Feeds

back to article Heat sink breakthrough threatens ventblockers

A US government lab has opened for licensing a novel way of improving the cooling technology used in everything from CPU and GPU coolers to air-conditioning units: make the fan the heat sink, and the heat sink the fan. "We describe breakthrough results obtained in a feasibility study of a fundamentally new architecture for air- …

COMMENTS

This topic is closed for new posts.

Page:

Happy

@ ... waiting for Dyson to get to work in this area.

you wanna clean the dust outta the computer at the same time?

0
0
Silver badge

Very clever

I was sceptical at first, but reading comments above this looks to be an ingenius idea.

WRT "Several thousand RPM is going to sound like a jet engine"... Most PC fans I have come accross, at full speed, run at over a thousand RPM. Many of those on budget coolers or those which bundled come with CPUs run at 2-3k (I may be a little behind the times, but they did with the last one which came with a CPU I bought). I suspect that it will be able to be slowed, just like a standard fan, although probably not to the same extent (to maintain the air cushion). I guess it's something which would need investigating.

I can't beleive, though, the number of people who just seem to automatically poo-poo ideas like this. Whether they will work well in real life, or suit your specific needs, or will be economical to produce, they are interesting to read about.

2
0
Silver badge

CPU fan speeds

No, you're not behind. I bought an AMD Phenom II last month, and have just maxed out the stock cooler at 3462 RPM. It sounds awful, too. I just can't make up my mind what to replace it with.

0
0
Flame

Physics are fine - what about mass production?

Tolerances on that air gap are very tight, considering it separates two substantial masses - this seems to rely on a degree of precision manufacturing not widespread in consumer devices. Get that even a bit wrong, or just have too high a variation, and these will be difficult to trust.

It gets even harder when you scale it up to bigger things like air conditioners.

1
1

mini fridge?

"Looks almost identical to the type of fans found in mini fridges."

was a comment i saw on forums.overclockers.co.uk

ive never seen one. if it is they how can he patent?

1
0
Silver badge

@Citizen Kaned

Because those fans in those mini fridges are just that, fans, for the vast majority made of plastic. They just move air.

This thing is essentially a spinning heatsink that to the untrained eye looks like an impeller fan.

2
0
Mushroom

Fried Mice

The benefit of a heatsink is that you get a period of grace if the fan isn't working to shutdown. With this method the CPU would fry instantly in the event of an impeller fail. This may be OK for larger and (less time critical) failures in air-conditioning etc but I think the metal block on the CPU is here for a while. its a lot cheaper to replace a heatsink fan than a CPU!

1
2
FAIL

@Fried Mice

RTFA - or even just RTF headline

It is a heatsink that spins

If it stops spinning it will be a heatsink that doesn't spin

1
0
FAIL

"Hard disks are sealed units"...

No they're not, look closely and you will find the small breather hole in the unit. The one with the sticker that says do not cover. If it was sealed it would probably blow up due to internal pressure.

0
0
Bronze badge
Windows

Wait a minute, folks....

Surely it's a prototype, and not necessarily yet perfect.

See: http://www.theregister.co.uk/2011/07/13/coke_can_acoustic_lens/

and my comment:

"How things are made by sometimes trying what may appear ludicrous."

Rome. Day. Built. Not. OK now?

2
0
Thumb Up

Back to basics

Surface area and temperature differential is still all that is involved.

Bringing more hot surface area into contact with cooler air.

Seems to me that this device gets its efficiencies from higher speed airflow which improves the differential.

Be interesting to see the actual for energy usage (with some proper controls).

Noise presumably won't be that much of an issue as this is currently a long way from the domestic market.

I could see a domestic application using a slower rotating heatsink passing through an air flow - the major price there would be space.

Of course with space to trade in a domestic box you could always increase the heat sink surface area by using both sides of the mobo

0
0
Devil

There is something better but we refuse to use it.

TEC PEOPLE!!!!!!!

Thermal Electric Cooling.

It works!

0
0

TEC - It works

But not very well - almost anything is better than a peltier - about the only use they have in computers is no space, no noise environments.

1
0
Go

"most desktop PCs have the board mounted vertically"

maybe domestic and SoHo minitower PCs do, but lots of corporate small form factor PCs are horizontal. Some SFFs work either way.

