Room Thermostats Heating/Cooling

@Axel85: Theoretically, the flow temperature could be lowered significantly, but condensate would form at the bottom. Nevertheless, there is some effect. 3-4 degrees are definitely achievable, and in my opinion, that is enough in summer.

The problem will only be if all the thermostats are simply turned up all the way, then basically no regulation is left. At night, for example, the heat pump also runs, and with temperature fluctuations, you would constantly have to adjust the flow temperature in summer. Or?

Do you have additional shading in summer?

Alex, that works wonderfully with an air-to-water heat pump. It’s called active cooling and provides more than just the passive cooling via brine.

You really have to explain that to me in more detail. I still don’t get it. :) You have to bring the warm indoor air to the water in the surface heating. That’s the crux. The heat pump can only transfer the heat from the water to the outside air. The brine-to-water heat pump would clearly have the advantage here, since the cold brine provides a medium to lower the temperature of the water in the surface heating.

Or do you mean by "active cooling" the blowing of cooled air into the indoor rooms and/or cooling down the water in the underfloor heating? Then we are no longer talking about a reversible heat pump but an air conditioning system?!

Where does the cold come from? :)

The underfloor heating releases energy to the indoor air in winter, and in summer it extracts energy from the indoor air. The only small difference is that warm air rises upwards. Cold air sinks to the floor. However, since gases tend to assume a homogeneous state, the effect at today's supply temperatures is not that dramatic.

The underfloor heating releases energy to the indoor air in winter, and in summer it extracts energy from the indoor air.

But only near the floor...

The only small difference is that warm air rises. Cold air sinks to the floor.

Unfortunately, this is not a small difference, but the biggest difference and also the biggest problem. For this reason, cooling ceilings are usually installed instead of cooling floors to effectively cool buildings.

That a heat pump can do this is of course not bad... nonetheless, the hoped-for effect will fail to materialize.