water or air?

The alternative to direct air cooling

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cmthomson
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Post by cmthomson » Mon May 25, 2009 2:27 pm

~El~Jefe~ wrote:I have no radiator fans and my pump is silent. actually silent.
It's unusual to have no radiator fans. Good on ya.

The pump can't possibly be silent, since nothing with moving parts is. It may be inaudible in its environment, but then so are the parts in my air-cooled system.

~El~Jefe~
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Post by ~El~Jefe~ » Mon May 25, 2009 10:01 pm

I really have to say that I have had 20+ models of recommended silent fans over the years.

from the original Papst fans that were made and balanced by hand, to the years of Nexus and now scythe's. I have done panaflo's too.

All at 5-6volts they were louder than my water pump. the water pump is an eheim 300, it is very light duty. However, that's all one needs for almost any reasonably priced system.

The radiator thing is simple, I think at least. You get more radiator and you dont need a fan. two big ones strung together is a massive surface area that can be passively cooled. Pricey? a bit, but it's permanent for all other builds.

also, you never get dust in a wc system like my old air did, and, psu's stay cold as there is no case heat, so they are very effecient.

Jipa
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Post by Jipa » Sat Jun 06, 2009 1:06 pm

~El~Jefe~ wrote:....All the things he said....
It's easy to see that you're very much in love with your WC-setup, but I'd really, REALLY love you to realize that the rig you stated earlier ("I use a 2.2 ghz dual core amd, 3870 vid card") just isn't modern by any means. Reserator doesn't really cut it with current hardware, and to get a passively cooled radiator, it needs to be HUGE.

Now this leads us to the main point, do you, or do you not want to move your rig? I mean ever? If you have all the space you need, sure you can fit a huge rad somewhere, and be happy with the quiet operation. If you want the rad to go along with the case (I guess most do) it WILL need fans. The fans may be quiet, but there are fans nonetheless.

It sure was nice to just slap in a reserator a couple of years ago, to cool the CPU and GPU, but now you'd need a full-cover block on the graphics, likely a block on the NB and another on the regulators. It's just not as straight forward and cheap as it used to be.

Overall I'd say yes, you can get lower temperatures at the same noise level as you would with air cooling. Also yes, you are going to pay more for the cooling. It just all depends on what the user wants and how much he/she's willing to pay and tweak. Just try to see the both sides, while water cooling has its advantages, it IS possible to very quietly cool a rig using air cooling as well.

As for the water wetter.. Well I don't want to even go there. All the hype just makes me wonder how much they are paying you :roll: The 30-50% glycol setups are something I've never ever seen.

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Post by Olle P » Mon Jun 08, 2009 1:17 am

Jipa wrote:Reserator doesn't really cut it with current hardware, ...
I disagree. The Reserator is fully capable of handling a Core i7 580, a NB and a Radeon HD 4670.
That's a "current" setup fit for serious computing and able to run Vista Aero without sweat.
It's only if you add powerful graphics to the mix that the passive cooling capacity doesn't quite cut it.
Jipa wrote:Now this leads us to the main point, do you, or do you not want to move your rig? I mean ever? If you have all the space you need, sure you can fit a huge rad somewhere, and be happy with the quiet operation. If you want the rad to go along with the case (I guess most do) it WILL need fans.
Mobility is a non issue here. Anybody that wants a mobile computer will not spend many seconds contemplating a Reserator in the first place.
There are a couple of mobile solutions featuring truly passive heatsinks that are on par with the Reserator, for example Innovatek Konvekt-O-Matic MAXI/ULTRA Plus and the Cape Cora radiator system. A full tower with two Konvekt-O-Matic Ultra will dissipate 360W fully passive, which is sufficient even for a "current" gaming rig, if not very high end.
(For example, as calculated using Innovatek's load calculator: Core Quad Q9770 + Radeon HD 4870 + motherboard NB and MosFET = 347W.)
Jipa wrote:As for the water wetter.. Well I don't want to even go there. All the hype just makes me wonder how much they are paying you :roll: The 30-50% glycol setups are something I've never ever seen.
This I agree with.

Cheers
Olle

Jipa
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Post by Jipa » Mon Jun 08, 2009 5:17 am

Ok I may have under estimated the Reserator. Maybe it's the "meh"-reputation of Zalman watercooling in general? I just don't see many people using those things..

