Heat sink breakthrough

SouthBit

Dealer
Joined
Jan 6, 2011
Messages
1,173
Reaction score
23
Location
Cape Town
Interesting new heatsink design which basically combines the heatsink and fan together.

http://www.theregister.co.uk/2011/07/12/air_bearing_heat_exchanger/

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-cooled heat exchangers," wrote Jeffrey Koplow of the Sandia National Laboratories in Livermore, California, when he first unveiled the technique in a 2010 research paper entitled "A Fundamentally New Approach to Air-cooled Heat Exchangers".

Today's typical heat-exchange system involves blowing air across a collection of fins that dissipate the heat contained in that air. While this method works acceptably well, it has a few inherent problems: first, a boundary layer of air encases the fins, limiting their ability to dissipate the heat from the air flowing past them – an unavoidable aspect of fluid dynamics.

Second, fins get fouled with debris – as has been amply demonstrated by Reg readers again and again. When a heatsink's fins get clogged, their ability to dissipate heat is compromised, so fan speed needs to increase, which uses more power and creates more noise.

"The tension in the market place between the need for energy efficiency and logistical considerations such as equipment size, cost and operating noise has resulted in a compromise that is far from ideal," Koplow wrote.

His solution is elegance itself, and attacks the limitations of traditional designs on all levels: it effectively eliminates the boundary layer, prevents clogging from dust and debris, and allows for quiet, energy-efficient operation.

Koplow combined the heatsink and the fan, spun the resulting portmanteau, and voilà: the "Air Bearing Heat Exchanger" – which was rebranded by the Sandia National Laboratories' PR department as the "Sandia Cooler" before they opened it up for licensing last week.
Sandia National Laboratories fin fan

The 10-centimeter prototype that he developed in his lab consists of three basic parts: an aluminum base plate that is bonded to the surface to be cooled (a CPU package, for example); a finned "heat-sink-impeller", as he calls the rotating element; and a brushless motor to spin the impeller.

Cool air is drawn down into the center of the impeller, which is spinning at "several thousand rpm," Koplow wrote. The cool air comes in contact with the hot base plate, and is centrifugally flung out past the circumference of the device, drawing the heat with it.

In his prototype, the impeller floats on top of the base plate on a thin (~0.03mm) gap of air, "much like the bottom surface of an air hockey puck and the top surface of an air hockey table," he wrote, also adding the analogy of a hard drive's read/write head, "but with many orders of magnitude looser mechanical tolerances".

Koplow's 2010 prototype was just that – a first attempt. With further work, he expects to achieve closer tolerences and improved efficiencies.
Sandia National Laboratories fin fan schematic

He has high hopes for this "Fundamentally New Approach", envisioning a 30 per cent improvement in such energy-hungry devices as "air conditioners, heat pumps, and refrigeration equipment", which could result in what he estimates to be a five per cent reduction in overall electrical power consumption in some scenarios – a figure Sandia bumped to seven per cent in a recent release.

Such hefty reductions, Koplow wrote in his 2010 paper, could result in a "significantly increased grid operating margin, and significant reduction in heat-wave generated load spikes."

IT would benefit, as well, with more-efficient cooling allowing system designers to break through what Koplow refers to as the "Thermal Brick Wall" – the inability to run CPUs and GPUs at high clock rates due to temperature constraints. More-efficient heat-sink tech could also result in more-efficient data centers, which continually wrestle with the expensive problem of cooling.
Sandia National Laboratories fin fan test bed

Koplow's 48-page research paper is replete with charts, graphs, photos, and details of the prototype's fabrication and testing. And, understandably, it ends with a wrap-up that's traditionally penned by research scientists: a not-too-subtle request for funding.

"Limited resources have necessitated an extremely conservative approach to device development," he wrote, "and at this point it has become clear that a more aggressive approach to developing this breakthrough technology is warranted."

We're hoping that Koplow's efforts have been successful, seeing as how Sandia is now seeking "licensing opportunities in the field of electronics chip cooling" to earn a little cash from his work. If you're interested, you have until this Friday to get in on the ground floor.

If you'd like to apply the Air Bearing Heat Exchanger Sandia Cooler technology to air conditioning or other larger-scale projects, however, you'll need to wait – but hopefully not for long. The lab says it will be offering licensing opportunities in other areas "soon"
 
The problem with that design is that you need the heat to pass between a layer of air first, which is a bad conductor.. I would replace that pocket of air with a metallic liquid that allows for better heat exchange. But the constant moving would also create extra heat in the liquid.. But it quite an interesting design.
 
The problem with that design is that you need the heat to pass between a layer of air first, which is a bad conductor.. I would replace that pocket of air with a metallic liquid that allows for better heat exchange. But the constant moving would also create extra heat in the liquid.. But it quite an interesting design.

Read the article. Because the air layer is so thin (0.03mm), it conducts heat perfectly well.
 
