View Full Version : Effect of 7 volt mod
I need some new 80mm fans and I'm debating between going with the Sunon 50 cfm at 12 volt, or getting the Delta 80 cfm monster and running it at 7 volts. I am NOT willing to put up with the noise of the Delta at 12 volts. However, I want a fan with good airflow and good static pressure.
I'm trying to find out what the effect of running the Delta at 7 volts will be. Does anyone have any data on how the 7 volt mod affects the CFM and pressure of a fan. I'd even welcome data about how the 7volt mod affects RPM. Perhaps from that I could at least make some educated guesses.
If you've done the mod on any fan and have some numbers to share, I'd love to see em.
nihili
Also, does anyone know whether the fans in a given Delta series have differ in ways other than the motor?
chuckchippie
11-07-01, 07:29 PM
I have the same question about the 120mm Delta's...i might just got with a rheobus.
Intraveinous
11-08-01, 10:45 AM
I do know that between the 80mm 68CFM SHE Delta and the 80mm 80CFM EHE Delta, the only difference is the motor. The lower CFM Delta 80mms are only 25mm thick rather than 38 and do not have the vanes for directing the airflow. I've only got the 68CFM, and I have neither a flow meter nor a decible meter, so I don't have any hard numbers for you, however, with a 5W Radioshack Rheostat that probably doesn't take it down much past 9V, it's noticibly quieter and still moves a decent volume of air.
Sorry these are only subjective observations, but it's the best I can do currently. I'd set up a mic and send you some sound samples, but I'm at work right now... Perhaps later tonite if I have time.
Peace
John
Intraveinous,
Do you know what the fan speed is at 9v?
Given that the rotors are the same, the flow properties should be dependent only on RPM. So if I know how the change in voltage effects RPM, I should be able to calculate the rest off of the tables.
Also, the relation between percentage voltage drop and percent RPM drop should be the same for all fans, so if anyone has info on the effect of voltage change on RPM for any fan, I'd be interested.
Thanx
nihili
Intraveinous
11-08-01, 11:13 AM
I dunno if my fan just doesn't have an RPM monitor at all, or if it just doesn't have a wire for it, but regardless, I don't have a way to find out the RPM... I'm just no help at all today :D
John
Owenator
11-08-01, 12:06 PM
Originally posted by nihili
I need some new 80mm fans and I'm debating between going with the Sunon 50 cfm at 12 volt, or getting the Delta 80 cfm monster and running it at 7 volts. I am NOT willing to put up with the noise of the Delta at 12 volts. However, I want a fan with good airflow and good static pressure.
I'm trying to find out what the effect of running the Delta at 7 volts will be. Does anyone have any data on how the 7 volt mod affects the CFM and pressure of a fan. I'd even welcome data about how the 7volt mod affects RPM. Perhaps from that I could at least make some educated guesses.
If you've done the mod on any fan and have some numbers to share, I'd love to see em.
nihili
Also, does anyone know whether the fans in a given Delta series have differ in ways other than the motor?
Here is Deltas "fan curve" for the 80x38mm fans (a zipped pdf). I wonder if you can use the power and RPM to estimate what they will do at lower voltages. Ex. the 68 cfm model pulls .58 A so at 12 V is 6.96 W if you use the same power draw .58A times 7V you get 4.06W which puts you into the range of the 45cfm version. I know at lower voltage the current draw is usually higher so this may nott be too great a guess.
O
ButcherUK
11-08-01, 12:44 PM
low voltage means greater current for a given power, however the thing to note with a motor is that it's obeys ohms law: I = V / R. So lowering V causes I to drop as well (R is a fixed property of the motor coils).
Good points.
I've got some info from another thread of someone seeing a 1500 RMP drop by dropping the 68k delta down to 7 volts. Applying the same percentage drop to the high end 80mm series would say that the the 68CFM models should produce about 50cfm at about 7 mm H20 pressure and about 42 db. The 80CFM model should produce about 62 CFM at about 10 mm H2O pressure and about 46dba. (These estimates are based on the assumption of a 22% drop in RPM and no change in pressure curve as a result of decreased voltage.)
I'm not sure how reasonable the assumptions underlying those estimates are, but it's my guess at this stage. If theyre right then the delta 68CFM running at 7v should be about on a par with the best Sunon at 12v in terms of CFM and dBa. I believe that the delta will whup the Sunon in terms of pressure though, which would be important for trying to push air through a high end heatsink or for those of us using ducts.
