Hello,
has anyone tried piezo fans (for example http://www.piezo.com/prodfan0nav.html) for cooling?
Are they really noiseless (60 Hz sounds like - well, 60 Hz...)?
Regards,
Chris
Experience with Piezo fans?
Moderators: NeilBlanchard, Ralf Hutter, sthayashi, Lawrence Lee
Re: Experience with Piezo fans?
This is the first time I have heard of them, but they seem like an interesting concept. Hopefully someone else knows something about them.
Re: Experience with Piezo fans?
that 60hz is not referring to sound, it's an AC fan that runs at 115v 60hz which is wall outlet voltage in N. America.
I don't see anything there referring to noise. But this is something intel has been working on and it seems they have patents pending, but this stuff all seems (at least in references I can find) to require high voltages.
EDIT: http://www.piezofans.com/ says Quiet / noiseless. now this is interesting.
I don't see anything there referring to noise. But this is something intel has been working on and it seems they have patents pending, but this stuff all seems (at least in references I can find) to require high voltages.
EDIT: http://www.piezofans.com/ says Quiet / noiseless. now this is interesting.
-
multiplexer
- Posts: 41
- Joined: Wed Jul 13, 2011 4:11 am
Re: Experience with Piezo fans?
It's really interesting from a cooling efficiency point of view (2cfm for 30mW is awesome), but the prices are prohibitively high. The price really needs to come down more than an order of magnitude to become something recommendable.
Re: Experience with Piezo fans?
My thoughts on this, there is a lower voltage version that uses an inverter that puts out a special wave (equal to the resonant frequency) from a flat DC voltage. So I do see this as being viable for PC's Otherwise, we would have to see some sort of modification to the ATX psu spec; Or else a 110v line coming in the case, separate from the standard PSU supply connector. But with improvements I think we will see them become viable. Short of the voltage issues, I see a few potential enthusiast issues. These things are, it would seem, basically "digital" fans, in that you can not just drop the voltage for less flapping. It seems (And I may be wrong) that it's very binary.. off or on. But the speed is, it seems = to the wave frequency. but I'm not sure what range (or for that matter how much range) they are sensitive to, or if it would have a equivalent decrease in CFM. The inverter shown on that website has a trim that lets you adjust the frequency and can go from 50 to 150hz. So you would pretty much literally be overclocking your fans (Ok not really, since they aren't clocked, properly. Maybe overflapping will be the new word). But I suppose, if these things are silent it's largely moot to this community, outside of higher flow rates.
Regardless, their positioning is still a bit of an issue. With their axis of airflow I think you might find a lot of difficulties mounting them until cases are built to support it... or someone makes a special chassis that fits in a fan bay. But at 2cfm for the footprint, while operating, of approximately 2 side by side AA batteries (but about 3/4" longer), you will need arrays of these things to approach what a silent fan does these days.
In example a scythe fan at 800RPM can push 40cfm at 100ma.
12V x 100ma= 1.2w
I estimate at 1/2" by 1" you could fit 6 rows of 9 so (very)approximately 36 of these on the surface area of a 120mm fan bay. 36x2cfm = 72cfm at approximately 32mW each so
32mW x 36fans = 1296mW
1296mW = 1.3w (1.296 to be more exact)
But then we gotta throw on the efficiency/draw of the inverter.. also times 36
But you can't forget in all this the depth at about 3 inches vs a 120mm fan typically being 25mm deep which is about 1 3/rd of these piezo fans.
So they seem to compare very well IMO with my very off the cuff calculations (Please correct me if it's off)
But this all assumes 36 on the surface area of what a 120mm fan uses, and you may have to cut off 1 row of 9 for them to fit when flapping I am just now sure what if any clearance they would need or how / if they would at all sync (IE on power up would they reliably all flap up and down in a synchronized fashion?
My conclusion.
---------------
It should be noted for my above calculations I used the better performing fan specs, which seems to far outstrip the performance of the fan which uses the inverter so I am currently using best available parts in a non realistic situation, without over*clocking* since I do not know what sort of flow rates you would get at higher frequencies. (Actually it's just beyond my sleep deprived brain right now.. ok not just "right now" but always)
I see big potential though. in the mini/HTPC market you should have flexibility to have just as much CFM as you want or need only limited by the surface area available. and the depth will be a factor. Also the presence of a chasis to hold them in the various openings that may be available, or else you may have to come up with an inventive way to mount them yourself.
On the standard size silent/quiet front, it has pretty similar potential for integration to what you might see in the standard market. However, I do not think you will see these get significant standard market or enthusiast market until you see them get app. triple the current 2 CFM, which will probably be easy, or be able to push the same CFM per unit at 1/3rd the length, which could be a tall order.
Regardless, their positioning is still a bit of an issue. With their axis of airflow I think you might find a lot of difficulties mounting them until cases are built to support it... or someone makes a special chassis that fits in a fan bay. But at 2cfm for the footprint, while operating, of approximately 2 side by side AA batteries (but about 3/4" longer), you will need arrays of these things to approach what a silent fan does these days.
In example a scythe fan at 800RPM can push 40cfm at 100ma.
12V x 100ma= 1.2w
I estimate at 1/2" by 1" you could fit 6 rows of 9 so (very)approximately 36 of these on the surface area of a 120mm fan bay. 36x2cfm = 72cfm at approximately 32mW each so
32mW x 36fans = 1296mW
1296mW = 1.3w (1.296 to be more exact)
But then we gotta throw on the efficiency/draw of the inverter.. also times 36
But you can't forget in all this the depth at about 3 inches vs a 120mm fan typically being 25mm deep which is about 1 3/rd of these piezo fans.
So they seem to compare very well IMO with my very off the cuff calculations (Please correct me if it's off)
But this all assumes 36 on the surface area of what a 120mm fan uses, and you may have to cut off 1 row of 9 for them to fit when flapping I am just now sure what if any clearance they would need or how / if they would at all sync (IE on power up would they reliably all flap up and down in a synchronized fashion?
My conclusion.
---------------
It should be noted for my above calculations I used the better performing fan specs, which seems to far outstrip the performance of the fan which uses the inverter so I am currently using best available parts in a non realistic situation, without over*clocking* since I do not know what sort of flow rates you would get at higher frequencies. (Actually it's just beyond my sleep deprived brain right now.. ok not just "right now" but always)
I see big potential though. in the mini/HTPC market you should have flexibility to have just as much CFM as you want or need only limited by the surface area available. and the depth will be a factor. Also the presence of a chasis to hold them in the various openings that may be available, or else you may have to come up with an inventive way to mount them yourself.
On the standard size silent/quiet front, it has pretty similar potential for integration to what you might see in the standard market. However, I do not think you will see these get significant standard market or enthusiast market until you see them get app. triple the current 2 CFM, which will probably be easy, or be able to push the same CFM per unit at 1/3rd the length, which could be a tall order.