There seem to be a lot of readers who've never checked their existing fan rotation speeds (it's often shown in the BIOS, or HWmonitor or similar will show it if it's a Window box).

0
0

@AC

"There seem to be a lot of readers who've never checked their existing fan rotation speeds (it's often shown in the BIOS, or HWmonitor or similar will show it if it's a Window box)."

The issue is more than rpm, this system seems to rely on creating turbulence, that will increase acoustic noise. In addition this is a heavy lump of metal doing 2000rpm, rather than a lightweight plastic or ali. 'normal' fan, which means more energy and more destructive power.

Agree with Colin Millar, Peltiers are very much a last resort due to cost, poor efficiency and long term reliability issues.

0
0
Bronze badge

read the pdf??

Just one thing, I think the diagram shows the wrong rotation direction.. if air goes in at center, the fan will rotate anticlock... unless the arrows indicate air flow coming OUT of the disc...

these may have been answered, blame the authorization delay... :(

"heavy and necessarily sharp edge spinining flywheel"? that would be most good HS/fans then.. plus the *production model* has *fan guards* :/

"air gap for thermal transfer" - this is the SAME gap that exists in most fans!

As for the need for fans.. there are enough HUGE heat-sinks about, and if you are NOT doing a massive overclock, a fan may not be needed.. if you do, liquid colling is easier..

Dust? plenty of cases that include fine dust filters, so it stays outside, and 'positive case pressure' will ensure air goes OUT of the cracks, not in.. :)

0
0
Silver badge

Sticky dust?

How will it cope with (amongst other things) cigarette smoke?

0
0
Silver badge
Holmes

Filter the smoke-

You could pass it though a tube into a couple of bags.

The bags catch the smoke particles.

You could call the bags... 'lungs' or something.

/BC

1
0

I've sometimes wondered...

about the possibility of using a Sterling engine to power a heatsink fan - after all, it'd be drawing it's power from the heat it needs to dissipate and the hotter the CPU got, the faster the engine would work. Unfortunately, it'd probably need a normal motor to get things moving until heat levels are high enough and there's probably several dozen other flaws I haven't thought of yet :)

Back to this device: dust getting into the airgap seems like a potential concern: there's plenty of stuff which can get into a 3-micron gap (http://www.engineeringtoolbox.com/particle-sizes-d_934.html). I'm not sure weight is an issue though - if anything, I'd expect a "Sandia" cooler to be lighter than a standard "metal+fan" heatsink: as it's more efficient, less metal is needed for the same "cooling" capabilities and it also doesn't need the plastic frame and fanblades of the fan (though it still needs the motor). And I'd assume that the centrifugal forces would keep the airgap size consistent, regardless of the heatsink's angle relative to the planet's gravitational pull.

On the other hand, the electric motor has to spin a relatively heavy chunk of metal, rather than a set of lightweight plastic blades. So you'll need a more powerful motor; together with the high-precision needed to mill the two pieces for the airgap, it may be difficult for a Sandia cooler to be competitively priced against a traditional heatsink setup...

0
0
Silver badge
Happy

Big, noisy and power hungry?

AND expensive...?

Gamers will snap them up...

2
0

Case Filter any one?

As previously mentioned.

A simple case filter, plus positive case pressure = no dust clogging up the internals.

Five years on, my PC is still nice a clean on the inside.

Only need to clean the filter once every six months.

Big heatsink with very slow turning fan means very quiet too.

Just need to re-build with newer/faster components.

0
0
Thumb Down

Looks dodgy

The rotating bit is predominately just the fan with a fancy impeller.

The mathematical modelling of the gap is questionable: Using pipe flow instead of flow between moving plates is entirely different in fluid mechanics and therefore heat transfer. Further, the graph shown doesn't apply within a boundary layer. And there are two boundary layers in shear between the moving plates in the cooler. That is nothing like pipe flow.

Treating the air gap as a conductive medium, based on the width of the gap is a gross fudge. I'm entirely unconvinced by the calculations.

1
1

Expensive...

...prone to failure...bleeding edge...cranky

All the overclockers will _need_ one.

