PC Fan of the Future? 263
baptiste writes "While we marvel at the latest CPU release or new motherboard chipset, we still put the same old fans in the neon lit cases and then complain that it is too loud. Well, maybe someone has finally come up with the next generation PC fan. Y.S. Tech has announced a new fan which is driven at the blade tips by a magnetic motor in the housing. Without the motor in the middle they claim a 30% airflow improvement meaning, potenitally, you could get the same airflow of today's fans at a lower RPM meaning less noise. They also claim the fan tips result in the bulk of fan noise. In this design they are sort of enclosed, reducing noise further. There is also a PDF datasheet available."
All I can say is (Score:4, Interesting)
It seems to me that these fans sould also be more reliable. You don't need the axis to be anywhere near as complicated, since all it's doing now is providing a center of rotation. The motor is less likely to burn out, and also runs at a lower speed, which is always a good thing when it comes to longevity of hardware.
Re:All I can say is (Score:2, Informative)
there is slack in the Z axis causing it to rattle. A single washer of the right thickness is all that's needed to keep the fans running for the next few years.
FYI: The regular PC fan (as well as floppy) is driven by a brushless DC motor. The fan blade in the middle has a magnet. Solid state magnetic sensor(s) are used to fire electromagnets around it in sequence creating a rotating magnetic field. This is sort of like a rail gun except it goes round & round.
Re:All I can say is (Score:2)
As for that single washer, a little automobile ignition lube (one of the brand names of which is Ignition Lube) packed in around the washer already present does the trick nicely. Anyone needing to know how to disassemble their fan to apply it, e-mail me.
Re:All I can say is (Score:4, Interesting)
By putting in a 10-12 blade fan with a relatively narrow center with advanced fan blade designs, a CPU or system cooling fan could easily run a lower speeds while maintaining the same CFM as airflow as regular cooling fans. Lower speeds means not only less noisy fans, but also lower power consumption, too.
Egads! He's discovered perpetual motion. (Score:2)
Two caveats are that power consumption would only ever approach zero at infinite size, and, as you pointed out, that the fan would move increasingly slower as size increased -- but we'd still get a net positive energy (airflow)...
if only it weren't for friction. And inertia. And gravity. And thermodynamics. And so forth.
Sorry for the sarcasm. It just seemed funny.
Re:Egads! He's discovered perpetual motion. (Score:2)
Let's cite for example a small airliner powered by propellers, in this case the ATR72 built by a French-Italian consortium. Originally, the plane's two turboprop engines used two four-bladed propellers; however, later production planes used two six-bladed propellers. Going to six-bladed propellers offered two advantages: 1) propeller speed can be reduced, which cuts down on noise generation and 2) since the propeller doesn't need to spin so fast it also reduces the fuel consumption of the turboprop engine.
That's why my suggestion of a cooling fan motor with a small center spindle and carefully-engineered fan blades (10 to 12 blades) makes sense. This means the motor speed of the cooling fan can be lowered compared to regular fans, which 1) extends the life of the fan motor and 2) lowers the power requirements for the cooling fan. Alas, most of the more exotic CPU cooling fans such as the Golden Orb hasn't really used modern fan blade design; in fact, much of the benefit of these exotic coolers come from the larger heatsink properties of these units.
Re:Egads! He's discovered perpetual motion. (Score:2)
While the case of one particular airplane engine may have benefitted from an increase in propeller blades -- notice they didn't up it to 12 blades. Also notice that most engines still use two or three. There is always a mean. That's why they invented calculus.
As was posted by others, the center of the fan doesn't push that much air, so reducing the spindle size, or moving the turbine to the outer edge doesn't help.
So yes, I am confused.
interesting, I thought submersables used this (Score:3, Interesting)
interesting, I thought submersables used this already to get internal waterflow. because they couldn't have long lasting waterproof motors within the pipes, they had a fan that was driven by the outer ring so they didn't have the actual motor and electrical perts exposed to the water, I remember that they said something about the pressure and salt water being corrosive and the normal pumping systems not working well.
I'm still trying to fing an article, but it might have been in an issue of popular mechanics.
Re:interesting, I thought submersables used this (Score:2)
Re:interesting, I thought submersables used this (Score:5, Informative)
Common? (Score:2)
Re:Common? (Score:2)
There was a fence around it so that you couldn't get close to it. Within about 5' of the device, you'd risk screwing up a wristwatch, or a pacemaker (from the very intense magnetic field), so the fence was for safety of the tourists. One of the guides said that inside, the magnets were strong enough to pull the iron out of your blood, but I rather doubted that.
Re:Common? (Score:2)
Re:Common? (Score:2)
Can you cite some urls or something?
I still don't see a common example of this type of mechanism.
Background (Score:5, Funny)
Euck!
Fan of the future? (Score:1)
Free Sample (Score:4, Informative)
Price? (Score:2)
Am I the only one who didn't see a price tag on this little gem? I might spend as much as $1 more for this new fan design, but I wouldn't spend twice as much. From the lack of a price on their webpage, that's probably what it costs. Prices are usually not easily gotten when the manufacturer is worried that its outrageousness will steer you away from their product.
Re:Price? (Score:2, Insightful)
Re:Price? (Score:3, Interesting)
Re:Price? (Score:3, Interesting)
I'd spend twice as much if it'll last twice as long. Maybe three times as much if it'll cut the ambient noise level down by 10 decibels or more.
Re:Price? (Score:2)
Actually, Sun has some fairly decently (?) priced low end systems. 64 bits for a grand -- rack mounted. Only I think they still lock you in with proprientary RAM.
