Which radiator to use? (pictures)

Grizely1

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I now have a choice between two different radiators for my watercooling unit that I am building. Do not cast your judgement based on whether or not said radiator will fit in the case - I am not building an in-case unit. The radiator, pump, and resevoir have their own special case.

I cannot decide which radiator to use. The first (the top one) is much thicker and better built than the second (bottom) one. However, it's made of brass. The second one (bottom) is wider and taller, but not as thick, and made of aluminum. It's also a fair bit more beat up, as you can see in the pictures.


click here for pictures


Anyways, I need some good opinions. Thanks.
 
Where did you jank those from? LOL!
Some one who's bike dont work no more :)

I would vote for the thinner one...as i can not see the path on the other one...

what are the dimentions?

I was once gonna yank one from a motorcycle....But i was too much of a pain to ever make it fit the case...(boy that was long ago....back in shop class)

I am not sure about the performace of such a device....but would it not make sence to grab a computer one....more made for it....


can't go wrong with 3 120mm fans :)
 

MadHacker

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Question..
are they both all copper?
copper and aluminum don't mix at all...

if the chice is the two that you have pictures of..
the one that is 2 pass is good because
It will be less water resistants then the 6 pass one.
for best cooling performance to be used with powerful fan. the core is thicker and thus will need a stronger fan to blow the air through. (more noise)

the 6 pass core is thinner and therfore will need a fan of less force to push the air through. (less noise)
But may not be able to cool the water as well(not sure)
 

The_Gremlin

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Strictly from a cooling perspective, I'd put my money on the top radiator. It has substantially greater surface area for the internal coolant to interact with (and trade heat with) and should provide better cooling.
The bottom one isn't really even a radiator ... it's essentially a tube with some cooling fins. Yes, it will provide cooling, but probably not as much as the top unit.

As an experiment (and before you install either into your enclosure) why not do a tomshardware-style test with each and measure your temps??

Speculation Zone - It looks like both "rads" were yoinked out of the climate control system of a car/truck/automobile. The top one looks like the heater core and the bottom one looks like the air conditioner core.

Been cruizin' the wrecking yard, eh? :p
 

DPolkowski

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If you are going to use those I would suggest the top one. There looks to be a lot of surface area because of its thickness. While the other appears to have better airflow from that top down view, I think the more compact will offer better dissipation.

Let us know how it turns out.
 

Grizely1

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Thanks for all the replies guys, and most of your opinions have confirmed what I already figured would be the answer.

The top one is a two pass, the 2nd a 6 pass. The top one is a copper core (copper tubing) with brass fins, the bottom is purely aluminum. I don't want to mix my copper waterblock w/ the aluminum either, corrosion sucks.

I never thought about doing a test, for some odd reason. I will set up a little test for them and try it out :)

btw they were from heaters/ACs from vehicles, you were correct:)
 

chuckshissle

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Well the first one is high-flow dual pass design and have thicker fins for better cooling. It's is also smaller and can be easily fitted inside the case or the backside. The second one is multiple pass and have thinner dimension which can be fitted internally as well like in the side panel. I think either one is fine as long as you have the right fan to fit in it. I think both can sport a 120mm fans front and back. Use them long and skinny zip ties to install the fans. Preferably I choose the first one.
 

ih8makingupnames

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I have always wanted to do something like this but I have never had the time. Looks like a fun project. I think that I would go with the aluminum one after checking on the thermal properties of brass vs aluminum. http://www.engineersedge.com/properties_of_metals.htm It looks like you have about the same amount of surface area on both with the one being thicker and the other being wider. If the pipes that run through the aluminum fins are aluminum as well then I would go with it where aluminum has about twice the thermal conductivity as brass. I hope this helps and let us know how it goes. I would be interested in seeing some pics and discriptions of the finished project.
 

Grizely1

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Yeah, I've already cleaned out the copper one, I'm running water through the other one right now. I'm about to setup a little test where i will see which one cools better. 2x 120mm fans each, everything the same except im going to switch out the radiator.
 

apesoccer

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Noice...

You know they both hold water under pressure? If so, you could test them both, to see which cools better. In all likelyhood no one here is going to be able to tell you which of those two is going to cool the best...Most of the guys here are probably going to have had experience with aluminum coolers...

Or hell, if you've got enough pump...Use em both. Might be overkill, and create unneeded extra problems though. =) But what's the point, if you can't overdo it. =D

Anyway, that's pretty bad ass that you're creating this from scratch. i hope it all works out for you.

p.s. - you HAVE to post pics of the finished product, and it'd be cool to do a write-up on it as well, because there will undoubtly be other people who want to try it as well.

EDIT: oops i guess i took too long to hit send... =)
 

Grizely1

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Using both.. never though of that. I may, although there's still the corrosion problem to worry about. Once the pump I am going to use comes in the mail I'll try it with both radiators, and see what the flow is like.

I am definately going to take pictures along the way, and make and article/post on it once it's finished.
 

Grizely1

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could be lead coated, not sure. tbh i havent looked at it very much, because frankly i dont care what it smade of as long as i know the core is copper.

the other one is 100% aluminum. with a coating of some kind.
 

306maxi

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Aluminum is non corrosive and will not react with other metals. So you have no worries there. But i'm not compleatly sure that the tubing is aluminum. It may be steal.

