LWZ 504 with or without buffer tank

In addition to the summer cassette The summer cassette automatically turns the ventilation off and on in summer. Off when the outside air temperature is higher than the inside air temperature and on when the outside air temperature is at most the inside air temperature

Ah ok and will the summer cassette be integrated into the "cabinet"? Can I do that myself? How much does it cost approximately?

Regards

PS: and on the topic of funding. I have read several times that people did not receive the BAFA funding even though the application was submitted on time. In these cases, it apparently failed due to the annual performance factor. So what must the heat pump look like to ensure I definitely get the funding?

Yes, you can change it yourself. It's not difficult and doesn't take long. On YouTube you can find videos. I mean, it was explained on the 304. No idea what they cost individually. It was included with us.

Can no one help me with the annual performance factor? So can I just specify something standard, is there a fixed subsidy for the 504 regardless of installation conditions? Or do I have to calculate and prove something...?

In the online application of Bafa, it already says that air-to-water heat pumps are not eligible for funding - which probably applies to most. But obviously many have already received funding for the LWZ 504.

I don't really know how to approach this...

In the online application of the Bafa it already says that air-water heat pumps are not eligible for funding

Where does it say that? I only read that air-air heat pumps are not eligible for funding.