Aerocool HT-101.....fake copper?

Bluefront · Post by **Bluefront** » Fri Oct 08, 2004 11:01 am

So I'm lapping the base of my HT-101 before using it for the first time. Then I lap the little lower fin section (it had scratches) that holds the mount brackets to the heatsink. After a few minutes on 1000 grain paper, I discover this little copper-colored fin section is actually anodized aluminum.

Now I wonder if the actual heat-sink fins are really copper? I know this is a relatively light heatsink for the type and size. Maybe this has been reported before....but it's a new one on me.

rbsteffes · Post by **rbsteffes** » Fri Oct 08, 2004 11:22 am

Hmmm how do you feel about dunking your HS in water?

Anyone good with physics want to calculate the displacement?

Vihta · Post by **Vihta** » Fri Oct 08, 2004 12:36 pm

Density=m/V

m=weight and V=displacement

The density of copper is 8,96 kg^3/m^3 (8960kg / one cubic meter).

So if you are interested enough you can calculate this fairly easily. Fill some container completely with water and place it inside a larger container. Now put your heatsink into the water and then measure the volume of the water which leaked over into the bigger container. You can find the necessary equipment in your kitchen.

Ofcourse you can also calculate the displacement of the heatsink after measuring it's physical dimensions. I don't know what kind of equipment you can come up with so it's a bit hard to say which method yields better results.

Maybe it's better to measure the volume of the water which leaks over. One can purchase very accurate syringes and stuff from medical stores etc.

Hey, stop laughing! I know my english sucks.

I hope you can understand what I just wrote. Good luck

Post by **Rusty075** » Fri Oct 08, 2004 1:17 pm

rbsteffes, Vihta,

That's good thinking, but it won't work.

The HT-101 isn't a solid, uniform material. It has heatpipes, which have a very, very low, but unknown density.

Vihta · Post by **Vihta** » Fri Oct 08, 2004 1:28 pm

Rusty075 wrote:rbsteffes, Vihta,

That's good thinking, but it won't work.

The HT-101 isn't a solid, uniform material. It has heatpipes, which have a very, very low, but unknown density.

Edit: Nevermind.. I just checked what the HT-101 looks like. If the heatpipes can't be removed it's pretty much impossible to do what I suggested earlier.

Bluefront · Post by **Bluefront** » Fri Oct 08, 2004 1:58 pm

Well....all you need is to find someone to put a heavy scratch on the flat section of one of the fins. Aluminum would definately show through. (If it was aluminum)

One other thing about the HT-101. I've heard the fins are soldered to the heat-pipes. Wrong. They are a press-fit only. A very slight amount of tweaking will remove the fins. Of course if you leave the shroud in place they're not likely to loosen. But the heat transfer from the heat-pipes to the fins would be better if they were soldered.

hofffam · Post by **hofffam** » Fri Oct 08, 2004 4:31 pm

It is uncommon to plate aluminum. I don't believe aluminum responds to the same process used to electroplate metals. Copper is commonly used to plate nickel (think of U.S. coins). Most "colored" aluminum is anodized, which is not the same as plating. Anodizing does not put another metal on aluminum - it hardens the surface by creating a thin layer of aluminum oxide. Dye is added for color. I wonder if the base of the HT101 is not aluminum but nickel?

I'm not sure soldering guarantees a better thermal transfer. It can if it "fills in the gaps" between two surfaces. Solder is widely used of course for electrical connections but a high pressure crimp is considered superior (for electrical conductivity) because there is no 3rd material in the signal path.

jones_r · Post by **jones_r** » Fri Oct 08, 2004 4:38 pm

One other thing about the HT-101. I've heard the fins are soldered to the heat-pipes. Wrong. They are a press-fit only. A very slight amount of tweaking will remove the fins.

Maybe this explains why I got my HT-101 with one of the fins missing!!!.

