Hello everybody!

After trying to figure out how to mod existing ATX cases to truly support my needs, I became frustrated enough to give myself a try at designing and building chassis on my own.

Of the fact that I post about the project here you might already guessed that silence/quietness is one of the major goals :-).

The problem is, I play a lot and I also like to tinker with my PC, so I'd like to have a case that can dynamically alter cooling/noise balance and that is powerful enough to cool silently powerful possibly overclocked gaming rig. And I wouldn't mind if it looked good, too.

I am keeping work log about my advancements in finding a solution to these more or less conflicting goals: http://zds.iki.fi/zds/projectlog/

In addition to silencing commentary, I accept and appreciate language corrections, since I am not native english writer but I'd like to learn to be better. It's just that most of you still understand my bad english better than my good finnish :-].

As some of you might have read, I have had my Laing Delphi (also sold as Swiftech MCP350) for some time and have now had time to play around with it a bit.

Here is picture of the beauty after swapping in the acrylic top and changing water inlet fitting to the top:



Bigger version:
http://zds.iki.fi/zds/projectlog/images/pump_0.jpg

The waterflow cannot of course be judged at this point as it has not been tested with restrictive loop yet, but it looks very promising. Especially I like the acoustics: it is quieter than I expected, even at 12V. When holding it in my hand, I have to put ear quiet close to hear it properly and the sound is mostly lowband and pleasant.

My estimate is that when properly mounted and inside the case, the rest of the machine has to be really quiet for this pump to be heard at all.

Care must be utilized when mounting, however: the level of vibration from this pump is fairly high and as it lacks mass, it makes a lot of noise if placed on hard vibrating surface.

I haven’t yet made undervolting tests, nor have I made subjective tests against some noise source with known level, but these are my first impressions.

I think the acrylic top might also reduce the noise level a bit. It’s carved out of thick (19mm, 3/4″) piece of acrylic and the standard cover is just thin plastic. And the acrylic top also enhances the looks significantly and enables flow rate mod (http://systemcooling.com/mcp350_mod-01.html) with just exhanging the inlet fitting and the top cap.

Here is flow rate graph about the one modded by http://systemcooling.com/:



I really like this pump.

Your English is excellent.

The project log is very impressive, should be interesting to see how you work through the contadictory requirements.

Edit: Double post

Couldn't put it any better myself...


So I cheated and quoted clocker...


Keep up the good work, and please keep us updated.


Pete

did you create the top yourself?

No, I bought the pump and the cover as a DIY kit from Coolputer: http://www.coolputer.fi/.



I have seen the acrylic top also available separately: http://www.watercoolingshop.com/catalog/product_info.php?cPath=42&products_id=408

(For complete worklog, see http://zds.iki.fi/zds/projectlog/)

As the quietness, efficiency and bling-factor of the cooling are some of the most important aspects of the whole project, I have spent a lot of time trying to find perfect fans for both upper and lower compartment. It’s especially hard to figure how the UV reactive parts will look like in real life without seeing them.

Early in the project I decided to utilize 120mm fans for all my air-cooling needs. Besides the size, the Main criteria in selecting the upper compartment fans were:

* quietness
* good airflow per dB(A) ratio
* they had to look good with and without UV light
* and after lot of pondering: they had to be red

Amongst the finalist were Coolermaster, Antec and Thermaltake. After a lot of googling for real-life images and experiences about them I decided to go for Thermaltake: their UV fans come without leds (I want to be able to turn down the bling level easily), are one of the most silent and do not look pale, orange or pink in the normal light as many of the UV red stuff does. The specs from Thermaltake claim:

* sleeve bearing - must have for silencing enthusiasts
* 0.3A rated max current
* 1400+-10% RPM @ 12V
* max airflow 54.45CFM
* 21dB(A)

After unsuccesfully trying to locate a dealer to ship Thermaltake UV fans to Finland, I finally contacted first Thermaltake and then by their suggestion Jimm’s PC Store, who is their official dealer in Finland. And low and behold, after a bit less than a months wait I am now proud owner of three red 120mm Thermaltake UV fans:



They came in sturdy but easily openable (and re-closable!) package. Notice also the nice tidy sleeving for power input wires:



And here is the manufacturer information from the fan in a close-up, since I know you silencing folks want to examine it:



I really like the bluish deep red of the fans - they look yet better in real life than in these photos.


