No competition, why only HWlabs?

[Cathar]

Originally Posted by Marci

I'll go make up the bed in the spare room...

I have to respond to your email too....

While I'm on my way to Europe, I should pass by India and pick up a few extra pairs of arms and heads (reference to various Indian deities who seem to have the right idea for the modern world with multiple faces and sets of arms).

[Marci]

No rush d00d... I know yer workload etc will be keeping u snowed under... am still awaiting 40mm shroud at this end. Will start knocking up test bed based on suggestions earlier in thread and start collecting data... and just remembered to update me sig for clarity!

[bobkoure]

Originally Posted by Marci

Half of the noise generated by a fan/rad combi is from the friction of air passing over the fins.

Hmmm... now there's something interesting to focus on. How exactly does airflow through fins translate to noise? Is the frequency proportional to the airspeed? If it is, what airspeed corresponds to "noise" under 15Hz or so (where normal humans can't hear it)? Or is there a relationship between airspeed and passage size (or even length)? I would guess that noise is related to turbulence - and the downside of reducing turbulence would probably be reducing efficiency-for-radiator-size and efficiency-for-airflow.
Just guessing here - feel free to slap me silly if you've answers rather than my not-very-useful questions...

[Delirious]

Originally Posted by Marci

... and just remembered to update me sig for clarity!

Just curious, whats your affiliation with thermochill?

Its exciting to see that people are working towards water cooling components that are optomized for computers.

[|kbn|]

Originally Posted by maxSaleen

This is moving away from the original goal of optimizing a radiator for a specific fan. Cath specified roughly 43cfm of flow with a pressure I'm too lazy to look up. For these given specifications, Caht's design works best. Increasing the frontal area, 180x180, might help performance. Increasing the depth to 100mm would actually hurt performance as it would reduce airflow. Increasing the FPI count might also hurt performance as it would also reduce airlow.

Not if a higher pressure fan would be used

I think we all do. I was excited the first time I fired up a 12cm tornado, but the novalty wore off in about a minute as I began to lose my hearing. Until someone comes up with a maglev/magdrive fan we are stuck with traditional bearings/sleeves and traditional motors. Perhaps deeper fans with more blades and more curvature to the blades would help with back pressure. This is going into territory where I can only speculate.

All of this is beyond me.. Im just suggesting and learning from your comments
One thing is ive not seen a fan which has bearings on both sides of the fan, with the frame on both sides.. would that not help to stabalise the blades and make it more balanced also reducing niose?
Im jut trying to understand this stuff... I mean there are HDDs that spin at 7200rpmand are comleatly silent because of FDB bearings.. could they not be used in a fan?
Then theres the problem of airflow noise... I think lowering the RPM and changing the curvature would lower the noise a very large amount.. and also make the pitch much less annoying.. ive looked on google for stuff on fan design.. anyone found any good sites that explain thi stuff?

Originally Posted by Marci

Half of the noise generated by a fan/rad combi is from the friction of air passing over the fins. You increase the FPI, the noise level increases also. As either FPI or Core Depth increase, a fan with higher pressure is required to penetrate. Most 120mm fans with higher pressure mean higher noise output due to higher CFM. Higher CFM means more air blown over fins means more frictional noise.

Never noticed any increase of niose from placing a restriction on a fan..maybe but I dont think its significant. I think the noise is from the high RPM, much like if you drive in 2nd gear at 30mph, much louder engine becuase of the rpm than in 3rd gear or 4th gear.

Waste of good air... if it's going anywhere other than thru the rad, it's inefficient.

I know.. that was an example of something I realised.. as before I forgot and assumed that the motor would slow down - which it does.. but the effect of air bouncing back is much greater

Sorry for going o/t, Ill start another thread

[TheXtremeDude]

I'm getting ready to strap on 4 new Delta 120mm tri-blade hi-pressure fans onto my Weapon shrouds in a push/pull for my 69-72 chev pickup single pass core.
Nice quiet, hi-pressure fans, give them a try. I love them! Sidewinder has them in stock.

[|kbn|]

Originally Posted by TheXtremeDude

I'm getting ready to strap on 4 new Delta 120mm tri-blade hi-pressure fans onto my Weapon shrouds in a push/pull for my 69-72 chev pickup single pass core.
Nice quiet, hi-pressure fans, give them a try. I love them! Sidewinder has them in stock.

push/pull is pointless for that I think... your cfm wont change much with both fans... your rad wont have that much restriction... You would be better having a double size rad either to double/triple the restriction (then doubling up the fans) or doubling the flow (fans in parrelell).

