making radiators

[Antimatter]

has anyone made their own radiator? i was thinking of getting some copper tubing, a tube bender, and a bunch of thin sheets of copper and making my own. i could make it exactly the right size and everything then.

has anyone tried this? it might be a little difficult to get the fins close together enough => lots of labor. sound like a good idea? waste of time?

[hara]

Search a scrapyard for a heatercore/radiator. Go to a radiator shop and have it resized

[bigben2k]

Actually, you'd want a square copper tube, and solder Aluminium fins to it, but soldering Alu is a PITA.

The scrapyard is more "time efficient".

[dax]

maybe i could make smallish rads like this that would fit in 1-2U cases... dunno if it would be feasable though

[bigben2k]

That would be most feasible! Start collecting those cans of pop!

[dax]

cans of pop? hmm nah i'm not going to try to solder alu, way too much work! thin copper plate or a few layers of copper wire would be better i think... i could always try this (read: if i have the time)

How large would it have to be in order to be a bit efficient? any ideas? And would serial or parallel be better (water going through a S like thing, or water being split over a few tubes)? My vote goes for parallel.

[bigben2k]

I think it'd be best with a single S design. The copper tube shouldn't be much of a restriction (if 1/2 or larger).

As for size, it's hard to tell, but I'd go ahead and fill a 1U height with it (12 inches deep? by 19 inch wide)

The problem is that if you want airflow from front to back, you'd be better off with an S design, where the water flows in the opposite direction of the air, if you know what I mean.

[dax]

hmm ben i was still talking about those small rads, not ones to fill entire 1U cabinets, heh... Just the ones to create a seperate loop for each 1U/2U rackmount

[hara]

most tranny coolers are usually thin enough to fit in 1u chasis

[bigben2k]

Nice call, hara!

Now to find one in copper...

[dax]

finding a copper one might indeed prove to be difficult... as my goal isn't overclocking, i might get away with an all alu system though

[Antimatter]

Originally posted by bigben2k
Actually, you'd want a square copper tube, and solder Aluminium fins to it, but soldering Alu is a PITA.

The scrapyard is more "time efficient".

is there some problem with copper fins? copper is much more thermally conductive than aluminum right, and thus a better radiator material?

watercooled 1u servers! that would be cool (har har).

i was thinking of not bothering with soldering, just drilling holes in the copper sheets and then interchanging them with washers or something on the copper tubes. you might loose some conductivity from tube to fin this way, but not so much if its tight right?

[dax]

the problem with copper is weight, and, soldering isn't that hard, i'ld still recommend you to actualy solder the fins on it...

[bigben2k]

Aluminium makes for a better heatsink with air, because of its low density. Copper is best with water, so for a rad, you go for copper tubing, and Alu fins.

[hara]

Aluminium makes for a better heatsink with air, because of its low density. Copper is best with water, so for a rad, you go for copper tubing, and Alu fins.

I think what you're saying is a false rumor

[bigben2k]

He he, no, it's correct. I'd refer you to Dave's article on AMDMB, but I still can't find it.

The copper is great for direct contact with the heat source, which makes it an excellent base for an HSF, but the Alu will give you more surface area, for the same weight.

Copper's thermal properties are so good, that air has a harder time getting all the heat out of it.

Now all this assumes that the Alu fins are in good contact with the copper tube. If one uses lead to solder the fins, you can forget about it: you might as well have copper fins because it won't make much of a difference.

Where's my MIG welder?

[hara]

I read that article on amdb's website. It is true that copper is denser i.e. the same volume weighs more in copper than in aluminium but who cares about weight in pcs as long as it cools :shrug: ?

The reason heatsink manufacturers use aluminium is because it is cheaper to obtain/manufacture. It is true that it's also lighter. Fusing metals together is another option.

[redleader]

Copper's thermal properties are so good, that air has a harder time getting all the heat out of it.

Dear god why won't this garbage die. Its so wrong its not even funny.

[bigben2k]

Sorry, sometimes I just spurt out garbage.

Here is Dave's article (at the relevant page, #4 and on).

Note that on page 7, you can see that Water's thermal capacity is not only 4 times higher, Water is also 1000 times denser, giving it 4000 times the heat capacity (heat transfer is another subject).

[hara]

Thermal conductivity is the most important to dissipate heat.

[bigben2k]

Water and air both cool solids via convection. The primary difference is the convection coefficient of water compared to air. At the same conditions (temperature, flow velocity, etc.), water is on the order of twenty times more efficient at convection than air is.

[hara]

I'm sorry I haven't clarified. I meant about heatsinks/waterblocks (the metal)

[natopotato]

actually there is some truth to the Al disipating heat rumor. It's all due to the fact that aluminum has a lower specific heat than copper. it takes more energy to heat a mass of copper than an equal sized mass of aluminum. Likewise, aluminum also looses heat quicker. However, in most applications(ie. heatsinks) copper is the better metal for heat disipation.

[Antimatter]

Originally posted by bigben2k
If one uses lead to solder the fins, you can forget about it: you might as well have copper fins because it won't make much of a difference.

Where's my MIG welder?

what is wrong with lead based solder? i have heard that lead has pretty good thermal conductivity properties.

silver solder? (i have no idea how much silver this actually has in it, but...)

eh... this is starting to sound like a lot of work, but it will probably be worth it.

[MadDogMe]

*********************************************

False Perception: Since aluminum cools more quickly once a heat source is removed, it must be more efficient at convection.

Truth: The heat source driving energy into the heat sink remains in effect until you turn off your computer. If you have aluminum pins or fins, congratulations, they will cool off more quickly than copper ones after you shutdown your PC.

Now let us go back to the aluminum versus copper debate. Copper’s higher conductivity means is that a thinner copper fin can transmit as much heat as a thicker aluminum fin. However, on a weight-basis, aluminum can conduct more heat than copper. If weight was no object, copper holds the edge. When weight is a limitation, aluminum has the advantage. Conductivity multiplied by density is a "weighted" measure of a material’s conduction efficiency. It is this "weighted" efficiency that leads to the use of aluminum in the fins/pins of many heat sinks. It is certainly not because "aluminum gets rid of heat better than copper".

Taken from myv65(AKA~Dave Smith*)'s article...
*famous hydro~thermal Guru!