ᐅ Heating and ventilation system for a KfW40 energy-efficient house

Hello,
My name is Alex, and my family (wife and child) and I are currently planning a KfW40 house of about 190 sqm (2,045 sq ft).
My personal challenge is with the hot water, heating, and ventilation systems—I want to do everything correctly if possible.
I am interested in installing both photovoltaic panels and a solar thermal system; is this still considered a modern solution?
Which combinations make sense or are feasible (heat pump, solar, air-to-air heat exchanger, etc.)? As I mentioned :-) ... I’ve lost track of what is actually practical.
I hope you can advise me and provide support on this.

Thank you in advance,
Best regards
Alex

Let me put it this way. If you heat with gas, you also use gas to heat your hot water. So solar thermal systems are a good way to reduce this load. It saves gas.

If you heat with any type of heat pump, you use electricity because a compressor always needs to be powered. These systems essentially work like air conditioners, just in reverse. Producing your own electricity with photovoltaic panels fits well as a way to reduce this load. Karsten

Hello Nordlys,
thank you for your reply. Which of the two would you recommend? Heat pump or gas?

Best regards
Alex

Proteus schrieb:
KFW40

It is almost impossible in combination with a gas boiler.

Caspar is probably right. Gas is a fossil fuel that is not renewable and produces CO2. As such, it negatively affects the calculation of the energy performance certificate according to KfW and would need to be compensated with very high levels of insulation and very efficient windows. We are not questioning the rationale behind this calculation here. That is simply how it is. Karsten

Hello Karsten and Caspar,
thank you for your answers. It seems that a heat pump will probably be necessary? Something like that combined with the ventilation system + solar? Or do you have other suggestions/ideas? Which systems would you recommend?
Kind regards
Alex