The only radiator I've seen personally was the Koolance case with the three fans on top. I suppose they could be slowed down but I doubt they would be as quiet as Seal's 120mm system. That did not seem very quiet, so you know where I'm coming from. :-)

I wonder if it would work to have the normal front 120 blow over a HD cage and then through the radiator?

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Post by silvervarg » Sat Nov 29, 2003 2:38 pm

I do like to debate and keep an open mind for everything. What I tried to do was to give a brief list of pros and cons of watercooling.
I do not rule out watercooling as an option, although I have no watercooled system myself because in my situation in current builds the pro vs con have so far pointed me into aircooling.
For every single system I build I will consider all available alternatives for cooling before building.
Superstar:
Why should the weight of the system matter? The only problem lies with heavy heatsinks attached to the cpu that are in excess of AMD/Intel weight limits.
I move my box from time to time, so total weight is an issue, not just weight on CPU-sockel.
Your next comment is quite wrong. An electronic flow sensor is available, and is bundled in some kits, that provides a signal to the motherboard header. If flow fails then you have the identical signal that a failed processor cooling fan would give.
Thanks for the input. I have not seen first hand any water cooled system with flowsensor. Probably because of budget choises.
Yes the cost is greater. But then so is any added expense in the pursuit of quietness. Why single out water cooling? Water cooling is an investment that gives a quiet system with low operating temperatures and longer component life. Use passive radiators and it's even quieter.
You do have a few points here. Cost is usually one of the major cons for watercooling. There are a few cheap tricks to quiet air cooling frequently used here.
Depending on what temps you are satisfied and the work you put in you can passively aircool a system as well using heavy radiators. Check Fmah's system for a real world example.

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Post by Gooserider » Sun Nov 30, 2003 11:36 pm

An electronic flow sensor is available, and is bundled in some kits, that provides a signal to the motherboard header. If flow fails then you have the identical signal that a failed processor cooling fan would give.
I have also seen many arguments against a flow sensor...

1. They add flow resistance to the coolant loop, at least theoretically reducing the cooling.

2. They cost $$$ (Note, there are two classes - a flow sensor that merely turns on and off when it detects a threshold flow, vs. a flow meter that attempts to measure the flow volume. On/Off flow sensors are somewhat cheaper and less restrictive.

3. They aren't needed! - Any failure will cause CPU temps to go up, and if you simply have temp monitoring on the CPU, then that can be setup to trip off a shutdown.

Better is to note that the primary cause of flow failure is user error in the form of not turning the pump on, and wiring the pump with a relay or other technique to ensure that it isn't possible to turn the PC on without turning on the pump...

Supastar - Noting that you describe yourself as an Innovatek vendor, can you supply any information in English (not 'Googlized German') on the Innovatek 'Fan-O-Matic' fan controller? A few folks suggested it a while back, but I was never able to find much out about it, other than that it was VERY expensive...

1. Will it work under LINUX (*NO* Windows solution is acceptable!)

2. Is there English language documentation and software for it?

3. What would it cost to get one in the US?

Thanks,

Gooserider
[/quote]

Gerco
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Post by Gerco » Fri Dec 05, 2003 7:50 pm

Watercooling is basically quieter then aircooling because you have full control of "heatmanagement". With aircooling you have to lose the heat on the place where its created, where sometimes isnt much room or ease of installation. Also with aircooling every device creating heat needs to have a fan mostly, which adds up for most computers with many "devices"

With watercooling you can "collect" the heat from all devices in the water and then only the radiator needs to be cooled, which requires normally only one or more large low rpm fans or in my custom case, NO fans :)
in my case I watercool my CPU/GPU/NB/ 4 x HD and soon also my DDR and hopefully also my PSU. I am using a stainless steel 50 x 70 cm passive radiator that works very well. My case also has an "active" radiator with 2 12 cm fans but I only turn that one on when my system is busy at night, virus scan or data copy or something else. When stability is important and I am not around to mind the noise :)
if you are curious about my case, see here for pics
http://www.xs4all.nl/~gercomar/PCcase/done/ and http://www.xs4all.nl/~gercomar/PCcase/

I have spent much time on my "Quest for Silence", working on getting a fanless PC. Also because I have a (clear) case in a (clear) case, the double insulation helps to block out the harddrive noise, and any other current noise, like from my case fan at 4 V and my Enermax 365 papst PSU. But hopefully soon that noise can be eliminated as well.

I will try to give more information soon here about my case if there is interest in it. 8)

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Post by silvervarg » Sat Dec 06, 2003 4:58 am

Gerco:
Watercooling is basically quieter then aircooling because you have full control of "heatmanagement". With aircooling you have to lose the heat on the place where its created, where sometimes isnt much room or ease of installation. Also with aircooling every device creating heat needs to have a fan mostly, which adds up for most computers with many "devices"
I don't agree with your statement.
When heat is generated you have to transfer it away from the source in some way. The heat can be transfered through solid material (e.g. metal), liquid (e.g. water), gas (e.g. air) or through a material that undergoes phase-change (e.g. heatpipes).
Usually this is used to transfer the heat a small distance and then transfer to another media (often air).
For a typical water cooled system lets have a quick look at Seals picture in this thread. He uses 5 fans, 1 pump and 1 radiator to cool his system.
In my typical air cooled system I use 3 undervolted fans to cool the system.

