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Solid State Fan, Ionic Cooling Hits The Big Time!
Posted: Tue Mar 18, 2008 11:12 am
by jaganath
http://www.physorg.com/news125057974.html
Silent, microchip-sized 'fan' has no moving parts, yet produces enough wind to cool a laptop
The compact, solid-state fan, developed with support from NSF's Small Business Innovation Research program, is the most powerful and energy efficient fan of its size. It produces three times the flow rate of a typical small mechanical fan and is one-fourth the size.
"The RSD5 is one of the most significant advancements in electronics cooling since heat pipes. It could change the cooling paradigm for mobile electronics," said Singhal.
Within the intense electric field that results, ions push neutral air molecules from the wire to the plate, generating a wind. The phenomenon is called corona wind.
the researchers were able to control the micro-scale discharge to produce maximum airflow without risk of sparks or electrical arcing. As a result, the new device yields a breeze as swift as 2.4 meters per second, as compared to airflows of 0.7 to 1.7 meters per second from larger, mechanical fans.
"The technology has the power to cool a 25-watt chip with a device smaller than 1 cubic-cm and can someday be integrated into silicon to make self-cooling chips," said Schlitz.
Posted: Tue Mar 18, 2008 12:15 pm
by FartingBob
Sounds very intriguing. Although the "intense electric field" part sounds like something to keep at a safe distance from my HDD.
Posted: Tue Mar 18, 2008 1:27 pm
by tehfire
Does sound very cool, though at 2.4m/s it seems that wind turbulence would still be an issue...
Posted: Tue Mar 18, 2008 2:01 pm
by FartingBob
tehfire wrote:Does sound very cool, though at 2.4m/s it seems that wind turbulence would still be an issue...
Well it would make sense that by changing how much power you give the "fan" the airflow could go up and down. This would allow for very high CFM or a near silent option with CFM that we are used to seeing today.
Posted: Tue Mar 18, 2008 2:06 pm
by jaganath
tehfire wrote:Does sound very cool, though at 2.4m/s it seems that wind turbulence would still be an issue...
turbulence is necessary for good heat removal.
Although the "intense electric field" part sounds like something to keep at a safe distance from my HDD.
the electrodes are specially shaped to concentrate the electric field. I expect the voltage is not actually that high.
Posted: Wed Mar 19, 2008 10:35 am
by walkingjohn
I recall people being worried about charge buildup from the ionized air from these--but apparently this moves only neutral particles, so the ionization would be only inside the "fan".
Now, how much do you suppose it buzzes?
Posted: Wed Mar 19, 2008 3:19 pm
by spookmineer
jaganath wrote:tehfire wrote:Does sound very cool, though at 2.4m/s it seems that wind turbulence would still be an issue...
turbulence is necessary for good heat removal.
A 120 mm fan spinning at about 1000 RPM will push approx. 40 CFM.
That is about 1.3 m/s.
Even at very low speeds, air will become turbulent (influenced by hitting hardware/obstructions inside a case amplifies this).
Some users will not even notice the air noise much at this speed, and at lower speeds the noise will become practically inaudible.
So, ± 1 m/s is "quiet", but there is a considerable amount of air moving.
Is this what causes the air/wind noise?
Is CFM more of a contributing factor to noise than the speed of the air itself?
A "fan" producing 3 times as much flow at a quarter of the size of a normal fan will produce less CFM than the normal fan. The airflow is more concentrated, therefore the speed is higher, but the amount of air moving is only 75%.
So... I don't know if this will make more or less noise than a normal fan...
Posted: Wed Mar 19, 2008 5:29 pm
by edlight1
Perhaps if they make a bigger one and run it conservatively, then the airflow through each part of it would be slower and hence quieter, unless the technology buzzes.
Posted: Wed Mar 19, 2008 8:01 pm
by Felger Carbon
edlight1 wrote:Perhaps if they make a bigger one and run it conservatively, then the airflow through each part of it would be slower and hence quieter, unless the technology buzzes.
You have just re-invented the "250mm" fan, widely ignored here at SPCR. Congratulations.
The energy of a fan's airstream is proportional to the cube of the air velocity. It doesn't matter what propells the air. Same CFM, same "whoosh". Interesting idea though: I don't see ball bearings anywhere and no ball bearings in a fan is a really good idea.
Posted: Wed Mar 19, 2008 11:44 pm
by edlight1
Felger:
I meant if they made a larger fan replacement grid thingy. They're talking about little ones that move lots of air, but could be loud. What if they made a 120mm one and barely ran it. How about fan replacements that fit standard 80mm, 92mm, and 120mm mounts.
