Quieting a watercooled rig

[N7SC]

I have a Swiftech H2O-120 system on a Lian-Li PC-A10 case, and would like to quiet it down some. It is not really noisy now, but I'm shooting for silent, or as close as I can get. Details below:

The stock 120mm exhaust fan on the rear has been turned around and is pulling air in, the 120mm radiator is mounted on the outside of the case directly behind the 120mm fan. I used the fan from the Swiftech kit because it is quieter than the ones that came with the Lian-Li. The fan and radiator are mounted against, and screws through, rubber grommits. This fan is hooked up to the System Fan header on the DS3 motherboard, and I am letting the BIOS throttle it. It rarely goes above 1400 rpm (it is good for around 2000 to 2200 at full throttle). However, I would like to quiet it down a lot. Do you think one of the Noctua SF-12-1200 fans would work here, and would it be quieter, considering that it is pulling air over the radiator for the cooling rig? Or is the radiator's disruption of the air flow causing the bulk of the noise?

The top. or blowhole, fan on the case: The only one that is not mounted on grommits of some kind. Do you think that a silicone pad and grommits would help here? Certainly is cheaper to try them before going for a second Noctua fan.

The rest of the fans in the system are virtually silent, so if I can bring the two above down to the noise level of the others, I will be happy.

Thanks.

 

[tool_462]

Fan grommets work especially well on top blowholes since they have so much open surface area of steel/aluminum to vibrate. I would do that first.


I'm a little confused though, so your radiator is mounted on the back of the case, and you have two fans on it in a push/pull setup? And they are pushing air into your case from the back?

 

[michiganteddybear]

quick question/suggestion.

you have grommets between the fan(s) and the case, but are the screws that hold the fans able to touch the case (screw head is the thought here). if so, then the screw will transmit some of the fan vibration to the case.

definatly isolate the blow hole fan somehow, as I would be certain its transferring vibration to the top of the case, and that will act just like a speaker cone.

 

[N7SC]

Sorry if I was not clear about the fan/radiator arrangement, and the blowhole fan. Thank you for your ideas and suggestions. Just in case a clearer description of the problem might lead you to a different suggestion, let's see if I can clear up any confusion.

Rear 120mm fan/radiator
The 120mm rear fan is inside the case, in the stock location, but it is sucking air into the case (normally it blows air out of the case), actually pulling air in through the radiator. The radiator is mounted exactly behind it, outside the case, with foam weatherstrip sealing/cushioning it to the case. The radiator is covering the vent hole on the back for the 120mm fan. They are, in fact, mounted to each other, with the case "sandwiched" between. Long screws (from Swiftech) go through the fan, then the case/grommits, then into the threaded holes in the radiator. There are grommits in the screw holes in the case, and these grommits stick out on each side of the case somewhat so that the fan and radiator never actually touch the case. There is no external fan pushing air through the radiator, only the one inside the case, described above, pulling air through the radiator.

I don't think that there is any, or much, noise being transmitted to the case directly here, just air flow noise. But, of course, I could be wrong. Was wondering if a Noctua silent fan would help reduce the noise here because the fan I'm using has a noisey blade design, or if the noise is being generated by the way the radiator fins break up the airflow.

The blowhole
The blowhole fan is mounted directly to the case with the usual, little, fat fan screws. This is the only fan, out of four built into the case, that Lian-Li did not mount on grommits or isolation mounts. Reason appears to be aesthetics: the screws and mesh covering it are visible on top of the case and look very good. They must have thought that clunky rubber grommits would look lousy on such a sleek case.

I'm thinking of either using a silicone isolation pad and grommits on this fan, or changing to the Artic Cooling 120mm fan because of its built-in rubber suspension
http://www.newegg.com/Product/Product.aspx?Item=N82E16835186008
(no need to uglify the beautiful Lian-Li if I use the Arctic fan), or try a silicone pad and grommits on the fan I have.

 

[michiganteddybear]

ok, that makes it a lot clearer in my mind anyhow.

somehow isolate the top fan, we are pretty sure thats a problem. I have seen some silicone mounting systems for fans (I dont remember where they came from) that were a rubber 'stick' for lack of better words. the rubber stick would go thru the case, and thru the mounts on the fan and hold it without screws of any sort. on the out side of case is a small silicone rubber 'head' (flat, not very thick) and on the inside of the case, right inbetween the fan and the case is a tapered part that keeps them seperated. hell if I had a pic, you would understand what I am talking about.

I think one of the major case makers might supply these with the cases (antec?)

The fan is totally isolated from the metal of the case.

another possibility not to be overlooked, is maybe the rear fan you have (for the radiator) is a little out of balance?? I have seen that before.

and since your watercooling, how about the pump?? is it isolated from the case as well? (a possible source of noise being transferred to the case)

 

[tool_462]

To see if the fan pad will even help, or as an alternative:

Get a fairly thick rubber band and cut four 1/2" pieces and poke a hole in the middle of each one. Just reinstall the fan and poke the fat screws through the hole and tighten a little loosely, but still sturdy. So the rubber band is being compressed but not to the point where it just transfers the energy right to the case, defeating the purpose.

