How loud is the Iwaki MD20RZ?

[Tyler Durden]

I am testing my new set up with three radiators, powered by an Iwaki MD20RZ.

The pump seems loud at the moment..much louder than I had expected.

There is still air in the reservoir, but the flow is quite good (from what I can tell squeezing the tubes!)

Anyone else have an Iwaki and can let me know how loud it is running for them?

First home built water cooler..

THANKS..

[Cathar]

I have an MD-30RZ. It emits a medium pitched turbine whine, albeit fairly quiet. A mid-speed 8cm case fan is about the same volume, and a CD drive spinning up is much much louder. The pump does vibrate though, so are you sure that the sound really isn't the sound of the vibration of whatever the pump is sitting on?

I sit my pump on some foam rubber to stop the vibrations transferring to the surface that the pump sits on, and only if I turn everything else off in the room then can I really make out the noise of the pump.

[Tyler Durden]

Thanks Cathar

The whine of the turbine is about the equivalent of a 80mm fan..that was my first thought for comparison..

The pump does vibrate and the case it is in also vibrates - probably resonantly!!

I have the pump mounted on a 1cm layer of foam with rubber washers - clamped with nuts and bolts. Not sure what I did wrong

I have a set of rubber case feet - maybe that will help?

How is your pump mounted to avoid the resonant vibration?

THANKS again.

[nikhsub1]

The best thing to use to combat the vibration that I have found is neoprene (mousepad material). If you cut up a mouse pad to the size of the mounting plate of the pump and then crazy glue the pad on there, then bolt the pump to the case. That should work much better than foam as even though foam can be tall, sometimes it lacks density.

[Since87]

For serious vibration dampening, go to:

http://www.mcmaster.com

and search for "high damp PVC grommet".

These are used in isolating hard drives from shock and vibration. They are very effective at converting vibration to heat.

I don't have any idea whether a person could tell the difference between using these and a mousepad though.

[Tyler Durden]

Thanks.

I plan to use a mouse pad and some noise dampener material (thick and dense) between the pump and case. Hopefully that should solve the vibration issue.

I think I will replace the four Y connectors I am using to feed into the dual bay reservoir with two manifolds - a two port and a four port. The space need to run four channels into one is considerable. I imagine the restriction of one four port manifold may be far less.

I hope the pump will calm down after those changes.

Is it possible the pump is damaged?

[Tyler Durden]

Still having sound volume issues!

I have mounted the pump on two neoprene mouse pads between the pump and case and another below underneath the pump between the nuts and case.

The case itself still vibrates resonantly...I can hear the sound of metal vibrating

There is no air in the system as I have been running for 24 hours and eliminated the trapped air.

I am concerned the case needs some reinforcement.

Even more vibration dampener??

[nikhsub1]

Originally Posted by Tyler Durden

Still having sound volume issues!

I have mounted the pump on two neoprene mouse pads between the pump and case and another below underneath the pump between the nuts and case.

The case itself still vibrates resonantly...I can hear the sound of metal vibrating

There is no air in the system as I have been running for 24 hours and eliminated the trapped air.

I am concerned the case needs some reinforcement.

Even more vibration dampener??

What case are you using? I suppose a more 'flimsy' case would resonate more than a steel heavy sturdy sucker like the Lite-On FS-020. Maybe look into a beefier case?

[pHaestus]

I don't know how your rig is set up, but you can also get vibrations from the reservoir and from hoses touching the sides of case. I'd check if putting a bit of neoprene under res helps (if you have one)

[Tyler Durden]

I have a bay reservoir - I tightened the bay fixing and it has helped a little - THANKS

I touched the radiators but they seem stable.

The top of the case still vibrates almost visibly and no doubt resonantly

Would mounting the pump on rubber "cotton reel" fixings eliminate the vibration? The pump would be moving a lot though - not sure it is designed to work best under those conditions...

[Blackeagle]

What case are you working in Tyler?

And what is rubber cotton reel fixings? Sorry but that is a new term to me. :/

[Gooserider]

A few thoughts...

1. Make sure none of the securing hardware is touching the case. It might be worth considering replacing the nuts & bolts with a tiewrap or other soft fastener.

2. How sure are you that its the pump and not some other part of the system (PSU fan, HDD, etc)

3. Try adding some vibration damping material (aka 'Mass loading") to the case under the sound absorbing pads. Asphalt roofers tape is good, or you can get mastic sheets from McMaster Carr. This stuff needs to go right up against the case metal, and can really do a good job of reducing resonant noise.

Good luck.

Gooserider

[Tyler Durden]

The rig is an external cooling system - just the rads, res and pump, housed in a Lian Li PC50.

I have added two layers of neoprene and it has helped but I still feel the pump is too loud

I would judge it to be about the same as a medium 80/92mm fan.

[Blackeagle]

While I understand that you want your system to be as quiet as possible, how loud is it now vs when it was air cooled?

