ᐅ Ground source heat pump primarily used for cooling – does that make sense?

Dear Forum,
we are building our first house. I am a layperson, not very technically inclined, and apparently looking for a solution that doesn’t quite follow the usual standards. Usually, there are good reasons for that, which I don’t fully understand yet. That’s why I’m posting my question here and hope for your expertise.

For our new build, I am mainly looking for a cooling option using surface heating systems (underfloor and ceiling heating), as I don’t want an air conditioning system nor exposed pipes inside the house (which is also why I don’t want a mechanical ventilation system). I guess I am a very old-fashioned person: I open a window and it gets cold, I turn the radiator and it gets warm, I light a fire and it gets hot. I understand that this might be a disaster in terms of efficiency, but automatic/central controls and linkages, for example using an outdoor thermostat with underfloor heating in all rental homes we have lived in so far, always lead me to bypass them somehow by keeping about one-third of the windows tilted open almost all the time (which makes the formal energy efficiency completely pointless). Probably, my perception of temperature is very subjective and fluctuates more than the actual measured temperature. In general, all modern well-insulated new builds feel way too warm to me, and I’m a fresh-air enthusiast who loves open windows! Unfortunately, I also don’t find that a mechanical ventilation system gives a subjectively comparable effect to frequent airing by opening windows wide.

Now to the question: since I mostly find the temperature bearable only in the basement during summer, we are considering installing a cooling option. Since air conditioning and mechanical ventilation are out of the question, the only remaining option seems to be a heat pump with cooling function, which we would of course also use for heating. We plan to drill ground probes (geothermal probes) and most likely install underfloor and ceiling surface heating.

My main concern is that even if we install a modern heat pump, we might not use or benefit from the technology properly. Our focus is not primarily on a specific energy efficiency level. If we omit mechanical ventilation, it seems there might be risks of condensation and mold? Then I would keep windows open permanently as before (which does not bother me personally), but of course, this would cause huge energy waste, as the automated heating, cooling, and heat pump would constantly be working against my “manual interventions.”

Does it make sense to install a geothermal probe and brine heat pump mainly for cooling under such ventilation behavior and without mechanical ventilation?

Many thanks, and please don’t be too harsh right away. Maybe in the end I will come to accept the apparently modern and energy-efficient full setup of heat pump plus mechanical ventilation — or we will put electric heaters or coolers in individual rooms as needed, or... or?

Good luck!