Air-to-air heat pump experiences?

Does it make sense to combine the gas heating with photovoltaics? Weberhaus offers a combination here.

1. Thicker exterior wall for better insulation
2. Photovoltaics on the roof
3. 3kW storage battery in the technical room for self-consumption of the generated energy.

The whole thing costs €15,000 and turns the house into a Kfw 40+ bunker, which in turn is subsidized with €15,000. This probably makes sense for the LLWP, but for gas?

Which heating technology to choose for the new house was also the most difficult point for me. Many "salespeople" swore by the air-to-air heat pump from Proxxon. At first, I was very enthusiastic about the concept behind it. Well, in the end, I went with an air-to-water heat pump from Buderus combined with photovoltaics. But it was a gut decision after weeks of research on the web beforehand...

Is the air-to-water heat pump in use at your place now? Or is the house not built yet?

The house is still in planning, so no child has fallen into the well yet. Although the heating type is firmly regulated in the house contract, meaning: change = extra charge.

With an air-to-water heat pump, I have concerns about the noise. Those things can really hum in winter, and throttling doesn’t make sense because then they freeze up. There have already been disputes in our wider neighborhood because of that. The air-to-water heat pump seems to be one of the loudest types of heating. I would prefer a gas/condensing boiler, but then I can no longer meet the KFW standard. Arghh! The agony of choice.

So I looked at several different models both as a split unit and without. Yes, there were a few noises (felt like one in 10), but I didn't find them massively disturbing.

Here we are, I think, treading on thin ice, since hearing is known to be in the eye of the beholder. Take a look at Hi-Fi forums; one swears by Heco speakers, another finds them excessively bass-heavy...
If you like it whisper-quiet and don't want to take any risks, you shouldn't get a heat pump. As for me, I decided very quickly. And thousands of households (take a look in a new development area you know, every second house is built with a split unit here) do the same. Can so many be wrong? I can't judge that, but just ask the homeowners or neighbors of the operators of an air-source heat pump...