Solar & water-guided heating insert

Hello everyone,

we are currently planning our new single-family house. We are building a solid house (MZ7 stone); in terms of standard, we will probably achieve Kfw55 / Kfw40.
So, it is a well-insulated house. We are a household of 4 people.

For the heating system, I am planning a wood insert stove (on the ground floor) with a water jacket. In terms of output, it will probably be a stove around 10KW with a water portion of up to 70%.

A solar system (15-20 sqm) will be installed on the roof, which is intended for hot water and heating support. We want only one storage tank. So, a buffer storage tank with an integrated domestic hot water tank (coil in the upper area).
An electric heating element will also be installed in the buffer storage tank, which is intended for emergencies. In case we have no sun and do not want to heat with wood.

About 200 sqm of space need to be heated. We have underfloor heating throughout the house.

The solar system goes on the roof (southwest orientation). We have a total of 40 sqm available here. The rest, which is not needed for hot water, we will equip with photovoltaic modules for electricity generation.

I wanted to ask who has experience with such heating concepts and maybe has a few tips for me.
What do you think, is the output of the stove sufficient?
How big should the solar area be?
How many liters should the buffer storage tank have?

Thank you very much for your help.

Regards

Michael

Hello,

... We are building a solid house (MZ7 stone); from the standard, we will probably achieve KfW55 / KfW40.... So it is a well-insulated house.

The respective standard is not determined solely by the thermal envelope of the building. ;)

... The solar system goes on the roof (southwest orientation). ... The rest that is not needed for hot water, we equip with photovoltaic modules for electricity generation.

Has the whole thing ever been balanced by a professional or are these personal assumptions?

... What do you think, is the stove’s output sufficient? How large should the solar area be? How many liters should the buffer storage have?

These questions will be clarified by the MEP planner, although I am almost certain that a small heat pump + photovoltaic system would probably be the better concept. ;)

Best regards

What do you think, is the output of the stove sufficient?

You can't say that like this. A heating load calculation is required. The heating load calculation shows the heat or heating demand of the house with 4 people.

For the heating load calculation, the following documents are needed:
- Thermal insulation calculation for the new building with information on the component surfaces and insulation values, ventilation technology, etc.
- Planning documents (floor plans, sections, site plan)
Such a calculation can be performed by the SHK specialist craftsman or a qualified engineer.

If a room-air-independent wood stove is used, contact should also be made with the district chimney sweep to agree on the requirements for a possible acceptance.

How large should the solar surface be?

First, it must be clarified which system type is to be used. Domestic hot water solar thermal or heating-supporting solar thermal? Vacuum tube technology or flat plate collector?

How many liters should the buffer tank have?

This can only be answered after clarifying the aforementioned questions.

Regards

T.H.