Combine heat pump and water-bearing fireplace

Hi guys, I happened to come across this thread because we also planned a heat pump + water-bearing fireplace. So far, we have only tendered earthworks + shell construction, but the building services will follow soon. The majority here is against this solution, and I am almost convinced to give up the water integration and switch to a regular fireplace. My problem at the moment is that the fireplace (I mean 6kW) was included in the energy balance for KfW55. Do you think it can still be changed? I also don't feel like having everything reassessed by the energy consultant unless absolutely necessary.

Tell me more about your design. Flow temperature. Etc. :-)

Is it possible? Yes!
Sensible? Yes, all kinds of air machines are insane power guzzlers at below zero degrees. That’s exactly when photovoltaics usually don’t help either.
Technically feasible? Yes, but not every heating engineer masters it.
Affordable to implement? No!

Is it possible? Yes! Sensible? Yes, all kinds of air machines are insane power guzzlers at subzero temperatures. Exactly then, photovoltaic usually doesn’t help either. Technically feasible? Yes, but not every heating technician masters it. Affordable to implement? No!

. Absolute nonsense. It is not sensible because it is not economical, technically highly demanding, and prone to errors. What is supposed to be sensible about that now? Even if the air-to-water heat pump requires a few more kWh in the dead of winter, who cares? This year at -18 degrees it ran without heating rods and still with a COP of 3.0. This solution brings no advantages. Make a fireplace without water circulation. It provides nice, cozy warmth and is visually a real eye-catcher anyway.

Why absolute nonsense? I also wrote: Not inexpensive and most heaters can't do that properly? By the way, I myself have the combo you described and am very satisfied with it. Less aggression, my dear... is better for the psyche

OK, you're right, I probably got stuck on the "Sinnvoll, ja". How do you come to the conclusion that it is sensible, under which aspect?

Under the above-described... the purely technical weakness of the air-water heat pump is precisely the deep winter, I see that with my own. It consumes about 80% of its annual demand from December to February, the heat source simply has less energy content. I always heat the fireplace during freezing temperatures, which indirectly helps the heat pump (I would have actually preferred brine, but I couldn't find a company with a reasonable offer for our soil class); fireplace heat is pleasant and also looks nice with the three-sided panoramic fireplace. However, it excludes the water jacket. I would have still liked it, and if Madame hadn’t wanted the 3 glass panels... whatever. Financially, it’s all nonsense anyway; in my opinion, the cheapest heating option is a gas boiler. Everything else is usually expensive, still far from mature gimmicks. I know that from my previous work: according to my experience, the craziest in terms of malfunctions are pellet boilers with vacuum fuel feeding systems.