ᐅ Heat Pump: Domestic Hot Water with Storage Tank or Tankless Water Heater?

Hello,
I am planning a 250 sqm (2,690 sq ft) single-family house with two bathrooms and two additional restrooms.

The heating system will use a heat pump combined with photovoltaic panels and a battery storage system. Heating is provided by underfloor heating.

What is considered state-of-the-art heating technology for domestic hot water?
Should I use a hot water storage tank connected to the heat pump, or an instantaneous water heater, such as a so-called fresh water station?

What would you recommend?
Thank you!

tourmalet schrieb:

What is considered "state-of-the-art" heating technology for domestic hot water? Should I use a hot water storage tank connected to the heat pump or an instantaneous water heater, also known as a fresh water station?

Both.
Both options have their advantages and disadvantages. In terms of use and the final result—sufficient hot water—they are comparable with proper planning. However, fresh water stations are generally more expensive to purchase.

nordanney schrieb:

Both.
Both options have advantages and disadvantages. In terms of use and the final result of "sufficient hot water," both are equal with proper planning. However, a potable water system is more expensive to install.

Thank you.
What would roughly be the pros and cons?
What would you install in my case?

tourmalet schrieb:

What would roughly be the pros and cons?
What would you install in my case?

Many years ago, I read about a third option here in the forum. I can’t say whether it makes sense or not. It definitely hasn’t become widespread, probably because it’s simply more expensive and requires more space.

In addition to a (dedicated) heating heat pump, install another heat pump for domestic hot water generation. The indoor heat from the utility room, generated by appliances like the washing machine, dryer, heating system, router, etc., should be used to produce the hot water. In summer, the heating heat pump can be completely turned off, and the hot water heat pump will also extract some heat from the house. Both heat pumps could be designed smaller and operate more efficiently.
Does it work? – No idea.

The first part of my post was lost:

The tankless water heater is usually installed close to the point of use, so hot water is available immediately. With a central heat pump, the pipe runs are long before hot water arrives, or an additional circulation line with a pump must be installed. However, the heat pump uses energy more efficiently.

This often means:
Heat pump: higher water consumption
Tankless water heater: higher energy consumption

tourmalet schrieb:

What would roughly be the advantages and disadvantages?

Advantage of a hot water storage tank: inexpensive, works well
Disadvantage of a hot water storage tank: risk of Legionella bacteria (but this is mostly theoretical)
Advantage of instantaneous water heaters: very hygienic, works well
Disadvantage: significantly more expensive