I've got a Swiftech Laing D5 Vario MCP655 12V DC Pump

It's pretty quiet when set on low, but I was wondering if there are any ways of making it quieter? I've tried adjusting the speed, and I've also mounted it on foam, and made sure nothing is touching it...

Is there anything else I can do? Wrap it in foam maybe?

one would be to case it in cardboardbox which is lined with foam, seal it completely and cut the holes for tubings. Thus make pumps noise then isolated and kills almost entirely direct sound path silencing it more when placing inside the case...

but if the pump heats alot that might not be wisest thing....

It does not even get warm, I'll try this and keep an eye on how hot it gets. Great idea, thanks.

For the last few years I've used a Resorator1 with a bunch of different waterblocks. And even a watercooled PSU. The Resorator1 came with a Eheim pump. Which started to rattle. I had it replaced, and the friendly people at the store gave me even another (heavier) 3rd Eheim pump. In case the replacement pump would break too.

All 3 Eheim pumps started to rattle after a while. I cleaned them, I remounted them, I tried all kinds of stuff. I've come to the conclusion that those Eheim pumps are just crap.

So I'm planning to buy an external pump. But I wanna make sure I get a real silent one. Do any of you have a suggestion ? Currently I only cool my CPU. But when I buy a new videocard, I might put a waterblock on it again. (I had my 8800GTX watercooled, but I fried it when rust particles blocked the flow in the EK waterblock, which had a crappy design with crappy cooling fins inside the block). I don't think capacity of the pump is really an issue. Even if I cool my videocard too.

Any suggestion for an external pump ? Which brand/type is supposed to be the most silent ? I prefer a 230V pump. I might use the trick with "foam in a box". But it would be nice if the pump was quiet by itself.
TIA.

I would assume that by definition, the pump is watercooled ! Can't go wrong there.

Eheim 1046 runs on 230V. Flow is the same as the pump in a reserator 2 (and IIRC same as reserator 1), but head is higher.
I don't think you will end up putting it in a box, it's very quiet.


Part of the heat of the pump will be transported by water, but pumps don't function like a waterblock, most parts are plastic. Some part of the heat will have to be transported by air, a closed box means there *might* be a problem.

You understand the basics:
1) slow the pump,
2) isolate its vibrations from other components,
3) contain & damp its noise.

Bobkoure has noted that the water lines can transmit pump vibration to other components and recommends soft silicone tubing for quietest running. Can you feel vibration in your tubing?

Or you can Simply switch out pump the DC 655 and the 355 are noisey, get 2 350's and rum then serial after mounting them of soem pading or foam/ gel for vibrations they should be slient and allmost as powerfull with aftermarket tops, thats what i'm going to do.

The pump inside the cooling tower is an Eheim? I didn't know that...

The rattling sound is a well known "feature" of Eheim pumps. It's the impeller that is loosely fitted to the axle to avoid breakage if a small stone or other dirt from the aquarium happens to be sucked in.
The standard fix is to wrap a thin layer of adhesive tape around the axle before refitting the impeller.

Only if it is drowned in the water tank.
Otherwise the motor part will be air cooled.

Cheers
Olle

Not a chance. I run my DDC at ~9-10V to reduce its noise output, and it's certainly not silent at the lower speed. I'd go crazy if my WC system required 2 of them.