Soundproof wall against neighbor's heat pump

You can't just brick them in. [...] I suppose.

If set up in-house on the exterior wall, these slats are placed in front, like with exhaust systems of underground garages. That way, you can also enclose these things, like garbage bins. And inside the enclosure, you can then install sound diffuser mats like in recording studios or something. Breathing freely doesn’t have to mean making noise freely.

I'll say something uncomfortable now. I'll put myself in the neighbor's role. He has built. They sold him this air-to-water heat pump thing, and he likes it. He probably complied with all the regulations. Now there's some budget left for landscaping and a hedge.....now the OP comes along and complains about the pump. It hums. Like an insect. He now wants to enclose it or relocate it....is he crazy? He thinks to himself. I did everything right and he's making trouble because of the buzzing. Everyone around here has one of these.

I guess if I were an air-to-water heat pump owner, I wouldn't do anything and would think, neighbor, chill out, every exhaust vent in the wall is louder. People will have to get used to the pumps. By the way, the much-appreciated wood stove is not nuisance-free either. A poorly adjusted motion sensor floodlight and a nocturnal cat can also be annoying....Life is just not clinically clean. Our new neighbor has those things too. It just hums a little...Karsten

I have to push back. There is already excessive noise everywhere. A constant humming or buzzing is really stressful. We have the coal excavators next door. I know what I'm talking about. I hope every day that we still manage the energy transition and finally shut those things down.

What noise can be avoided should also be avoided. I can't just blow my noise emissions at the neighbor. Then I have to expect that he will complain. No matter who was there first. If he didn't suspect this, he is either stupid or ignorant. In any case, he is now paying his dues.

It doesn't always have to mean that someone is stubborn. Maybe the damage can be shared.

"4 m how can that be?" Well, it can also be 4.5, but no more, since it is densely built and 2.5 m distance area times 2 plus distance to your own house wall cannot be more. Are there legal minimum distances?

First, you would need to know where you are located:

Immission guideline value day (6:00 am to 10:00 pm) Immission guideline value night (10:00 pm to 6:00 am)
6.1 Core, village and mixed-use areas 60 dB(A) 45 dB(A)
6.1 General residential areas 55 dB(A) 40 dB(A)
6.1 Pure residential areas 50 dB(A) 35 dB(A)
6.1 Health resort areas, hospitals and nursing homes 45 dB(A) 35 dB(A)

The value is measured

at built-up areas 0.5 m outside in front of the middle of the opened window of the noise-affected protective room (e.g. bedroom window);

What model does your neighbor have? There are quite a lot of differences. Then just google the data sheet or the name of the system.

One that I know has, for example, 65 dB(A) during the day and 60 dB(A) at night. At 6.5 m distance (measured would be 6 m) d

Depending on that, you can make sure that your neighbor has to do at least the following:

Outdoor installed devices can be equipped with a soundproof hood or installed behind a noise protection wall.

On Wärmepumpe.de there is a /sound calculator/

There you can nicely calculate it. For example, with the above-mentioned device and a pure residential area.

I hope every day that we will still manage the energy transition

We will never manage it like this. The problem is: in construction (besides financing) there are so many parties involved, all of whom want to do as little work as possible. It is easiest to consider each legal and credit subject "builder" individually. That is why every homeowner plans their energy stuff for themselves as if they lived on a lonely island. In the batch size of "one residential unit." In which the systems used of all kinds share one thing: that they never, ever operate economically optimally. But what about installing a shared combined heat and power plant on one of the garages with six neighbors? - is undermined at the latest by the three heating engineers and four subsidy consultants, each of whom prefers to do their quick business with only one builder rather than one with all of them as a consortium, which first has to be brought under one roof.

At least for semi-detached houses, I think it should be mandatory that only one heat energy system is used.

Da kann man das schön ausrechnen.

At least 3, better 6 dB(A) should be subtracted again from the immission guideline value. No individual system should be allowed to fully exploit the immission guideline values. First come, first served principle. Otherwise, I see my opinion confirmed. With air heat pumps planned and installed completely without regard for birds, there will be a big "crash" in the coming years.