[MOD] Proposed Avalon noise reduction/cooling increase for B1/B2/B3

[dogie]

Objective:

• Reduce jet engine to crying baby noise levels

Hypothesis:

• The cases are constructed using perpendicular nut-bolt things. Great for small scale quick production, but not great for a tight seal.
• These connections have quite a large open gap at every screw, on all size.
• If you feel over the gaps, there is a significant amount of airflow [*read pressure] leaking.
• This is not useful pressure, we want to be exhausting through the heatsinks and not through these random holes - they serve no cooling purpose.
• =fans are spinning faster than required to get the same pressure.
• Airflow through these holes will also be much more turbulent and so will also be generating some of the frequencies we hear.

Method:

• Tape those badboys up, simple electrical tape would do it.

Results:
*pending*. The only unit I have in stock at the moment is reserved for an auction, but if that falls through I will give it a go. I don't have a temperature controled room so I can't make it a scientific test though.

Conclusions:
*pending*



tldr: Case has holes at the screws, lowering air pressure inside. Fans spin faster to compensate = more noise than required.


EDIT: V2 ready, see below.

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[tarui]

interesting

getting mine soon. so i will be doing some testing or small mods of my own.

will update this thread with my progress once i get it.

[dogie]

Anyone have any results?

[-ck]

I can't imagine this would make a significant difference.

[lastbit]

I don't think this will make any (significant) difference.
One of the problems in my opinion is the huge "gaps" between heatsinks. A lot of air is running without doing any cooling. The air coming out is "cold", but the heatsinks are definitely "hot" because the plate of the case to which they are attached is "hot".
I intend to put something to force more air on the fins and PCB surfaces. But I have now bigger problems with my avalon , so I'll delay this.

[jarhed]

The other two fans are compensating for the one pointing directly at the cables. Freaking whirlwind in there. Those screw holes may actually help with pressure release.

[HellDiverUK]

Going by the pictures of these things, I'd be constructing air guides using card.  Build a tunnel from each fan to the heatsink, and cover the open top of the sink to force the air though the heat sink.  It's basically the way 1U and 2U servers are cooled.

[lastbit]

In Avalon3 there are only two fans. They rotate differently (for example 2520 ans 2400 rpm); maybe the one spinning faster is the one near "PS, command and control" part of the Avalon3.
For sure screw "holes" in this particular case do not improve cooling; but they're to small to do any harm anyway.

[lastbit]

Going by the pictures of these things, I'd be constructing air guides using card.  Build a tunnel from each fan to the heatsink, and cover the open top of the sink to force the air though the heat sink.  It's basically the way 1U and 2U servers are cooled.

Yes, my plan also.
In Avalon3, space on top of heatsink is almost completely obstructed by hashing modules ribbons and power cables, so it's not need in there. Only between heatsinks.

[dogie]

The other two fans are compensating for the one pointing directly at the cables. Freaking whirlwind in there. Those screw holes may actually help with pressure release.

That's the reverse of what pressure does. You want massive pressure inside, that's what fans are doing.

In Avalon3 there are only two fans. They rotate differently (for example 2520 ans 2400 rpm); maybe the one spinning faster is the one near "PS, command and control" part of the Avalon3.
For sure screw "holes" in this particular case do not improve cooling; but they're to small to do any harm anyway.

Try putting a tiny hole in your air bed, suddenly you need a pump just to maintain current pressure. Or a hole in your hose pipe. Then try 20 holes.

[dani]

The other two fans are compensating for the one pointing directly at the cables. Freaking whirlwind in there. Those screw holes may actually help with pressure release.

That's the reverse of what pressure does. You want massive pressure inside, that's what fans are doing.

I disagree to a certain degree. You don't get massive pressure from fans, thats not what they do. They move air. Did you look up what pressure a "normal fan" gets you? http://www.corsair.com/de/cpu-cooling-kits/air-series-fans/air-series-sp120-high-performance-edition-high-static-pressure-120mm-fan.html this has 3.1 mm/H20 which equals to around 30 Pa. If ambient is 1 bar, this will put another 0,0003 bar on top of that (I don't use psi, but you can convert it I easily). So 0.03% increase in pressure is not what they do, they move air like i said.
No offense, just wanted to state this (correct me please if I'm wrong in someway)

[lastbit]

The other two fans are compensating for the one pointing directly at the cables. Freaking whirlwind in there. Those screw holes may actually help with pressure release.

That's the reverse of what pressure does. You want massive pressure inside, that's what fans are doing.

In Avalon3 there are only two fans. They rotate differently (for example 2520 ans 2400 rpm); maybe the one spinning faster is the one near "PS, command and control" part of the Avalon3.
For sure screw "holes" in this particular case do not improve cooling; but they're to small to do any harm anyway.