[eander315]

I'm using a 285mm x 280mm x 19mm (13 or 14 fpi) radiator in a box with 4 120mm Yate Loon low-speed fans. I'm still working on slowing the fans a little more to bring them down to near silence. The MCP350 also needs more sound dampening to eliminate it as a noise source, though really that's not an issue for this thread. The only problem with this radiator is that it's a Derale 8000 series transmission cooler made entirely of aluminum (which is why I asked about aluminum issues in a couple of other recent threads). I got tired of looking for a copper one with these dimensions, so I got this one to use until I can find something made entirely of copper. I don't have the equipment to accurately measure the temperature drop across the radiator, or even just the basic water temperature. I tried measuring it with a cheap thermometer, but the difference was so small it didn't register. When I get time I'm planning to measure the actual voltage for each fan to try to estimate the total airflow. Currently this probably isn't too helpful to this discussion due to the lack actual temp data, but practically speaking, this radiator/fan arrangement is very quiet and appears to be coolig the water to near room temperature.

If you'd like to see pictures, etc, I posted it a few days ago on the SPCR watercooling forum.

[Cathar]

Originally Posted by TheXtremeDude

I'm getting ready to strap on 4 new Delta 120mm tri-blade hi-pressure fans onto my Weapon shrouds in a push/pull for my 69-72 chev pickup single pass core.
Nice quiet, hi-pressure fans, give them a try. I love them! Sidewinder has them in stock.

Sorry - anyone who uses the words "Delta" and "quiet" in the same context, especially when talking about the multi-blade fans, really doesn't understand the nature of what's trying to be achieved in terms of actual "quiet".

Let's express this yet again. By "quiet" - we're talking about getting out of bed at 3am when it's dead silent outside and in the house, everything else in the house is turned off, walking to one's computer, turning it on, and apart from the flashing lights and the monitor, not actually hearing any particular change in the noise level of the room.

On that score, Delta fans are positively thunderously loud, even when undervolted.

eander315 above is someone who is really seeking silence from their PC. His radiator box is much like mine. Every time I have guests over, they remark that they can't hear my PC, but to me it's still noticably noisy.

[BillA]

"Let's express this yet again. By "quiet" - we're talking about getting out of bed at 3am when it's dead silent outside and in the house, everything else in the house is turned off, walking to one's computer, turning it on, and apart from the flashing lights and the monitor, not actually hearing any particular change in the noise level of the room."

very nice, a good functional description; my goal as well
but perilously close to fanless, which translates for the psu as airless
offtopic:
anyone heard of a psu good for still air ? (i.e. no forced circulation)

[Cathar]

Originally Posted by unregistered

offtopic:
anyone heard of a psu good for still air ? (i.e. no forced circulation)

The Antec Phantom?

Okay for still air if not overvolting stuff. If overvolt/clocking, then yeah - will still need a modicum of air-flow, but in this scenario a 5v Yate-Loon fan should do the trick if set up properly.

Pricey PSU's though. >$200.

That Zalman heat-pipe based totally silent case is now sold commercially if you want to follow that path.... Again, very pricey - ~$1000.

[eander315]

You could always add the PSU to the loop if you need 400+ W. It looks like a pain in the rear to modify, will add at least a little restriction, and might add enough heat to require a larger radiator, fan, etc., but it looks like the only totally silent way to run a big power supply. They're available commercially in Germany. Must not be a big enough market in the states yet, unless someone is already working on it

[aaronspink]

Originally Posted by unregistered

very nice, a good functional description; my goal as well
but perilously close to fanless, which translates for the psu as airless
offtopic:
anyone heard of a psu good for still air ? (i.e. no forced circulation)

Antec Phantom is the closest available design to what you want. When Zalman finally releases their new external PS that would be the first true still air PSU.

Silent PC Review has a decent review of the Phantom.

Aaron Spink
speaking for myself inc.

[maxSaleen]

push/pull is pointless for that I think... your cfm wont change much with both fans... your rad wont have that much restriction... You would be better having a double size rad either to double/triple the restriction (then doubling up the fans) or doubling the flow (fans in parrelell).

Look at some of the pH has done with fan stacking and airflow. Running push/pull configuration actually DOES help airflow. How could this be?

