Air heat pump or use gas and solar?

The costs for heating were a joke. I gladly forgo any subsidies and don’t care about ecology; the state doesn’t pay my bill, I do alone.

Gas, solar, 108 sqm, only Energy Saving Ordinance standard version. E.On rates us at 750,- per year. I will see what it will be in September. Price was 5000 under air-water heat pump. Junkers both offers. Connection 750,- gives 4250 surcharge heat pump. Is it really worth it? I don't think so. Warm room is warm room. Both do that. Karsten

Whether it is worth it can be answered in twenty years. And the question then is more how many kWh were used. But: the underfloor heating should be properly designed anyway. Because even with gas the boiler then runs more efficiently and if necessary can be converted to a heat pump without worries in 20 years if needed. Unfortunately, not many are up to date with technology. And also avoid it. But that is another topic.

But: the underfloor heating should be properly designed in any case.

How can this be checked? Is there a specific document that you have to request from the general contractor, where this can be checked? It won't be the heat load calculation.

Yes, indeed, the correct room-by-room calculation. Then the underfloor heating is designed accordingly. Preferably according to your specifications. Consult with the energy advisor.

The flow temperature should be a maximum of 35 degrees. The individual circuits should be almost identical in length. No more than 100 meters per circuit. No bathroom radiators but wall heating. Hydraulic balancing is a must.

Then the topic should be well chosen. The heating technician must be knowledgeable about this and the minimum output low. This prevents constant on/off switching.

The HB does not make such a committed impression on me. He sells his standard products and pushes them out. He charges what is required by regulations but that’s it.

Yes, there are probably many of those. Less of a problem with gas. With a heat pump, it might get tricky. But that doesn't help you. And as an interested layperson, I can't contribute any more.