Try putting a tiny hole in your air bed, suddenly you need a pump just to maintain current pressure. Or a hole in your hose pipe. Then try 20 holes.

Total surface of the screw holes is much less than the "hole" in the back. IMHO they're too small to do any harm or improvement.
But... have fun. Stick some tape over the holes and tell us the results.

BTW, you know how the inventions appear. All the people know that some things are impossible. From time to time, a guy who doesn't know appear

[dogie]

The other two fans are compensating for the one pointing directly at the cables. Freaking whirlwind in there. Those screw holes may actually help with pressure release.

That's the reverse of what pressure does. You want massive pressure inside, that's what fans are doing.

I disagree to a certain degree. You don't get massive pressure from fans, thats not what they do. They move air. Did you look up what pressure a "normal fan" gets you? http://www.corsair.com/de/cpu-cooling-kits/air-series-fans/air-series-sp120-high-performance-edition-high-static-pressure-120mm-fan.html this has 3.1 mm/H20 which equals to around 30 Pa. If ambient is 1 bar, this will put another 0,0003 bar on top of that (I don't use psi, but you can convert it I easily). So 0.03% increase in pressure is not what they do, they move air like i said.
No offense, just wanted to state this (correct me please if I'm wrong in someway)

"Pressure ratings" you see on fans is the static pressure the fan can overcome, and isn't the pressure it generates. Its all bernouli's equation, airflow is being converted into pressure into airflow into pressure etc.

The easier way to imagine it is in watercooling. If you add a component, it creates a resistance. The pump then needs to overcome that resistance. That power to overcome is the rating you see on fans.

tldr: the pressure generated inside the case is not the same integers as the pressure rating on fans.

[dogie]

The other two fans are compensating for the one pointing directly at the cables. Freaking whirlwind in there. Those screw holes may actually help with pressure release.

That's the reverse of what pressure does. You want massive pressure inside, that's what fans are doing.

In Avalon3 there are only two fans. They rotate differently (for example 2520 ans 2400 rpm); maybe the one spinning faster is the one near "PS, command and control" part of the Avalon3.
For sure screw "holes" in this particular case do not improve cooling; but they're to small to do any harm anyway.

Try putting a tiny hole in your air bed, suddenly you need a pump just to maintain current pressure. Or a hole in your hose pipe. Then try 20 holes.

Total surface of the screw holes is much less than the "hole" in the back. IMHO they're too small to do any harm or improvement.
But... have fun. Stick some tape over the holes and tell us the results.

BTW, you know how the inventions appear. All the people know that some things are impossible. From time to time, a guy who doesn't know appear

I did have a go but the tape I found first was shitty poundland electrical tape which wasnt sealing properly.

[dogie]

V2 mod to create wind tunnel. Should be no wasted air now [ignore 4th module area, have one incoming so not taped it yet].

[tarui]

did u replace the top led fan with something else? or was it part of batch 2?

anyway so how was the results for the tape mod u did? any improvements in noise or temps?

i'm getting some akasa noisemats soon.

[WinTame2012]

V2 mod to create wind tunnel. Should be no wasted air now [ignore 4th module area, have one incoming so not taped it yet].

[img skipped]

Any significant improvements on temps/Utility?

[dogie]

did u replace the top led fan with something else? or was it part of batch 2?

anyway so how was the results for the tape mod u did? any improvements in noise or temps?

i'm getting some akasa noisemats soon.

Its a B3 but physically B2. Top fan is important to prevent back flow.

Hard to quantify the improvement as my units are almost always on lowest fan RPMs. Temps are +23 and +25 over ambient.

[tarui]

ok
I just did a similar mod for the Batch 1

all i did was tape the open areas between fans and the units. the units in batch 1 are very closely packed together so there's no need to tape it between the modules like dogie did.


Anyway results are rather clear from just 20mins of run time

temps stay the same but the fans work lesser to lower the temps.

they tend to stay at their max rpm for a shorter duration when it reaches the threshold temp
most of the time it's below 3000rpm  (the fans are delta afc1212de instead of the nmb ones)

[dogie]

ok
I just did a similar mod for the Batch 1

all i did was tape the open areas between fans and the units. the units in batch 1 are very closely packed together so there's no need to tape it between the modules like dogie did.


Anyway results are rather clear from just 20mins of run time

temps stay the same but the fans work lesser to lower the temps.

they tend to stay at their max rpm for a shorter duration when it reaches the threshold temp
most of the time it's below 3000rpm  (the fans are delta afc1212de instead of the nmb ones)

I found similar results. In my setup they never have to run at max rpm anyway, so the 'idle' or maintaining rpms are lower for the same temps.