Controlled residential ventilation in winter, dry air, what can be done about it

Internet prices for the enthalpy variant are unfortunately still somewhat higher, sometimes even by the entire amount of the heat exchanger, which I find quite cheeky. Then I'll get this one for retrofitting and keep the other for hard times or try it on Ebay.

Usually, the simple cross-flow heat exchangers also do not consist of just one piece of sheet metal.

That is known to me, sorry if I was imprecise in the short time. Apparently, the only difference is the material from which the heat exchanger is made. And a membrane is simply more expensive (because it is more complex to manufacture) than a "sheet metal," even if it is a specially profiled one for a plate heat exchanger.

Both are polymer plates, each only once flat, impermeable, and untreated. Only the housing is made of sheet metal.

I once read that some people install the moisture recovery element in new buildings only afterwards because of the high humidity in new buildings. I have no experience with this, as we are still planning the new building ourselves.

That is nonsense. You don’t buy a car with a smaller engine and then replace it with a bigger one after 2 years.

The possibility of moisture recovery through a heat exchanger is limited. Thus, the moisture that is "too much" is vented out with or without an enthalpy exchanger. Provided the system is running continuously.

I once read that some people install the moisture recovery element in new buildings only afterwards due to the high humidity in new buildings. I have no experience with this myself, as we are still planning the new building.

We were also talked into it. The end of the story: After 4 weeks in the new house, I ordered and installed the enthalpy exchanger. About 900 EUR.