How do i soundproof/insulate a noisy water pump?

bazwaldo · 25-02-2014 2:18pm

I read that the Grundfos MQ pump is self cooling with the water flow so it can be encased.

From its spec sheet "Being self-cooling, the pump requires no space or ventilation at the sides".

m_stan · 25-02-2014 2:38pm

I have an update on what I did above. Even after the dramatic decrease in noise after adding the siliconed slab under the pump, there was still quite a lot of noise. To rectify I built an MDF box, lined it with sound insulation foam, had the pump disconnected and re-plumbed into the box and placed another sheet of the sound insulation foam between the concrete slab and the MDF box. The pump continues to be connected via flexi piping to the main copper piping. I did the box making - just took my plumber 30mins to do the re-plumbing. Result? Almost complete silence - incredible difference. Will post some photos later if I get the time. Happy to speak to anyone directly about this over the phone - send me a PM.

bazwaldo · 25-02-2014 2:59pm

m_stan wrote: »

I have an update on what I did above. Even after the dramatic decrease in noise after adding the siliconed slab under the pump, there was still quite a lot of noise. To rectify I built an MDF box, lined it with sound insulation foam, had the pump disconnected and re-plumbed into the box and placed another sheet of the sound insulation foam between the concrete slab and the MDF box. The pump continues to be connected via flexi piping to the main copper piping. I did the box making - just took my plumber 30mins to do the re-plumbing. Result? Almost complete silence - incredible difference. Will post some photos later if I get the time. Happy to speak to anyone directly about this over the phone - send me a PM.

Delighted to hear it can be made almost silent. Whats sound insulation foam and where do you get it? So if I can get him to put on the flexible pipes, the rubber mat and screw it down, I should be able to encase it after.

I reckon its the noise of the motor and not so much the pipes that are the noise. The sound seems to come directly from the pump itself. I would guess that covering the pump snuggly will make the biggest difference (and thick rubber underneath).

m_stan · 25-02-2014 3:57pm

Here's the exact foam I bought: http://www.adverts.ie/other-music-instruments-equipment/acoustic-soundproofing-foam/4141725

I would not screw it down and then encase it. I would make the box, get the sound insulation foam and get your plumber back to re-plumb it ensuring you have floor, foam, box in those layers and the pump inside the box which itself is insulated on all sides internally.

In my case the majority of the noise was through vibrations through the floor and pipes rather than noise from the pump itself, so the foam between the floor and the box was critical to the soundproofing - moreso than the insulation of the box itself. Hope that helps. Again happy to discuss on the phone if you want to have a realtime conversation about it.

ART6 · 25-02-2014 4:16pm

bazwaldo wrote: »

Delighted to hear it can be made almost silent. Whats sound insulation foam and where do you get it? So if I can get him to put on the flexible pipes, the rubber mat and screw it down, I should be able to encase it after.

I reckon its the noise of the motor and not so much the pipes that are the noise. The sound seems to come directly from the pump itself. I would guess that covering the pump snuggly will make the biggest difference (and thick rubber underneath).

Pipes are very good indeed in transmitting noise throughout a building. They need to be fixed firmly and connected to the noise source (the pump) with flexibles that won't transmit the vibrations. The sound can only come from the pump/motor assembly, but the pipes will transmit it.

bazwaldo · 03-03-2014 11:59am

Talked to the plumber and he's to get back to me about the flexibles. The pump has two connections. 1 is 1 inch and the other is 3/4 inch. He has never seen a 1 inch flexible pipe before and doesn't know if they are available.

Can anyone give more information on these flexibles? Are they the braided type? Should they be available from the larger plumbing suppliers?

There is definitely a lot of vibration from the copper pipes going on. Fitting flexibles will definitely help.

Joey the lips · 11-03-2014 9:28am

The tile and silicone was prob ignored by the plumber because it involves more work. The rubber mat in my experience does not work unless its a thick thick rubber mat in which case the silicone and tile work better.

i cannot agrue with the plumber all i can tell you is any plumber thats worth there salt knows that fitting these without buffering will give you terriable noise.

bazwaldo · 11-03-2014 9:40am

He put the flexibles on so I have plenty of room to manoeuvre and build a box around it, and silicon under etc. So my plan is the following.

