DIY heatsinks

[Peter Daniel]

What's the heatpipe?

[Jarno]

Hello all,

I found my heatsinks at a scrapyard, they take apart all sorts of electronics and make their money off the aluminium (or the copper, stainless steel or plain steel, depending on what they take apart.
The guy at the scrapyard told me that he came across "things" like that often.
Well, from the looks of it I think they are from some sort of power supply or controller.
Size: 200mmx370mmx40mm (2 pieces). I had to pay 3 Euros per kilo. 2 Heatsinks weighed 7 kilos, so that's 20 Euros (I did some haggling, not very much though).

Greetings,

Jarno.

[miguel2]

Hi,

There are a lot of ideas here. I have to say that this idea come after seeing the "lotusblossom" webpages (thanks Carpenter). I just turned it 90º to have bigger fins and not to drill so many holes. I agree with the questions you raise about surface contacts lowering the heat transference. But I find hard to accept that the square tubes between the fins don't do the job. Aluminium has a very high heat conduction and the limiting process should be in the surface contacts - that is why I chose 2 cm tubes. The heigh of the chassis can also be increased to get more heat dissipation (under reasonable limits...).
But I never done heatsinks before so your opinions so I guess I 'm biting my nails

BTW I am from Portugal.

[carpenter]

I think of the spacers between the fins as a pathway for the heat to travel. The trapped air in the center of the spacer tubes acts as an insolator and restricts the heat's path to the outer perimeter. The bar stock is capable of transferring more heat. This could be likened to pedestrians trying to cross a fenced court yard on a small, surrounding sidewalk. If the center of the court yard is accessable more people can cross.

I'm not an engineer and this is just the way I view things.

On the flip side: A chassis on Pass Labs was constructed using tube spacers and seems to be working well.

John Inlow

[moses]

Peter: A heatpipe is generally a hollow tube, often copper, filled with a liquid that vaporizes at relatively low temperatures. Basically one side of the pipe is where the liquid becomes a vapor. As it absorbs heat it becames vapor, and moves to the other end of the pipe, where it condenses, releasing heat on that side of the pipe. So you would mount one end on your transistors, where it would asorb the heat, then carry it to the other end where your heatsinks are, where it would release the heat. The concept has been around for a long time, often in heating/cooling system, however the decade or so they have been using the concept in high-end servers, and lately the computer ethusiest market, making it easy to get heatpipes of varies sizes and types these days.

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And no, I can't spell, and my grammar sucks.

[carpenter]

Here's a mono block chassis. Dimensions are roughly 19" x 24" x 7". Fins are 5.25" x 5.0" each.

[fcel]

Carpenter,
How about some more pictures showing the close up of some of the details? Is this the 1st one that you actually built of your own design? Looks nice.

[Peter Daniel]

This is one cool (running) chassis.

[carpenter]

Thanks for the nice comments, guys. This is my second chassis and the second design. The first design was fabricated for the original Zen. You can find that design on my web page.

John Inlow

[hifiZen]

Hmm, neat idea... just the opposite of how a refrigerator works. I guess the downside is that there's a slight efficiency loss, since the heatsinks will always have to be cooler than the transistor mountings in order for it to work. Ultimately, it would still be better to mount transistors directly to the heatsinks, but a heatpipe sounds like a good way of transporting heat around...