ᐅ Fresh water station and buffer tank: a technically better choice?

We have now decided on a ground-source heat pump. Two heating installers have offered different technical options:
1. Alpha Innotec heat pump with a 400-liter (105-gallon) domestic hot water storage tank and no buffer tank
2. Alpha Innotec heat pump with a fresh water station and a large 800-liter (210-gallon) buffer tank

Which option is preferable, or how can I evaluate the advantages and disadvantages?

800L buffer tank just for the domestic hot water? How many people do you plan to supply?

What flow rate do you need?

Are the 800 liters (approximately 211 gallons) for the heating circuit?

The 800-liter (210-gallon) tank, as I understand it, is for the heating system, and when fresh water is needed, this warm water is used for domestic hot water production through a heat exchanger/fresh water station. In other words, the water in the tank is not potable water.

Domski schrieb:

800l buffer tank just for the domestic hot water? How many people do you want to supply?

What kind of flow rate do you need?

Well, there are about 6-7 people in the two apartments. The buffer tank is actually just for heating.

If you need an 800-liter (210 gallon) heating buffer tank, option 1 is clearly the best choice!