Actual manufacturer

The nameplate of the fans read “Hong Sheng” and it indeed seems there is company with such name manufacturing air-cooling products and many of them look very familiar, even thou I have never heard about the company before. They look like a chinese subcontractor for the bigger names. Even the product images give me some serious déjà vu feelings, so I wouldn’t be surprised if they actually manufactured some very familiar products.

Anyway, I didn’t found exact match for the TT fan, but these are the closest: http://www.hong-sheng.com/ebusiness/EN/product_detail.asp?catalogid=4&productid=242. Technical drawing looks the same, and extrapolating from the three given models I assume TT is based on same design, but just runs even slower and is made of transparent red UV reactive plastic.


Subjective noise analysis

To get some rough idea about relative noise levels of the fans, I performed some subjective analysis to the two 120mm fans I now had - Silverstone FM121 and Thermaltake 120mm UV fan.

As my currently only fan controller is still installed to the machine I write this on, I ran the TT fan just on 12V and 5V. The FM121 comes with control knob, so I put them side by side and adjusted the FM121 until their noise level sounded the same to me.

Other test setup parameters: I took power from ancient 120W ATX PSU, which comes with the fan. It is fairly quiet and I muffled it as well as I could, but still it was the noise floor in this test. I will later on mod old 12V battery recharger PSU brick to provide current without noise, but now I had to live with what I had in hand.

Listening tests were performed in our only windowless room at 4AM, so ambient noise was very low, sans the aforementioned PSU and distant hum of our home server (in neighboring room, in closet).

I also measured airflow with such a primitive way as holding a paper in front of the fans and examining which one could bend it more. To get repeatable results, I used several different papers and turned each or them 180 degrees and repeated the test.


Results

At 12V TT is quiet but audible. 2 meters was not far enough to not hear it at all when being in direct sound path. Adjusted to similar noise level FM121 seemed to push a bit less air. Both were pleasent to listen to, mostly just whoosh of the airflow with some motor noise. As FM121 is rated for almost double the airflow and double the RPM at 12V, it had lower pitch and it sounded a bit rougher, like bigger engine running idle. TT had naturally the advantage of running at its nominal voltage, so it had smoother character.

When setting TT to 5V and trying to match same noise level with FM121, I found both of them to be very quiet. In these test conditions at 50cm away in direct soundpath their noise ceased to be heard (remember the ambient noise). It was impossible to set both to exactly the same noise level so all the comparison at this voltage is even less accurate than the rest.

At this voltage TT had some irregularities in sound; it started ok at 5V, but now and then there either was or was not some resonance-like additional noise. However, that noise was so quiet that it’s hard to count it as a defect - I could hear it only from some 20-30cm distance. The FM121 had a bit more pleasant motor noise, mostly due to lower frequency and it also felt like it was moving a bit more air.

All in all, both fans sounded, looked and felt like quality workmanship. When soft-mounted and enclosed inside good computer case, the TT fan should be either entirely inaudible or barely audible depending on your other components and noise floor. At 5V it definitely is inaudible it not in direct soundpath.

Silverstone FM121 performs also very well considering that it is rated for whopping 120CFM at 12V. It undervolts nicely and at all speeds it has pleasant sound and good airflow per noise ratio. At full speed it’s of course nowhere near silent, but the noise is mostly just pleasant whoosh and it moves *a lot* of air. It looks and sounds like a very good compromise between wide operating range and noise.

I will return to this subject when I have time to disassemble some 80mm fans from my primary computer and set up closed loop for the Laing Delphi pump. Then I can hopefully say something more than “wow, they are nice fans”, since I can compare them to some fans with known noise level.

I will also test all the samples against each other when I get to that point, so I can give you some idea about sample variety. I will have three of both fans, which should be enough to count out some uncertainty, altough the all TT fans are from the same batch.

In general I am very happy with these fans. Both are of high quality and seem to provide good CFM/dB(A) ratio.

I started posting progress about this project to Bit-Tech forums in addition to my home server.

The advantage is that now those who want to stay alerted about the modding parts, too, can subscribe to follow the progress.