Preview! (Score:2)
Actually, Sun has some fairly decently (?) priced low end systems [sun.com]. 64 bits for a grand -- rack mounted. Only I think they still lock you in with proprientary RAM.
Too Quiet (Score:2, Insightful)
Finally no center motor! (Score:5, Insightful)
This is why dual-fan HSF setups primarily dominated, especially back when slot CPUs were still popular: you didn't have that static area of air. Sure, you had a hell of a lot more airflow from two fans, but one can argue that a lot of the kinetic energy is lost when air from the two fans collide.
Either way, this is a great improvement for CPU fans. Bravo, Y.S. Tech, it looks like you're taking the crown back from Delta (which is just more RPM, albeit much more noisy, for better performance).
Another "Too Cool to Be Useful" cooler (Score:4, Insightful)
useful" cooling fans.
Center area has minimum effect on air
transportation. Outside region of blade
has most effect on air transportation.
Too sad that blade diamater is redudced
because "motor" sits outside.
Heat from chip goes into heat sink. Heat
sink has very good thermal conductivity
(Alumininum or copper, much better than
transition region heat sink -> air). So
think of heat sink as an ideally stirred
container. Weak additional middle air
flow doesn't improve cooling. Reduced
outside air flow _does_ reduce cooling
performance.
What makes an effective cooling device?
* High surface heat sink with good thermal conductivity.
* High volume, turbulent of air flow over whole surface.
* Fancy design does move your money but doesn't move heat.
I agree, likely to be louder too. (Score:2)
Re:Another "Too Cool to Be Useful" cooler (Score:4, Insightful)
Getting better, more uniform airflow that can circulate the entire heatsink without increasing RPM is the best way to go, and improves performance while reducing noise, per the design at the product page linked from the article.
And making heatsinks bigger just isn't an option. Yes, more surface area helps, but as you increase the distance of the thermal transfer material (Al or Cu), it's effectiveness drops. Making very thin fins makes much more delicate and expensive heatsinks. There is already a surge of copper heatsinks on the market, and their surface area can't be improved too much because of their mallability (bends easily). Also, with processor dies shrinking, the ability for larger heatsinks to transfer heat from such a small surface area is reduced. The only way to improve upon this is for CPU manufacturers to spread out their die sizes, or reduce heat output with each new stepping, which won't happen because of wafer costs. So much centralized heat on such a small surface area just makes newer heatsink designs pointless.
Re:Another "Too Cool to Be Useful" cooler (Score:2)
Re:Fan aerodynamics (Score:2, Informative)
some papst fans use sintec sleeve bearing with ceramic sleeves - they are most quiet fans and life nearly as long as ball beared ones.
it is also better to take bigger fans for they are more efficient and can achiefe the same airflow als smaller fans but with lower rpms.
i humbly suggest to use a papst 8412 ngl fan - it is the quietest fan in that size, although not cheap.
the problem with the center of the heatsing being not cooled properly because of the motor in the middle of the fan can be solved quite easily - put the fan a bit higher.
Re:Fan aerodynamics (Score:2, Insightful)
Since the blades in a circle and the mounting package is a square, there is not mucf (if any) space is lost.
great! (Score:5, Funny)
Re:great! (Score:3, Funny)
There's a device which is generally used to monitor whether or not your system is responding to your input.
It's called a monitor.
Re:great! (Score:2)
Um... access whatever data it's serving?
(Actually, you've hit on one of the reasons why I like using an old 486 laptop as a webserver. It was cheap, has low power consumption, and a built-in monitor for whenever I need to check up on it!)
Trend is positive... (Score:5, Insightful)
A big part of this for me is being able to turn off the MP3's every so often and have enough silence to think! I'd rather have a 500mhz that can do all the development I can throw at it, than a 747 powered fan sitting on top of a Gigahertz!
Seems that some of these companies are catching on that it might be possible to have the best of both worlds. My hope is that consumers will follow along enough to bring the cost of production low enough that even I can afford them. :)
Can you afford a Mac? (Score:2)
Similarly for the iBook (now up to 600MHz), and there's a variable speed fan in the iMac (800MHz, but I suspect the lower 700MHz will run cooler).
Macs have been known for a while as quiet computers.
Re:Can you afford a Mac? (Score:2)
When my CPU is at 100% for long periods (like compiling Mozilla in the background or rendering iMovie projects), the fan kicks in and is fairly noisy.
But in day to day useage, the fan never kicks in. The keyboard, the mouse click, and the occasional drive seek make the most noise, in that order, followed by the fan.
Anyway, I hope you like OS X. It's such a pretty system, and clean, and cool
Re:Trend is positive... (Score:2)
* get a better heatsink and a slower fan for your cpu -- you don't need a 60mm 7000rpm delta fan to cool a 1.5ghz processor; FAR from it. A good quiet 4000rpm fan sitting on top of a Thermalright SK-6 would still be overkill.
* get an office class PC -- they're designed with noise levels in mind, not performance. So they're quiet. And generally cheap, unexpandable, and have low quality components which annoys the living daylights out of me, but if you arn't into building your own computer it should be more than adequate.
Good Blower (Score:3, Insightful)
The website shows here [ystech.com.tw] some of the interesting effects of moving the motor to the outside. The most important implication is that airflow is inceased near the perpendicular axis to the fan, ie., more air blows in the center of the fan than the traditional design allows. This helps out in heatsink designs in that it allows more air to cool the inner parts of the sink and thus cool it closer to the cpu core itself. The efficiency of the heatsink is now improved without a major redesign.