Anyway, what's the point of all this ?, the HT-101 is still one of the best heatsinks (if not the best) available for Athlon XP. My temp sensor isn't calibrated, but I can tell you that using the same motherboard, I get the same temps with my new Athlon XP2400 CPU and HT-101, under idle/load, as I got with the old 1.13GHZ CPU and stock fan @12V (4500 rpm), only now I use 80mm fan spinning at 380 (!!) rpm. I know of no other heatsink capable of such performance. There is practically no airflow going through it, about 4 CFM to cool down a 2000mhz CPU (68.3W).

Bluefront · Post by **Bluefront** » Fri Oct 08, 2004 5:27 pm

hofffam.....You're probably right about metal/metal contact being the best for heat transfer, in a perfect world. But with the design (six pressed holes in each fin) there is no way the metal/metal contact can be perfect. In my case the upper fin just slipped off. Jones_R had his upper fin fall off somewhere and get lost. So the fit of the fins to the heat-pipes definately would be improved with solder.

Jones_R.....The point here is deception. I thought the whole thing was solid copper. Silly me. Your heat/temperature experience with the HT-101 sounds pretty good. But to someone else with a different setup, the cooling advantage of solid copper might mean a few degrees, maybe a few hundred lower rpms.....

jones_r · Post by **jones_r** » Fri Oct 08, 2004 6:19 pm

But to someone else with a different setup, the cooling advantage of solid copper might mean a few degrees, maybe a few hundred lower rpms.....

You're right, I wouldn't mind a few hundred lower rpms shaved from what I already got. How can we get a true copper piece ?

hofffam · Post by **hofffam** » Fri Oct 08, 2004 6:21 pm

Bluefront - I agree with you that solder may be the most practical solution for many places where two metals have to be joined.

I think you exposed an interesting issue with the HT101 - is Aerocool trying to deceive us? Their website says the cooler features "Full copper cooler."

What does that mean? Fully copper-plated? Your sample is obviously not 100% copper.

sganimefan · Post by **sganimefan** » Fri Oct 08, 2004 7:18 pm

Maybe they'll say it's actually copper-plated silver.

silvervarg · Post by **silvervarg** » Mon Oct 11, 2004 1:30 am

It could be possible to calculate the approximate volume of the cooler by accurately measuring.
The density of copper is about 8.9 g/cm^3.
The density of aluminium is about 2.7 g/cm^3.

The large difference in density should make it possible to find out even if the measurement is slightly off.

Comapring the HT-101 with the older DP-102:
HT-101 fins: 76*50mm = 3800 mm^2
DP-102 fins: 66mm round = 3419.5 mm^2
Not counting the "missing" part of the fins due to the heatpipes going through.
Number of fins seems to be about 36 on both of them.
Since I can't really check now I assume the fins have equal thickness.
Fins of HT-101 should be slightly heavier than fins of DP-102.

The HT-101 has a small heatsink at the base, but thinner base plate.
I would still say that the base of the HT-101 including heatsink contains more mm^3 of metal than the DP-102. The majority of the base-plate of the DP-102 is made out of aluminium (no fake here). Only the fat heatpip is copper, the rest is aluminium.
The weight of the 6 small heatpipes seems fairly close to the weight of the single fat heatpipe.
If made from the same material this should make the HT-101 heavier than the DP-102.

The weight of the heatsinks without fan, but including shroud are:
HT-101: 470g
DP-102: 580g

Since this is exactly the opposite of what we would have expected the only reasonable conclusion that we can draw is that they are at least partly made of different materials. The HT-101 must contain more light materials than the DP-102.

If I constructed a heatsink and thought about using different materails, than I would use copper where you had the highest heat, so that would be the base of the heatsink. Since the HT-101 does not use copper there it would not make any sense to use copper in the fins either.
Assuming that HT-101 uses aluminium in the fins, then ~20% weight difference to the DP-102 is probably not enough to let the DP-102 have copper in the fins either (sigh!). Since I just need to know I will make a big scratch in one of the fins in my DP-102 when I get home to find out if it is copper or just copper plated/anodized.

