Ceiling valves in style - does such a thing exist?

Even though the normal, white ones appear unspectacular, this also has an advantage: they blend into the white ceiling. The attention should rather fall on the lamps than on the ventilation outlets (or smoke detectors, presence detectors, ... whatever else one might have).

Behind the slots is a 40x20cm box with a flap that can be adjusted.

is right, invisible would of course be better but unfortunately that is not the case with the usual vents.

These are our rectangular ones and made of aluminum. I would have to look up the names. If there is interest

Yes, gladly, even if my wife doesn't like aluminum silver look, but maybe they can be painted...

Exactly, invisible would be best, our ceiling lights will unfortunately be very plain LED panels (although that is certainly something to reconsider) and therefore not very distracting.

I had already asked if the valves exist as a combination with smoke detectors. My HSL does not know such a thing. That would actually be a market gap...

My HSL doesn't know such a thing. Would actually be a market gap...

Take a look at the filters of the exhaust air valves after a few weeks. We were shocked. Such a smoke detector is supposed to last 10 years, it would quickly be completely clogged. It doesn't work with the supply air either, as the smoke would be blown away.

Oh, I hadn’t thought that far to actually "in"tegrate it. I meant more to just put the sensor on the outside. With a model where the airflow is blown in/out more sideways. Just so you only have one unit on the ceiling and not two right away...

Of course, it's a matter of taste, I find the white round ones from Zehnder visually very appealing.

With such slots, I wonder how the regulation works? With the round ones, there is a scale inside for adjustment...

I can only recommend the Luna from Zehnder as well. Apart from that, after 3 days in the new house, you don’t even notice it anymore, like so many things you worry about beforehand ;)