In the near future, I'm sure this technology will migrate to large fans for the case and powersupply, where its reduced noise will be appreciated.
I dunno... (Score:5, Insightful)
Because this is an improvement on the *fan* and not the whole heatsink, I give it a little more credence, but I won't be that interested until I actually see some Tom's numbers on it.
And I really won't be interested in it until the pricetag falls below $100 for a fan. For that money you could water-cool, or just soundproof your case.
longer lifespan? (Score:4, Interesting)
The main problems I have with my cooling fans are balance, and dirt. When a fan has been running for a long enough time, somehow its balance shifts, and makes horrible loud noises. My server box is located in my closet, on the floor, with plenty of dust getting sucked into the case. It eventually got so bad that it caused the power supply fan to stop moving...
If this new fan design can overcome or lessen these problems, then I'll buy them as soon as they are available!
Re:longer lifespan? (Score:4, Interesting)
Re:longer lifespan? (Score:2, Insightful)
These things are very cheap at hardware shops and whilst not impeding the airflow they really do keep dirt out and uptimes up.
Re:longer lifespan? (Score:2)
But on Wednesday, I come into work and find that the previous night's backup had failed. Tape in question won't even erase. Go into server room, and see that the tape is still in the drive and won't unload (Quantum Powerstor DLT changer). Check the back, and find air blowing from the power supply fan, but nothing from the tape drive fan. Replaced it with a new ball-bearing fan, and the drive seems to be OK, but who knows how much lifespan was reduced, not to mention the three DLT tapes which were no longer happy after the problem and are now trashed. This is cost-cutting, pure and simple. If you decided that a sleeve bearing fan had some desirable characteristics over ball bearings, you could use a fan that reports RPM, or an airflow switch, or even a thermistor to shut down the components when the fan fails....
Power supply fan stopped turning?! Bad. (Score:2)
I wish I could get a power supply with a fan monitoring lead - my motherboard and OS (linux) both support it - but only my CPU fan has the capability.
Re:longer lifespan? (Score:2)
I've also thought about adding cheesecloth in front of my one fan to really cut down on the dust intake, but as of yet, haven't done so.
The secret to installing filters (Score:2)
Say you have a 80mm intake at the front, mounted to the main metal chassis. Then cut a 80mmx160mm hole in front plastic bevel, then screw in 2 80mm fab guards into the bevel & mount air-con filter foan behind the guards (mind you if you are going to modify the bevel you may as well cut a hole in the front chassis for a 12v@7v 120mm fan, so you get good cfm & good quietness [optushome.com.au])
If you have a blowhole on the side, say a 120mm fan blowhole, then you cut a 150mm hole in the side & mount a 160mm diametre 16mm or 35mm movie film tin behind the hole (the wider the better, given the clearance). The film tin should have a 150mm hole on the back & a 120mm hole on its lid. Screw the back against the inner side panel of the case, using the 4 or 2 screws that mount the 150mm fan guard you re going to have on the opening of the case. Attach a 120mm fan to the outside of the lid of the film tin, using a fan guard that's mounted in such a way (using washers or something) so its as far a from the fans intake as clearance allows. Cut a 150mm circle of air-con filter foam & stick it inside the film tin that's screwed to the side of the case - once you slide the film tin lid in place onto the film tin's back, the raised up 120mm fan guard on the fan's intake will push the filter up against the 150mm fan guard on the case's side panel, pushing it away from the fan with enough clearance so that air will be sucked throughout the breadth of the 150mm filtered hole before going through the fan. So really this is just a 150mm blowhole using a 120mm fan, where there's a movie film tin being used as a filter box, between the fan & the 'hole'.
Of course you must have enough clearance before you can use this 'movie film tin filter box' idea.
Who needs a stinking fan!!! (Score:5, Funny)
This postsoon to be modded down by humorless people......
Re:Who needs a stinking fan!!! (Score:2)
Er, the new iMac does have a fan. It has no CPU fan (it does have a big heat sink), but it does have a case fan. It sounds like it has no fan mostly because the G4 sucks way less power then the P3/P4/K7, and partly because Apple is very big into variable speed fans. Get PhotoShop up on the iMac and crank through some complex filters on big images and you will hear the fan.
Apple does make nice machines, but I don't think they currently make any fan less ones (er, unless the CRT iMacs they still make are sans fans...).
Re:Who needs a stinking fan!!! (Score:2)
Re:Who needs a stinking fan!!! (Score:2)
I donno, I run OSX on my laptop, and don't notice it's fan kicking in when I minimise a bunch of windows and scroll around a lot. It is "only" a 667, and only one of 'em. Either you are exagerating, or there is some serious spin lock issues :-) (or for some reason the graphics "card" in the PB G4 is better then the one int eh G4 Towers...)
Why not make the fans bigger? (Score:5, Interesting)
The point is that airflow increases with rpm times the SQUARE of diameter, which means if you make the fan 2x as big, you can make it 4x slower. The original NeXT boxes used a big, slow-turning fan to keep noise down, and it was quite effective. PC's usually use 3 inch fans but with some case mods could probably be set up with 5 inch fans, which for the same airflow could quiet things down a lot.
Add to that a hard disk with a fluid bearing spindle motor [ibm.com] (pdf) and you've got a rather civilized box on your desk. I'm using one of these drives now (Travelstar 30GN) and the difference between it and an old drive is wonderful. The quietness is like getting rid of a toothache.
Re:Why not make the fans bigger? (Score:2, Informative)
This is entirely correct: ask anyone from an aeronautics background: tip speed is king when you consider noise, and that's it. Huge effort goes into reducing the noise produced by the high blade tip speeds of turbo-prop engines.