I'd still like to get more information if anyone has it, so I can firm up these estimates. Also does anyone know where I can get the pressure figures for Sunon?
nihili
Not sure where you work Nihili, but if you are around a lab that uses centrifuges see if you can borrow their digital tach. It uses a little stick on dot to put on your fan then point the sensor at it and it will give you exact rpms.
nihili:
I've got some info from another thread of someone seeing a 1500 RMP drop by dropping the 68k delta down to 7 volts. Applying the same percentage drop to the high end 80mm series would say that the the 68CFM models should produce about 50cfm at about 7 mm H20 pressure and about 42 db. The 80CFM model should produce about 62 CFM at about 10 mm H2O pressure and about 46dba. (These estimates are based on the assumption of a 22% drop in RPM and no change in pressure curve as a result of decreased voltage.)
Your conclusions are wrong. RPM are not linear with voltage so a 50% volt drop for example won't translate into 50% lower rpm, although it should be close. Also the the volume of air a fan can blow not only depends on RPM but fin design, some Fans work better at high rpms and others at low rpm. Noise is caused because of air turbulence, it has to do with the fan RPM, fins, temperature and air density among other things. Depending on these conditions the noise a fan makes can vary a lot. Also you should consider that manufacturer claims are far from real and may reflect optimal conditions.
Originally posted by Cotita
Your conclusions are wrong. RPM are not linear with voltage so a 50% volt drop for example won't translate into 50% lower rpm, although it should be close. Also the the volume of air a fan can blow not only depends on RPM but fin design, some Fans work better at high rpms and others at low rpm. Noise is caused because of air turbulence, it has to do with the fan RPM, fins, temperature and air density among other things. Depending on these conditions the noise a fan makes can vary a lot. Also you should consider that manufacturer claims are far from real and may reflect optimal conditions.
I'm happy for my conclusions to be wrong, they often are, but you've misunderstood my reasoning. I did not claim that RPM was linear with voltage. Also, I only extrapolated the results to other fans in the same series by the same manufacturer. These fans all have the same fin shape and same basic motor design. So the effect of the 7 volt mod should be porpotional on them. F
First I found someone else measurement of the effect of the 7 volt mod on the RMP of the 68 CFM model. I inferred the effect on the RPM of the 80 CFM model based on the assumption of porportionality. I then estimated the CFM and noise by comparing other fans in the same series at the estimated RPM. I guesstimated the static pressure by comparng pressure curves for fans in that series.
Certainly manufacturer's claims are biased. I only intended my guesses to be comparative based on the manufacturers claims. I'd be happy to have soem real life data about the effect of the 7 volt mod. I've been unable to find any. In the absence of hard data the best I can do is to speculate carefully and try to clearly identify the assumptions on which the speculation is based. Undoubtedly some of my assumpptions are wrong. I'm not an engineer. I'd be happy for you or anyone else to help me tidy them up.
nihili
Tecumseh
04-10-02, 06:59 PM
There is an interesting new article on the front page.
The plot is very interesting, indeed.
http://www.overclockers.com/articles560/
Yes, based on that data and my own intolerance of noise I'm thinking I may not get an AX7 after all. I'd sure like to see how the Swifty and Alpha perform on that.
nihili
gone_fishin
04-10-02, 09:58 PM
I have an 80mm Thermaltake smartcase fan. It has a thermister which adjusts it between 7volts and 12volts. Heres what it says on the package:
7volts=2900RPM @ 27 dB(A) 46CFM
12volt=5000RPM @ 39 dB(A) 53CFM
Rated Current .18AMP ~ .45AMP
Rated Input 2.16W ~ 5.4W
Originally posted by gone_fishin
I have an 80mm Thermaltake smartcase fan. It has a thermister which adjusts it between 7volts and 12volts. Heres what it says on the package:
7volts=2900RPM @ 27 dB(A) 46CFM
12volt=5000RPM @ 39 dB(A) 53CFM
Rated Current .18AMP ~ .45AMP
Rated Input 2.16W ~ 5.4W
Great. So at 7V that's
58.3% volts
58% RPM
69.2% dB(A)
86.8% CFM
It's interesting to me that CFM drops off much less than either RPM (not surprising) and noise (this surprises me). I'd love to see numbers form other fans if anyone has them.
nihili
Silversinksam
04-10-02, 10:42 PM
Nihili I hate to sidetrack this discussion but have you considered just buying a Rheostat and set the audible value to your liking?