1. Build a box out of ply/mdf leaving two inches on each side bigger than the pump to have the sound insulation. Encase the pump. Check the noise level.
2. Silicone a heavy porcelain tile to the floor and silicon the box to the tile. Check the noise level.
3. Check each pipe and ensure they are tightly clipped to battens on the wall to cut out any minor vibrations. Check the noise level.

bluesteel · 09-04-2014 12:03pm

bazwaldo wrote: »

He put the flexibles on so I have plenty of room to manoeuvre and build a box around it, and silicon under etc. So my plan is the following.

1. Build a box out of ply/mdf leaving two inches on each side bigger than the pump to have the sound insulation. Encase the pump. Check the noise level.
2. Silicone a heavy porcelain tile to the floor and silicon the box to the tile. Check the noise level.
3. Check each pipe and ensure they are tightly clipped to battens on the wall to cut out any minor vibrations. Check the noise level.

How did you get on with this? My pump is not Gryundfos but similar - I have flexi connections and most of the noise is resonance from the tank and pipes rather than the pump itself. I'm thinking of getting a brick and screwing/glueing it for maximum dampening - as it recommends 1.5 times the weight for dampening

I noticed in the Grundfos handbook

Foundation suspended on vibration dampeners
Optimum solution with controlled vibration
transmission, see figure 2.1.9.
As a rule of thumb, the weight of a concrete foundation
should be 1.5 x the pump weight. This weight is needed to
get the dampeners to work efficiently at low pump speed.

http://www.grundfos.com/content/dam/Global%20Site/Industries%20&%20solutions/Industry/pdf/Pump_handbook.pdf

bazwaldo · 09-04-2014 11:40pm

That's an interesting piece of information on the Grundfos. I haven't made the progress I thought I would unfortunately. I cut the pieces for a box out of ply and have the sound proofing ready but found fitting the box around the pump tough as the flexible pipes are not that flexible.

I removed the rubber mat from under the pump and did the floor, silicone, tile, silicone, pump thing. I found that this has not reduced the noise while standing beside the pump as the noise is from the pump motor directly, but the sound from other rooms has reduced good bit. The silicone tile seems to absorb some of vibration so there is less transfer of vibration onto connected pipes.

The tile I used would not be any where near 1.5x the weight of the pump. You'd need a concrete slab for that weight.

I must try the sound proof box soon.

ART6 · 10-04-2014 8:48am

bazwaldo wrote: »

That's an interesting piece of information on the Grundfos. I haven't made the progress I thought I would unfortunately. I cut the pieces for a box out of ply and have the sound proofing ready but found fitting the box around the pump tough as the flexible pipes are not that flexible.

I removed the rubber mat from under the pump and did the floor, silicone, tile, silicone, pump thing. I found that this has not reduced the noise while standing beside the pump as the noise is from the pump motor directly, but the sound from other rooms has reduced good bit. The silicone tile seems to absorb some of vibration so there is less transfer of vibration onto connected pipes.

The tile I used would not be any where near 1.5x the weight of the pump. You'd need a concrete slab for that weight.

I must try the sound proof box soon.

You can buy a440 x 220 x 160 mm concrete block from a builders providers for around €1 !

bluesteel · 10-04-2014 8:50am

actually my pump is a Stuart Turner Twin SW15 pump. I reconsidered it and I'm thinking that maybe a lot of the noise is actually from the pump not just the resonance/ pipe vibration.

I noticed the installation instructions which the plumber had left discarded beside... saying more or less the same as this

Locate the pump in a dry, frost free position where it cannot be sprayed with water. It should be positioned horizontally on its anti-vibration mounting feet and should not be screwed down

Does this mean it cannot be dampened?
(by attaching a weight)
http://www.taps4less.com/pdf/Showermate-Eco-Standard-Single-Twin-Installation-Guide.pdf

Now I'm not sure what to do apart from rubber feet and acoustic foam

ART6 · 10-04-2014 9:03am

bluesteel wrote: »

actually my pump is a Stuart Turner Twin SW15 pump. I reconsidered it and I'm thinking that maybe a lot of the noise is actually from the pump not just the resonance/ pipe vibration.