If you want a quieter fan: slow the blade tip speed, simple as that. (although I think this new fan design does have advantages, particularly the increased air-flow near the fan axis).
Re:Why not make the fans bigger? (Score:2)
Almost all Apples SILENT (Apple 2,Mac+,IIfx,iMac ! (Score:5, Interesting)
That is almost the main engineering case design criteria and why so many fussy demanding people like artists, musicians, scientists (chemists, biologists) and even programmers continue to support apple products.
PeeCees are like load aircraft carriers or at least Vaccuum cleaners comapred to the majority of the most popular selling Apple Computers.
Did you know the Apple 2 had NO FAN at all?
Same with the Mac Plus... no FAN at all.
and most all the products since the IIfx have a variable speed fan that increases rotation only if truly needed... like the Wallstreet G3 laptops.
When Steve jobs created the NeXT workstation he designed every cable to be one long 10 foot single cable so that the machine (almost quiet) could be hidden insode a closet or put very far from your monitor! He hates noise of all kinds.
Hurray for quiet or semi-quiet hardware.
Re:Almost all Apples SILENT (Apple 2,Mac+,IIfx,iMa (Score:4, Informative)
Neither does the Tandy 1000 RL I've got sitting over here. So what? They're both old and slow, and neither has the processor power to justify a fan.
What about now? (Score:2, Informative)
Now the iMac, iBook and PowerBook all have fans. And Power Macs now have 3 fans!!!
So much for the silent office...
Re:Almost all Apples SILENT (Apple 2,Mac+,IIfx,iMa (Score:3, Interesting)
Yet, my base TI-994/A ran off of a wall wart.
Recall that until around the 486 DX/2 days, there (in general application) wasn't anything hot enough inside the PC case to warrant its own fan. The fan behind the power supply is/was always meant to cool the *power supply* anyway.
Re:Almost all Apples SILENT (Apple 2,Mac+,IIfx,iMa (Score:2)
hidden insode a closet or put very far from your monitor! He hates noise of all kinds.
Maybe he designed it that way, but that's not the way any of mine are. My Mono ones have a short cable, and the Color ones make like even more fun with the sound box stuck in the middle of it all...
Re:Almost all Apples SILENT (Apple 2,Mac+,IIfx,iMa (Score:2)
Oddly enough, the hard disk survived this abuse, with all data intact!
Re:Almost all Apples SILENT (Apple 2,Mac+,IIfx,iMa (Score:2)
Re:Almost all Apples SILENT (Apple 2,Mac+,IIfx,iMa (Score:2)
Re:Almost all Apples SILENT (Apple 2,Mac+,IIfx,iMa (Score:2)
But having something that ensures a flow of cooler air onto the processor would probably be more effective, allowing for fans that aren't as loud. Apple actually does something similar in the current powermac G4s (there is a hood over the cooling fan for the processor that allows the fan to pull air in from outside the computer).
For a totally quiet computing experience (and a high powered computer) a simple water cooling solution on an un-overclocked system would allow one to remove all fans from the various areas around their case (cpu(s), various chipsets, hard drives) and inside give one single surface that would need to be cooled (the radiator). Actually, I guess if you got a large enough radiator, you could use a chimney on it, inside your case, but it would have to be really big (the radiator) which means more water to move, which means a bigger pump which could make more noise.
Re:Almost all Apples SILENT (Apple 2,Mac+,IIfx,iMa (Score:2)
I'd imagine a radiator could be set up like a like the ammonia fridges used in travel trailers -- use the CPU as the heat source to expand and move the liquid thru quarter-inch metal tubes, with a chokepoint and nozzle for cooling the liquid by expansion. Then run some coils from the chokepoint thru the areas you want to absorb heat from, and put the rest of the coil outside the case to let it air-cool, then back to the nozzle for another round. This is good for about 50 degrees of cooling a space of 5 cubic feet using ammonia, so I'd think a plain water system would be sufficient to cool a much smaller space like a standard tower. No fan or motor required at all. (I once had one of these ammonia fridges, so I know of which I speak. The only sound is a faint hissing from circulation in the pipes.)
With desktop cases and smaller towers, the majority of cooling actually takes place by heat exchange thru the metal case-- not via the fans at all. Cover the top and sides (leaving the fan holes open) with a blanket, and see how quickly your system overheats! Conversely, with such boxes you can get away with NO internal fans, so long as you have a fan blowing across the case itself.
I used to cool my campstove-emulator 286 that way whenever its power supply fan died and I hadn't yet got around to finding a new one. And that critter ran as long as 22 months without a reboot, let alone a powerdown. Nowadays, during the summer months I set a room fan to blowing at the newer machines, because the external airflow makes a world of difference in how hot they get.
Amazing how creative one can get if one's case fans die
Pure PR (Score:5, Interesting)
First, the velocity of the blades near the hub are too slow to put work into the air and therefore the air tends to leak backwards near the hub. This is why putting the motor in the hub area does not degrade fan performance.
Second, while the fastest parts of the fan (the blade tips) make most of the fan noise, changing their shape does the most to reduce the noise. The noise has nothing to do with the "motor parts" that reside in the blade tips in this design.
Third, the pressure generated by the fan is solely dependant on the fan design and has nothing to do with how the fan is powered.
Fourth, of course the torque is more effective at a larger radius, but this has nothing to do with efficiency.
Fifth, any increase in air flow has to do with the shape of the blades and the speed of the fan and can probably be improved a somewhat by blocking the hub a little.
