Summarizing for me, on the one hand, it is discussed whether cooling via the underfloor heating brings a temperature difference of 2-3 degrees or then actually a full 4 degrees and is therefore a cost-effective alternative to a real air conditioner from a cost-benefit perspective. Or whether only the air conditioner cools in hot summers and noticeably dehumidifies the air.
For me, the discernible calculation formula from the discussion is: In a hot summer with an outside temperature of 37 degrees, every degree Celsius costs a thousand. Cooling via underfloor heating with 2-3 degrees thus costs 2,000-3,000 EUR (in one post even 4,000 EUR), the air conditioner over 13-16,000 EUR. Whoever feels comfortable at 33-35 degrees indoor temperature is satisfied with the 2-3 thousand EUR, whoever would like 21-24 degrees must put a five-digit amount on the table for cooling their single-family house. But these will always be two different things, both in terms of effect and price. Comparing both, I find is nonsense.