And as for the HUGE passive rad, I meant something that you'd take off a freezer in a store. You know, one of them large things with ice cream and an open top? A friend of mine has one of those hooked to his water cooling, and that's something I would do as well if I had enough space and weren't about to move this year :roll:

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Post by Olle P » Mon Jun 08, 2009 2:16 pm

Jipa wrote:And as for the HUGE passive rad, I meant something that you'd take off a freezer in a store.
Good for cooling, I agree, but neither stylish nor convenient.

Personally I'd go for the more subtle approach to use a regular wall mounted convector normally used for heating the room.

Cheers
Olle

Jipa
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Post by Jipa » Mon Jun 08, 2009 3:31 pm

Then again, if you don't move the computer and have a 200x80 cm sized desk like I do, why the hell not? It would be easy enough to suspend a 200 cm long radiator to the back of the desk without it even being visible.

But enough of that. It's just something I MIGHT do, maybe in addition to in-case rads (so I could unplug the fans when at home)... Plans, plans, always major plans. :roll:

spookmineer
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Post by spookmineer » Mon Jun 08, 2009 4:16 pm

I'm genuinely "intrigued" by the wall radiator concept (I know, I watch too much Star Trek).

Personally I think some of the bathroom radiators look more stylish.

In either case, I'm concerned what kind of waterpump is needed to provide the appropriate flow. Jipa, do you know what kind of pump your friend has?
The internal resistance of such a radiator would be higher than a reserator but I couldn't guess by how much.

If someone knows of some pics with "household" radiators in combination with a PC, I'd like to see just to get an idea how they went about it.

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Post by Olle P » Tue Jun 09, 2009 9:27 am

spookmineer wrote:The internal resistance of such a radiator would be higher than a reserator but I couldn't guess by how much.
Not really. The pipes are quite thick, so internal resistance is a non issue. Tubing between the computer and radiator can also be done using thicker tubes that those used for the reserator (at least 12mm ID), so there won't be much pressure loss either.

Therefore any regular pump will do.
spookmineer wrote:If someone knows of some pics with "household" radiators in combination with a PC, I'd like to see just to get an idea how they went about it.
There was an article by a Norwegian who did this several years ago. He used a smallish rad to cool his Athlon XP and claimed the water temp stayed 5 degrees above room temperature.
Unfortunately that site is now gone.

Checking around and doing some maths I found that around here a cheapish option would be to get a Purmo Compact type 11, 60cm tall and 140cm wide. That can cool off 350W of heat with an average water temp 18K above room temp.
Buying second hand radiators is very cheap, but they're usually very dirty inside and need very thorough cleaning before use.

Cheers
Olle

Jipa
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Post by Jipa » Tue Jun 09, 2009 1:39 pm

spookmineer wrote: In either case, I'm concerned what kind of waterpump is needed to provide the appropriate flow. Jipa, do you know what kind of pump your friend has?
The internal resistance of such a radiator would be higher than a reserator but I couldn't guess by how much.
I'm not sure what kind of pump the guy I'm talking about is using, but I've seen this kind of large watercooling sets relying on Grundfos. A central heating pump should definitely put enough flow through the hoses/rads, but may also turn out a bit too loud. They were commonly used before watercooling came mainstream and the purpose designed WC-pumps became so readily available, so atleast they're already tested in this use.

Anyway apparently you can also get away with long hoses even with pretty small pumps:
http://koti.mbnet.fi/overvolt/autotallijaahy.html
(it's in Finnish, but you get the idea. A car rad, hoses through wall to the garage...)

On the other hand, here's a Grundfos in WC-use. It sure looks beefy :)
http://www.janiahola.fi/tietokone/chief ... A4%C3%A4hy


EDIT: He's using Eheim 1048. Deffo a large thing, but not quite in the league of the Grundfos.

spookmineer
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Post by spookmineer » Wed Jun 10, 2009 3:27 pm

Thanks for the replies.

Mounting it upside down (or temporarily holding it like that) would make it easier to fill, I'm not sure about degassing it (res2 was already stubborn in that aspect).

Not sure if the Purmo (or other radiators) have the surface prepped internally as well, if not: steel and copper again will be susceptible to galvanic corrosion.


Olle, how did you find out a 140x60 cm can dissipate approx. 350 Watt?
[For the first type, 1425 W is indicated at 75/65/20, an average temp difference of 50 °C.
At a temp difference of 18 °C the heat dissipation will be less.
In the radiator, the difference between water in/out is 10 °C. In a watercooling setup, this difference will not be realistic: typically, the difference between water in/out is about 1 °C, so the amount of heat the radiator can dissipate will be a lot less, about 1/10th of the power it could dissipate if water in/out were 10 °C.
I probably made an error somewhere, but I don't know which.]

