House planning final: heating components, what makes sense - no air heat pump

Hello construction expert,

thank you for your detailed answers. Yes, your suspicion about the provider is correct and also the conclusion that if this option does not work out, no other option offered by this provider will be available. I am still wavering whether this might become a deal breaker... Friends of ours built with this provider and the Nibe 750, however without a photovoltaic system, which supports it. They currently end up at Kfw55 with 4700 kw/h in the same house type and with 4 people.

Larina: How satisfied are you with the Stiebel Eltron and the choice of technology? Do you already have a first consumption estimate or even actual consumption data?

4700 kWh mean 93€ heating costs per month. Even if the photovoltaics cover 100%, it would take 11 years until it pays off. Questionable whether the battery will still be alive then. By the way, 3.3 kwp is not really that much either...

We are still in the planning phase, so we do not have actual consumption data yet. This month is sample selection. We are starting the application for the Bafa funding today...

Thank you for your answers. Since this weekend, we have completely moved away from the Nibe 755 as the sole system for hot water and heating. We visited 3 houses by V.. and looked at the heating cost statements. Appearances are deceiving: last year, we had practically no winter. Extremely mild. If I only take a moderately cold winter as standard, it comes to 130 euros upwards per month, just for hot water and heating.

Visually, we also did not like the decentralized air inlets. Ergo: if we build with this general contractor, only an air-to-water heat pump is an option. That is again a Nibe, an F2040-8 outdoor unit with VVM320 in combination. Central ventilation with counterflow heat exchanger, photovoltaic system and Tesla battery. That would then even be 40 Plus standard. From a business perspective, I won't recoup the extra cost, I know that, but solely because of the disadvantages of decentralized ventilation and the advantages of controlled residential ventilation (it is one, or is there more differentiation?). If I factor in the additional 5,000 euro repayment grant, the fun costs me exactly 10,000 euros more. A stove is no longer under consideration.

I am curious what the heat load calculation will show. The above combination seems more sensible to me than the pure exhaust air heat pump. My only concern is the noise development of the outdoor unit. Are there any experiences with the Nibe air-to-water heat pump? Regardless of the acquisition costs: do you consider the combination of components reasonable by comparison? And is the comfort gain from controlled residential ventilation also worth a thought besides the pure heating aspect?

Even if the photovoltaic system covers 100%, it would take 11 years for it to pay off. Questionable whether the battery would still be alive then.

Unless a Chinese mystery box is used, for sure. Panasonic® btw. guarantees 5000 charge cycles, which corresponds to a battery lifespan of about 20 years. Rhineland greetings

I am curious about the heating load calculation results.

Before signing the contract? This approach of the esteemed competitor colleague would actually be new to me. Rhineland greetings