I noticed the installation instructions which the plumber had left discarded beside... saying more or less the same as this

Does this mean it cannot be dampened?
(by attaching a weight)
http://www.taps4less.com/pdf/Showermate-Eco-Standard-Single-Twin-Installation-Guide.pdf

Now I'm not sure what to do apart from rubber feet and acoustic foam

All that means is that if you screw it down and so compress the anti-vibration mounts then they will no longer work, since the screws will be transmitting the vibration right through them. Standing it on a concrete block as I suggested above will still help without screwing down, as the mass will still absorb a lot of the airborne vibration, particularly if you put a box over it.

bluesteel · 10-04-2014 9:35am

ART6 wrote: »

All that means is that if you screw it down and so compress the anti-vibration mounts then they will no longer work, since the screws will be transmitting the vibration right through them. Standing it on a concrete block as I suggested above will still help without screwing down, as the mass will still absorb a lot of the airborne vibration, particularly if you put a box over it.

thanks. I've had wooden floors put down recently, they come in to the cabinet almost to the pump's footprint so I may cut them away as much as I can.

the Stuart Turner pump specifies that air flow is required not water cooled) so I'll try applying foam around the cabinet first to keep a bit more circulation.

I measured the noise using an app on my phone - turns out it's more or less within 70dB @1m as per the manual. Still bloody annoying!

And I'll put foam insulation on the pipes; no harm anyway

ART6 · 10-04-2014 9:58am

Another point worth mentioning here is that if the flow of water to the inlet side of the pump is insufficient or restricted then the pump impeller will "cavitate", which means that it will be pulling air out of the water and making a surprising amount of noise. This can happen if the pipework from the header tank is long, or has too many bends. The longer the pipe the higher its flow resistance, and every 90 degree bend and valve reduces the flow further. So it is quite possible to have sufficient inlet head as specified by the pump makers, but still not sufficient flow.

There are ways of dealing with that: If, say, the pump has a 15 mm inlet connection but the supply pipe would have to run for 15 metres, then running it in 22 mm with a reducer at the pump end would vastly improve the flow. Equally, using swept elbows rather than 90 degree elbows in the pipe run would help considerably. So too would locating any shut off valve at the pump rather than at the tank, particularly if it was installed in the larger diameter immediately before the reducer.

The whole point is that if the pump is expected to pump, say, 2 litres per minute, then it must be receiving 2 litres a minute from the tank! If it isn't quite getting that then it will be noisy, and the flexible connections and vibration dampers won't make much difference.

ART6 · 10-04-2014 10:07am

bluesteel wrote: »

thanks. I've had wooden floors put down recently, they come in to the cabinet almost to the pump's footprint so I may cut them away as much as I can.

the Stuart Turner pump specifies that air flow is required not water cooled) so I'll try applying foam around the cabinet first to keep a bit more circulation.

I measured the noise using an app on my phone - turns out it's more or less within 70dB @1m as per the manual. Still bloody annoying!

And I'll put foam insulation on the pipes; no harm anyway

What matters is the frequency of the sound (in Hertz), not simply the volume in dB. The lower the frequency the more dense the sound insulation has to be to absorb it so, for example, insulating foam will have no effect on low frequency sound. In such cases it would be simple enough to enclose the pump in a plywood box covered in lead sheeting on the inside (a roll of lead flashing from a builders providers would provide more than enough).

For an air cooled pump an air vent could be left at each end of the box. Some sound would get out there, but it would be greatly reduced.

lawred2 · 16-02-2016 10:30am

Kashkai wrote: »

My pump is in the attic so how would I go about noise insulating this?

One guy suggested putting it on a rubber mat?

Waste of time

Ours is fixed using rubber mounts on a shelf which is itself fixed to the gable wall in the attic using rubber mounts and the f***ing thing still vibrates...

