Which storage/drinking water heating is used in district heating?

I would go for a hot water storage tank. But 160l is empty after the bathtub. You would need to check how long it takes for the water to warm up again

We thought so too, but that's not true and depends on the water temperature in the tank. Do you bathe at 55°C? Probably not. We have a 120l tank. It only becomes tight when the kids have bathed (constantly running the water) and two people want to shower afterwards. 1x bathing + 1x showering directly one after the other or simultaneously is no problem. Also 3-4x showering directly one after the other works without problems.

Hmm, sounds like an Inuit family. I have 190l and 49°C (there should even be more thermal energy). If I or the little one had a bath, my wife cannot shower immediately afterwards. I might be able to shower after a bath (I shower colder than the two), but without hair conditioner.

The problem is not just the pure amount of hot water, the problem is that cold water immediately flows back into the tank. Cold water is about 15 degrees. If you now fill the tub with 40 degrees, you need about 2/3 hot water at 55 degrees. And then it’s a calculation exercise how big your tank has to be so that afterwards more than lukewarm water comes out.

Whereby it does not completely mix either. If the tank is not constructed completely poorly, the fresh water comes in at the bottom. Then it should still be relatively warm at the top. But yes, the more you have already used, the colder the rest becomes. But yes, I would say 160l is a bit too little for 4 people. On the other hand, I find 500l a lot.