Controlled residential ventilation with cooling: brine geothermal heat pump instead of air-to-water heat pump?

I will stick to an air-to-water heat pump, but as far as I know, this could also be completely replaced by a brine heat exchanger. With deep drilling, no problem at all. As a ground collector, as far as I know, also feasible, but probably not doable. You need really long pipes for that, and with today's small plots, it's not realizable.

Who says that? Define cooling. If you mean that it doesn't replace an air conditioner, then true. A controlled residential ventilation system achieves about 2-3 degrees, and thus a controlled residential ventilation system can cool. But yes, not comparable to an air conditioner that reaches a specific temperature (e.g. 18°C).

We are currently planning to preface the controlled residential ventilation system with a register that cools the temperatures slightly in summer. 2-3 degrees are completely sufficient for us because it makes a difference whether you have 26° or 24° in the room, and it's also better for the immune system ;-)

Just nonsense... the controlled residential ventilation system maybe has 60 watts and is supposed to reduce the air circulation in the entire house? Every person present already produces approximately 60 watts of waste heat alone. The controlled residential ventilation system reduces nothing... not even in a noticeable way. That is total nonsense!

What does the performance of the Controlled Residential Ventilation have to do with cooling? Of course, the Controlled Residential Ventilation does not cool, but it distributes the cooled air. The air can be cooled beforehand either via a ground collector or a register. For example, if the outside air is 35°C and the room temperature is 28°, it already makes a difference if, instead of 35°C air, only 26° cooler air is drawn in through the Controlled Residential Ventilation. The cooling does not occur through the Controlled Residential Ventilation.

That still has nothing to do with "cooling," but with preventing the controlled residential ventilation from "heating" :) It is also called Sommerbypass ..

Another example: If we heat up the living room to 25 degrees using the fireplace and the bedroom is at 16 degrees (we had that the other day at minus 10 degrees).. what do you think? Does the [Kontrollierte-Wohnraumlüftung] warm up the bedroom even by 0.1 degrees? It does not..!

This still has nothing to do with "cooling", but rather with preventing the controlled residential ventilation from "heating" :) It is also called summer bypass ..

You are confusing something here. A summer bypass means that heat recovery is not activated during the summer nights so that as much cold air as possible comes directly into the apartment instead of being preheated like in winter. In summer, heat recovery can also be used during the day to use the cooler indoor air to cool down the warm outside air. Like in winter, just the other way around. That has nothing to do with cooling, that is true.

We are talking here about a ground heat exchanger or a cooling coil that cools the outside air before it enters the controlled residential ventilation.

I also don’t understand what you mean with your example living room/bedroom. If you know the setup of a central controlled residential ventilation, then you know that the room temperatures of the individual rooms do not influence each other, because the air from one room is not blown into another room. That would be something else, the exhaust air from the kitchen heats the bedroom and the exhaust air from the guest bathroom the living room. But you have already noted that the controlled residential ventilation does not warm the bedroom by 0.1 degrees.

Ok. Then I mixed that up. But I stick to my opinion: cooling with the help of [Kontrollierte-Wohnraumlüftung] does not work... the air that the [Kontrollierte-Wohnraumlüftung] circulates... is ridiculous. Everything else is more like marketing talk from the seller.. If it is hot for a longer time in summer (like last summer), your place will eventually get very warm too. Whether it’s 26..27..28 degrees doesn’t matter at all. It is very warm.. and only one thing helps: air conditioning!