Shower buffer storage

Hello everyone,

a buffer tank with 150 liters has been planned for us, and there are a total of 3 showers under construction, of which I would like to be able to operate at least 2 simultaneously with hot water.

Raindance overhead showers with a water consumption of about 15 to 17 liters / mixed water consumption per minute are planned everywhere (1 x S300 and 2 x S120).

Hot water is generated by the Cerapur module 9000 i type GC9000iWM20/100S23 (max. nominal heat output (hot water) is 30 kW). According to the manufacturer, up to 15 liters of hot water per minute will probably be produced.

That all sounds plausible to me. But since I don't want to be wiser afterwards, it would be nice if someone from practice could report whether it really doesn't get cold in the shower.

Wrong topic... unfortunately I have nothing to contribute.. we have water-saving shower heads and a compact WP .. it hardly gets further away from your question

Seriously? No calculator at hand?

150/30=5

5×15=75

75/30=2.5

2.5×15=37.5

So I estimate that after 8 minutes the storage is empty.

If production and storage are warmer than the shower consumption, you will probably last even longer.

I think it will work in the normal case, because people will hardly coordinate that much while showering, let alone shower synchronously for 20 minutes.

hm no bathtub? then the 150 liters run out quickly....

I think we have 250 liters and 2 showers. My wife really enjoys showering and for a long time

Calculated the other way around, the hot water production manages to operate one shower continuously. So the storage must be sufficient for the second shower process. 150l at 50 degrees is maybe 250l at 38 degrees... so also game over after 8 minutes.

As long as person No. 2 manages with 10 minutes, it should be sufficient in my opinion.

Our 250l tank only starts to struggle when the shower and bathtub are running simultaneously and the bathtub is repeatedly refilled for an hour.

And then only because we disconnected the electric instantaneous water heater in the heat pump.

Well... as written at the beginning, it's not about the calculation experts who were already active anyway, but about practical experience with 150 liter storage.