Heating System Noise

[imb123]

We have a Joule and Samsung heat pump system in our new-build timber-framed home, by Willan Living of Cumbria. The system installer was DJ Taylor Plumbing & Heating Ltd of Appleby-In-Westmorland.
The water tank and associated pumps are in the garage. Above the garage is our master bedroom.
Willan Living says all Building Regulations have been adhered to, Joule says its equipment is operating normally, the installer isn’t interested, and we can’t sleep in the master bedroom because of the awful noise from the garage. This is despite setting the nighttime temperature on all thermostats in the house to the lowest possible (5 degrees C) so that the heating does not operate at night. The noise is therefore, presumably, solely from maintaining the water temperature within set limits.
We need to be able to sleep without being disturbed by the heating system, and I want to have the option of having the heating always running, which is what it was designed to do. I initially thought that the solution was sound proofing, which I thought the builder should have installed, but I now think that this would be at best a partial solution. I think that vibrations from the system are being transmitted through the structure and that resonance is involved. Sometimes it seems like the noise in the bedroom is louder than that in the garage. It certainly seems like that at night when the only sound we hear is from the water being heated.
We also suffer from bangs and creaks, which I suspect is from thermal expansion of pipes that are in contact with structural elements of the building. As well as being annoying in itself, I suspect this also provides a means of transmitting vibration into the building.
We need ideas for how to solve this, without (at least initially) bringing in an acoustics expert because they seem to charge £1,000 for just a brief inspection without any guarantee they will solve the problem.
Are there heating engineers with expertise in acoustics?
Why isn’t it more widely discussed that a heat pump system must operate at all hours and that therefore buyers of these systems and the houses they are installed in should consider the noises from all elements of the system and whether they can live with them, not just the noise from the heat pump itself? I wish we’d never bought this house.
People should realise that Building Regulations won’t help. In the words of a member of our local Building Control department, “the Building Regulations are silent in respect of noise being produced by plant and services within a dwelling”.

I think it is widely discussed that heat pumps are designed to run 24/7 rather than be switched on and off like gas boilers.

You are right about resonances. In the past I have designed some complex equipment that has fans inside and the structure of the housing when added increased the noise level by quite a few dB and changed the fan noise to a more annoying pitch (that I was immune to!). When I was operating it at the design/build stage I had all the lids off and the noise was much less, so I didn't really notice it so much. The housings increased the noise so much that one of my customers couldn't work in close proximity to it and I had to redesign it.

The only thing you can do is change stuff round, it is too hard to model -or at least not worth the work involved to do it. Changing stuff round could be stuff as simple as using vibration isolation mounts and acoustic housings and repositioning where the devices actually are.

For example if a device is against a wall then you are right vibration can couple into the wall construction, so isolation can help in this case.

I don't quite understand what you say about the heat pump. Is it actually inside the garage ? Heat pumps have massive fans to suck in air so normally they are positioned outside.

What you have here is a system problem. The parts of the system are probably within spec. It is only when you bring all the different parts of the system together and try to operate them as one in a particular way that issues start to occur. The only way round this is to do extensive modelling in advance, which might be worthwhile for a multi billion dollar aircraft, but really isn't for a house builder, especially if the house is bespoke, and the parts of the system are contracted for separately, as the separate groups will just normally lay the blame on each other. It is a good reason why if you do these sorts of things that you have one party that is responsible for the performance of the entire system rather than multiple separate parties who only are responsible for their individual elements.

I would probably talk to an acoustic engineer.

Thanks for your response. To be clear, the heat pump is in the garden and the noise from it is not bad. The pumps in the garage are ordinary water pumps, and surely must be the source of the trouble. We may consult an acoustic engineer, but their charges are very high. I think modelling may have been a realistic option since we have timber framed house and there are many of the type of house we have.

You may be able to install acoustic plasterboarding in the garage walls and ceiling on top of whatever is already there. Rubber matting on the floor would also help, however I do not think you will be able to stop the noise fully. It is very bad designing to put the master bedroom over the garage especially knowing there will be pumps below it. The room above a garage will always be colder than other rooms and require more heating.

I am presuming, as there is a heat pump, the property is packed full of insulation, especially if you are in Cumbria. I doubt the garage will have the levels of insulation as the rest of the house, which will also lead to more sound. Garages are noisier as they are empty spaces so it is not surprising the sound is heard in the room above it.

It has been very cold in Cumbria, especially at night, the last few weeks, so your heat pump will no doubt have been working harder. It has been below 5 degrees, so I wonder if your heating has a frost setting, so may have been kicking in? All I can say, no solace to you in your new home, but I am grateful for an oil boiler and an unvented water cylinder - no noise at all.