 

[N7SC]

Thanks guys. That fan on the top of the case does seem like it is the biggest offender. I'll give the really great rubber band idea a try to see if isolation mounting will help there.

The rear/radiator fan is very well balanced, there is nothing but steady, smooth airflow noise there. I might just change how everything is wired up. Right now the rear/radiator fan is connected to the sysfan header on the motherboard (Gigabyte GA-965P-DS3, ver 3.3). And I think the DS3's bios is using the Northbridge temp, which it calls "System" to control the system fan speed. And the Northbridge runs pretty hot, thus it is running the rear fan higher than it needs to run. Even under "sysfan" control, that is 1200 to 1500 rpm, I never see above 45 deg. C on TAT at 100% load (TAT full load). So I can probably afford to lower the fan speed a bit and quiet it down some more.

I'll fiddle about later today or tomorrow morning and get back with results tomorrow. Meanwhile, thanks for the guidance and tips. Ironically I'm in the middle of building a new plenum box for my home's phase-change temperature control system (central A/C) or I'd do it right now.

 

[Rugger]

Cheap/effective way to figure out the noisy culprits in your rig:
1. Get the cardboard tube from an empty paper towel roll
2. Turn off rig and open side panel.
3. Turn on rig.
4. Put tube to ear and point it at the interior of the case at any possible noise sources. Then point it all around the interior of the case the possibly detect noise from vibrations with no readily apparent source.

Other notes:
1. Great low-cost, quiet fan Yate Loon D12SL-12 - you can get four of these for less than the cost of one Noctua. I think you'll be pleasantly surprised with these fans.
2. Petra's Gel Stuff is awesome isolation material to prevent your pump from vibrating your case.
3. What PSU?

 

[N7SC]

Well. . . never got hold of a big rubber band today. Will get to it soon and post results so others can benefit.

Gotta get that plenum box finished. I live in Florida, near where the big wild fires are, and between the heat and the heavy smoke and ash in the air it is killing me. Gotta get cooled off and filtered out.

BTW, I'm listening to music as I type this, sitting right next to the computer that I'm trying to silence and it really does not bother me much. And I listen to classical music, so it has lots of very soft passages. Maybe it is not so bad after all, and I'm just being picky. But. . . I will keep at it and try to make it as quiet as I possibly can.

 

[03flat4]

If I may butt in here, I have a fairly quiet system, a P180 case that is water cooled, with 2 of its fans running. one on the top location pulling cool air in through the radiator that is sitting on top of it, and a rear fan for exhaust. I replaced the tricool fans recently with low speed coolermaster LED fans that are relatively cheap low speed, put through decent air, and are quiet. I think that I would also like to silence my 2 rear fans case vibration more with one of these methods. PLEASE let us know how it goes I also like the idea of the petra gel under my pump, but I am thinking about where I can find a gel like that locally instead..I am not cheap...just hate the idea of paying S&H that will be more than the price of the product...any idea where I can find some kind of a similar thermoelastic polymer like that? i wonder if I make some kind of a rubber supspension for it that wont wobble around much...firmly placed but suspended and vibration dampened perhaps?

 

[N7SC]

Will let you know how it goes, when I actually do it. Between many projects around here, some minor health problems at the moment, and being a semi-retired househusband, it may be a week or two.

That gel stuff looks good, but I agree about not liking to pay more for the shipping than for the product.

Was inside the case today for other things, and did notice that the pump does whine. I have to have the case side cover off to actually hear it directly, but I wonder if it is contributing to the overall noise signature even when closed.

Also, I did cinch down pretty tight on the pump mounting nuts/bolts. Maybe the neoprene would work better (and ditto any gel stuff that I may find) if I loosen them up a bit so the rubber or gel is not so compressed.

Right now I think the top or blowhole fan is the main culprit, with noise from the rear fan pulling air through the radiator. And likely the pump contributes a little too. Maybe I'll pick up a big rubber band while I'm out tonight.

 

[03flat4]

Will let you know how it goes, when I actually do it. Between many projects around here, some minor health problems at the moment, and being a semi-retired househusband, it may be a week or two.

That gel stuff looks good, but I agree about not liking to pay more for the shipping than for the product.

Was inside the case today for other things, and did notice that the pump does whine. I have to have the case side cover off to actually hear it directly, but I wonder if it is contributing to the overall noise signature even when closed.

Also, I did cinch down pretty tight on the pump mounting nuts/bolts. Maybe the neoprene would work better (and ditto any gel stuff that I may find) if I loosen them up a bit so the rubber or gel is not so compressed.