I will however continue to post here the stuff that directly relates to silencing. Since most of the stuff is just modding, I will not encumber SPCR forums with it.

As in so many projects, once you dig deep into it, you begin to add more and more things to it. Making use of the thermoelectric coolers (TEC) was first just a crazy idea, but has since become integral part of the project.

Earlier this week I ran into very interesting article article in Electronics Cooling. It discusses how to select TEC configuration that gives best results per watt.

Some of the charts were eye-opening, like this:



As you can see, contrary to popular belief, it is possible to get much better than 0.4-0.7 for CoP (coefficient of performance; amount of heat (W) pumped per power (W) fed to TEC). If you run your TECs at low enough voltage and design your system to have low ΔT, you can far beyond CoP of 1, even close to compressor-cooler territory (CoP of 2-9).

In laymans terms: if you throw in more TECs and run them at lower voltages, you can pump a lot more heat with same amount of electricity.

I knew it was not recommended to run TECs at more than 80% of their nominal voltage, but if the graph above holds true to Kryotherm modules, it means I might want to run my TECs as low as 20-25% of the nominal voltage.

So I went to Kryotherm website again and found a very handy TEC information and simulation tool. Now I am beginning to discover how peculiar devices TECs really are.

After finding out how much CoP (coefficient of performance, amount of heat pumped divided by amount of power supplied) is affected by voltage and temperature gradient I decided to go for the most powerful (in terms of heat pumping capability) Kryotherm model, DRIFT-0.8.

Here its specifications:
29,90 €
Qmax: 172W
Umax: 24,6V
Imax: 11,3A
DTmax: 69°C
Size: 40 x 40 x 3,2mm
Weight: 20g

Using the Kryotherm simulator I searched for the best combination in terms of cost, cooling capability and power usage.

Below are two graphs showing how number of DRIFT-0.8 modules and radiator/waterloop efficiency affects the TEC power draw (in Watts). Temperature of the cold side of the elements was kept at constant 16°C. This temperature was chosen since it's my best guess for lowest condensation-safe temperature in finnish climate. Ambient temperature was assumed to be 22°C.

In this simulation TECs were connected parallel. For each data point I adjusted the TEC voltage at 0.1K incements until I found the lowest voltage that still kept cold side of the TEC at 16 degrees or cooler. Power draw of TECs was then written down, and is shown in the graph below.

In the Y axis is power consumed by the TECs (W). In X axis is the number of DRIFT-0.8 elements used. Each line represents certain K/W (or C/W, if you prefer) value at 0.1 intervals.

Here the thermal load is assumed to be 200W (estimated maximum power draw for high power AMD system with Radeon X800XT):


Here the thermal load is assumed to be 120W (estimated maximum power draw for high power AMD system GPU stress):


Looking at these, the optimal point for my purposes seems to be between 4 and 6 modules (inclusive). That would be 120 to 180 euros.. Cheaper than phase-changing system, but still a lot of money.

The reason why I added four different K/W levels is that I want the machine to run as silent as possible. This means that under normal load (no heavy gaming) I could run the fans near the minimum (estimated to be 0.3-0.4 K/W) and under heavy load (gaming) the fans would be allowed to run faster (0.1-0.2 K/W).

I know 0.1K/W is fairly low even for watercooled system, but remember that I am using a car radiator and six 120mm fans.

I have to say I am pretty amazed to what you can do with peltiers. They cost a pretty penny, but 60W extra power to keep your CPU and GPU cooler at constant 16 degrees when under maximum load isn't bad at all. And under "just" full CPU load it drops to 26W.

What was even more surprising was that if I accept CPU temperatures a bit over 30 degrees Celsius, TECs will draw just one or two Watts of power. This means I can propably have two separate loops. And 30 degrees is not bad at all, if you just want to surf web at stock speed. At there heat loads I might even be able to run the system with all fans turned off.

And for the record: if the 16 degrees sounds to be a bit on the warm side, those TECs can do a lot more, if asked to. With six modules and 12V of power (the highest you can get from regular PC power supply) you could keep the coolant liquid 6 degrees below freezing point, at full 200W load. This of course comes with the cost, in form of 380W of power draw for the peltiers alone.