Sixth, I do not see how the fan improves the efficiency of cooling anything. Increased air flow will cool anything better, according to how much horsepower do you want to put into your fan. And, it matters a whole lot where the parts to be cooled are in relation to the exit air stream, etc.etc.etc. Nothing but PR here.
Re:Pure PR (Score:5, Informative)
I thought of this concept a while back, even started modelling it in Simulink (part of Matlab).
"First, the velocity of the blades near the hub are too slow to put work into the air and therefore the air tends to leak backwards near the hub. This is why putting the motor in the hub area does not degrade fan performance."
First of all, the hub is smaller, meaning the there is more air intake near the hub...anything which calls for a greater air debit at the top of the fan is good. The air will only 'leak back' if the air pressure under th fan is greater than on top, which doesn't happen until you hit high RPM's. What you will get is vortices under the fan near the hub, which is good...it means a lot of airflow over the die of the chip, which leads to cooling of the chip. Note that this happens under the fan, which is where you do want vortices.
"Second, while the fastest parts of the fan (the blade tips) make most of the fan noise, changing their shape does the most to reduce the noise. The noise has nothing to do with the "motor parts" that reside in the blade tips in this design."
The thing is, the tips of the blades are in the ring surrounding the fan...now the air first gets led through a bounding area before it gets spun by the fan...it goes from vertical to horizontal directly, like in any good pump, without having that airflow distorted by the boundary conditions created by the tips of the fan being near but not touching the side of the fan case. Vortices on top of the fan only make for a decrease in airintake which is bad for cooling.
"Third, the pressure generated by the fan is solely dependant on the fan design and has nothing to do with how the fan is powered."
But here the method of powering the fan has led to an improvement in fan design (more air intake due to higher area of the fanblades).
"Fourth, of course the torque is more effective at a larger radius, but this has nothing to do with efficiency."
Thiuss hasd no bearing on the situation other than stating that the larger a fan is, the better it works...duh, we already knew that.
"Fifth, any increase in air flow has to do with the shape of the blades and the speed of the fan and can probably be improved a somewhat by blocking the hub a little."
No, that would only limit the area of air-intake, which is bad...you want a big area of intake, to get as much air down the fan as possible. Blocking the hub is a Bad Idea(tm)
"Sixth, I do not see how the fan improves the efficiency of cooling anything. Increased air flow will cool anything better, according to how much horsepower do you want to put into your fan. And, it matters a whole lot where the parts to be cooled are in relation to the exit air stream, etc.etc.etc."
Yeah, you got the idea...this new design improves airflow, which is good!
Not PR, just airflow...they increase the airintake (by having a smaller hub, which also means better cooling near the centre of the fan) while lowering vortices near the airintake (by having a seamless fancase-fan interface), thus creating better cooling.
Flame exchange. (Score:4, Interesting)
He made more sense then you do. You: I thought of this concept a while back, even started modelling it in Simulink (part of Matlab).
Nice work, drawing pictures lends credibility. Nope. I'm a Mechanical Engineer. I've done some rudimentary fan designs (you know vector diagrams, work balance, that kind of thing), but I won't play a fan designer on TV or stomp reasonable people. Him: "First, the velocity of the blades near the hub are too slow to put work into the air and therefore the air tends to leak backwards near the hub. This is why putting the motor in the hub area does not degrade fan performance."
You: First of all, the hub is smaller, meaning the there is more air intake near the hub...anything which calls for a greater air debit at the top of the fan is good. The air will only 'leak back' if the air pressure under th fan is greater than on top, which doesn't happen until you hit high RPM's. What you will get is vortices under the fan near the hub, which is good...it means a lot of airflow over the die of the chip, which leads to cooling of the chip. Note that this happens under the fan, which is where you do want vortices.
He's right, again. If your fan does not give you any pressure increase, you have a poor difuser or a poor fan or both. There is zero motion at the axis. The best thing to do with that air is to redirect it outward towards your blades. If your hub does not do this, you might get some recirculation there that will do what your hub should have. Him again: "Second, while the fastest parts of the fan (the blade tips) make most of the fan noise, changing their shape does the most to reduce the noise. The noise has nothing to do with the "motor parts" that reside in the blade tips in this design."
You: The thing is, the tips of the blades are in the ring surrounding the fan...now the air first gets led through a bounding area before it gets spun by the fan...it goes from vertical to horizontal directly, like in any good pump, without having that airflow distorted by the boundary conditions created by the tips of the fan being near but not touching the side of the fan case. Vortices on top of the fan only make for a decrease in airintake which is bad for cooling.
Huh? What does that have to do with what he said about decreasing noise by changing blade shape? Any axial fan will create an axial vortex above it unless you put stator blades in the way. If you want to get rid of the blade tip vorticies you change their shape, or you could put a ring around them but that makes other problems. Him: "Third, the pressure generated by the fan is solely dependant on the fan design and has nothing to do with how the fan is powered."
You, again: But here the method of powering the fan has led to an improvement in fan design (more air intake due to higher area of the fanblades).
You are starting to repeat yourself, which would be OK if you were correct or even consistent. You know, he's right again. While you fail to actually contradict him, you do contradict yourself by not bothering to say anything about pressure differences that you don't understand very well. Him: "Fourth, of course the torque is more effective at a larger radius, but this has nothing to do with efficiency."
You: Thiuss hasd no bearing on the situation other than stating that the larger a fan is, the better it works...duh, we already knew that.
Ummm, that's not what he said, but it's nice to see that you have the spirit to be condesending. Can you explain why a larger fan works better for us? Is it because the ends may be turning faster? Isn't this why axial turbines are generally rows of blades mounted further away from the axis than they are long? Would they be more efficient with a large hole in the center? Him again: "Fifth, any increase in air flow has to do with the shape of the blades and the speed of the fan and can probably be improved a somewhat by blocking the hub a little."
