Air intake in light well?

Well, these are the problems I see with intake in the basement without towers – we have the same problem with the chimney fresh air.

Besides, I would never draw air from floor level

Towers look really bad, shafts are better. But you say floor-level intake is not good. Again a dilemma, so an alternative would be in the attic.

On the other hand, I was at my brother-in-law’s yesterday, he has an LWZ403 in the basement, intake around the corner via basement shafts.

Basically it works for him. However, a few negative aspects:

During construction, one of the shafts once filled up completely and everything entered the unit. Someone from Stiebel Eltron came, took the device apart and cleaned it, everything works again, that was 10 years ago. The only protection against backflowing water is that the duct is open downward so it can drain. Since then no further incident. Personally, that seems a bit risky to me.

On level 3 of 3 you could clearly hear the system outside if you were quiet. On level 1 of 3 only when you got close (for me a question, because I want to place my terrace there). The air outlet seemed louder to me than the intake.

Inside it is similar. On level 3 it's clearly audible, at level 1 there is a quiet rushing noise. Breathing with an open mouth while sleeping is louder than that.

At some ceiling outlets you can clearly see dirt on the surrounding wall/ceiling. You can easily wipe it off but it’s there. I wonder if increased dirt is promoted by floor-level intake. He changes the filter regularly, so some dirt always gets through.

He especially dislikes the dryness in winter. On average, according to the hygrometer, humidity is <20, with really freezing temperatures even less. Two humidifiers had practically no effect after several weeks of use. In some places, the plaster cracks, veneers warp. The house is too dry. But that is not the topic of this thread here.

The intake should also be at least 2 m above ground level. Today, I would recommend the enthalpy heat exchanger (i.e., with moisture recovery). That’s also what my colleague says, with a roughly 10-year-old controlled residential ventilation system without moisture recovery in a passive house... they also had humidifiers set up in winter (however, they had very good experiences with them, the devices also filter dirt from the air, a side effect).

Outside, at the openings for supply and exhaust air, our system is also most audible (and of course in the utility room next to the device). I definitely wouldn’t want that on my terrace. Here it is on the front of the house, visually of course a matter of taste, but everything else is fine.

Since we don’t have perforated valves, I can’t say anything about the other things, but yes, over time the airflow might possibly leave its marks there.

He especially dislikes the dryness in winter. On average, according to the hygrometer, he has <20 humidity, even less at proper subzero temperatures. Two humidifiers have practically had no effect after several weeks of use. In some places, the plaster cracks, veneers warp. The house is too dry. But that is not the topic of this thread.

We have planned the controlled residential ventilation system to protect the house from damage caused by moisture. If the air is too dry, why not simply set the system to a lower setting or turn it off completely for a while?

well, if the device is in the basement, which is an option for many, then the pipes would have to go through the living room or whatever is directly above.

I just thought of another question.
A GU planned two basement shafts for supply and exhaust air.
However, the room was supposed to already have such a light shaft.
Does it make sense to use separate shafts there or should they be separated?

Does it make sense to use separate shafts there or should they be combined?

Huh?

I would separate supply air, exhaust air, and lighting.

If the air is too dry, why not simply switch the system to a lower level or turn it off completely for a while?

Somehow you still have to ventilate, and dry air in winter is not a new phenomenon (in the past, when the house was so drafty, we still hung water containers on the radiators that provided additional moisture; those were real finned radiators that got really warm). Today, you can choose the simple solution, so to speak, all-around carefree, namely controlled residential ventilation with heat recovery and moisture recovery.