You know Hoot sells about the best quality rheo's available....maybe shoot him a PM
They look like this:
I have my 68cfm delta at 7volts but I can only help you in respect to my subjective idea of noise.
It sounds about the same (lower pitch) as a Glaciator. Just a whooshing of air.
Originally posted by Silversinksam
Nihili I hate to sidetrack this discussion but have you considered just buying a Rheostat and set the audible value to your liking?
You know Hoot sells about the best quality rheo's available....maybe shoot him a PM
They look like this:
Actually I need to do that. I currently have all my fans running on a 7V mod, but I'd like a bit more control. In any case though, I'm still interested in knowing the effect that voltage reduction has on fan performance. This thread started because I was debating whether it was better to use a loud fan at 7V or a quiet fan at 12V. It's a question of design optimization. Certainly a rheostat is the optimal way to go. But I want to understand precisely what effects lowering the voltage has on noise, flow, and pressure, so that I can make optimal choices in designing a system. I'm actually now thinking that it may in general be better to buy the huge Deltas and throttle them rather than buying quieter fans.
Btw, it occurs to me that my calculation of dB(A) reduction as a percentage may be misleading due to the logrithmic scale. Could some kind soul who understands that better than I calculate the percentage reduction in noise energy? thanks.
nihili
Malakai
04-10-02, 11:10 PM
Originally posted by Cotita
Your conclusions are wrong. RPM are not linear with voltage so a 50% volt drop for example won't translate into 50% lower rpm, although it should be close. Also the the volume of air a fan can blow not only depends on RPM but fin design, some Fans work better at high rpms and others at low rpm. Noise is caused because of air turbulence, it has to do with the fan RPM, fins, temperature and air density among other things. Depending on these conditions the noise a fan makes can vary a lot. Also you should consider that manufacturer claims are far from real and may reflect optimal conditions.
no need to be rude man, Nhili comes up with cool formula's and stuff all the time.
reading your posts is always nice Nihili, allways very well articulated man, good job
-Malakai
question for nihili
i buy DELTA 80mm 80.6cfm , 52.5 dba 5700rpm but is very noisy
i change ground wire a +5v and run my fan a 7v is more low noise (your recomendation)
because i not know rpm, cfm and dba
what is better ?
use my delta a 7v or buy panaflo Panaflo 80mm
Model FBA-08A12H. 80mm 2950 RPM, 39.6 CFM, 32 dBA
what is more low noise and more cfm
my delta a 7v or this panaflo??
Intraveinous
04-11-02, 10:08 AM
This relates back to nihili's original question... If we can get the original question answered, we will be able to answer yours as well..
My gut feeling says that the Delta will be better, but probably a little louder too. I think that mostly because of the "focusing-vains" that the delta highspeed fans have. Same airflow can be more effectively utilized because it is going directly where it needs to be.
Peace
John
Originally posted by Gosu
question for nihili
i buy DELTA 80mm 80.6cfm , 52.5 dba 5700rpm but is very noisy
i change ground wire a +5v and run my fan a 7v is more low noise (your recomendation)
because i not know rpm, cfm and dba
what is better ?
use my delta a 7v or buy panaflo Panaflo 80mm
Model FBA-08A12H. 80mm 2950 RPM, 39.6 CFM, 32 dBA
what is more low noise and more cfm
my delta a 7v or this panaflo??
Malakai
04-11-02, 10:18 AM
i cant compare to a delta at 7v, but i have 4 46cfm panaflo's and all u hear is the wooshing of air, there is no whine like a delta at all.
the panaflo is actually kinda pleasant
-Malakai
At this stage no one knows which is better. We just don't have enough data. My suspicion is that the Delta is better for the reasons Intraveinous already said. But I really don't know. I'd say that if you're ok with the noise and cooling level, stick with what you've got.
nihili
I just did the 7v mod on my 131 cfm 120mm screamer. Now it's very quiet, and I didn't gain any cpu degrees.
Even my harddrive is louder than this thing.
