Air-water heat pump current consumption and data

Which invoice? There are three numbers 8-)

If you assume for simplicity that the energy price is almost identical when considering the annual performance factor, it’s about the direct comparison of the investment gas boiler vs heat pump. Additional costs (chimney, etc.) are more likely with gas, subsidies more likely with heat pump. You really have to look at the individual case.

Something different would be gas with conventional radiators (so no underfloor heating). That is probably by far the cheapest option.

Am I correct in assuming that the comparable calculation for a smaller area (let's say 120-150 sqm) would look different or shift in favor of the heat pump? After all, the fixed costs for gas (meter, chimney sweep...) would weigh more heavily here!?

As my predecessor said, it is not that easy to answer. The heat pump would become cheaper in terms of investment. A gas boiler is not exactly maintenance-intensive and chimney sweep is not expensive. However, a slight improvement would certainly be present.

I once did a calculation out of interest for my case, whether gas - air-water heat pump - brine-water heat pump would be more economical. [...] 220 m² heated area KFW55 (consumption value 4500 kwh heat quantity)

Are the 4500 kWh correct? With an annual performance factor of 4, that would be 1125 kWh at €0.23 (by the way €0.205 for me), so €260. Or is it the fourfold amount? Here, gas heaters with smaller (but older) radiators cost around ~€700 p.a. and I with a new semi-detached house KfW70 and exhaust air heat pump (was specified) at ~€600 p.a.

We are not talking about photovoltaics here but about gains through the windows.

Alright. I could look up the values sometime. It feels like quite little heat passes through the triple-glazed pane compared to the solar heat outside the pane.

Are the 4500 kWh correct? With an annual performance factor of 4, that would be 1125 kWh at €0.23 (by the way €0.205 for me), so €260. Or is it four times the amount? Here, gas heaters with smaller (but older) radiators are around €700 p.a., and I with a new semi-detached house KfW70 and exhaust air heat pump (was specified) around €600 p.a.

Ah mistake the 4500 is electricity consumption, heat quantity is of course four times as much in reality with air-to-water heat pump. But that doesn't change the values.

18000kWh for a somewhat modern building is quite a statement. In the 70s building, we used 22000kWh for 210sqm including a heated conservatory (new gas boiler, radiators)