Air heat pump in combination with water-carrying fireplace

I am not aware of any funding options for something like this and consider it highly uneconomical. You are installing piping, controls, and hydraulics costing thousands of euros to operate the heat pump permanently uneconomically (huge hot water storage) because you are afraid of the eventuality that the electric heater might kick in. As already mentioned, nowadays they only turn on at -10 degrees. Better invest your money in a good heat pump, spending 1-2k€ more. Or opt for a ground source heat pump right away, if possible.

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You build piping, controls, and hydraulics worth thousands of euros to operate the heat pump permanently uneconomically (huge hot water storage tank)...

Everyone says something different. I just spoke with a heating engineer who said that especially with a heat pump, the support of a water-bearing chimney is very beneficial.
The water storage tank is separate... I can't recall the exact term right now. Thus, only one half is buffered with the heated water.
I really find it hard to decide, especially because opinions on this differ.

That would be optimal, yes, but I think it will start up more often. Do you know roughly what it amounted to for you when the heating rod turned on? I also see the disadvantage that the additional water in the tank has to be heated more, due to the larger volume.

It was an insane 300 kWh in total, but you have to say that the heat pump was in emergency operation for 5 days due to a mounting inaccuracy during significant subzero temperatures. Without this blunder, it would probably have been not even 50 kWh, or rather significantly less.

For funding, search for BAFA and "Förderübersicht Biomasse". Good luck.

Hello everyone,

we are in the middle of construction and I have to decide on a heating system soon.
My question is: Is a water-bearing fireplace worthwhile for me in combination with the air heat pump and the controlled residential ventilation?

Best regards
Almo

Short answer: No.
Long answer: No, because: You have a building heating load of 6.5KW at worst-case temperatures. The internal gains were (certainly) not taken into account. So people, cooking, showering, etc. Your stove will easily have 5 KW on the air side. If it burns for 5 hours to fill the storage, you will have a room temperature beyond good and evil.

If you enjoy carrying wood in your underwear, then it’s a good idea.

What you must not forget either: Your parents live in a Swiss cheese house. You live in a fairly tight KfW house.

And finally: The two-flue fireplace (because of controlled residential ventilation) costs about 5000€. The pressure switch about 2500€. Then another 5000-7500€ for the stove and control system... Plus chimney sweep every year.

Thank you for your answers!!

And finally: The two-flue chimney (because of controlled residential ventilation) costs about 5000€. The pressure monitor about 2500€. Then another 5000-7500€ for the stove and the control system... Plus chimney sweep every year.

Thank you for your opinion. Pro and con opinions are slowly balancing out! Some are completely sure about it.... it brings quite a bit with an air heat pump, and others are completely convinced of the opposite.

Regarding the costs: We will definitely have a chimney. It is only a question of whether the chimney insert will have water guidance or not. I am leaving out the two-flue chimney from the cost calculation, since it is already installed because of controlled residential ventilation. The pressure monitor is said to cost about 600-700 €, which I also need because of the controlled residential ventilation. My heating engineer will prepare everything needed up to the chimney for 400 €. In addition, there are the costs for an 850-liter storage tank instead of 300 liters. The 850-liter storage tank is divided so that the hot water is only buffered in one part of the tank. The chimney insert will cost me more, and the control system connection will be handled by the heating engineer, but the electrician and chimney sweep must also be involved.

In total, I have additional costs of about 3,000-4,000 € for the water-guided chimney compared to the chimney without water guidance. And I find it difficult to decide whether this 3-4k investment will pay off in the near future, since some are completely convinced and others are not.

It should not get too warm, as the underfloor heating is regulated with the water-side heat from the chimney and the air heat pump, and the excess heat does not flow into the underfloor heating (my assumption).

I hope I was able to fairly well present my difficulty in deciding.

Best regards Alex