ᐅ Control the climate using underfloor heating or through the ventilation system?

I tried that once. You get great cold air in the room with the indoor unit. To use it in other rooms as well, the temperature has to drop. Then it becomes unbearable in that room. It simply doesn’t work!
Multisplit systems or, if the pipe runs are too long, several small units are the way to go.
Monoblock units can be forgotten; even good devices (Siemens in my case) are extremely noisy and don’t provide nearly enough cooling capacity. Sleeping with such a device is not possible.

So, if the house is well insulated, you can cool the entire house with a ceiling cassette unit... you don’t need multiple indoor units, but you can install them if you want...

Whichever way you build it, both options have their pros and cons...

The operating and purchase costs are similar for both options...

For this, all doors need to remain open; nothing works individually anymore. In addition, the unit must have an adequate cooling capacity – so it's more likely designed for commercial use.

I would still not expect it for an entire house, but rather for one floor.

If it were possible to conveniently and comfortably control the temperature on a floor from a single location, you wouldn’t need to install radiators or underfloor heating in every room, but only in the hallway.

Sebastian79 schrieb:
For this, all doors need to be open; individual control is no longer possible. In addition, the unit must have the appropriate cooling capacity – so more like a commercial setup.

I still wouldn’t expect this for an entire house, but rather for one floor.

As I have found, around 3500 watts per floor is sufficient for a standard house… so nothing commercial… also, the doors don’t have to be open… I think you are installing a mechanical ventilation system with heat recovery, which already distributes the air since there are overflow zones or openings.

And you often mention yourself that large temperature differences from room to room are hardly possible with heating… well, practically the same applies when you cool the house…

We are talking here about air cooling with the worst heat transfer medium – and a controlled ventilation system with heat recovery actually cancels out that effect.

So you are mistaken – otherwise, in commercial areas, you could skip the numerous cooling systems and just install one system.