Let's put it this way:

Your brand X 12cm fan touts that it pushes 50cfm at 22db. Placing one on top of the other will not help airflow (practically speaking). We all know this. HOWEVER, your radiator, regardless of its design, will restrict airflow. If using a 1" core it might drop your airflow rate 30% (ballpark, depends on FPI) meaning that your fan is only pushing 35cfm. If using a 2" core it might drop your airflow by 60% (ballpark again) meaning that your fan is now pushig only 20cfm. If you have one fan that is pushing, adding a second fan to pull will create an area of low pressure on the opposie side of the core. This area of low pressure assists the pushing fan in blowing air through the radiator. Hypothetically, I'll say this reduces the airflow drop by half, meaning that a 2" core will drop your airflow rates by only 30% (ballpark yet again).

Clear? :shrug:

[eander315]

NMB has an engineering page with several whitepapers and other useful documents. In particular, the Fan Engineering 101 .pdf is full of good information (warning: link points directly to a PDF).

Basically, parallel fans are better in low static pressure situations, while fans run in series are better for high static pressure.

[slicey]

i read all this talk about noise control, along with pictures of ext. radiator boxes that have fans and cores mounted on exterior walls. come on guys! "think outside the bun" for once. i want the performance/low noise solution most everyone here wants. only i'm doing something you guys can't seem to figure out, maybe not even Cathar. there's lots of info on ducted airflow systems that deal with low noise and other issues. my external W/C box is like nothing i've seen in forums. let's just say you can't see the fans or the core unless you open up the enclosure. i found lots of info-this should get you started. BTW, i've never put links in my SO few posts and have no idea if these are going to work.

http://www.vent-axia.com/sharing/ductingair.asp

http://www.nidec.com/aircooling/ap.htm


start GOOGLING!

[maxSaleen]

Ducting air can be very effective at managing airflow/noise/heat dissipation. The problem lies in the fact that most ducting is unique to each case and radiator placement within the case. Cath's goal was build a radiator optimized for any placement within a case with certain perameters regarding noise and heat dissipation.

edit: you have a point though, slicey. When properly implemented, ducting can provide high airflow with minimal noise (think of the a/c system in a house). The problem lies in mass integration.

[Delirious]

Originally Posted by slicey

i read all this talk about noise control, along with pictures of ext. radiator boxes that have fans and cores mounted on exterior walls. come on guys! "think outside the bun" for once. i want the performance/low noise solution most everyone here wants. only i'm doing something you guys can't seem to figure out, maybe not even Cathar. there's lots of info on ducted airflow systems that deal with low noise and other issues. my external W/C box is like nothing i've seen in forums. let's just say you can't see the fans or the core unless you open up the enclosure. i found lots of info-this should get you started. BTW, i've never put links in my SO few posts and have no idea if these are going to work.

http://www.vent-axia.com/sharing/ductingair.asp

http://www.nidec.com/aircooling/ap.htm


start GOOGLING!

Id like to see your rad box, do you have any pictures you could share with us?

[slicey]

Originally Posted by maxSaleen

Ducting air can be very effective at managing airflow/noise/heat dissipation. The problem lies in the fact that most ducting is unique to each case and radiator placement within the case. Cath's goal was build a radiator optimized for any placement within a case with certain perameters regarding noise and heat dissipation.

edit: you have a point though, slicey. When properly implemented, ducting can provide high airflow with minimal noise (think of the a/c system in a house). The problem lies in mass integration.

I was actually talking about a stand alone rad box. in order to construct an enclosure w/ internal ducting and doing so by following the basic dos and don'ts of ducting w/ inline fan of the size i'm using or even w 4" fans, requires a huge box!
my bad for overlooking the fact cather wants this setup mounted in PC. memory is crappy, but thought i read few pages back, cather commented that a member's rad box looked like his?

don't think exactly like that of an a/c system in a house, though. you don,t want the air velocity in the ducting to move too fast. that only increases friction and raises system impedance. i think that info is in one of the links i posted.

i tried adding some excellent reading to my post called, IMPROVING FAN SYSTEM PERFORMANCE: A SOURCEBOOK FOR INDUSTRY but the file is like 1.7MB. great reading, though

[slicey]

Originally Posted by Delirious

Id like to see your rad box, do you have any pictures you could share with us?

no camera, thus no pictures.