LiquidConfusion
04-11-02, 02:19 PM
Has anyone considered the effects of the 7V mod on your power supply? By putting the +5V line in place of the ground you are effectivly shorting your +5V and +12V voltage regulators together and removing the ground which is necessary for return. The rheostat is a much better way to go. Sorry but in my opinion as an Electronics Tech a little quieter isnt worth the wear and tear on my $90 PS that can be saved a lot of this stress with a few dollar mod using a rheo.
mcduffiem
04-11-02, 02:30 PM
Originally posted by LiquidConfusion
By putting the +5V line in place of the ground you are effectivly shorting your +5V and +12V voltage regulators together and removing the ground which is necessary for return.
I hadn't thought of the stress on the PS (although like most things it seems obvious in hindsight). I haven't tried the 7V mod yet, but I was considering it for a short term fix while working a circuit controlled solution. Looks like I need to rethink things first.
Thanks for the info.
Tecumseh
04-11-02, 02:56 PM
I think the 7V mod using the +5 in place of the 12V ground
is a BAD idea. Yes, some people seem to get away with it
just fine, but not all PSUs are the same. LiquidConfusion,
is right on the money with this. I know the designers never
planed for this trick and ANYTHING goes.
Don't do it. Get a Rheostat!!!
Yes, according to what 2 people just said the PSU could be damaged.
However, I'm not worried. I have 3 or 4 psus from my other computers. If my PSU ever does break you guys will hear from me on the board.
RE: The 7 volt mod
When you take the return wire from the +12V fan, (which would normally connect to ground) and move it to the +5V line, you are just feeding the fan current to the devices that are connected to the +5V power supply. You are simply reducing current drawn from the +5V supply by the amount of the fan current. There, of course, is nothing wrong with this and it would, in fact, allow slightly more +5V power capability.
The only potential problem would occur if you switched on the power supply with the motherboard and other devices disconnected and only the fans connected. But, you are not supposed to do this anyhow with the power supplies that I have used. And even then, the power supply probably draws enough internal idling current on the +5V line to prevent any damage from the small fan current.
If you are into electronics, you can Thevenize to demonstrate how this works.
John
damage or no damage my psu??
Originally posted by Gosu
damage or no damage my psu??
NO Damage!
Tecumseh
04-11-02, 06:16 PM
Of course, JPSJPS will buy you a new PSU if it is damaged or
causes damage and pay your liability insurance for this mod.
:D :D :D
What? you wont? Shame on you....:)
A rheostat is definitely a better idea. While I have no doubt that LiquidConfusion and Tecumseh are correct in their claim that the 7 volt mod represents some risk to the PSU, it is worth pointing out that the 7 volt mod is very common. Despite the fact that I have heard many many people say they use it, I haven't heard anyone claiming to have PSU problem as a result. This does not, of course, prove that the mod is perfectly safe. But it does suggest that the risk isn't generally great. In my own case, I've had the 7 volt mod in place for about 4 months and have noticed no change in the performance in my PSU. However, as with all things in overclocking, your mileage may vary.
nihili
Tecumseh
04-11-02, 07:52 PM
That's a great summary, nihili. I think a more important issue
is that the 7V mod is "stuck" at 7V. With a rheostat you have
a lot more flexibility, usually 7V to about 11V.
Note: Go too much below 7V and the fan may not
start. This is NOT GOOD. :eek:
yeah, I need to get off my butt and order some rheos from Hoot.
nihili
Originally posted by Tecumseh
Of course, JPSJPS will buy you a new PSU if it is damaged or
causes damage and pay your liability insurance for this mod.
:D :D :D
What? you wont? Shame on you....:)
YES, in fact I DO offer to buy Gosu a new PSU if it is damaged or causes damage and no liability insurance is necessary!
I would not have posted an answer if the question had been outside of my field of knowledge! I will leave that to others like yourself who then also make a feeble attempt at being rude.
As I stated, there will be NO damage to the PSU from this mod as long as the PSU is operated with the motherboard connected (or any other 5V devices connected that draw as much +5V current as the fans draw at 7V). Gosu's Delta at 7V will pull well under an amp! If you have never measured +5V system current, look at a PSU label to get an order of magnitude value of the expected +5V current draw.
I do not know if the RPM output signal will be acceptable under these conditions.
This analysis is a pretty trivial excercise that requires a minimal knowledge of electronics. Kirchoff's Laws and Thevenin theory are taught at the college freshmen/sophomore level in beginning DC circuit theory (beginning electricity/electronics).
