ᐅ Calculating heating demand to determine the size of the ground source heat pump

Yes, we do have several projections, but don’t be mistaken about the basement – why would it be heated as well? Through the ventilation system? Then you could save a lot on heating surface.

What are you curious about? Once the heating system is installed, it’s there – or do you mean the cycling?

That’s quite a few square meters being heated additionally. How many meters of underfloor heating do you have?

The basement is heated along with the rest of the house, including the unheated rooms, because it is fully within the insulated building envelope. This means that with only a few degrees of temperature difference compared to the rest of the house, the heat flow from the house to the unheated basement is about the same as from the basement to the outside. As a result, our basement never gets colder than 16°C (61°F). If I turn on the heating in the basement now, the additional energy required is only enough to raise the temperature from 16°C (61°F) to 20°C (68°F). After all, I already have to provide energy for this indirect heating. The difference is that the heat then goes directly into the basement rooms, not via indirect paths. This is not just theoretical, but based on practice (measuring consumption when heating the basement vs. not heating it). So I don’t think I’m mistaken.

I’m curious about the consumption and other details for comparison. In my neighborhood/acquaintances, there are few with brine-to-water heat pumps.

You do heat more square meters with a fully heated basement, but it is only about 4°C (7°F) warmer during the coldest months compared to mine.

With nearly KfW 55 standard and an 8 kW heating load, your figure seems high to me, since mine is actually under 5 kW. If we both included 1 kW for hot water, that would be 7/4, or 75% higher heating load—not in proportion to 75% more floor area. Or do you have a fully glazed façade or something similar? That would definitely increase the heating load.

Oh, right, yes, but it will take some time until I have reliable figures.

At the moment, I am heating with 48 kW

You can practically count the euros on the electricity meter.

Remember to ventilate well; with this amount of combustion, a lot of water vapor is produced, of course only if the appliances are installed indoors.

No, the flue pipe is inserted into the chimney flue – it has basically "broken it in."

Yesterday evening, I ran it at full power for almost an hour and the temperature rose from 7°C (45°F) and 99 percent humidity to 27°C (81°F) and around 35 percent humidity.

However, it is now set to 15°C (59°F). Still uses fuel like crazy...