Comparison of geothermal heat pump with LWW pump

You want to compare passive with active cooling? The power consumption differs immensely. The cooling performance is limited by the dew point in both cases.

General question regarding this: Cooling using underfloor heating. Heating, ok. The floor is 2-3° warmer than the room, heat rises, the screed releases the heat into the room. But: why does the screed also release cold to the room? Isn't that significantly more energy-intensive than heating?

You want to compare passive with active cooling? The power consumption differs immensely. The cooling capacity is limited by the dew point in both cases.

Actually not. As far as I know, I can hardly or not at all achieve a cooling effect with the air-water heat pump (e.g., in midsummer). With the brine-water heat pump, I can achieve passive cooling. That's why I wanted to know if that is true? It's not insignificant in times of climate change.

Regarding the heat pump, I can't tell you anything about that, but the underfloor cooling works OK. We have it in the office. The first summer it was not active/installed (landlord and craftsmen claim different things ;)) it was almost unbearable, the second summer with cooling it was significantly better. However, it still remains warm and you have to keep the windows closed from late morning onward, otherwise it doesn't work. And if you don't properly shade, it doesn't work at all.

I don’t quite understand that. So you actively cool down?

But: why does the screed also release cold into the room? Isn't that significantly more energy-intensive than heating?

The screed does not release cold but absorbs heat and transports it to the heating system. There, the heat is transferred to the medium (brine or air) via the heat exchanger.