In fact, Kirchoff's Laws & Thevenin theory concepts involved are MUCH simpler than they sound and are obvious even to many people who have no formal education in electricity. I will explain them in a few paragraphs relative to this discussion if you desire to learn.
However, I came here primarily to learn and get new ideas from others.
Respectfully, John
John,
Welcome to the forums. You've inadvertently stumbled into a bit of a hornet's nest. Let me assure you that Tecumseh does in fact know his stuff. I'm the main ignoramus around here, but they let me hang out anyway because I have a cool beard.
We do have a tendency to rib each other now and then and I suspect that Tecumseh meant no more than that. It's good to have another person around with a technical background. There's a growing group of *very* technically minded people that tend to hang out in the same threads, so you'll probably run in to Tecumseh again and again.
Now, about that offer to teach me some electronics. I'm happy to take you up on it. Fire at will, but be aware that the techies here tend to just assume that criticism is welcome. We actually consider it a sign of affection I think.
Welcome again,
nihili
cyber mouse45
04-11-02, 09:04 PM
I was going to do the 7v mod on all my fans but my Antec 400w doesn't work with it. It just shorts out as soon as I turn it on. On the other hand, two of my other psu worked with the 7v. Anyway, I’d go with a rheobus or something. That’s what I did, and I love mine. :)
Tecumseh
04-11-02, 09:12 PM
John AKA JPSJPS, nihili has it exactly right. I am sorry if
I have offended you. That was not my intent.
Hang around for a while. We love to hash stuff out in a
very direct way. Everyone is welcome here, at all
levels.
I like to think we are all brothers and sisters , a family, and
sometimes we love to get a dig in!!! You know the drill. :)
Thanks for posting!!
LiquidConfusion
04-12-02, 12:30 AM
Hi John my concern was not necessarily with the power supply just quiting with this mod my concern with this mod is with the overall lifespan of the power supply. I am very familiar with both kirchoff's ohm's solid state theory and any other form of electronics and I work billions of US taxpayers dollars worth of gear and take pride in knowing what im talking about and doing. This mod will probably not have an immediate effect on your PS but it can and will degrade your PS over time. You are right about def not turning it on with just the fans attached as your 5V line would no longer be in parrallel with your other 5V lines but would then be in series and all the rules change.
nihili, if you are intrested in learning some basic electronics here is a link to a NAVY site for the NEETS modules and it has downloadable pdf's of each volume these may not be the best books for this but they are good and have been used by the navy for decades. here it is
http://www.advancement.cnet.navy.mil/navigation/neets.htm
-Will
If you dont want to download them as they can get to be very large. I have them all on CD and will mail you a copy if you would like just email me at w_klingler@hotmail.com
Ghost68
04-12-02, 01:44 AM
Originally posted by nihili
I need some new 80mm fans and I'm debating between going with the Sunon 50 cfm at 12 volt, or getting the Delta 80 cfm monster and running it at 7 volts. I am NOT willing to put up with the noise of the Delta at 12 volts. However, I want a fan with good airflow and good static pressure.
I'm trying to find out what the effect of running the Delta at 7 volts will be. Does anyone have any data on how the 7 volt mod affects the CFM and pressure of a fan. I'd even welcome data about how the 7volt mod affects RPM. Perhaps from that I could at least make some educated guesses.
If you've done the mod on any fan and have some numbers to share, I'd love to see em.
nihili
Also, does anyone know whether the fans in a given Delta series have differ in ways other than the motor?
last i checked the 80cfm and the 68cfm use different motors...
about the 7volt mod i tried it and it works great (on my 68...) it went from sounding like a hair drier to sounding like a normal desk fan without much air volume loss... I also tried 5v > verry little air volume almost silent....
wow... beyond me here... I think the only thing I got was the 7v mod! :rolleyes:
:p
First off, nil, why are you so quickly dismissing water cooling?
Yea know yea wanna... Come the the water side!
You can feel its power telling you what you know you want....
Second, welcome aboard john, You lost me with 90% of what youve said, but its always nice to have more people that know their stuffs!~!
Originally posted by IFMU
First off, nil, why are you so quickly dismissing water cooling?
Yea know yea wanna... Come the the water side!
You can feel its power telling you what you know you want....
