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Hardware Technology

Quiet Cooling With a Copper Foam Heatsink 171

Zothecula writes: The Silent Power PC is claimed to be the first high-end PC able to ditch noisy electric fans in favor of fully passive cooling. In place of a conventional fan, the unit uses an open-air metal foam heatsink that boasts an enormous surface area thanks to the open-weave copper filaments of which it's composed. The Silent Power creators claim that the circulation of air through the foam is so efficient in dissipating heat that the exterior surface temperature never rises above 50 C (122 F) in normal use.
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Quiet Cooling With a Copper Foam Heatsink

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  • Dust (Score:0, Interesting)

    by Anonymous Coward on Wednesday July 30, 2014 @01:26PM (#47567735)


  • 500? (Score:4, Interesting)

    by hooiberg ( 1789158 ) on Wednesday July 30, 2014 @01:26PM (#47567741)
    This factor of 500 is a strange number. The copper fins of my CPU-heatsink also have a quite a large total area. A claim of two orders of magnitude needs a bit more justification than just a mention. Otherwise is just seems like a movie title.
  • Re:Perfect (Score:5, Interesting)

    by MDMurphy ( 208495 ) on Wednesday July 30, 2014 @01:40PM (#47567877)

    Dirt and dust is what I thought of also. While no moving air will help in that it won't draw as much air through it as a filter might, it will still collect lots of dust in hard to clean areas.

    The only thought I had, which seems impractical, is to be able to remove the heatsink and place it in a ultrasonic cleaning bath like those used for jewelery. I could see it as an interesting curiosity, one I wouldn't mind cleaning once a year so so if it were on display. But I can't see it being a practical alternative for home use.

    If it's very efficient maybe there's a benefit on putting them on rack-mounted servers that have cool, clean, air blown through them. Might decrease the density of servers you can put in a rack though, so there'd have to be a pretty good efficiency gain over active cooling to make that worthwhile.

  • Reynolds number (Score:5, Interesting)

    by TeknoHog ( 164938 ) on Wednesday July 30, 2014 @03:27PM (#47568877) Homepage Journal

    basically means that for slower airflow, you need larger gaps for air to flow through. This is why the sponge is bad for heat dissipation, and great for insulation. It's kind of intuitive, but it's nice to have some science backing to it. Having a large surface is good, but it doesn't help if the airflow across the surface is limited.

    On a side note, I've been on a quest for quiet cooling since the very early 2000s, incidentally after getting a physics degree. It's mostly in the last couple of years that I've started to see really sensible coolers in the general market. For example, the usual CPU cooler in the olden days had a fan pushing right against the CPU with minimal fins in between, meaning there's a considerable high-pressure centre with no airflow. No one with a fluid mechanics 101 would design crap like that. OTOH, the traditional CPU/mobo setting is a little problematic; first you put the most heat-concentrating element in the middle of everything, and then later you realize it needs cooling. (I'd put the CPU socket on the reverse side and use the case as a huge heatsink...) Now finally the designers have the sense of using a straight sideways airflow, combined with heat pipes. Why the fsck did this take so long?

    I used to strive for pure passive cooling, but in the end I don't mind a large, slow fan -- it's enormously better than no fan, and still indistinguishable from other background noises. This is another nice thing to see in cooler designs, from the 1-inch whiner in my first Linux laptop to the 140-mm quiet giants that can easily manage a couple of hundred watts of GPU.

    BTW, if you ever need to explain somebody how a heat pipe works, take them to a sauna.

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