Why is shading particularly important in newly built houses?

It's interesting for all NRW residents

There is a general subsidy. At Helios, the individual approval didn't cost a cent - it was just initially unclear and a bit annoying due to the waiting time. The service at Helios is not only top here but above all fast!

Differential pressure switch = pressure monitor = Why connect it? You can do it that way, but any ordinary pressure monitor simply cuts off the power supply and that's that. I wouldn't pay any attention to it...

Why your installer doesn't know anything about it, I don't know either - really marketing is not meant for the subsidy.

I assume that the Vallox has the DiBT approval and the Brötje (not yet) does not. That's why he might have concluded: There's a 1000 EUR subsidy for the Vallox, but not for the Broetje. Which, if I understand you correctly, is wrong. I should ask him what exactly he meant/thought. The contract with the installer has already been concluded a long time ago and the pipes have already been embedded in the KG and EG ceilings. From what I quickly read, all the funding stuff must have been done beforehand, so the whole topic is basically over for us.

The Brötje was our alternative, and the post-cooling and free cooling also sound like that to me from our offer.

Yep, unfortunately that's the case with all funding - if you stick to the official route.

Night cooling is the activated bypass, where heat recovery is deactivated. Activating the heat exchanger during the day is called "passive cooling" or "heat protection" by some. Inside, the air is cooler than outside. When both then go through the heat exchanger, the outside air transfers its energy to the exhaust air.

Correct. The heat exchanger does not care at first on which side it is warm or cold. Heat always flows from warm to cold.

In some cases, even warmer air went outside than was already outside.

But then via the bypass.

Then but over the bypass.

No, over the heat exchanger. But you are right, it doesn't make sense, it was a thought error. In this case rather a measurement inaccuracy of the sensors.