You, sigh: No, that would only limit the area of air-intake, which is bad...you want a big area of intake, to get as much air down the fan as possible. Blocking the hub is a Bad Idea(tm)
Do you know any other tune than, "this thing rocks because it has a smaller hub"? I think I've alrady stated the purpose of the hub. Go figure. Him: "Sixth, I do not see how the fan improves the efficiency of cooling anything. Increased air flow will cool anything better, according to how much horsepower do you want to put into your fan. And, it matters a whole lot where the parts to be cooled are in relation to the exit air stream, etc.etc.etc."
You: Yeah, you got the idea...this new design improves airflow, which is good!
Same tune. You know what is good but not how to achieve it. He does. But wait, you have a conclusion: Not PR, just airflow...they increase the airintake (by having a smaller hub, which also means better cooling near the centre of the fan) while lowering vortices near the airintake (by having a seamless fancase-fan interface), thus creating better cooling
OK. Does anyone have any numbers around here? Like flow vrs current for various radiuses? Yes that would be useful, a repeatable experiment comparing various available designs. The data sheet is slashdotted. Perhaps you can CAD up some drawings of a test bench for us?
Re:Pure PR (Score:2, Interesting)
looks like both of you guys should be yanking your old Heat Transfer, Accoustics, & Fluids books off the shelf and plan on doing a little review.
I can debunk almost all of (both of) your claims.
Firstly, you both argue about the significance of Airflow around the hub. BFD. Airflow is not everything!! Heat Transfer is everything.
There are 3 types of Heat transfer.
Radiative heat transfer: this is what makes your black colored car much hotter than the surrounding summer breeze. In this case it is insignificant compared to Conduction & Convection. (therefore it wouldn't matter if your fan was white or black)
Conduction heat transfer This is the movement of heat from within ONE Material. In other words, put just an edge of your frying pan on the stove and the rest of the pan will eventually get hot. The main application of Conduction heat transfer occurs within the heat sink.
Convection heat transfer This is the movement of heat between 2 materials. Convection occurs between the processor & Heatsink, Conduction then moves the heat to the other side of the heatsink, and then Convection transfers heat from the fins of the heatsink to the air. Sound simple? It's not.
a ns _-_power_control_met.shtml
Since There is a heatsink that acts as a buffer to the heat transfer, I argue that the 2nd A.C.'s claim is misleading. Yes, if we mounted a fan directly to the processor it would likely help to aim airflow at the center. In that case it might be nice to have a hub-less fan. Since only fools would run without a heatsink, it doesn't really matter much.
Remember our lesson on Conduction and Convection?
Well in our case, conduction moves heat away from the core (the center) and does it much more efficiently than convection. One reason for this is related to Fluids.
In fluids you learned that as a fluid (in our case Air is the fluid) moves around an object, a boundary layer occurs. For Maximum Heat transfer, This is a Bad Thing. We want to introduce a "micro turbulence" that will break up the boundary layer. The great engineering problem to solve is to find the best comprimise between airflow, turbulence, and noise.
So what's the best solution?
I doubt that there is a single solution for all computer users, but here is what I like:
http://www.procooling.com/articles/html/quiet_f
It's a circuit that will Automatically
adjust the speed of your fan to maintain an appropirate temperature. Unlike adding a Rheostat, it doesn't create a larger current draw, and you don't have to continually adjust it.
For those of you that would like to learn more about heatsink/fan benchmarks check out this site:
http://www.dansdata.com/coolercomp.htm
some prior discussion (Score:4, Informative)
amdmb [amdmb.com]
ars [infopop.net]
A cynical viewpoint or insightful? (Score:5, Insightful)
Too much heat on the oil seal
Looking at this compared to a ordinary fan, it looks as though the bearings and oil seals are evenly dispersed over the surface area of the heat sink, where most common fans have the bearings and oil seals right in the center in the middle of rising heat. Iâ(TM)m not a thermodynamics expert but I can tell you from experience that I have been able to bring many a dead CPU fans back from the dead simply by peeling the sticker off in the center and dropping a dab of oil in there.
Anyways thatâ(TM)s my 2cents
Re:A cynical viewpoint or insightful? (Score:2)
Huh??? The site got slashdotted before I could download the pdf or anything with a decent picture, but where do you get this? It sure looks to me like the bearing is still on a shaft up the center. It should help that it's a thin shaft with air moving around it, rather than the bearings being stuck up into a hot electric motor hanging above the hot center of the chip.
Are you thinking that the bearing is all around the rim? That would make for a lot of bearing surface with one surface moving at extremely high speeds. If that's where they put the bearing, no wonder the fans cost $100 -- but I still don't think it would be very long lived, because at the high RPM's times the radius, it racks up the miles too fast.
Re:A cynical viewpoint or insightful? (Score:2)
Aside from CPU heat there is also heat caused from the fan motor's coils. When the oil is gone and the fanblades seize these get hot quickly. Their close proximity to one another in a standard fan design sorta focus the heat in one area.
That's the whole point I was trying to make. Fans fail because the oil breaks down causing the bearings to seize. I've seen them get so hot that they've actually melted plastic. I don't see that flaw in this design. Even if there is a center spindle with bearings, the coils on this fan are located far enough away from them that thermal breakdown of the oil from the heat of the motor coils isn't even an issue.