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Post by Olle P » Wed Jun 17, 2009 4:35 am

spookmineer wrote:Not sure if the Purmo (or other radiators) have the surface prepped internally as well, if not: steel and copper again will be susceptible to galvanic corrosion.
The inside is steel. Anti corrosion additive is mandatory.
spookmineer wrote:Olle, how did you find out a 140x60 cm can dissipate approx. 350 Watt?
I used the general formula for heat dissipation (DIN 4703-3), coupled with the approximation that the water flow is 3 l/min.
(Purmo provides lots of useful info in Swedish that's missing from their UK site. The formulas are on page 10 of this document.)

- Combining the data for the chosen radiator with 350W output gives us delta T (logarithmic over temperature) just below 18C.

- Combining the water flow rate, dissipated heat (350W) and water heat capacitivity give us the difference in temperature between inlet and outlet at 2.3C.

- Maximum water temperature in the loop is the inlet temperature, which is slightly more than half the in-out difference plus delta T plus room temperature. (Ends up at room temp plus 20C.)

Cheers
Olle

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Post by ATWindsor » Wed Jun 17, 2009 6:18 am

PizPump wrote:Once you go with liquid you'll never go back.

I have to laugh when people try to talk air up like it can even come close. It can't.
I am considering going back, I have a reserator setup. It works well, and was a very good solution durings its day. But now? I can hear the pump, even when placing the radiator on a mat, and its cumbersome to move the setup, or change equipment, furthermore its less compatible with a height-adjustable desk.

For the GPu it's not enough to just cool the chip itself anyway, and an i7 can be cooled very quiet with a HR-01 or similar cooler.

AtW

spookmineer
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Post by spookmineer » Fri Jun 19, 2009 9:17 pm

Olle P wrote:
spookmineer wrote:Olle, how did you find out a 140x60 cm can dissipate approx. 350 Watt?
I used the general formula for heat dissipation (DIN 4703-3), coupled with the approximation that the water flow is 3 l/min.
(Purmo provides lots of useful info in Swedish that's missing from their UK site. The formulas are on page 10 of this document.)
I tried getting some meaningful results from this formula, but the one thing I can't figure out is the exponent n (temperature exponent) in this:

ф = фn x (ΔT/ ΔTn)^n


How do you obtain the temperature exponent?


Without using the temperature exponent n, I can't complete the formula.

[With Tin=37, Tout=39, I get ΔT just below 18, ΔT/ΔTn=0,36 and a whopping Q of 514 Watt, much bigger than your 350 Watt: apparently I do need the exponent n, but I don't know what it is]

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Post by Olle P » Wed Jun 24, 2009 12:57 pm

spookmineer wrote:... but the one thing I can't figure out is the exponent n (temperature exponent) in this:
ф = фn x (ΔT/ ΔTn)^n
How do you obtain the temperature exponent?
It's provided in the data sheets for all the radiators. One number for each height/model. (Page 11 on.)

Cheers
Olle

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Post by spookmineer » Thu Jun 25, 2009 4:51 pm

Thanks! Now these numbers make sense.

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Post by swinster » Sat Jul 18, 2009 2:15 pm

Ok, so I've been thinking about water cooling for a HTPC/gaming rig. This will be based on an OrigenAE s16v case (http://www.origenae.com/en/htpc_s16v.htm) which has as standard a 92mm intake and 2x80mm exhaust fans. I haven't spun these up yet so I have no idea how quiet they are.

The equipment to be put in the PC won't be exactly bleeding edge, but probably more powerful than that of a "normal" HTPC. I'm looking at either a Radeon 4870/90 or Nvidia 285 GPU and probably a Quad Core Intel of some description - not sure whether to go for the i7 or not. OC'ing will not probably be something I will dabble with, however, I do like tweaking my other systems to never say never.

Whilst I appreciate the cost of water cooling, I don't think that this will be a barrier 'IF' it will provide as good cooling with lower all around noise emissions to all air cooling.

What is the current state of good low noise water cooling and air cooling components. Has anyone got some suggestions of water systems and/or options for air cooling this type of system.

Olle P
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Post by Olle P » Fri Jul 24, 2009 5:42 am

swinster wrote:Has anyone got some suggestions of water systems and/or options for air cooling this type of system.
I suppose that with such a big case you could opt for standard quiet heatpipe coolers, at least provided that the case has plenty of free air around it.

For water cooling I'd recommend using some larger external radiator solution, like for example Aquacomputer Aquaduct 360, combined with a full cover block for the graphics card. Estimated price tag for the entire water cooling system ends up at ~$400.

Cheers
Olle

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