Posted: Thu Mar 20, 2008 1:13 am
by jaganath
You have just re-invented the "250mm" fan, widely ignored here at SPCR. Congratulations.
FC, a standard 25cm fan would take up most of the internal space in a standard laptop! these grids are intended to be not much larger than the chip/die package, and integrated onto them in the manufacturing process.
Posted: Thu Mar 20, 2008 5:16 am
by FartingBob
The small ones would be good for targeted cooling (GPU and CPU chips), while larger ones would be better for general airflow and exhuasts.Now we just have to wait 5 years for them to become cheap and more efficient.
Posted: Thu Mar 20, 2008 5:52 am
by BillTodd
Better picture of the thing here:
http://www.thorrn.com/technology.html
The curved and vented (aluminium?) part becomes the heat-sink when integrated onto a chip. There are (not visible in the picture) ultra fine wire electrodes that stretch down the length of each vented gully.
Posted: Thu Mar 20, 2008 6:38 am
by NeilBlanchard
Hello,
My first question about this technology is does it produce ozone?
Posted: Thu Mar 20, 2008 6:39 am
by BillTodd
jaganath wrote:
the electrodes are specially shaped to concentrate the electric field. I expect the voltage is not actually that high.
Yes. The device shown is 15 x 15mm, each 'gully' is ~3mm across, so air gap to electrode is ~1.5mm. Air breaks down at about 1100V/mm (if memory serves) so maximum voltage would be less than 1650v
Posted: Thu Mar 20, 2008 6:42 am
by BillTodd
NeilBlanchard wrote:Hello,
My first question about this technology is does it produce ozone?
Probably not, certainly no more than a laser printer, photocopier, CRT, microwave oven etc.
Posted: Thu Mar 20, 2008 8:01 am
by BillTodd
What a homebrew one might look like:
Posted: Fri Mar 21, 2008 10:53 am
by Felger Carbon
NeilBlanchard wrote:My first question about this technology is does it produce ozone?
Mine is, what happens when dust - somewhat conductive dust - settles on the very narrow electrode spacing? ZZAP!... or does the fan simply quit blowing air? Will circuits that shut down the computer be needed when the air stops blowing and cooling?
Posted: Fri Mar 21, 2008 11:40 am
by Krumb
"This device is also more dust-tolerant than predecessors" I would still be worrying about that. its still going to collect dust and if left unchecked could be dangerous.
If you have ever looked through the instructions off the small plugin air purifiers using this kind of technology you will see all kinds of warnings, the most worrying being fire.
Posted: Sat Mar 22, 2008 8:23 pm
by wwenze
We learnt in physics lessons:
Neutral and charged objects
Neutral object gets attracted to charged object
Dust is neutral, the device is not
Hello dust heap.
Posted: Sun Mar 23, 2008 3:55 am
by NeilBlanchard
Hi,
I'm curious: which direction does the air flow?
Posted: Sun Mar 23, 2008 10:57 am
by Felger Carbon
NeilBlanchard wrote:I'm curious: which direction does the air flow?
I'm curious about the energy balance. Real mass (air) is being accellerated from standstill to a moving column of air, just like a regular fan. Thus, the air gains kinetic energy. This energy has to come from somewhere. So at least one of the two electrodes of the ion machine will have to have input current, such that the electrical power input is at least as much as the power output. Do both electrodes require power (electrical current), or just one of them? Is the ion engine efficiency 100%? 10%? 1%? What?
Posted: Sun Mar 23, 2008 12:15 pm
by Willy Higinbotham
Felger Carbon wrote:NeilBlanchard wrote:I'm curious: which direction does the air flow?
I'm curious about the energy balance. Real mass (air) is being accellerated from standstill to a moving column of air, just like a regular fan. Thus, the air gains kinetic energy. This energy has to come from somewhere. So at least one of the two electrodes of the ion machine will have to have input current, such that the electrical power input is at least as much as the power output. Do both electrodes require power (electrical current), or just one of them? Is the ion engine efficiency 100%? 10%? 1%? What?
http://www.thorrn.com/technology.html
Quoting from the link above
It involves application of a voltage difference between two electrodes; a geometrically sharp electrode and a blunt electrode.
It doesn't say how many "volts" though.
Posted: Sun Mar 23, 2008 12:45 pm
by BillTodd
NeilBlanchard wrote:Hi,
I'm curious: which direction does the air flow?
same direction as the electrons; from the thin wire to the blunt heat-sink
Posted: Wed Mar 26, 2008 5:04 am
by Ozkar