Any stove can cook the ceiling.

Showroom thermometers hang high, where every heater looks like a hero. You do not sit at the ceiling. The only number that matters is at your shoulders, on the bench, twenty minutes in.

Eye level · 90°C · where saunas are judged

Löyly is a capacity question.

Throw water on an undersized stove and the temperature dives for ten minutes. The steam you feel is stone mass and spare kilowatts, nothing else.

undersized stove after löyly −12°C dip right-sized recovery under 2 min stone capacity that holds steam 90 kg+

Bench · 82°C · where you actually sit

The bench ledger, from the manuals.

indoor rooms 5 to 8 m³ 6.0 kW class outdoor barrels 6 to 10 m³ 8.0 kW class off-grid or purist wood-fired, 14 kW eq. every glass door adds +1.5 m³ of load uninsulated log walls add +25%

Specs verified against installation manuals, never against marketing pages. No brand pays for a line in this ledger.

Floor plaque · carve your own number

The heater sizing

Measure the room, tick what applies, read the kilowatts. Round up to the next stove size, never down.

Width m

Depth m

Height m

GLASS DOOR / WINDOW UNINSULATED STONE / LOG OUTDOOR BARREL

6.0 kW

For 7.6 m³ with standard insulation. This is the bench number, not the showroom number.

Fits the 6 kW class: reaches 82°C at the bench in about an hour on a standard 240V circuit.