Not as much as when the original plumber fixed it to the subframe of the house mind but it's still audible.

justagirl · 27-02-2016 12:37pm

Sorry to cut in on this thread, very informative and got me looking at my own extremely noisy water pump!!! It is sitting in the hot press direct on the wooden floor screwed in with one screw and a layer of bubble wrap underneath- which I am assuming does nothing ?!! Where can you buy the vibration dampeners?

cnocbui · 27-02-2016 2:57pm

justagirl wrote: »

Sorry to cut in on this thread, very informative and got me looking at my own extremely noisy water pump!!! It is sitting in the hot press direct on the wooden floor screwed in with one screw and a layer of bubble wrap underneath- which I am assuming does nothing ?!! Where can you buy the vibration dampeners?

The best stuff for preventing the transmission of vibrations i am aware of is a stuff called Sorbothane I'd just peruse eBay

To really deaden the sound I think one needs the pump to be in a box with sound absorbing foam or fiberglass on the inside, but you will always get some noise transmitted as vibrations through the pipework - even with flexible connectors.

But if a lot your sound is coming from what it's sitting on, then sorbothane should help a lot.

Calibos · 27-02-2016 3:40pm

justagirl wrote: »

Sorry to cut in on this thread, very informative and got me looking at my own extremely noisy water pump!!! It is sitting in the hot press direct on the wooden floor screwed in with one screw and a layer of bubble wrap underneath- which I am assuming does nothing ?!! Where can you buy the vibration dampeners?

Is your pump connected to the pipes with Flexible metallic braided hoses? If it is it shouldn't be screwed to the floor I don't think. Thats just coupling it/transferring vibration from it to the floor.

Heres my Hot/Cold pump in my boiler press. Flexible braided hoses connect it to the solid pipework. It has black rubber 'shoes' which are supposed to isolate the vibration from it. However they were useless. I then read about using tiles and flexible silicone to isolate a pump. At the time I only had a few small tiles but I gave it a try. One runs a bead of silicone around the tile and uses matchstick spacers and puts the other tile on top. When the silicone has cured one removes the matches. One does the same under the bottom tile. This isolates the pump vibration from the floor and causes the tiles to vibrate instead. The vibration is converted to heat in the tile instead of being transferred to the floor and vibrating the floor and joists (Thats how the noise spreads to the rest of the house)

It cut down the noise of the pump quite a bit and now I could only hear it in the bedroom beside and below the pump and at a much lower volume instead of the whole house. However, the bigger and heavier the tile the better. ie. More Mass is better for absorbing the vibration but I only had some small tiles.

Recently I changed bedrooms to the one right beside the pump/boiler press. I realised there was still quite a bit of noise resonance transferring into this bedroom via the wall/floor. I found a much larger spare tile and some black neoprene packing foam. I cut it into strips and put the strips under the big beige tile under my original small isolation tiles and pump. This made a huge difference again. There is now little to no vibration transferring to the floor. One can put ones finger on the pump feet and feel loads of vibration, then put ones finger on the small tiles and feel less but still quite a bit of vibration, then put ones fingers on the beige tile and feel less vibration again. Finally when one puts ones fingers on the wooden floor beside the beige tile you feel little to no vibration at all. Before I added the beige tile one could still feel a good bit of vibration in the floor (which is transferring through the floor and joists)

Now, I pretty much can only hear the airborne noise from the pump motor itself and theres not really much you can do about that unless you can build a ventilated enclosure around the whole pump.

Poncke · 18-06-2020 7:20am

justagirl wrote: »

Sorry to cut in on this thread, very informative and got me looking at my own extremely noisy water pump!!! It is sitting in the hot press direct on the wooden floor screwed in with one screw and a layer of bubble wrap underneath- which I am assuming does nothing ?!! Where can you buy the vibration dampeners?

https://smile.amazon.co.uk/etm-Anti-Vibration-Washing-Machine-Mat/dp/B00QVN1QQW/ref=sr_1_12

How do i soundproof/insulate a noisy water pump?

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