Right now I think the top or blowhole fan is the main culprit, with noise from the rear fan pulling air through the radiator. And likely the pump contributes a little too. Maybe I'll pick up a big rubber band while I'm out tonight.

same here. I BARELY hear my swiftech pump when the case is open, never mind when it's closed. I will unlilkely do anything to that. Hell, i actually usually touch the pump to make sure it's even working, that it's so quiet!

Yeah I also think it's my fans making the most noise, as I don't think my Seasonic S12 quiet PSU makes much noise at all. That rubber band trick, or whatever trick, could be the key to an even quieter PC, as it is already very tolerable for me as is.

I have actually installed a low speed ball bearing fan to my northbridge heatsink, so that also could be a source of noise for me, but I tihnk it is unlikely, as it is very quiet, and mounted using those rubber mounts, in essence the fan is somewhat floating on soft rubber in front of the heatsink.

I wonder if I can find some source of gel to push to the outside and inside end of the fan screwes to dampen the vibrations..still trying to think of a homebrew if the rubber bands don't work out.

 

[N7SC]

Had a little time yesterday evening, so, lacking a rubber band, I simply disconnected the top or blowhole fan. The result was astonishing. Nearly absolute silence. There was either no or very little change in temps too. This is with the Swiftech radiator fan running on 7V now, and the Lian-Li hard drive fan and card bay fan on "medium."

So I'll either try to shoehorn an Artic Cooling 120mm fan up there, the fan with the built in suspension. Or buy a silicon gel gasket/mount and screw grommits.

Must point out that silencing the top exhaust fan let me hear things that were previously masked by its noise. Of course, they are much quieter than the top fan was, but nonetheless. . . And, so, onward marches the quest for the ultra-quiet or silent high-performance, water-cooled PC.

Interesting how I can have those really big rubber bands around here for years when I don't need them. But when I need one they are nowhere to be found.

 

[03flat4]

maybe a quick stop by the dollar store you can find them :lol:

 

[mike99]

Why did you reverse the rear fan? You are sucking warm air from rad INTO the case! If you put the fan back as it was you will get same cooling of rad, but heat will blow away from the system.

Mike.

 

[03flat4]

There is not much in my case that needs to be cooled at the moment. The only real hot piece is the CPU, so I am not worried about case temp much...and doing that has really not raised case temp much anyways.

I did dwell on this for a bit, and decided, that I would rather pull in cool ambient air through the radiator than to push warm air over it. That takes care of my CPU. I have a small fan on the northbridge cooling that, and my video card has a nice Arctic cooling fan keeping it in good shape.

 

[N7SC]

Dollar store = good idea. They probably have all kinds of stuff that I can use for many of my different projects. Will get there tomorrow during usual weekend errands.

Mike, fan is sucking air in because Swiftech says that will give you the best CPU cooling. The small amount of heat brought in by this arrangement does not seem to have much effect on the "system" (i.e. the Northbridge) temps.

Keep in mind that I have a very conservative overclock, and there is a ton of airflow in this case. Am still working out the final cooling solution, in terms of which fans to use, what speeds to run them at, and which way they will push or pull air.

All of the highly unreliable temps reported by all the highly unreliable software we all use (TAT, speedfan, etc.) to check on these things are showing Northbridge temps at or below 50. As for the CPU temps, who knows? TAT shows 32 at idle, around 50 at TAT 100% 10 minutes, ambient at 29 to 30. The software is so inaccurate, non-linear, and unreliable. The highly regarded, nearly worshiped, C2D temp guide sticky is virtually worthless if you read it critically and carefully. So, who knows? But the CPU overheat warnings have never triggered, nor has the CPU Thernal Monitor 2, so I guess that I'm keeping the CPU cool enough. No lockups or freezes either, other than a Windows brain-belch once (clearly NOT hardware related), so I guess everything other than the CPU is doing well too.

 

[N7SC]

Over the weekend I went to a "Michaels" arts and crafts store. These kinds of places can be a gold mine of goodies for modded PCs, and for quiet PCs too.

They had some thin foam sheets, 12" X 18" for $0.79. I bought two of them, one white, one black. They measure 1.98mm thick. I cut out a square the size of a fan from a sheet, then used the Lian-Li blowhole grille (a very pretty perforated metal affair) as a template to cut out an opening for the grille. Then "X'd" four holes for the fan mounting screws. Takes longer to write this or read it than it did to actually do it.

Put it in between the grille and the case. From the top down, the order of materials is: Case top, foam sheet, perf. metal grille, fan. No metal is touching the case top now.

Found two grommits laying around from the Swiftech kit, used them between the fan screw heads and the outside of the case. Will buy nicer looking ones, and four of them later.

Worked like a charm. With the blowhole fan running full speed it is now as quiet as it was with the blowhole fan disconnected. Now, on to remounting the pump and ferreting out all remaining noise for a truely silent, water-cooled, high-performance, overclocked PC.

It is rare that you get a great deal on something so useful for modding a computer. Only $0.79. Hell, you can barely buy a fan screw for that little. And there is enough foam in each sheet to make six or eight fan gaskets.