Which heat pump? Ventilation system / Air-to-water heat pump

Grym... you are exaggerating. No house consumes 12 kkWh of electricity (3,000 €) with an exhaust air heat pump and only 2 kkWh (500 €) with a ground-source heat pump - that is already mathematically nonsense - it would mean that the ground-source heat pump has an annual performance factor of 6.0 - assuming that the exhaust air heat pumps were direct electric heaters. Exhaust air heat pumps are not the heroes of work, but they are not that bad either. Here are the consumptions of the Viebrockhaus houses:

We do not need to discuss selected individual cases. Both the figures are exaggerated, as is your table, since there are many counterexamples. An exhaust air heat pump can work, but you have to be fully aware of its limitations. In most cases where an exhaust air heat pump works, an air-to-water heat pump would work better.

I’m with you on that. An exhaust air heat pump is simply "affordable" because it handles both ventilation and heating in one device.

Just a quick question on the side: How many cubic meters of water does a groundwater heat pump approximately pump per hour/per day?

The miserable heating question is bad. I can fully understand the back and forth.

We have been dithering forever about district heating or heat pump systems.
Conclusion:
District heating: already way too expensive to install
Air heat pump: there were far too many bad experiences found online and the consumption was sometimes insanely bad.
Air-water heat pump: very dependent on the brand and calibration. But otherwise many good experiences, also in our environment. In Rechlinkghausen Heinz von Heiden equipped an entire residential estate with heat pumps (with split units). The noise level was not noticeable and apparently no bad experiences were made (we spoke to 3 people there).
Ground-water heat pump: most expensive in acquisition costs, but the most economical. However, it really takes a long time for the additional costs to pay off.

So we chose the golden middle way and took an air-water heat pump. Plus a 300l tank (included in the offer). They say for a 4-person household with "normal" consumption a 180l tank is enough. For guests, I wouldn’t take significantly more unnecessarily. Here maybe also take a middle way.

Regarding the fireplace. Ask yourselves very carefully how often you would actually light the fireplace. For many, it is more of a decorative element. That means once a week in winter they might light it. Therefore, I wouldn’t use it as an argument in favor of an air heat pump.

Just a quick question on the side: How many m³ of water does a groundwater heat pump pump approximately per hour/per day?

In my opinion, it depends on the heat pump (performance), or am I wrong? I once heard something about 2m²/h for a normal single-family house.

What do you generally think of groundwater heat pumps? If they are approved, they are more expensive than an air-water heat pump, but cheaper than a brine-water heat pump and ultimately more efficient. But how does it behave with not quite perfect groundwater? If you have relatively high groundwater, the drilling is by far not as expensive as with 1-2 drillings that go 50-100m into the ground, right?