How complicated are heat pumps in practical operation?

It does come in through controlled residential ventilation as well, only it seeps in slowly and continuously so that you don't really notice it. When I sniff directly at the grille, it always smells like "outside".

Especially when one of the neighbors turns on the grill. Then you can smell it very well "outside".

Really? I don't have neighbors who grill. I want to really smell spring, not just sniff it. But mostly I am outside then. I am the crazy one who also enjoys a coffee outside in peace at minus 20 degrees.

I am then the crazy one with the grill at -20°C. Been through everything already in snow and constant rain.

Just a quick reminder: The inertia of underfloor heating and the peculiarities of a [controlled residential ventilation] have nothing to do with heat pumps. I'm just saying this because otherwise, a resistance heater might be reading along here and come up with the idea that with heat pumps you always have to keep the windows slightly open and the towels don't dry :eek:

After the first year in the new single-family house is over...

If I were to build again, I would definitely build again with a heat pump. What would I do differently? I would spend the few hundred euros on an external professional heat load calculation.
Why?
I built with separate contracts/architect. The architect wasn’t particularly interested in the topic (which is not really his job anyway, that’s what mechanical, electrical, and plumbing engineers are for).
Due to the order situation (already back then), it wasn’t exactly the case that you got an offer from 15 heating engineers who all wanted to work according to a client-specific requirement catalog. I then took one who was at least willing to accommodate some things. But he showed little initiative himself. I even did a heat load calculation with the help of a forum to show him that a 35-degree flow temperature design is not necessary. But that was my calculation and only almost too late.
You must not forget two things about this whole heat pump story:

First, no matter what kind of device and additional components are installed, the most efficient heat pump on the market with the most efficient scheme without buffer storage without hydraulic balancing valves and so on...won't help if you need a 35-degree flow temperature to get 21 degrees in the bathroom.
And conversely, if the underfloor heating is very well designed, then I can mess up a lot in the technical room, but it still works quite well. I may have then spent a few hundred euros on components that wouldn’t be necessary (hydraulic balancing valves, hydraulic switches, etc.), but the difference between super optimized and not really only amounts to a few euros per month.

And second, the lower the heat load, the less of a problem it is for me in absolute terms. So if I am building a house that needs very little heating energy anyway and now I have a system that is somewhat botched because the heating engineer installed it according to a suboptimal manufacturer standard scheme, then I just need 10% more energy. Then I just have 55 EUR instead of 50 EUR heating costs per month. Nobody becomes poor because of that.