Good single low rpm fan for HR-02

systemlayers · Post by **systemlayers** » Sat May 14, 2011 8:29 am

Hey everyone I just got an HR-02 in my Silverstone FT-02B case. It's fine passive but with a single low rpm fan seems to shave off a couple degrees without adding any perceivable noise. Case fans are volted down to 500rpm.
I have the asus p8p67 deluxe so fan control is fine.
Right now i just have a slipstream 1200rpm @ 800rpm so it's not ideal.
PWM would be convenient. TY140mm looks to be pretty good but I'm not sure of its noise level @ low rpm? Or the noctua 140mm. I'm looking for something that won't add any perceivable noise at least at idle.

mkk · Post by **mkk** » Sat May 14, 2011 9:22 am

PWM is certainly nice, but in this case a regular Slip Stream 800 is also fine. My older and not so fancy on fan control motherboard can regulate it down to around 550 RPM which is a good idle level. At its practical maximum near 900 RPM at full speed it's cooling pretty well while still not directly noisy for a high load situation. You'll likely not need or even want more airflow than that with a HR-02, presuming you don't overclock very much.

systemlayers · Post by **systemlayers** » Sat May 14, 2011 1:46 pm

Right now even with all the fans @ constant 500rpm and the slipstream undervolted my gpu (460) and cpu under synthetic benchmarks the 2600k @ 4.4ghz only just barely breaks 70 degrees.
It's a very nice heatsink. Do you think the slipstream 800rpm will be the best fit directly against a heatsink? Create enough pressure? Right now I have the slipstream on top of the HR-02 and removed the stock top fan.

Here's an exceptionally crude image of what I mean:

Wondering if I should instead mount the single fan on the other side and create a cpu duct towards the empty stock fan area.

mkk · Post by **mkk** » Sat May 14, 2011 2:51 pm

Pushing will be more efficient than pulling air at least without modifying/shrouding a tower cooler. Pressure won't be an issue with a low impedance(plenty of space between fins) cooler like the HR-02. In fact it isn't an issue even with my good old TRUE which have relatively tightly fitted fins. I'd keep the top exhaust fan in any situation, since at low speed it doesn't really add to the noise level anyway. By all means experiment with a duct as well, but I suspect it's not wortwhile.

systemlayers · Post by **systemlayers** » Sat May 14, 2011 3:10 pm

So you're saying two slipstreams @ 500rpm one at the top and then one pushing on the 'bottom' side of the cooler would be most efficient low rpm low noise solution?

I also can't find the 800rpm model in stock ANYWHERE. Despite spcrs review do you think I can be fine with picking 2 of the SY1225SL12SL (500rpm) models locally for $9 a piece? I'm sure at 500rpm I could even get 3 fans really without any difference noise wise.

fumino · Post by **fumino** » Sat May 14, 2011 4:14 pm

i would advise against using a slipstream mounted horizontally, its bearing wont last very long in that position.

iirc the ty140 should do very well at low speeds... another fan to look at is the prolimatech 140mm from the genesis review. it looks like the 600rpm thermalright 120mm fan from the new venomous-x review would be an excellent choice as well.

ces · Post by **ces** » Sat May 14, 2011 4:23 pm

systemlayers wrote: Despite spcrs review do you think I can be fine with picking 2 of the SY1225SL12SL (500rpm) models locally for $9 a piece? I'm sure at 500rpm I could even get 3 fans really without any difference noise wise.

Why not. How often does your machine run at full load, other than when you are benchmarking?

And I would use one of these thermalright ducts to duct the air out:
http://www.thermalright.com/new_a_page/ ... _duct.html
The red one is shorter than the blue one. get both and see which one fits best.

If you add the duct and then reverse the case's airflow I would expect that alone to drop your cpu temp by a significant amount.

As a general rule, all things equal, you should expect to get more cooling with less dB with two slower fans than from one faster fan.

systemlayers · Post by **systemlayers** » Sat May 14, 2011 4:48 pm

ces wrote:
systemlayers wrote: Despite spcrs review do you think I can be fine with picking 2 of the SY1225SL12SL (500rpm) models locally for $9 a piece? I'm sure at 500rpm I could even get 3 fans really without any difference noise wise.
Why not. How often does your machine run at full load, other than when you are benchmarking?

And I would use one of these thermalright ducts to duct the air out:
http://www.thermalright.com/new_a_page/ ... _duct.html
The red one is shorter than the blue one. get both and see which one fits best.

If you add the duct and then reverse the case's airflow I would expect that alone to drop your cpu temp by a significant amount.

As a general rule, all things equal, you should expect to get more cooling with less dB with two slower fans than from one faster fan.

Yep I know the last general rule in my last 775 based computer i had my (not supposed to be passive) zalman flower copper heatsink with 4 500rpm fans in a p182. Very very quiet. Only time I approach load is in video games or rendering.
Fumino is probably right though none of the slipstreams are meant to be horizontally mounted? What other low rpm fans are meant to be horizontally mounted? Are the 600rpm fans in the thermalright venom even sold retail?

ces · Post by **ces** » Sat May 14, 2011 5:06 pm

systemlayers wrote:Fumino is probably right though none of the slipstreams are meant to be horizontally mounted?

The conventional wisdom is that sleeve bearing fans have a shortened life when run horizontally.

The only true ball bearing fans generally available for PCs are the Scythe Gentle Typhoons. All the others are sleeve fans - some a fancied up with grooves and fancy names.... but they are all sleeve bearings.

That being said, I believe MikeC has said that he has never personally encountered a problem of shortened life of a sleeve fan from horizontal placement with modern sleeve fans. It is something that is difficult to test for. Most of MikeC's sustained use experience is likely with his Nexus reference fans. But you would have to look pretty far and wide to find one person with more experience in such matters.

Scythe, as an institution, may have more experience than him. Scythe ships CPU coolers with fans in all sorts of positions... and all of their fans (except for the Gentle Typhoons) are some type of sleeve bearing. They must know what they are doing with their own fans.

I think you should disregard that rule. Get what you want. Use it the way you want to. See if it fails... and if it does, then consider replacing it with a Gentle Typhoon.

ces · Post by **ces** » Sat May 14, 2011 5:11 pm

systemlayers wrote:Are the 600rpm fans in the thermalright venom even sold retail?

I don't know. They sure are nice fans though. The 500rpm and 800rpm Slipstreams are nice as are the 500rpm, 800rpm and 1125rpm Gts. You can run them at a straight 12 volts and they all do well without any fancy manipulation of voltage or speed.

systemlayers · Post by **systemlayers** » Sat May 14, 2011 7:10 pm

Think I'll pick myself up 3 500rpm scythes and try several different configurations. Will post results.

ces · Post by **ces** » Sat May 14, 2011 7:35 pm

systemlayers wrote:Think I'll pick myself up 3 500rpm scythes and try several different configurations. Will post results.

There is no substitute for experimentation.

Good single low rpm fan for HR-02

Good single low rpm fan for HR-02

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