(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:
* 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
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.
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.
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.