To me the idea of a whole system only being as loud as a medium 80/92 fan would make it mighty quiet.

[Tyler Durden]

Put like that, it does sound unreasonable

I am sure my set up will indeed be quieter than even the EXOS and minimal forced air I currently run.

EDIT - I would compare it to a 60mm Delta or a higher middle range 80mm - say a Sanyo Denki 50cfm.

I wonder if the pump should be noticeably louder than an Eheim 1250. Most people describe them as inaudible. I suppose I want to ensure I am getting the best out of my pump and set up - noise versus performance.

The noise is of a higher pitch than I would like - much like a higher rpm fan. Whilst the sound of the air moving is less irritating, the whine of the motor and blades at high speeds produces a more unpleasant sound.

I have found that some of the tubing is vibrating against other tubes and the case is still vibrating in a few places - no doubt resonantly. I am trying to pad where necessary and shorten tubing if possible...

It is getting there - paying the price for choosing an aluminium case over a steel one!! :shrug:

[rocketmanx]

The HD cages on my Chieftech case rattle, actually it's the locking handles that rattle occasionaly. If your Lian Li 50 is built anything like my 60 then I'm sure the rattles either the HD cage or one of the chassis pieces that's fitted with a rivet that's not holding the panel tight.
To find out where it's coming from start putting your hand on all the different parts of the chassis until you find the place where touching ti makes it quit.
Iknow of the rattle you're talking about since my upper HD cages locking handle, when tight, would actually not ahve any tension on it and make a metallic rattling sound. It's a light sound but very annoying. Not a consistant sound you can get used to like the whir of a pump.
Aluminum cases aren't very good for making quiet cases out of. AL isn't very good at dampening and with aluminum being so light it takes very little energy to make it vibrate. Any loose rivet or mechanical device will cause a rattle. So even 5 inches of padding on the mounts will still transfer enough motion to make buzzes.

If you want to make it as quiet as possible you can make the panels dead quiet.
It requires taking the case apart though. You could take the case apart, in other words remove all the rivets, and where every panel or brace meets another place some 1/4" self adhesive weather stripping like you find in any hardware store. Then get some Dynamat or any other self adhesive sound deadening material and place pieces about 3/4's the size of you side panels to each one. That saves on the amoount you need and still does the job.
You caould also place weather stripping pieces in small strips on the HD cage or any other removable part so that when they touch they are resting against the WS and not AL to AL.
Anyway, thought I'd throw those out there in case you found something useful

[Tyler Durden]

Thanks. Very interesting.

I lack the skill to rebuild my case, but I have been testing the case for vibration - you were right about certain parts making the majority of the noise. The motherboard tray is the biggest culprit. I think I shall try to line it with thick noise dampener.

Much appreciated.

[Gooserider]

You might try Silent PC Review (SPCR.com) for sound reduction advice - I look at them as the silence experts just as ProCooling are the cooling experts. Their standard is that computers should not be heard - period. Alot of the noise reduction stuff that I've mentioned comes from them.

I would repeat my earlier suggestion of sound dampening material, NOT sound absorbtion! The lowest cost stuff that I've found which works very well is available from good hardware / home improvement stores like Lowes or Home Depot, it's called "Roofers Tape", and is essentially a thick layer of rubbery asphalt adhesive with a thin layer of aluminum over it. Total thickness is around 40 mills (.o4") It KILLS resonance. It's about $15 for a 6" X25' roll, more than enough to do a case. Just cut it to fit with a utility knife, peel off the backing and stick it on. strips can be overlapped or run next to each other, and it isn't neccesary to cover all of a panel. The only downside is that it's a fairly irreversible process, once the stuff has had a chance to bond, it is NOT going to come off without a major battle.

Note that the tape has to go on the metal, underneath any other sound absorbing foam...

I did a bit of experimenting when I was treating my case panels - I hung the panel on a peice of wire and whacked it with a screwdriver handle to see what kind of noise it made. Before treating, it made a pretty decent gong, and would ring for about 10 seconds. After treating, it just gave a dull 'thud' about like hitting a plastic trash can - absolutely no resonance.

To reduce noise transfer between metal parts, I would use the earlier suggestion of putting foam weatherstripping tape between parts that are designed to come apart.

For parts that are permanently assembled (riveted), I would get one of the "GOOP" products, or possibly silicone RTV sealant, and run a bead down each joint, working it into the joint as much as possible. This should reduce rattling and do some damping.

Another thing I've seen done is to use bungie cord or other heavy duty elastic to suspend the pump in space so that it can vibrate without transfering any vibrations to other metal. This is more common with hard drives, but I've seen it done with pumps as well.

Hope this helps,

Gooserider

[Blackeagle]

A good source for noise damping foams is McMaster's. They have a couple types that will work pretty well for computer noise reduction.

Costs are reasonable as well considering what PC sites charge, McMaster's is cheap!