By the way the fins on the upper one are lead coated copper not brass.

Not strictly true. Aluminium will oxidise. That's why you should never just put tapwater into your radiator because it will **** the alumiun head on your engine if it's an aluminium head.
 

MadHacker

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Using both.. never though of that. I may, although there's still the corrosion problem to worry about. Once the pump I am going to use comes in the mail I'll try it with both radiators, and see what the flow is like.

If you have a copper water block don't use the Aluminum core.
Don't mix it with copper!!!
the alluminum will corode a litle bit creating Aluminum oxide which will protect the aluminum tubing. but it will make the copper dicintergrate. and in 6 months you will have a hole in your CPU block or in much less time a hole in your heater core if you run both cores. then you will be replacing oyur motherboard, video card, and anything else that get's shorted...
not worth it.

but don't take my word on it. do a little bit of research on "Galvanic Corrosion"
 

The_Gremlin

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If you have a copper water block don't use the Aluminum core.
Don't mix it with copper!!!
the alluminum will corode a litle bit creating Aluminum oxide which will protect the aluminum tubing. but it will make the copper dicintergrate. and in 6 months you will have a hole in your CPU block or in much less time a hole in your heater core if you run both cores. then you will be replacing oyur motherboard, video card, and anything else that get's shorted...
not worth it.

but don't take my word on it. do a little bit of research on "Galvanic Corrosion"
I wasn't going to, but I must step in to make some corrections.

If MadHacker had actually read up on "Galvanic Corrosion" :p , he would have noticed that Aluminum is more anodic than copper and would therefore serve to lessen the corrosion of the copper CPU/GPU blocks. So, yes, aluminum and copper do not mix, but if they are mixed, it is the aluminum that will be corroded and NOT the copper.

Additionally, depending on what kind of cooling fluid you have in your system (i.e. if the fluid is non-conductive), it is possible that the copper/brass/aluminum/etc could be electrically isolated, and therefore there would be no chance for galvanic corrosion to occur. (remember that the metals need to be electrically connected for dissimilar metal corrosion to occur)

Now for a [edit] not so [/edit] short lesson on thermodynamics (heat transfer):
The transfer of heat works similar to a bunch of resistors (or insulators) that slow the movement of heat and would follow a path similar to this:
R1 - Heat must move within the fluid to get to the interior surface of the rad
R2 - Heat must transfer from the fluid to the rad material at the interface (fluid to metal)
R3 - Heat must move within the rad material from the fluid surface to get to the air surface of the rad
R4 - Heat must transfer from the rad material into the air at the air interface (metal to air)
R5 - Heat must move within the air to the general air of the room

The total heat transfer of the system would be proportional to 1/(R1+R2+R3+R4+R5), so minimizing the resistance to heat transfer of any one of these would improve the system.

Lets compare each "resistance" for the two rads in question:
R1 - the best way to move heat within a fluid is stirring and turbulence=stirring. The TOP rad has the best internal mixing hands down.

R2 - the key word here is surface area, and again the TOP rad has by far the greater surface area between the rad and the fluid.

R3 - copper is a better heat conductor than aluminum, and both are better than lead. Without actually doing the calculations it's hard to say which rad would do better. BUT, since R3 is going to be the smallest resistance of all the Rs (probably by several orders of magnitude) it's probably safe to say that it really doesn't make that much of a difference! (it would make a difference if we were comparing identical designs of different material, but we're not, so it doesn't)

R4 - like R2, surface area is one of the key variables here, but it's also going to be dependant on the fans in use and the air flow through the rad. We've already stated the TOP rad wins on surface area. As for air flow, IMHO they will both flow fairly well.

R5 - completely dependant on the fans and the flow rate through them.

Sorry for the novel/lecture, but it's not as simple as saying this one has 6 passes so it's better, or this one's made of copper so it's better.

However, I stick by my original recommendation that the TOP rad will perform better.

:wink: Patiently waiting for Grizely1 to get his pump and post some results. :wink:
 

Grizely1

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Thank you, that post was VERY informative. Not just applying to radiators.

I am going to conduct the test this afternoon (hopefully). I have a double sink in my basement, so I'm going to constantly feed one with hot water that i've already determined stays at a constant temperature. i have two water thermometers and i'm going to measure the input temp and output temp of the water. same fans, pump, tubing, just switching the radiator.
 

MadHacker

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I wasn't going to, but I must step in to make some corrections.

If MadHacker had actually read up on "Galvanic Corrosion" :p , he would have noticed that Aluminum is more anodic than copper and would therefore serve to lessen the corrosion of the copper CPU/GPU blocks. So, yes, aluminum and copper do not mix, but if they are mixed, it is the aluminum that will be corroded and NOT the copper.
...

Well I stand corrected... been a few years since I read about it...
 

Storm1234

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Remmber to post some pictures of your project // experiment, I would like to see it threw, and I would imagine others would also.

Thanks Storm
 

Grizely1

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My original idea didn't work.

So, I filled the sink with hot water. The pump drew its water from the sink (it was an underwater pump), went through the rad, then back into the sink. I waited until the water temp was 64C even, then started the fan/pump. Ran the fan/pump for 16 minutes, taking temperature readings every 2 minutes. I will write a very short summative article including pictures asap.