Wood stove - efficient addition to air-to-water heat pump?

Hello,

we have successfully completed building a single-family house and have been living here for two months.

For heating, we have an air-to-water heat pump, supplemented by a room-air-independent wood stove, not water-bearing.

Now the question to the experts (!): Is additional heating with the wood stove efficient or energy-saving in relation to the consumption of the heat pump? It is well known that the heat pump becomes increasingly inefficient at colder outside temperatures.

Brief data about the house:

-Single-family house Kfw 70 standard, 2 1/2 floors, fully basemented, in the basement three storage rooms not heated, underfloor heating in the house, open staircase from the basement to the gallery, central controlled residential ventilation
-200 m² area, 950 m³ volume
-Air-to-water heat pump installed indoors, wood stove on the ground floor two meters away from the staircase, 6 KW max power, 80 % efficiency according to the manufacturer, room-air-independent, about 6 meters from the intake opening of the exhaust air of the controlled residential ventilation, only heatable with wood (-brickets/pellets, no coal)
-Controllers for the underfloor heating in every room except the hallway

Thanks for the assessment!

Efficient: hardly. Do you have a controlled residential ventilation system with heat recovery? That might actually help. Otherwise, you will (like us) always have the problem that you overheat one room and the heat never properly reaches the other rooms.

How high are your actual heating costs in winter? 600 kW? That makes 5 euros a day. How much do you realistically want to save? 1 euro? Then you end up saving 30 euros/month but need just as much to obtain the wood.

Forget it, it's only good for the ambiance. My opinion without detailed calculations.

Yes, we have a fairly good controlled residential ventilation system with heat recovery, about 90% recovery according to the manufacturer. My question is: I have the wood stove on every day and burn wood (-briquettes/-logs) worth maybe 1 - 1.50 €. The ground floor and the hallway upstairs are 3-4 degrees warmer than before (the heating reaches 20 degrees). In the bedroom, children's rooms, and basement, it is not much warmer. So: Just a nice little fire toy or do I roughly get the money for the wood back, or do I even come out somewhat ahead? Especially on cold days with well below 0 in the evening, when the air-water heat pump is no longer very efficient?

So you could calculate it yourself. Using the coefficient of performance of the heat pump, i.e., heat meter and electricity meter, you can calculate what it costs to keep the house warm. Compared to that, the costs for the briquettes. For this, you need the calorific value x 80%. My tip: you add a margin. Do you want it to be 3-4 degrees warmer?

Now come on.... just if you invest 4 hours in research now, that's more than you can save.

I'm with Joedreck's tip... but who cares... if you like the fire warmth it's a gain for you that you can't measure in numbers. You won't make a huge loss, but also no profit. In the end, you'll be moving around plus or minus 10 euros per month.

Book wood stove under nice to have, but not for saving.