Old but quiet (Score:4, Informative)
Duct it (Score:2, Insightful)
Email from the manufacturers (Score:5, Informative)
Thank you very much for your high interests in Y.S. TECH's revolutionary new product: T.M.D. FAN (Tip-Magnetic Driving Fan).
After the announcement of the T.M.D. FAN, we have been receiving uncountable inquiries everyday to review the T.M.D. FAN, to obtain the T.M.D. FAN samples and to attain developing schedule. To deal with all of your inquiries and be fair to everyone, here is what Y.S. TECH would like you to follow. We appreciate for your cooperation in advance!
1. Please visit Y.S. TECH web site at http://www.ystech.com.tw to obtain the detailed information (including technical issues).
2. We hereby enclose some images (.jpg at 72 dpi) that you are very welcome to apply them to your web site's product review and news announcement.
3. After your post or announcement of the T.M.D. FAN in your web site, please inform us the links. Then we will deliver physical T.M.D. FAN samples (possibly with heatsink) for your test and review purpose. The samples will be delivered to you in the middle of April.
4. After your test on the T.M.D. FAN, you will be much appreciated, if you post the test results and comments in your web site. It doesn't matter the results or the comments are positive or negative. The general public needs the truth.
Here is the rough schedule for the dimensional development of the T.M.D.
FAN:
Now: 70x70x15mm is now available. It is targeted for Pentium 4 CPU cooler.
April: 70x70x15mm T.M.D. FAN will be shipped out to variable locations over the world.
May to June: 60x60x25mm, 80x80x25mm T.M. FAN will be released to the market. These two dimensions are targeted for AMD CPU cooler and case cooling.
Again, thank you very much for your interests in T.M.D. FAN!
Should you have any questions or comments, please feel free to contact us. Y.S. TECH will reply to you as soon as possible.
Note the "uncountable enquiries..
I think their attitude about the reviews is very good. It's a shame more companies aren't like that.
--
Andy
One thing is for sure... (Score:4, Funny)
(air, that is.)
Which makes them ideal for your WinXP box.
Re:One thing is for sure... (Score:2)
fan solutions and fain noise solutions (Score:2)
A near silent pc is easy to do if you want to spend the money and get good at metal modification and engineering your own isolation mounts. I have a server that uses a squirrel cage blower on the back the intake is via a pair of filters and I produce a 4psi static pressure INSIDE the case with all the "stock" fans reversed to blow out instead of suck in dust.
Re: Squirrel Cage Fans are Inhumane (Score:2, Funny)
And forget about cleaning out the damn things. Most squirrels don't last more than a week.
Poor little bugger, being made to power a fan by application of 110 volt AC. It's inhumane I tell you.
QuietPC Fans (Score:2, Informative)
Interesting, but... (Score:3, Informative)
Another positive thing is that this design (but not the device itself) allows for relatively easy improvement -- even though the picture looks like the bearing is the same as I have described above, this can be converted into a "reversed" bearing design without the motor getting in the way -- a pin can be attached to the plastic base/grille at both ends, and a pipe (or ball bearings, or whatever) -- to the middle of the hub. Then the fan will be also symmetric and even less vulnerable to the vibrations. "Classic" fan design can be converted into this, however then the rotating pipe would push back already tiny coils and cores of the motor. With coils outside, and reduced vibrations in the first place this would be more efficient (and oh, btw, if some asshole will try to patent this, I would be happy to see him in court, with this comment as an evidence of the prior art
The disadvantages are also obvious. First, blades, even with heavy magnet ring on their ends, are still flexible and prone to deformation. This may affect the balance of the rotor in the long run -- "classic" fan has a smaller ring magnet in a sturdy plastic cup of the hub, and therefore is almost invulnerable to this (until the bearing wears out enough to shift the center -- but by then the fan would be dead already). Second, this, and plain need to accommodate heat expansion, precision of manufacturing, etc. increases the necessary gap between magnets and cores. That would require larger, stronger coils, but there isn't that much space available for them in the corners.
I'm a fan of PCs! (Score:2, Funny)
Then again, I also used to like tractors, so does that make me an ex-tractor fan?
....sorry... I couldn't resist it [badpuns.com]....
Evironmentally friendly fans!! (Score:2, Funny)
Maybe this way coders will write more efficient programs. If they don't - they'll hyperventilate, hmmmmm
squirlcage fans (Score:3, Informative)
Question (Score:2)
I have a question to some air-flow engineer out there that I've always wondered about this issue.
Is it possible to use the temperature differential between the heat inside the case and the outside to create some passive cooling system? It seems like it should be possible to use the energy in the heat someway to move the air around.
Is there just not a good technique to do this, or is there some other problem that I'm not thinking of?
Re:Question (Score:3, Insightful)
1. No extreme hot spots -- like Pentiums. They are too small and make too much heat, so I don't think passive air cooling alone can handle it. Scale back your MHz, or add a liquid-filled heat spreader.
2. The case is designed for air flow, the cables are tied out of the way, and the customer can't get inside and f* it up.
3. The case a tower, and it is always operated right side up with the covers on and the vents clear. Techs have to know how long they can keep the power on while the box is open to work on it. A customer that lays something on the vent, or puts his tower on it's side is going to have trouble.
Yes, it is certainly possible to cool fairly high-powered electronic devices passively, but this device wouldn't be used the way PC's are.
Uh, this is not a new concept... (Score:2)
But seriously... (Score:1)
Re:Magnetic fans... (Score:2)
Yeah, why not? There are no parts sensitive to magnetism in an IC at all. The only place it could be dangerous is at the harddisks, and only if there is a magnetic field outside the fan at all, which I doubt.
