ᐅ What service do we need for our fireplace?

Hello everyone,

I’m not sure if this is the right place, but I can’t think of a better category for my question at the moment.

In our new house, we would like to install a fireplace (wood stove). Primarily, it’s about creating a cozy warmth during the cold season, not about replacing the main heating system or installing a fireplace that also heats water or anything like that.

Nevertheless, we do expect the unit to produce a noticeable amount of heat. You should really feel it when the fireplace is on... otherwise, a TV screen would do the same.

The location will be the living/dining area, which has a size of about 39 sqm (420 sq ft), with the kitchen separated by a large sliding door of about 18 sqm (195 sq ft). The warmth should be noticeable in both of these rooms.

We already visited a specialist retailer, and the helpful gentleman there suggested a fireplace with an output of 4 kW would be sufficient. The idea is to avoid too high a kW rating, otherwise it gets too hot (or the combustion is reduced, causing the glass to get black).

If I consider the common rule of thumb I found online (1 kW per 10 sqm (100 sq ft) of living space), that would actually be too low in terms of output.

Do you have any experience with this? What do you think?

Best regards

S

Define "new house"....

New construction or "newly" purchased for you?

In a modern house, I would expect underfloor heating and a fireplace that can be turned on when desired.
That should be completely sufficient.

Appel2000 schrieb:

If I now assume the usual values you find on the internet (1 kW per 10 sqm (100 sq ft) of living space), that would of course be too low in terms of output.

You need about 100 watts/m2 (9.3 watts/sq ft) for an uninsulated 1970s building at -10°C (14°F). At +5°C (41°F), heating with that output just for comfort using a wood stove—and you’ll either freeze or open all the windows. Neither is very comfortable, oops. For a new build, I would ask the heating engineer which size they would personally choose. 3 or 4 kW will probably be more than enough and might even be sufficient to heat a medium-sized KFW-40 house on their own if necessary.

Osnabruecker schrieb:

Define "new house"....

Is it a new build or just "new" to you because you bought it?

In a modern house, I would expect underfloor heating and an optional fireplace.
That should be more than enough.

Completely new build, with underfloor heating, but not built to any specific or special KFW standard.
And exactly, the fireplace is just for "coziness."

As I said, the fireplace installer recommended 4 kW. But when I look around, most stoves have 6 kW or more. That made me a bit doubtful whether 4 kW might be too low.

I’ll just rely on the fireplace installer’s opinion then.

The kilowatts are completely irrelevant. The question is how quickly the stove releases heat. Install adequate thermal storage bricks. Then you can easily go for 7 kW or more. The stove will then only raise the room temperature by about 2 to 3 degrees Celsius (36 to 37.4 degrees Fahrenheit).

Yes, that's how I had thought about it as well.
However, our desired fireplace has glass on three sides.

According to the fireplace installer, the fireplace releases a lot of heat very quickly through these glass surfaces, regardless of any heat-retaining bricks.
These bricks certainly help to keep the temperature somewhat regulated and also store heat after the fire has gone out, but the "weak point" in this system is indeed the glass surfaces.

That sounds quite plausible to me as a layperson.