Narvi Stone Cage 250×400 Black | Flue-Mounted Stone Basket for Narvi Wood Stoves

Built for these

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  Narvi Kuru Woodburning Sauna Heater From Finland
  The Kuru 14 and Kuru 20. Narvi lists STONE CAGE among the Kuru's optional accessories. See the full product and build your package →

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  Narvi NC – The 'Goldilocks of Thermal Mass'
  The NC 16, 20 and 24. Narvi lists STONE CAGE among the NC's optional accessories, and the NC manual specifically describes a Kota stone basket being installed around the connective flue when the stove is connected from above. See the full product and build your package →

• 

  Narvi Kaamos 20 Woodburning Sauna Heater from Finland
  The Kaamos 132 lb of stone for rooms of 353–706 cu ft, with the same 4.7 in connective flue. Narvi lists STONE CAGE among its optional accessories. See the full product and build your package →

• 

  Narvi 30 Wood-Burning Sauna Stove – 24 kW Finnish Heater
  The Narvi 30 at 24 kW, also on the same 4.7 in connective flue. Narvi lists STONE CAGE among its optional accessories. See the full product and build your package →

What’s included

• One Narvi stone cage, 9.9 x 15.8 in, black (stones not included)

What it does

Narvi’s own description: “With the aid of a stone cage, the heat of the flue can be utilized better. The steam lasts longer when the sauna water flows from the stone cage to the stones of the sauna heater. This is also a way of decreasing protective distances into flammable material. Stone cages can also be installed on top of each other, which gives your sauna a stylish look.”

The flue is one of the hottest surfaces in the room and all of that heat is on its way out of the building. A cage of stones around it puts thermal mass in the path. Water poured over the cage then runs down onto the heater’s stones, which is the “steam lasts longer” part.

Narvi states that a stone cage is also a way of decreasing protective distances into flammable material, without quantifying it. The clearance rules for the flue run itself come from your stove manual and your flue manufacturer.

Where it mounts

Around the connective flue above the stove. The NC manual is explicit about the case: “In case of connection from the above, a Kota smoke flue tank for heating water or a Kota stone basket can be installed around the connective flue.” The cage is 15.8 in. tall, so check that stretch of flue is clear and that you can still reach it to throw water.

Stone size is the thing people get wrong

Work the geometry from the published numbers. The cage measures 9.8 in. across the outside, and a Narvi connective flue is 4.7 in. That leaves no more than about 2.6 in, roughly 2.5 in., of space per side to fill.

Narvi’s manuals call for 4–6 in. stones in the heater’s own basket, and Narvi’s stone sets are supplied at that size. They are larger than the space around the flue, so basket stone will not go into the cage. Size stone for the cage to the gap instead.

Specifications