It's the first time I own a dryer.
When I poured out the water it has collected (a few liters per run) I quickly tested the EC and pH and found out, that it is almost identical to the one made by my reverse osmosis filter!
No wonder, since the dryer is basically just a big distillation machine.
Thats super neat. It will save me a lot of work filtering tap water.
I will collect it from now on and use it for watering my plants.
Why does it matter?
Plants really don't like tap water. Even in a country like mine, where no chlorine/ fluoride/ whatever is added, the dissolved minerals cause trouble. They will build up over time and make nutrients unavailable, even if you adjust the pH.
The buildup and nutrient lockout will harm the plants a lot in the long term, and you will have way more trouble checking and correcting EC and pH.
This is one of the newest generation heat pump dryers. Very energy efficient, since we in Germany desperately need exactly that...
It basically heats up air at one end, blows it around internally all the time, and then on the other end is a cool trap that removes all moisture from the warm air.
Said water is collected in a drawer-container and supposed to be discarded.