Chang · Post by **Chang** » Mon Oct 11, 2004 12:47 pm

I did see one review that noted that the "lower fin section" was aluminum. This shouldn't be too surprising seeing how it's there to hold the clip down, not to add surface area to the HS. That there's no thermal compound (nor instructions to put thermal compound there), should suggest its lack of importance to cooling. Making it out of Al makes sense since it's cheaper and lighter.

As for the fins, given their size and thickness, it must be cheaper to just make them out of copper than to make them out of aluminium+paint. Also, seeing how the fins pretty key to cooling, making them out of copper makes sense on that end too.

I don't think you can compare the HT-101 to DP-102 for mass comparisons. The DP-102 uses a metal mounting bracket for the fan -- the HT-101 uses a plastic shroud. The DP-102 has 36 fins -- the HT-101 has 31 fins. The weight of the heatpipes will vary depending on thickness and internal design -- so you probably can't say that 1 fat one equals six skinny ones.

Bluefront · Post by **Bluefront** » Mon Oct 11, 2004 1:32 pm

Chang....Welcome to SPCR. Those fins probably are copper, but ? That lower fin section was anodized, not painted. The fins could be constructed that way.....still would cost way less than copper.

The spring clips are stainless, which doesn't transfer heat very well to the lower fin section. I made a set of clips out of copper, which would transfer heat into the lower fins. Since they are in direct contact with the copper mount plate/heat-pipes, they could be of some benefit to cooling. But the thing cools very well as is.

Chang · Post by **Chang** » Mon Oct 11, 2004 4:21 pm

But again, the cost for anodizing the surfaces for 31 extremely thin and separate sheets of aluminum must be more the cost difference in material. Since I suspect you'd have to anodize each fin individually (since punching them out would reveal the true material), not only are you paying more to anodize, but your cost to manufacture has to go up too.

Now if it were a solid block of aluminum or there were only a couple fins, you might save enough money in material to make it cost effective. But I just can't see a heatsink of the thin fin design being cost effective to make out anodized aluminum.

ultraboy · Post by **ultraboy** » Mon Oct 11, 2004 5:25 pm

Chang wrote:..., the cost for anodizing the surfaces for 31 extremely thin and separate sheets of aluminum must be more the cost difference in material.

That's true if they do it only one set of HS. Imagine a 1000 units of HT-101 would have 31,000 fins, and I'm sure they make much more than that. Not to mention they have other products that will be using similar process as well. So this will lower cost/piece dramatically. They might even just buy the anodized pieces from an OEM guy whose line of work is anodized metal and nothing else. That'll make it even cheaper.

Sorry, this is a bit OT. Let's go back to the topic..

Bluefront, did you contact Aerocool? It seems they have a lot to explain on this.

canthearyou · Post by **canthearyou** » Tue Oct 12, 2004 7:19 am

I don't mind if it is aluminum because I would prefer the lighter HSF anyway, almost bought the aluminum Jr version.

There is a slight imperfection on one corner of a fin on my HT-101. I am looking at it under jeweler's loupe. There appears to be a darker metal underneath the copper on the edge where it might have been struck or a burr removed. I rubbed on it to see if it was something on it, but it's still there. I examined where the metal screws dig into the top plates, but could not see any clear evidence of another metal color where they go through the provided holes. I could see a little bit of copper colored buildup around the threads. The plates have a slight matteness to their finish, but are still fairly shiny. The flex easily with some springiness, more like copper than aluminum.

It would be simple to cost-effectively anodize the plates. You just punch the plates and assemble them onto the heat pipes then hang it from a hook into the anodizing bath and anodize the whole thing at once. You might see some of the original metal where the plates are punched to receives the heat pipes, but the anodizing should cover that up.

EDIT: Some relevant information.

http://www.finishing.com/134/37.html

"aluminum look like pewter, stainless steel, copper, brushed bronze or polished brass"

http://www.anodizing.org/definitions.html

Of course, Aerocool should not misrepresent their product.

Steve