Fireplace and underfloor heating - is air circulation or storage more sensible?

What kind of wood stove do you have? Or rather, which of the variants I described?

I said: I have no clue about this circulating air variant. We now have a certified Olsberg Palena in the new building (necessary with controlled residential ventilation, room air independent), I correct: not 7kw, but 5kw. Deliberately without storage stone, because we had storage stones in the old house and in our daily routine, morning going to work etc., we did not experience any sense or benefit. Everyone has to decide for themselves whether they like to cuddle up at the stove in the morning. We don’t. We use it as a comfort stove with the gain that the underfloor heating doesn’t have to "power" as much at increased temperature. The room itself remains warmer for hours afterwards than when only the underfloor heating is heating. I can only advise not to choose the kw too high for a closed room.

A circulating air stove is basically anything that is not a storage stove. We have a nominal output of 7.5kW in 70sqm of open living space, circulating air stove. If you fuel it with the amount the stove builder intended to achieve a proper burn (no black glass), we also get about +3-4 degrees, which I find very warm (22 degrees to 26 degrees). If I imagine 11kW in 50sqm, phew...

11kw are initially 11kw, just to have a comparison, what is the power of your heating system?

That is correct and yet somewhat misleading. The heating output of a wood stove is standardized and measured over a period of time (one or two hours, I can't recall exactly). The distribution of the heat output from the stove contributes to the comfort in the room – a very rapid output causes a very strong temperature increase. In well-insulated modern houses, this can contribute to a perceived overheating. Then only opening windows or turning on air conditioning helps. The latter borders on madness. The slower the heat release of the stove, the better. The better a house is insulated, the less heat output is needed to achieve a comfortable temperature. In connection with wood stoves, this means that either the heat energy is released as evenly as possible over time (storage) or it is not released into the room at all (e.g., going straight up the chimney). So in stove dimensioning, the specified heating output is less relevant than the heating curve and the minimal amount required for a clean burn. : Have the heating curves of the offers shown to you (flat is better for you) and ask for the minimal amount for a clean burn. After all, you don’t have to fill every stove completely, and a smaller amount of wood also produces less heat output and still burns nicely.

Thank you very much for your answers. I will address this tonight.

A brief and probably stupid question:
When I read the specification "useful power 5-12kW" from the manufacturers (e.g. Hoxter UAK), does that describe the minimum and maximum useful power depending on the load with wood, right? So less than 5kW (or the corresponding amount of wood, presumably just over 1kg?) would not be possible in terms of combustion, and the 12kW would be at the maximum load of the combustion chamber?

When I read the specification "usable power 5-12kW" from manufacturers (e.g. Hoxter UAK), does that describe the minimum and maximum usable power depending on the wood load, right?

Yes, you can imagine it like that, although converting kW into the amount of wood doesn't work well due to the heating-curve-dependent standard. A basic stove with an efficiency of around 90% can be specified with a value of 3.5kW despite a wood quantity of 13kg. This is because most of the heat energy is released into the storage mass, and the heating power measurement ends after one hour, even though a burn lasts and provides heat over 24 hours. So it is better if you specifically know the minimum loading weight the stove can handle. For our basic stove with Ortner insert, this is specified (6.5-13kg); unfortunately, for the boys' Hase stoves (Sendai and Dheli, each without storage), it is not.

Thank you very much for your responses. If we summarize the (subjective) feedback: - storage stove - pleasant warmth - convection fireplace without storage - 16kW on 75m² - about +3°C (pleasant) - fireplace without storage - 5kW on 50m² - heating for the whole house / partly too warm (ventilation) - convection fireplace - 7.5kW on 70m² - about +3-4°C (perceived as too warm) I am unfortunately still undecided about which choice is better for us. From I understood that we should inquire about the heating curves and minimum quantities for the two offers. I will do that. In sizing the stove, I have now noticed that these fireplace inserts are relatively identical. Variant 1 indicates a heat output range of 6.5 - 12.1 kW. Variant 2 says 5 - 12 kW. I have googled a bit more and also found various heating curves for freestanding stoves with and without storage stones. In addition, I found some articles on the different types of stoves (I unfortunately cannot link them here). Currently, I would tend more towards variant 2 with a pure storage fireplace because the heat release is probably more even and "pleasant" here. However, I would still welcome further feedback from you.