Re:Magnetic fans... (Score:3, Funny)
Re:Magnetic fans... (Score:2)
Re:Coinciding With Hammer (Score:3, Funny)
Re:This is nothing new (Score:2)
Re:Problems with magnets? (Score:2)
Every time I saw it happen, it was because the hard drive was mounted in the system almost directly behind where they stuck their magnet.
Apparently, the magnet was actually tugging on the metal drive head assembly and inducing disk I/O errors.
It's been around 6 years since I dealt with this kind of thing though (used to be a PC tech and system builder at one of the "mom and pop" shops, that are almost all extinct nowdays). Systems may be better protected against magnetic fields now.
Re:Problems with magnets? (Score:2)
It's more likely that the constant low-intensity field was disrupting the domains on the disk or interfering with the write head's field, rather than it's actual physical position.
(on the other hand, if the field acted vertically along the platters, it might induce head crashes, which would be entirely different than causing tracking problems, but would be fatal nonetheless).
Re:Problems with magnets? (Score:2)
Properly cleaning a fan... (Score:2)
Fan motors are really nothing more than funky four pole stepper motors, of a sort, with all the switching electronics built into a small board in the fan. They are true brushless motors (just like stepper motors). Coils are located on this board, and the fan rotor has a ring magnet which spins around the coils on a bearing (typically sleeve, but sometimes ball).
Now, the shaft is fixed to the fan blade rotor, and passes through the bearing, and out the backside of the drive electronics carrier board (the bearing is mounted to the carrier board). Look at the "backside" of the fan, where the wires enter the fan, and you will (or should) see a sticker, showing the make of the fan, rpm, etc. Remove this sticker, and there should be a hole where you can see a plastic or metal "lock ring" surround the shaft of the fan.
Remove the lock ring (don't lose it!) with a couple of small screwdrivers or a pair of tweezers (if you a real good, dremel the tips of the tweezers to make small hooks on the ends, forming a "puller") - the lock ring is typically only held on by friction (it doesn't need to be anything more, as the magnetic field of the rotor ring magnet keeps the fan aligned with the steel armature of the coils on the driver board).
You should now be able to remove the fan blades.
With the blades off, inspect them for dust and dirt around or one the shaft. Clean the blades with compressed air, maybe a qtip with some water - clean the shaft with rubbing alcohol.
Clean the circuit board and the fan cage with compressed air, and inspect the bearing. If it is a sleeve bearing, use a needle or other shaft size implement to drip some rubbing alcohol through, and disolve any old grease - if it is a ball bearing, you might try to do the same - if you can remove it, even better to clean it outside of the fan circuit board.
Once the shaft and bearing are dry, repack the shaft and the bearing. If the bearing is a simple sleeve bearing, apply some petroleum jelly to the shaft (just a little), and slide the shaft back on. If it is a ball bearing, apply the jelly to the bearing, putting some light pressure on it to force it into the bearing, and a little on the shaft, then reassemble.
Clean your hands thoroughly and dry them, then remount the locking ring. Clean the area around the hole (not in it!) with rubbing alcohol to remove any traces of oil, then place one of those "garage sale" round stickers over the hole to replace the original (and maybe mark the current/voltage ratings and cfm on it as well).
That's it! It takes a little time, but costs less than buying a new fan (especially if it is late at night or something and no place is open). Keep it under 15-30 minutes, and it is even worth your time, if you think that way. Most of the time, the reasons fans fail after using compressed air on them is that the dust and dirt either get blown into the bearing, or the fan is spun to an ultra-high speed past the bearing's rated speed, and the failure begins.
Hope this helps!
Re:Properly cleaning a fan... (Score:2)
Also suggest de-natured alcohol for cleaning and saving the rubbing alcohol for the medicine cabinet. A pint of de-natured will cost you 5 or 10 bucks, but you can use the rest for a year or three of cleaning other electronic stuff (with the power OFF!), including floppy heads and CD drive lenses.
Pretty much... (Score:2)
But yeah, it is like repacking wheel bearings - BTW, one other tip: Don't work on plush carpet
On another note - I recently had a fan in my power supply go out here at work on a Friday - the power supply was OK, but the fan would make this weird vibration noise - ramping up, sustaining, then ramping down. This would happen about once an hour, and was really loud.
Anyhow, I pulled the power supply out, pulled the fan, and went to work with the various tools I had (mainly a leatherman keychain). I got it apart, and could clearly see that the bearing was dry. I needed some grease.
Not having anything suitable (like, why would I carry vasoline in my backpack?), I went to my IT department, and asked around - no luck. Not even some WD-40 (not that I wanted to use it). So, I hunted around some more, when it hit me that our CIO, being female, might have some lip gloss or something - I went to her and asked if she had something. She told me she had some carmex - I asked if I could borrow it.
She gave me this strange look of "WTF?" - I proceeded to explain the situation, and she asked if we had any spare power supplies (we didn't). She then said "I could pick you up a fan, or a new power supply", which was fine by me. Then she said "How about we get you a new case?"...
Now, in this time of tight economies, why would you spend $70.00 on a tower case, or even $30.00 for a power supply, to effectively grease a bearing on a fan? I had the fan apart, I could get it together, no prob. I asked if I could simply use some of the carmex, and if she could pick me up a fan over the weekend, cool.
She reluctantly gave me the carmex, I took some, greased the bearing, put it back together, and reinstalled everything, and switched it on.
The next Monday, there was no fan on my desk. I never bothered to ask about it. So far, it has been about a month and a half - and my fan has yet to make another noise outside of the usual...
Re:Ovbiously (Score:2)