Vestaxx window heating - experiences?

The niche exists, but it doesn’t fit into marketing. The niche for window heating is – like for infrared, air heating, etc. – a house close to the passive standard that hardly needs heating. For such a house in the highest price category, I am no longer allowed to argue that the builders cannot afford photovoltaics. The category of builders with little money is certainly more efficiently covered by the Building Energy Act + underfloor heating + Daikin heat pump.

I will then add the required maintenance costs and a variant without photovoltaics to my calculation to have all variants clearly together:

150m² with 40kWh/m²a -> 6000kWh/a heating energy demand
10kWp photovoltaic + 5kWh storage -> ~15kWh/day in Nov, Dec, Jan, Feb. With 10kWh for household electricity including hot water, 5kWh/day remain for heating.
The costs of photovoltaics are not listed in this example, as the system already finances itself through feed-in tariffs and savings on household electricity.
I leave out hot water costs in each case, as both systems can provide this with a COP of 4 and thus make no difference; the electricity for hot water is included in the household electricity calculation.
Electricity purchase price 35ct/kWh
Feed-in tariff price: 8.2ct/kWh
Interest rate 3.5% (current rate for 10-year fixed term)
Electricity price increase 6% (average of the last 20 years)

Vestaxx + Photovoltaics:
Additional cost compared to normal windows: €10,000
Purchase and installation of BWWP: €5,000
Interest on purchase over 18 years: €5,239
Maintenance BWWP: €200/year
4 [months] * 30 [days] * 5 [kWh/day] = 600 [kWh] from photovoltaic electricity
Remaining 5400kWh as purchase
Totals (average, due to rising electricity prices) 5400*(35+35*1.06^18)/2+600*8.2 = €3,691/year
After 18 years this amounts to: €90,286

Heat pump + Photovoltaics:
Hydraulics: €80/m² * 150m = €12,000
Purchase air-to-water heat pump monobloc and installation: €20,000
Interest on purchase over 18 years: €11,176
Maintenance air-to-water heat pump: €250/year
Electricity demand: 6000/4 = 1500kWh
Remaining 900 to be purchased
Totals (average, due to rising electricity prices) 900*(35+35*1.06^18)/2 + 600*8.2 = €656/year
After 18 years this amounts to: €59,488

Vestaxx without Photovoltaics:
Additional cost compared to normal windows: €10,000
Purchase and installation of BWWP: €5,000
Interest on purchase over 18 years: €5,239
Maintenance BWWP: €200/year
Totals (average, due to rising electricity prices) 6000*(35+35*1.06^18)/2 + 600*8.2 = €3,691/year
After 18 years this amounts to: €94,558

Heat pump without Photovoltaics:
Hydraulics: €80/m² * 150m = €12,000
Purchase air-to-water heat pump monobloc and installation: €20,000
Interest on purchase over 18 years: €11,176
Maintenance air-to-water heat pump: €250/year
Electricity demand: 6000/4 = 1500kWh
Totals (average, due to rising electricity prices) 1500*(35+35*1.06^18)/2 = €1,011/year
After 18 years this amounts to: €65,878

This results in additional costs for Vestaxx in this example of €30,798 compared to the heat pump.
So for 18 years, pay €142 more per month without having the underfloor heating remaining at the end of the term!
All the money is gone to the energy supplier and mostly turned into CO2.

Some things are left out here (costs for underfloor heating)

Heat pump + photovoltaic:
Hydraulics: 80€/m²*150m=12,000€

Heat pump without photovoltaic:
Hydraulics: 80€/m²*150m=12,000€

- Prices for heat pump beautified

Purchase of air-water heat pump monoblock and installation: 20,000€

- Maintenance costs indicated that do not occur

- house electricity left out again -

Photovoltaic yields calculated over 30 days with 5 kWh/day and 4 months, etc. etc.

Studies and measurement series have been carried out comparing IR heating with heat pumps.
It says, among other things:
In new buildings: -> Whoever says infrared heating - must also say photovoltaic!
In old buildings: -> Whoever says infrared heating - must also say photovoltaic plus heat pump!

What I have already written here several times: In old buildings, the heat pump makes sense again - in new buildings it does not. Period!

Things are being left out here (costs for underfloor heating)

Prices for heat pump beautified

Maintenance costs stated that do not occur

The household electricity left out again

Photovoltaic yields calculated on 30 days with 5 kWh/day and 4 months

That's an understatement, otherwise you wouldn't have been able to convince anyone. :)

Oh, for the first time "he addresses my calculation," if numbers and sources follow now, I am happy to post the calculation again with different values. Otherwise, I will post it again as it is. In expert circles, underfloor heating is also called hydraulics and is of course included: . €20,000 for a heat pump including installation is already a lot and can be found by many experts as such (and even lower). It’s about maintenance costs. Air-water heat pumps and groundwater heat pumps are basically maintenance-free. However, with both, pumps, valves, etc. can break down over time, which is accounted for by maintenance costs. Otherwise, please provide a reason or source why an air-water heat pump has maintenance costs but a groundwater heat pump does not. ;) I already explained that. Household electricity does not affect the heating systems, only the photovoltaic system does. Photovoltaics are listed once in both cases and once omitted. This is an invalid conclusion. Just because A implies B, it does not follow that B implies A. Just because people always say photovoltaics, it does not mean they always mean infrared heating. Various calculations have shown exactly the opposite by now.