Split air-to-water heat pump

Would be interesting: approximately how many operating hours per day, how many kWh does it consume, does your hot water get warm enough, does the electric heating element in the hot water tank have to help, how long per day, etc.? I am currently choosing for the planned new building: ground probe heat pump or split system? Including ground probe etc., the first option is indeed significantly more expensive to purchase and whether you really get the extra effort compared to the split system back over a maximum 20-year lifespan? I am really still uncertain.

I cannot give you any experience-based information, but we are facing the same decision. Despite the significant price difference, we tend to choose the geothermal probe. Keep in mind that the drilling will still work in 20 years and will not need to be replaced. The split unit might need to be exchanged in 20 years. Besides, we do not like the idea of having to place the split unit outside somewhere.

You're right, the borehole will surely still be okay after 20 years, but that is "only" the heat source and the heat source for a split system is the ambient air, which will still be there after 20 years ;). What concerns me more is the heat pump itself, a brine heat pump also has a compressor, a filter drier, a heat exchanger, they don't last forever either and will eventually need to be replaced. The split outdoor units are really inexpensive... but for them, one probably has to assume only about 15 years of service life. I don't think the difference in repair/replacement costs is that great. My question is more about the operating behavior of the split units at outdoor temperatures below 0°C... they eventually turn into a pure electric heater the colder the ambient air is. Although only for a few weeks a year, but that is exactly what I find interesting...

I spoke with several SHK installers, masters, and engineers. The clear consensus from all was: in the short and medium term, the air heat pump is cheaper. In terms of comfort and in the long run, the ground source heat pump remains the better and more cost-effective choice.
The drilling is a huge cost factor for this type of heating. The other components are only slightly more expensive for the ground source heat pump than for the air heat pump.
It depends a bit on what you plan and what expectations you have. If you choose the air heat pump, you should set aside a little more in reserves, as the split unit will probably need to be replaced sooner. But that is always a bit of a gamble.
However, I am also interested in the experience of air heat pump users. So far, I only know of three ground source heat pump users in my circle of friends (all of whom are very satisfied so far).

Don't forget the possible BAFA subsidy for a ground-source heat pump of €4500, that will cover a good part of the additional costs.