Ventilation system in the warm summer

Even though it has absolutely nothing to do with the topic, I currently see many advantages of underfloor cooling:
- high efficiency: (air-water heat pump 5-7 COP, brine-water heat pump 50-200 through passivity)
- very cheap if air-water heat pump or brine-water heat pump is already available
- no dryness (air-air heat pump inherently reduces humidity. On humid days this is of course an advantage)
- silent
- no drafts (almost always present with air-air heat pump)
- maintenance-free (with air-air heat pump you should pay attention to hygiene due to resulting condensate, dust, etc.)

The disadvantage is the reduced performance at high humidity up to shutdown.
And those who do not like "cooler" feet will not be happy with it either.

it is right and important that you always point out the differences. However, often a sum is quickly reached that is not affordable. Then you really have to consider whether 200 euros might do as well - as a compromise.
Although is not wrong - it depends on where you live.
My Rhön is certainly not comparable to the Rhine valley.

I am now throwing out an outdoor installation that positively influences the microclimate. It does not replace any cooling, no matter which, but it is a building block so that not everything heats up so extremely. Allegedly, an up to 10 degrees lower ambient temperature is possible. How much can be achieved under realistic conditions (you can’t and don’t want to implement everything) remains to be seen. Everyone knows the pleasant coolness in the shade of a tree. It’s something different than a mere sunshade.
More information is available from "more green at the house" by the Verbraucherzentrale NRW - I find it very factual without eco-preaching.
Maybe one or the other measure will simply be taken - without breaking the bank.

The shutdown at high humidity was also my concern. In fact, I have 0-10 power throttlings per year due to high humidity; these are the days when we have a pool party and all the doors are open and a bunch of dripping wet kids keep running through the living room. The throttlings occur at times when I would reduce the air conditioning with the system currently under construction anyway. So yes, the throttling is present and works, but it does not pose a limitation for me in my situation.

Phew, I didn’t expect this to turn into such a discussion – but it is interesting to see. We feel like we are pretty much alone with our ventilation system in our new housing development. I have to agree with ... a lot more money flows into things like: interior design, painting, fireplace, etc... things that in my opinion should never be as important as a controlled residential ventilation system – but yes, tastes are simply different. Btw.: no idea who would sit in front of a fireplace with a tight building envelope? It feels like after 30 minutes it’s 28°C in the living area? :D I find it impressive how much money really still goes into areas like air conditioning, for example. But I think we should be happy with 22-23°C in the bedroom. Overall, that’s just complaining on a high level... in our old rental apartment, it felt like 28°C and absolutely bad air. Actually, you should appreciate the building envelope you have nowadays... the heat is stored extremely well, you act much more environmentally conscious, and need significantly less energy.

What I would wish for in my ventilation system is the ability to separate the exhaust air ducts so that not all exhaust air has to be channeled through the heat exchanger or bypass, but for example, in summer, to send "warm" rooms directly outside and only the "cool" rooms through the heat exchanger. Since the silencers are installed before the heat exchanger, I would probably need an individual control for each room... that would be very expensive and also really space-consuming. But in general, it would be nice if, for example, in summer, the exhaust air from the sauna/attic goes directly outside and in winter through the heat exchanger. Room upwards is always.

I'm glad that I don't live in a submarine, or rather 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 too much insulation is not conducive to a pleasant indoor climate

Well then, give yourself a pat on the shoulder.

Hmm…

The room is not even facing south and we have around 23 degrees in the room in the evening, although we open the windows wide in the morning, ventilate with cold air, and then close everything off to darken it.

Our bedroom in the attic unfortunately faces south. We ventilate in the evening, during the day the shutters are down. Nevertheless, or maybe because of that, it is actually not too warm to sleep. We have found that just 10 minutes of sunlight is enough to heat the room a bit, and you don’t get that heat out that easily.

I suspect that the ventilation system continuously blows warm air from outside (logically) into the bedroom, so the warm air accumulates in the bedroom.

A few days ago, when we had 26/27 degrees outside, I "bothered" myself (for this thread) and checked the ventilation in the bedroom shortly after 5 p.m.: definitely no warm air was coming out there, rather cool, so not cold, cooler than room temperature - I don't have exact temperature numbers, some values can be felt rather than read (house built in 2013, heating with controlled residential ventilation and heat recovery, just above Kfw55)
The tiles without air conditioning are also nicely cool and actually just right.