Just a FYI, the beauty of the 7/16" ID tubing is that it easily slips over 1/2" OD barbs for a snug fit that doesn't require clamping.

The tubing that I use, and recommend, is this one:

http://www.usplastic.com/catalog/pro...duct%5Fid=7689

Item No: 54047

Really good stuff. Much easier to work with than 1/2" ID tubing, slips over 1/2" OD fittings as noted, bends tighter radii without kinking and with MUCH less effort, does not sacrifice flow-rates if using less than 3 metere of it when slipped over 1/2" OD barbs, and is slimmer and neater looking.

Bookmarked, noted, and enquiry e-mail for trade supplies in quantity sent!

The only thing that meets that criteria is a moderate to low CFM centrifugal blower and the size precludes mounting it in a case. I graduated from loud PCs when I migrated to water cooling several years ago, so I appreciate quiet solutions. In my P160 case, with the sides on, the 24V Patriot , run at 12V is almost inaudible. Certainly not obnoxious like my push-pull 120mm Panaflos were when I was using a "Chevette" core, though their noise was mostly attributable to having the pull fan not far enough away from the radiator fins (~12mm) and hearing the forced air rivulets sheer against the blades.

Edit: Also consider the EBM/Pabst 7112 available from MPJA for the "Chevette" class of heater cores. Its 150x38mm size matches the 150mm footprint of that class of heater core perfectly.

Hoot

Why can't we delete our own messages?

...Hard to believe that I could reduce the tubing size and not take a hit in flow rates. If Cath says so, though, I'll take it as gospel. :cool:

Any chance the 1/2" tygon would fit over 3/4" fittings? Would this help flow rates if coupled with an appropriate pump (a mag 5 or an Iwaki 20RLT off the top of my head). :shrug: :shrug: :shrug:

Why not use a fan better suited to watercooling - if one exists?

More airflow = more noise.. but as much pressure as you want, not much niose?

What if a over rated (in torque) motor was used, but with a resonably low rpm (for a fan).
Its the airflow and bearings that seems to make all of the niose, not the motor?
The motor wouldnt slow down much with restriction.. giving the same airflow but capable of several times more restriction.. = better cooling..?


And fans are cheaper than rads (I think!).

What about blower style fans instead of axial?

Or am I compleatly wrong about current fans not being perfect?

Also, is there any link between fan thickness and presure ability?

Ive got a 172mm nidec (TA600DC A33142-10), seems to have bearing noise,not sure which type of bearing but any idea to quieten it a bit?

Centrif. blowers have a different optimisation point. They also tend to be a lot noisier than axial fans for the same level of air-flow, and they are not exactly things that can be mounted conveniently inside a case.

Keeping in mind that we want sustained air-flow through the radiator that is at least around 43CFM. 43CFM of air-flow has an inherent C/W of 0.04, meaning that a 0.04 C/W is as good as you can get given perfect heat transfer from the radiator into the air flowing through it.

If you take a look around the web, you won't find many blowers that can deliver 43CFM against pressure for low noise, where by "low noise", we're talking about ~20dBA noise levels. If you don find one, chances are it's also a fairly large unit, quite costly, and being run at very low speeds.

Remember, we're also talking about cost here. Hard to compete against a ultra-low-noise, small, compact, and light $5 fan with a large, heavy, noisier $50 blower, even if you can argue that the blower is better for pure performance.

The whole point with making the radiator larger than the 12cm axial fan was to decrease the air-flow resistance to the point that the low-speed low-noise axial fan is operating very high up on its flow curve. i.e. you don't need the pressures provided by a blower to get good performance out of the radiator.

Sure, as Hoot say's, if the radiator is now 16x16cm then let's stick a 15 or 16cm fan on it. Yes - you could do that and get better performance, but what I'm talking about here is extracting the most performance possible for the least effort (on the fan's part) and cost and noise.

To me, it just feel right that I'm matching a super-quiet, $5, 1W powered fan to a radiator designed to work with its specific traits, that provides cooling performance that matches larger/noisier setups. Yes - of course we can stick a larger/noisier fan on it, but then that's moving away from what I perceive to be the primary design goal.

Match the fan/radiator setup with a super-efficient super-quiet 5-10W pump (my other dream - but 15-25W will have to do for now until that day) and we have a setup that kicks anything else in the teeth quite hard in every respect (less power, less noise, low-space, smaller ID tubin, better cooling, moderate cost).

Maybe I should move to Europe. :evilaugh:

We both want silence :)
I know very little about fan, radiator, and watercooling design.. Im just suggesting that instead of low restriction rads, to achive the same with as-quiet fans, but much higher restriction, same noise, but also same airflow.

Where you say effecient, what do you mean? efficent in fan power? noise? airflow?
I think noise is most important, then air flow.. I couldnt really care how much power it takes within a resonably amount.. as long as the noise and performance are both good.
Would having less restriction, make the airflow less effective? much like a single large channel in a waterblock i less restrictive but compared to many smaller ones or jet impingement it performs a lot worse aswell.

Im currently using 2x200mm heatercores, with airflow in series, with a 172mm fan which is not THAT noisy. Its rated for 12w - 24v 0.55A (which is noisy!) but I have been running it at 7-10v (At a guess ~3-6w = 6-12v?) which is much much reduced niose - but the bearing used in it are crap.. with good bearings it would be almost silent - I think.

What causes noise in a fan?
Like a water pump, I think its not so much the actual motor but instead the bearings and the flow rate.

.'. keep flow the same, use the worlds best bearings, but chose a motor that is LOW RPM (dont want high pitch whine - I think below 1000RPM, maybe down to 500?!) also over-rated enough so it will require a LOT more restriction to slow it down than your going to get from a few rads in series. Might want a bit more power but are you going to hear any difference..

I think the ideal rad would be 180*180*100, much like my two rads together... *but* also with a higher FPI - how much will that affect performance assuming constant air flow?

I want the most airflow, for the least possible RPM, with the most possible pressure.
I think low rpm is important in reducing noise caused by bearings?

edit:
Done some quick tests and I have observed a few things which should be obvious...
1) air restriction does not slow down fan that much, instead the air bounces back through the fan
So all I can think of really, is a really wide fan, with blades curved so that they give the maximuim flow and pressure - allowing the RPM to be dropped a lot. ..

Anyway.. time for me to let this thread get back to where it was..

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.

I think we all do. :D 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.

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.

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

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

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).

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!

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...

Just curious, whats your affiliation with thermochill?

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

Sorry for going o/t, Ill start another thread

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).

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.

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.

"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)

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.

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 ;)

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.

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:

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.