Control climate with underfloor heating or via the ventilation system?

Good day,

I have already paid attention to the summer thermal protection under the roof (rafter insulation with wood fiber boards and rock wool), but I fear that this won't help in the long run .

There is a principle in our industry that we rarely agree on. "You can protect a house against almost everything and anything, except heat"

In this respect, I agree with 'Mycraft'. "If you struggle with sleep during high summer temperatures, only an air conditioner can help; regardless of whether it is split or central."

Rhenish regards

I wouldn't install any if I thought it was sufficient as is – although the amplitude shift is already quite significant. I'm curious to see how it will actually be later... according to the Sanimann, the climate in our tiny parents' bedroom will freeze us into an ice block anyway.

That will be fine... my 3500W system cools the bedroom down to about 21°, but since the doors are always open everywhere, the surrounding rooms are cooled as well and then are around 23-24°. You can really notice the temperature boundary when you go upstairs... and since you have two, it will work similarly or even better.

No, at the top we have three boxes, at the bottom one - but already chosen according to the room sizes.

Only 10sqm2 cool down quickly ;l

How is the noise level of the split units? Can I place them on the garage that stands on the boundary without any problems, or will the neighbor complain (justified/unjustified)?

If I understood correctly, I should therefore leave the better insulation of the roof and plan about 7000 euros for the air conditioning of two children's rooms, the parents' bedroom, and the living room? Right?