Ventilation system in the warm summer

Better controllable, dehumidification, coolness is properly distributed, powerful…

Absolutely agree, no question. I can sign off on every point.

One huge advantage of cooling via the heat pump: it cost me exactly half the price difference between normal room thermostats and cooling-capable thermostats for the whole house, so if I remember correctly, 200.- for that, I don't install a real aircon in every room in the house.

The waste heat goes into the pool.

I would actually love that too – currently the waste heat is simply blown out and I find that a shame, at least in the weeks when I have set up a pool. For my short-term pool operation, the effort would be disproportionate, but if you keep the pool standing all year round then it naturally looks different.

You can't cool effectively with a normally sized controlled residential ventilation system. It has to be significantly larger dimensioned.

So I cool the (of course already very well insulated) house constantly to 22° in the summer, and I don't care whether it's 32° or 34° outside. That's certainly not just the cooling alone; when it's cool in the morning during summer, I sometimes do a complete chimney draft from bottom to top from 6:00 to 6:30, the south-facing windows are shaded with blinds, over the terrace doors I have installed a large balcony that prevents any sun from hitting the windows in the summer and lets sunshine in nicely during winter... So at least for my setup I have to say: the cooling capacity is absolutely sufficient, I really don't want it any colder. Yes, of course, it depends on how the system is dimensioned.

With ventilating in the cool morning hours, shading and buffering via the FB, one can achieve between 2-5°C when it is hot outside for a longer period. Of course, this is relatively inexpensive to implement compared to a proper air conditioning system. That is the disadvantage of modern and well-insulated houses. Our system is an exception and is rather used in office buildings, etc. Waste heat in the pool only makes sense with permanently installed pools. Our waste heat is not enough for heating but only buffers a little. A small pool can also quickly become too warm.

One huge advantage of cooling via the heat pump is that it cost me exactly half the price difference of the normal room thermostats to the cooling-capable thermostats for the whole house, so if I remember correctly, 200.- and for that, I don’t install a proper air conditioner in every room in the house.

That’s roughly like me arguing: "One huge advantage of moving boxes is that they cost me a fraction of the price of a wardrobe."

Basically, that might be true, but the performance comparison just isn’t meaningful. I can buy a living area cooling system for several thousand euros, or get cold feet for 200 euros. I could use the first, but for the latter, I’d prefer the 200 euros. ;)

I am glad that I do not live in a submarine, or respectively in a plastic bag. Single-family house built in 1978, reasonable windows, reasonably insulated, currently 21.7 degrees in the well-ventilated bedroom. I believe that excessive insulation is not conducive to a pleasant living climate

I have no heat problem in my modern submarine or plastic bag and no cold problem in winter.