Here I wanted to give a final brief feedback:
The sauna is regularly in operation and we enjoy it very much. Especially the possibility to decide spontaneously in the evening to turn on the stove is really nice. :)
Unfortunately, we had quite some problems with the door. It was too open, which caused the warm air with moisture to escape. The anteroom got quite warm and water ran down the inside of the terrace doors. I have now gotten sealing lips from the glazier, which I installed on both sides; the top and bottom remain open. Now it is much, much better. They do not stand out at all as much as I feared.
Before, at 70°, the evaporator barely reached over 30% RH and ran almost continuously. Now I can easily set 70°/40%, and the evaporator switches on every 5-6 minutes for 2-3 minutes.
I am really glad about the decision to take a combination stove after all. I actually only use the sauna like that.