2
0
Anonymous Coward

Hmmmm

Issues I see...

1. If the fan fails or begins to there is no direct contact slab of heatsink to act as a buffer.

2. Big heavy chunk of non streamlined metal spinning at high speeds can't be quiet.

3. Big heavy chunk of metal spinning at high speeds likely to cause significant vibration unless very well balanced and fitted - it could rip itself off the motherboard. Also, possible gyroscope effects?

4. Still as likely to get coated in fine dust as a normal fan. If that air gap gets compromised in any way then things start going wrong very quickly.

5. It's being compared with normal HSF combo's with slower running fans. What's the comparison against high speed fans that would blow far more air (and probably be as loud).

0
0
Facepalm

no dust? Right....

It'll not work when off horizontal and when stationary those ducts will fill nicely with dust as it'll still be statically charged.

What I want is a high voltage grid that zaps and disintegrates incoming dust. No one selling these?

0
1
WTF?

Scientists at play - mind the gap

Very dubious about ALL of the claimed benefits, but, since the sponsor is after all the US Department of Energy/Sandia National Labs, let's focus on the topical " + Provides increased energy efficiency". Their "drastic improvement in aerodynamic efficiency" supposedly "translates to an extremely quiet operation", no less. The report and patent dangle even more prospects of violent and dramatic upheavals to the state of the art in CPU coolers.

Most CPU coolers use an axial fan for good reason: axial fans give a high flowrate and small pressure rise, which is appropriate to the duty of CPU and casing fans. A typical axial 80 - 120 mm CPU cooler fan absorbs 1.8 - 3.6 W peak power (~0.15 - 0.30A at 12V). Centrifugal (radial) fans are generally used for low flow, high pressure duties.

What we see here is a centrifugal fan with (lots of) thick, cantilevered vanes and no top shroud. It should be good to absorb at least as much power as a similarly sized axial: however, it is very unlikely to function at all effectively in pumping, and nothing like as efficiently, as a properly designed centrifugal. Poor aerodynamics generally also lead to flow-induced noise. And BTW, there will be pesky boundary layers all over the front and back surfaces of the numerous vanes, happily producing friction and absorbing power. For a 100 mm diameter fan, even at 5,000 RPM, these BLs will be nice and thick, helping to block the radial flow in the channels between the vanes.

Then, on rear face of the impeller, there is that magic fluid-filled gap between the rotor backplate and the stationary base plate with the heat source. The flow patterns in this space are complex, and depend on stuff like scale, shape, speed of rotation, fluid properties, surface temperature distributions... Leaving the complexities of the heat transfer aside, there will also be friction acting on the rotor, which requires additional power from the fan motor. Given good data (*) - yes Sandia, they're already out there - you can calculate this windage, and for the Sandia specs (100 mm diameter, 5,000 RPM, 25-micron air gap) it comes out around 2.9 - 3.6W ( air temperatures 20 - 100C; or about 10 - 12W for the 5-micron gap they seem to aspire to for better heat transfer. This ignores sealing issues between the rotor and base plate.

So the motor power requirement of the Sandia Cooler could be roughly at least DOUBLE, maybe FOUR TIMES, that of typical state-of-the-art CPU cooler. There's also the niggling issue of where that friction heat in the air-gap goes - it ADDS to the thermal load that must be transferred out to the impeller and dumped into your room.

That relatively heavy metal impeller (all those fat blades) and high rotation speed, would need balancing to avoid vibration and possible contact or rubbing. Also, both to prevent vibration and hot spots, maintaining a uniform 5-micron cavity gap would be important (and tricky).

"Simple, rugged, cost-competitive" - "Dramatic increase in cooling performance without resorting to exotic methods???" - NOT.

Hard to discern real progress there for CPU cooling, no matter how you paint it, and IMHO apparently not a good technical case for throwing more cash into.

* http://www.esdu.com/graphics/dataitem/di_07004.htm -- Engineers with hard-hats only, please

1
0
Silver badge

@juice

water cooling loop to get the heat away from the cpu, stirling engine driving a fan on the radiator?

I smell a patent - or a seriously "cool" bit of cooling tech :)

0
0

Page:

This topic is closed for new posts.