'Best' fans for dual heatercore

[funsoul]

Hi Folks

Finally getting everything moved over to the new case. Using a 2x120 heatercore with shroud (from moddershq) and am trying to figure out which fans to use.

The goal is a really quiet pc when idling but lowest possible temps under full load. Am going to run the radiator fans through the NoiseIsolator fan controller which lets the fans run from 7-12v.

The fans I've been playing with are:
- Panaflo FBA12G12M1A (86.5cfm/36dB/4.8mmH20).
- Delta WFB1212HE (108cfm/41dB/6.3mmH20)

At 7v, both fans are pretty noisey (close but the Panaflos actually seem to be a little louder than the Deltas at this minimum voltage). The mechanical noise seems to disappear on either set of fans at somewhere around 10 volts. At that level the Panaflos are almost silent (the Deltas are pretty quiet at that level). From there to 12v, the Deltas are significantly louder than the Panaflos.

Since sound is subjective and pressure for either fan isn't an issue when using a heatercore (if this is not true, please correct my understanding), the real question is will the 21cfm difference impact my full load temps (and if so, by how much)?

From what I've read and been told, anything over about 83cfm doesn't make a noticeable temperature difference (again...if anyone has empirical or experiential info, please let me know).

So....go with the Panaflos or Deltas to get lowest noise level @ idle and lowest temps @ load?

tia for guidance!
-funsoul

UPDATE: Spoken with a couple people who tell me that yes, the 21cfm and 1.5mmH20 extra 'should' make the system cooler but both have told me that the full-load temp difference would only be in the 1-1.5C range. Does that sound right?

 

[Stewie]

If you have a dense HC along the lines of a BIX II, I would sconsider the Panaflo FBA12G12U 120x38mm, 114CFM, 46dBA. Granted, that's quite a bit of decibles, but I am quite happy with mine when wired to a fan controller and undervolted (and even lower or off as my fan controller has that option).

When it's all the way up, you definetly hear it, but if you want the best performance, you need to sacrifice a little in terms of sound. If you're all about a slient setup, then you more than likely will not see the best performance out of your system.

Personally, I was willing to sacrifices noise for better performance. The rest of my case runs silent fans (2 80mm Vantec Stealths, 2 80mm Panaflo), so when it's crankin, the radiator fan is the only thing you can hear. I really only need to turn it up when gaming, and with a pair of headphones on or my speakers blaring, I don't even hear it.

 

[funsoul]

Thanks Stewie
Nah....it's (I think) one of the bonnie heatercores (very non-dense). That change things a bit? (the Deltas I have seem to have roughly the same specs as your Panaflos)

The main question is what the full-load temperature difference between 2x87cfm and 2x108cfm? Is there some kind of formula for calculating delta-T based on cfm?

 

[Stewie]

Well, when a HC is less dense than another of the same size, it's said that you don't need as high CFM fans since there is less resistance. This is generally the idea between the BIP and the BIX. With HCs, it may be a little different. I would just go with the higher CFM fans just to ensure you have the best cooling possible for your given situation.

The Panaflo I have is nearly the same specs as the delta as you noted, I'm just more of a Panaflo guy. Not that Delta isn't any good, but I'm a man who loves his Panaflos.

 

[funsoul]

yeah...the panaflos are very nice. I'm surprised they're so noisey at lower voltage, though (maybe that's just that particular model?)

 

[Stewie]

They're not too incredibly noisy at lower volatages; mine mostly is because it was too stupid/lazy to cut the back of my case where my fan exhausts and put a custom grill. Instead, it's blowing onto the sheat metal of the back of my case with those factory-cut fan holes (which are very restrictive).

 

[funsoul]

Hey all

OK....finally got everything together and into the new case (http://www.datamine.tk/forum/forum_posts.asp?TID=625&PN=1) and have the following observations and a question or 2.

At 7volts, the Panaflos are noticeably louder than the Delta's so I went with the Delta's on install. I figure to use 7volts when idling (or light load) as the airflow is more than enough to keep everything cool (about 35C). The mechanical noise is misery, though...I'd like to have a pretty much silent pc when it's not under full load.

At 12volts, the Delta's are clearly louder and I've found that there's no full-load temperature difference between roughly 75% and 100% cfm. It seems that for my setup, maximum deltaT happens with cfm in the 84-86 range. The Panaflos running at full speed yield almost the same full-load temps as the Delta's running at 75% (the Delta's are quieter at 75% than the Panaflos at 100%).

Now....the questions.....
What is the quietest fan on the market across the full spectrum between 7v-12v that still delivers 84+cfm at 12volts?

Which fans don't produce any audible (mechanical) noise when running from 7v-10v that would still deliver the 85-ish cfm?

Thanks in advance for any guidance, measurements, experience, etc!

 

[ls7corvete]

Hey all

OK....finally got everything together and into the new case (http://www.datamine.tk/forum/forum_posts.asp?TID=625&PN=1) and have the following observations and a question or 2.

At 7volts, the Panaflos are noticeably louder than the Delta's so I went with the Delta's on install. I figure to use 7volts when idling (or light load) as the airflow is more than enough to keep everything cool (about 35C). The mechanical noise is misery, though...I'd like to have a pretty much silent pc when it's not under full load.

At 12volts, the Delta's are clearly louder and I've found that there's no full-load temperature difference between roughly 75% and 100% cfm. It seems that for my setup, maximum deltaT happens with cfm in the 84-86 range. The Panaflos running at full speed yield almost the same full-load temps as the Delta's running at 75% (the Delta's are quieter at 75% than the Panaflos at 100%).

Now....the questions.....
What is the quietest fan on the market across the full spectrum between 7v-12v that still delivers 84+cfm at 12volts?

Which fans don't produce any audible (mechanical) noise when running from 7v-10v that would still deliver the 85-ish cfm?

Thanks in advance for any guidance, measurements, experience, etc!

None, all are noisy.

Try finding a fan controller that will go down to much lower voltage 3-4v. Also search for fans that speed control well, from the impression I get from you I think this is your best option.

85cfm is no where near silent range. You might try a 3 blade fan, there is one model I have been looking at, ill post a link.

 

[ls7corvete]

http://www.pwrpc.com/product_info.php?products_id=758

A little slower than you want but it may work, finding high pressue and high power fans that undervolt well is tough. STF for other users opinions, i have not tried them yet.

 

[funsoul]

hi ls7corvette

Thanks for the comment/suggestion. Yeah...the fans in the link are a little underpowered to give the needed deltaT on the heatercore. Agreed, high cfm/pressure fans that are actually quiet is very difficult (if there are any).

The Panaflos or Deltas would be fine if they didn't give off so much mechanical noise at low voltages. I'm really looking for comparable fans with the exception being that they're actually really quiet at those lower voltages. At higher voltages, I don't mind a little noise to keep things cool.

There's a pretty good thread over at spcr on the subject but they're mostly pretty low cfm/pressure fans.

Hadn't thought about running fans in the 3-4v range....would even lower voltage affect the mechanical noise, though?

thanks again for the feedback....I know others must've been through the same thing, wondering what they came up with

 

[ls7corvete]

http://www.ocforums.com/showthread.php?t=414771

Motor noise is the problem definetly, panaflos seem to have a week spot in this area, look for fans with less motor noise to allow lower voltage, you wont find anything that is silent at those speeds but you may find one with less motor noise that fits.