In a classic water cooled system you can decide where to put your radiator and most users choose to put it in the chassi with one or 2 fans attached to the radiator. This is not fundamentally different from having the same fans in the same location and use ducting to cool components.
I see no major differentce in control of heat management.

If you go to the extreme (like your system seems to be) by using huge heatsinks on the outside of the chassi your main concern will be how to transfer the heat to the heatsink and also make sure most of the heatsinks heat is dumped on the outside of the chassi.
The equivalent of your system without water cooling is Zalmans new chassi. It uses heatpipes to transfer heat to two big heatsinks (the sidepanels) and cools CPU/GPU/NB. It also uses heatpipes to cool HDD, but due to the low heat generation they dump the heat inside the chassi. It also cools the PSU passively, but I believe that heat is dumped out through a third heatsink.

Comparing your system to Zalmans cooling system I find that you have at least a pump going and they have no moving parts.

One fundamental difference is that you "collect" heat from all devices, when the Zalman chassi strives to take heat from the source the shortest way to where is can be cooled. From a scientific standpoint this has to be the best way to cool things, but perhaps not always the most practical solution or the most inexpensive.
The only two drawbacks I can see with Zalmans solution is price and added total weight of computer box.
I believe this is almost the same as drawbacks with your system. I guess you have lower price, and added work (depending on your hobby this is either good or bad), and your system can leak water. I can't tell what the weight of your system is, but Zalmans chassi+cooling+PSU weights in at 22kg.

With only traditional air cooling you can go low cost, low weight and for many systems reach an inaudiable system (over background noise). So as long as you can reach a point where you are satisfied with the cooling and noise level traditional air cooling is unbeatable.

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Post by Gerco » Sat Dec 06, 2003 8:44 pm

I dont agree with all you say but I do agree with your last statement, aircooling indeed is much simpler, low cost and low weight. And indeed with the great processor coolers out there these days you can already reach a very silent system by simply getting a quiet processor cooler.

However I have not yet seen a processor cooler with a 12 cm fan, which are almost standard for watercooling and much more quiet at 5V then about all of the standard air cooled processor coolers. And if you mount a waterblock on other devices that had a fan you eliminate more noise and can cool all with that one 5 V fan on your radiator. That is possible, but people can make watercooling with 5 fans or you can have only 3 quiet fans in your aircooled system. But do you also overvolt and overclock your processor ? Doing that with aircooling makes it very hard.

Yes a system totally based on heatpipes can indeed "beat" my system on noise however I am sure you will agree that those cases are very rare, I have yet to see one posted or modded somewhere. Making it custom like mine is hardly possible unless you make the heatpipes yourself maybe.
Also I dont know what the cooling capacity is of heatpipes, if they can handle heavy overclocking as I do. But I am sure just like my system you can add bigger components for more cooling power.
As for price and weight, I have spent quite some on my system as well, and it weighs 85 kg, so I can beat the Zalman in that aspect :)

Not sure if scientifically its best to cool as closest to the source as possible. One can also argue its most efficient to collect heat from all devices and then cool them in one cooling device which if heat is transported can be rather large and made to be efficient rather then close to the source. But depending on how you look at it this issue can be open for various explanations 8)

Leaks with watercooling ? I havent had any spontane leaks yet and dont consider it to be a risk at all. What I would consider a risk is cooling a $400 processor with a $10 cooler that has a $.20 fan on it.....

I agree with your final statement, indeed aircooling is way cheaper and you can reach good silent results with it that are exceptable for most people and much more simpler then any watercooling setup. However for people who want more like me and want an ULTRA silent PC watercooling is the only solution for now (apart from heatpipe cases)
I do however think that with a quality 5V 12 cm fan on a radiator you can make a quiet system that will be hard to beat for a fan aircooled PC, apart from exceptions :)

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Post by chylld » Sat Dec 06, 2003 9:09 pm

or we could just line the insides of both an AC system and a WC system with acoustic dampening material (like an acoustipack) and they'd both be silent.

aren't we spoilt for choice :D

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Post by Gerco » Sat Dec 06, 2003 9:18 pm

Yes, that is a good solution normally to make a case more quiet :)
However.....
I think you will agree that in my case as seen in http://forums.silentpcreview.com/viewtopic.php?t=8680
putting dampening material in my case is not really a solution :wink:
it wouldnt look great in a clear case :)
But I have fixed that "problem" by putting my clear case inside a clear case so the extra "air insulation" keeps all the noise on the inside.

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Post by snutten » Mon Dec 08, 2003 7:39 am

I use WC with 2x120mm radiators and with internally isolated alu case outer walls heated by the water. Sure, it´s quiet.
But to be honest, this can be achieved with AC too. Ducts and a good heatsink. I´d never recommend anybody to go WC.

The only advantage with WC I can think of (except OC, which I don´t) is that I was able to totally sound isolate the main HDD and cool it with water. That way I can use a Raptor as system disc instead of a slowish Barracuda or something. (But the HDD can´t take as high temps as the processors so water temps must be kept lower. Is nothing for free?)

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