Ice storage in prefabricated house (new construction) - provider

There is no problem with condensate. Even if some calculate that the floors would get wet. I have been cooling like this for 4 summers and have never had any problems

actually there is no condensate, the system regulates timely so that none is created. (I am not a plant technician, this is how it was explained to me or how I understood it). I only have cold feet in the bathroom, the rest is designed as wall heating (or cooling).

There is an internal sensor that measures temperature and humidity. The system automatically regulates down in case of condensation risk.

Where are the values measured? In the room air or in the screed? Measuring humidity in the room air makes little sense at least, doesn’t it? By the time it reflects in the room air, the dew point in the screed may already have long been undershot and moisture is spreading. There are tons of opinions on this in various forums. Some also report problems with moisture, musty odors after longer operating times and corresponding climatic conditions. We have also ordered the pre-installation for cooling via underfloor heating from the general contractor, but honestly, I’m still not entirely convinced about the topic. An acquaintance placed moisture sensors under the screed in the insulation layer and distributed them across different rooms. He justified this by saying that condensation occurs where the temperature difference exists – in the floor structure – and if this is not detected and counter-regulated, moisture ingress repeatedly occurs. The calcium sulfate screed will certainly not be happy about this moisture in the long run. This is less of a problem in cement screed, maybe that’s why it works better for some over longer periods than for others? The costs compared to active cooling via air conditioning are of course “tempting.” We might leave it at the pre-installation for now and see how well we generate tolerable room temperatures with external shading. Edit: Our general contractor does not want to assume any warranty if cooling via the underfloor heating is implemented and damage occurs due to cooling in the floor structure.

actually there is no condensate, the system regulates in time so that none forms

The system doesn't regulate anything. The corresponding thermostat would simply close if the humidity became too high. That's sufficient in the air, as the temperature drop can be taken into account. But it's pure theory, it has never happened to me.

The costs compared to active cooling using air conditioning are of course "tempting"

You can't compare that. Underfloor heating usually achieves 2-3K. That might be enough for better comfort, but it is no comparison to air conditioning, which above all also dries the air. In operation, passive cooling is almost free. A few circulating pumps, done.

Where are the values being measured? In the room air or in the screed? Measuring moisture in the room air makes little sense, doesn’t it? By the time it shows up in the room air, the dew point in the screed may already have been breached long ago and moisture is spreading.

That’s why I wrote: In case of condensation risk and not only when the sensor is soaking wet.

Our general contractor does not want to assume any warranty if damages occur due to cooling in the floor structure when implementing the cooling function via underfloor heating.

That was never a point of discussion with us, maybe also because cement screed was used.

As I already wrote in the other thread, it definitely depends a lot on the location. In more humid areas, an explicitly dehumidifying system that also provides the corresponding cooling capacity would certainly be appropriate. Here with me at 550m above sea level in the Alpine foothills, the weather is simply different than in Cologne on the Rhine.

But my main concern was actually the question asked from many sides why it absolutely has to be an ice storage system. We are all still waiting for an answer to that.