Yeah, I'd love to. the thing keeping me back is called MONEY. My next substantial chunk of change is already dedicated to getting a duallie.
nihili
This thread has almost evolved to the point of belonging in the Cases & Power Supply forum.
This has been my experience, but first, my opinion:
The 7V "trick" is a bad electronics practice.
My observation:
Whether you can get away with the 7V trick or not depends largely upon how much current you are trying to run that way. That is to say, the more fans, which contribute to the overall current drain, the greater the likelihood that your PSU may not like it. Also, the higher the quality of your PSUs overvoltage and overcurrent protection circuitry (read sensitivity), the greater the chance it will not tolerate the 7v trick. It, in all likelihood, will not harm your PSU, but it may contribute to sporadic shutdown or generally unpredictable behavior if your load is near the intolerable threshold for your particular PSU.
The other problem arises when using the tachometer output from your fan. That signal line shares the same return as the power line in your fan. That signal relies upon a low impedance ground on that return line to perform properly. If you route the return for your fan through the +5V regulation circuit in your PSU, then you do not have a low impedance ground path for the tachometer function and it may not read properly, if at all.
Hoot
Strangelove
04-12-02, 10:54 AM
Well, in my opinion the 7V mod is the easiest way to lower noice from your fans. The rheostat is the best for cheap. But the best way to change the fan RPM is using PWM. I'm getting this (http://crystalfontz.com/products/633/) cool device within the next couple of weeks and I can't wait to get it running!!! :D
[Whispering Winds]Join the Water Force[/Whispering Winds]
It is very possible to build a water cooling system with very little actual money. Trust me... lol... I am a master at doing things the very very cheap way. But understandable.
Well, there are other constraints too. Such as at the moment I have no tools and no workspace. But if my duallie plans come to naught, I'll definitely look you up.
nihili
Originally posted by nihili
Well, there are other constraints too. Such as at the moment I have no tools and no workspace. But if my duallie plans come to naught, I'll definitely look you up.
nihili
Understood! I do know how that is, living in an apartment like I did for the last year and a half, kept me from seriouslly working on my case.
One thing to keep in mind, slowly, very slowly! get things together to run a water rig if you are seriouslly interested. Spend 5 here, 5 there and get any parts you would have to buy that way... its slow.. but it doesnt cramp your budget...
Now, sorry 'bout the off topic.... IMO ~ I would get the rheostat thingy and play with that personally. I dont like cutting power to fans... granted Im not much of a fan man... but I know if that was my main effort for cooling, I would want it to be able to go full boar at that heat in there... Which with that you can, its idle, turn 'er down. Yea need it cuz your gamin or whateva and turn those puppys up and hear them roar!~!
Actually right now I've got an Alpha PAL8045 with a 50 CFM sunon ducted loosely to a 50cfm exhaust. I've got 2 50cfm intakes. All of those fans are on a 7volt mod. Then there's the fan in the PSU which runs at 12v. My temps never top 40C even though I keep it at full load 24/7. Running the 7volt mod only increased my temps by 1 or 2 degrees C. And it made the noise much more livable.
I still would like to try watercooling though. I've got a couple ideas for a waterblock that haven't yet been tried. If I can ever get to the point where I have the ability to make them, I'd like to see how they work. And Tecumseh, you can expect to have me knocking on your virtual door for opinions beforehand. ;)
nihili
Crazy Jayhawk
04-12-02, 01:48 PM
Just be sure your switch is well insulated.
Back when I still had my Dell, I replaced the back 92mm fan with a higher-power one. It was way too loud, so I did the 7V mod on it.
When I flipped the switch the first time there was a puff of smoke. I turned the thing off again to find that the insulation on the wires leading to the switch had melted.
Apparently, the switch butted up against the metal of the case. A little electrical tape around the wires fixed that. Also, it seems that Dell PSU's don't have short circuit detection.
My 5-position 12V/7V switch bus had 12V and ground shorted together by mistake, and fortunately the PSU wouldn't even turn on with it in place. I was able to fix it again and it works great now. :)
i can buy in electronic store one rehostat
15w 8ohms
this is good??
only 8ohms
my specifications fan is
Specifications: 80x80x38mm, -->80.16<-- CFM @ 5700 RPM, 52.5 dBA, 10.80w .90 Amp, 12v DC, 3+4 pin Molex connectors.
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