Combine air-water heat pump with water-carrying wood stove

Ok,
I gladly accept your information about photovoltaics. Ultimately, these are actual values.
My current electricity consumption is from a house with a gas boiler and [BW] in the circuit running 24/7.

The chosen heating boiler has the huge advantage of reburning for me. That means I have wood in the house for a week and no mess in the living room. I am reluctant to give that up. There is also one without water circulation, but then we sit in the sauna.

I will gladly take your advice regarding the brand Stiebel. My architect has had the same one in a similar new building for 2 years. Actual consumption values should be apparent here.

As a newbie: what does [BKA] stand for? B...air conditioning?

I will gladly take your advice regarding the Stiebel brand. My architect has had the same one in a similar new building for 2 years. Actual consumption values should be visible here.

As a newbie: what does BKA stand for? B...air conditioning?

BKA stands for the mentioned betorkern activation. You still have all the possibilities to install this in the solid concrete ceilings. Of course, you don't have this option with the roof beam ceiling, and the alternative ceiling heating is not really cost-effective in comparison.

Regarding the architect's experience values, I would be cautious. Most people don't want to admit to themselves and especially not to others that they might have made a wrong decision and then rationalize it. I prefer to base myself on the experience values of users of such exhaust air heat pumps that are discussed in forums. And generally, the first thing said to them is condolences. For example, take a look at the thread

newly built wooden house (prefabricated house) with a feel-good climate heating installed. After I developed dry skin, my husband bought a humidity meter. These show an average humidity of around 25%.

or just google exhaust air heat pumps in forums.

As for the water-bearing heating... Do you want to save money with it or do you simply want wood heat?

Regards Nika

That the wood heating can probably never be economical was clear to me from the beginning. But it is also a hobby, fresh air, and teaching the sons some physical work, and if I didn’t already have the 30rm of beech and didn’t constantly get softwood for free, well then I would only heat with electricity.

On a day like today, for example, when everyone is at home, around zero degrees, overcast sky, I can safely leave the air-water heat pump off. The 5-10kW from the stove easily keep the house warm.

I have now read up a bit on Nibe and IDM. IDM also promotes the combination of their heat pump with a wood boiler. I contacted them to ask how they suggest the hydraulic coupling. In Austria, a lot of heating is done with wood. I trust them the most in this regard.

I also find the decoupling of the heat pump from the ventilation system better now. So Nibe 2120 with a Nibe ERS 10-400, for example. An advantage of Nibe is also the separate control display in a second room, like the kitchen, for example.

Hi,

I now also find the decoupling of the heat pump from the ventilation system better.
So Nibe 2120 with a Nibe ERS 10-400 for example.
An advantage of Nibe is also the separate control display in a second room, like the kitchen for example.

You can find the hydraulic diagrams directly on Nibe’s homepage. Just have a look under Fachpartner there. However, you should always question the manufacturer’s specifications. With my Nibe, I also relied on their matching hot water storage tank. It’s not bad, but with a different tank without a mini-buffer, I would now have a better annual performance factor, and the system would also have cost less. In addition, I cannot easily replace the heat pump later with a device from another manufacturer.

The same applies to controlled residential ventilation and heat pump combinations. You then also have a lock-in to one manufacturer, and in case of a defect, you can no longer freely decide. Personally, I would choose storage, controlled residential ventilation, and heat pump so that all three can be replaced independently of each other.

Otherwise, you should prefer monoblock units for heat pumps. For IDM, it could be a split unit. AI would also be a candidate for good heat pumps. And as already mentioned, a geothermal heat pump with a trench collector generally performs best in terms of cost/benefit IMHO.

Regarding exhaust air heat pumps. Well, physics can’t be tricked. After the cross-counterflow heat exchanger, the exhaust air is at outdoor temperature. But the air volume compared to a proper air heat pump is so low that, to extract the same amount of heat from the air, the exhaust air must be cooled maybe 15 K below the outdoor temperature. A proper air heat pump, in comparison, probably only has to provide about 2 K of cooling capacity to extract the same amount of heat from the air. That easily makes a difference of 30% in the COP.

Regards, Nika

In the meantime, I have dealt a bit more with the subject.
The LWZ Premium from Stiebel Eltron up for selection has an extra supply and return connection for solar thermal. That means, through a pump circuit, warm water is taken from the upper heat exchanger of the buffer heated exclusively by the wood stove and fed to the heat pump. The heat pump transfers this heat regulated via an internal heat exchanger into the supply line to the compressor.
So, for a target supply temperature of the heating circuit of e.g. 30°, already 30° are fed into the circuit before the actual heat pump system.

The pump from the buffer is controlled by the heat pump. Optionally, a manual mixer can be integrated here to keep the supply at the solar thermal connection of the heat pump within limits. Via a temperature sensor in the upper part of the buffer, the heat pump receives the instruction to switch to solar thermal and to operate the circulation pump.

For heating the internal domestic hot water buffer, the energy is also taken from the controlled internal heat exchanger, only with higher internal supply temperatures.

Where is the catch now?

Hi,

we currently have a heat pump (but a brine-water heat pump) and a water-guided stove and ST But that has grown historically (house was bought). I would never build something like that. In fact, as already described, NT and HT heating systems don't really fit well together. It took 3 winters until I had the hydraulics set up so that it works well together. And that only because a friend is HB and I enjoy it. ........

I read something here about flow temperatures... are the NIBE flow controlled? I have an AiT, which is return flow controlled...... just out of interest.

What exactly is the DIFFERENCE between Monoblock and Split air-water heat pump? Does the Monoblock not have an outdoor unit? How is that supposed to work?

Regards, Andreas