ᐅ Combining a heat pump with a hydronic fireplace

berny schrieb:

As described above... the purely technical weak point of the air-to-water heat pump is clearly mid-winter, as I can see with my own. It consumes about 80% of its annual energy between December and February.

This is true for every heating system and is not specific to air-to-water heat pumps.

As I mentioned, even at minus 18 degrees Celsius (0°F), the coefficient of performance (COP) is 3. That is excellent, and temperatures are rarely that low anyway.

Well, with no other heating system is the "fuel" as expensive as with the heat pump. And not every air-to-water heat pump has a COP of 3 in actual operation. But I don’t want to complain too much; since this afternoon, the snow has been off the photovoltaic panels... starting tomorrow morning at 8 a.m., it will start feeding power back into the grid.

berny schrieb:

Well, with no other heating system is the "fuel" as expensive as with a heat pump. And not every air-to-water heat pump actually achieves a COP of 3 in real operation. But I don’t want to complain too much — since this afternoon the snow has melted off the photovoltaic panels... starting at 8 a.m. tomorrow, they will start feeding power back into the grid again.

Here, some people are reaching much higher COPs, up to 5. There has been a lot of progress in the last 10 years.

I also think gas is just simpler. A wood-burning stove is a luxury, as is controlled mechanical ventilation with heat recovery. Not cost-effective, but highly recommended.

Bookstar schrieb:

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A wood-burning stove is a luxury, like controlled residential ventilation.
...

That’s why I’m glad to have a house with a double chimney flue. It makes installing a wood-burning stove very easy. If a house doesn’t offer that option, it would be a deal-breaker for me (!) if I had the choice and were to make the decision again. Over the past few weeks, ours has been burning almost around the clock.

berny schrieb:

Is it possible? Yes!
Is it sensible? Yes, small fans of all kinds consume an enormous amount of electricity at below-freezing temperatures. That’s also when solar panels usually don’t provide much.
Technically feasible? Yes, but not every heating professional is familiar with it.
Cost-effective to implement? No!

Can you send me a private message? Unfortunately, I can’t do that...

Michlhausbauaa schrieb:

Tell me more about your design. Supply temperature, etc. 🙂

Sorry, I first need to clarify what exactly has been included in the energy balance. The fireplace was NOT planned as part of the water circuit and can therefore be modified without any issues. I have already arranged that. According to the architect, the additional cost for a water-based fireplace is about 8000 EUR, and for that money, we will instead install a larger photovoltaic system (+9 kWp) on the roof. The cost-effectiveness is clearly better that way.

The air-to-water heat pump is planned with a supply temperature of 35°C (95°F), and heating is done via underfloor heating. The project’s energy demand is 21 kWh/(m²·a) and the primary energy demand is 38, if that’s of interest. What exactly do you want to know? 🙂

Regards