Air-water heat pump, gas, solar thermal prefab house, advantages and disadvantages?

There are also wood pellets

Good morning

It has already been said that only gas is really practical, but a tank is rubbish and otherwise only a heat pump is somewhat fault-tolerant.
That excludes all other heat generators.


Olli

That was not meant like that... but the OP asks very blindly into the forest and expects simple black-and-white answers - that is what he got... and the hint that you need an HLB to make any statements.

Hello again

that was also expressed somewhat ironically by me.
The questioner asks and gets a black and white answer.

I have made it a habit in such conversations to ask what the customer's wishes are, what options they have, what is important to them about the building services/heat generation.
And then suddenly options like pellets, firewood, and solar thermal appear.

Olli

His problem is actually not the heating. The demand for that can be determined fairly reliably. His problem will be the hot water demand. When I read 2 houses, then suddenly (maybe not today, but in the future) quite a few liters of water can accumulate. And suddenly, if already 4 people want to shower one after the other, possibly extensively. Then, with a heat pump, the meter starts to spin. And that, possibly or especially in [Winter]. Now, of course, you can size the heat pump accordingly, but then it is probably completely oversized for the majority of the time. Additionally, there is the legionella problem with storage, etc. etc. I always wonder why the home builder doesn’t offer a concept for these things, or in the [Energieeinsparverordnung]-proof something should be stated, or is it a brand: sell anyway, the rest don’t care?

It is basically a single-family house... There are 2 small bungalows, one with 3 bedrooms and a bathroom, the other with kitchen, dining, living room, utility room, and storage room. They are separated by a hallway, which also leads to the basement. So a total of 220 sqm. It is fully basemented. But 100 sqm are for a garage. The other 120 sqm still have to be communicated. The bungalows and the hallway will be a prefab house, the basement will be built with masonry! We are 2 adults and 2 children, or eventually 3... Only the following options come into question: Geothermal energy - ruled out, soil too rocky. Pellets - ruled out, no space for it and too complicated for me. Oil - no one installs that anymore today. Gas possibly in combination with solar thermal, would be an option. And air-to-water heat pump possibly in combination with photovoltaics, would be an option. We will get the heating load calculation and the energy certificate soon, we have just signed... I think in terms of costs, also long-term, both systems won't differ much even over a long period... What do you think?

Have you ever considered a combined heat and power plant for the size?