A couple things
If it is using air only as a bearing then it can only mount onto a horizontal CPU. Its been a really long time since I've seen a non tower type case outside of server rooms. Will be fine for most other applications though
It also looks like it wastes a lot of space in the middle (just like any other fan). Could be due to its being a prototype, but I think thats more or less the size it needs to be since it has to spin metal and not plastic around. How big will motherboards need to be then for it to fit?
And finally - its spins at several thousand rpm... yeah, that'll be nice and quiet
 
Spins at several thousand RPM and then forces air through a 0.03mm gap... real quiet... will probably make a farty noise.
Cool idea though, would like to see if the air does actually cause a vertex in the direction shown(the path of most resistance) rather than in the opposite direction, away from the CPU..
Where are the results of the tests he done? Hope he compared against more conventional heat sinks.
 
Well if they quiet fans it should be fine, i have a 120mm fan that spins at 2500rpm and i can barely hear it.
 
A couple things
If it is using air only as a bearing then it can only mount onto a horizontal CPU. Its been a really long time since I've seen a non tower type case outside of server rooms. Will be fine for most other applications though
It also looks like it wastes a lot of space in the middle (just like any other fan). Could be due to its being a prototype, but I think thats more or less the size it needs to be since it has to spin metal and not plastic around. How big will motherboards need to be then for it to fit?
And finally - its spins at several thousand rpm... yeah, that'll be nice and quiet

The PDF (maybe not referenced from the above link, but available on slashdot) indicates that he tested it in a vertical configuration, and had no problems.

And, while it is a fairly substantial thing to be spinning around, your average case fan is also spinning at several thousand RPM, so no major difference there.
 
Spins at several thousand RPM and then forces air through a 0.03mm gap... real quiet... will probably make a farty noise.
Cool idea though, would like to see if the air does actually cause a vertex in the direction shown(the path of most resistance) rather than in the opposite direction, away from the CPU..
Where are the results of the tests he done? Hope he compared against more conventional heat sinks.

The 0.03mm gap is an air bearing, and does not get exchanged with surrounding air. The circulating air comes down the center of the heatsink, and then gets spun out through the fins, picking up heat during its passage through the fins, and taking it away.
 
The PDF (maybe not referenced from the above link, but available on slashdot) indicates that he tested it in a vertical configuration, and had no problems.

And, while it is a fairly substantial thing to be spinning around, your average case fan is also spinning at several thousand RPM, so no major difference there.
Ah ok, then vertical is not an issue
As for a quiet several thousand rpm fan... no. Most fans spinning at around 1200rpm irritate me because they are way too noisy, which is the speed your average 120mm case fan runs at. Not "several" thousand.
 
The 0.03mm gap is an air bearing, and does not get exchanged with surrounding air. The circulating air comes down the center of the heatsink, and then gets spun out through the fins, picking up heat during its passage through the fins, and taking it away.

Surely his direction of rotation is wrong then.
 
Read the article. Because the air layer is so thin (0.03mm), it conducts heat perfectly well.
Having played around a bit with thermal paste and it's application on CPU's even the tiniest bit of air can cause a substantial rise in temperatures. It would be interesting to see this benchmarked against current air coolers with a similar surface area and/or volume.
 
Keen to see some real world tests with this Are you deaf? :p

Nope i just buy good fans that don't make a noise. If you buy the cheap kuk it will sound like aeroplane if you spend a bit more on it you won't hear it :D. Silent fans ftw

Although 24db to some may be loud but i find it soothing :D
 
Last edited:
Care to share what these 24db 2500 rpm fans are? The actual airflow alone will actually be above 24db unless there is nothing covering your fan intake
 
Thermalright 2000 rpm, my bad thought it was 2500 rpm. I use double sided tape to put them on my box to absorb the vibration.
 
LOL dude there is something seriously wrong with that, they are claiming it's 48db :eek:, they must be on drugs or i must be because that is insanely loud, i should be able to hear it in the other room.

That chart cannot right. I did a bit of digging thermalright claim 38db but even that is excessive compared to what i hear, perhaps this double sided tape works a treat but goodness there is no way they make that much noise, i have 4 of them in place of the 20cm fan on my box. Impossible :eek:

Airflow should be 80cfm easily not 40. The oke who did that chart was on tik for sure.
 
All fan manufacturers spec higher airflow numbers than what any review ever gets. Go check the method they use to measure airflow and you'll see that it is the true airflow number, there is no way to warp the numbers. Noise is always tricky so I will try find the youtube channel I use to compare fan noise with then you can listen to different fans yourself.
 
Are you deaf? :p

x2

Some people's perception of sound differs. I can hear fans at 1000RPM depending on environment and noise floor.

LOL dude there is something seriously wrong with that, they are claiming it's 48db :eek:, they must be on drugs or i must be because that is insanely loud, i should be able to hear it in the other room.
Manufacturer claims can never be trusted. What is astonishing to me, is that ALL manufacturers claim better results than independant tests (which are usually worse or much worse). How deaf are you? :p

Seriously tho 48dB isn't very loud but easily audible.

Wikipedia: Sound pressure said:
Normal conversation at 1 m 40 – 60 dB
Link

Most rooms in a home will have a noise floor of about 10-20dB. Office space will have a noise floor of about 50-60dB.
 
Last edited:
Top
Sign up to the MyBroadband newsletter
X