A fundamental quality feature of a sauna cabin is its thermal insulation. Thermal insulation reduces heat loss and is an important factor in determining energy usage and duration of heating time.
Thermal insulation should not deteriorate during the lifetime of a sauna cabin. Thermal insulation should not be a potential health hazard; there should not be any possibility of fibrous insulation material being released into the air and then inhaled.
You have nothing to worry about with RUKU’s Isoholz thermal insulation. No fibrous insulation material is used for making Isoholz. Isoholz utilises the thermal resistance of air in a similar way to a triple glazed window: there are three layers of wood with an air chamber and reflective aluminium foil between each layer; no other material is used. The result: thermal insulation for a sauna cabin made with Isoholz is superior to any thermal insulation made with fibrous insulation material.
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Isoholz thermal insulation has a major advantage compared to insulation made with fibrous materials: through the years Isoholz will still maintain its thermal resistance to heat flow. In contrast: the thermal resistance of a fibrous insulation material will be reduced once it has absorbed moisture, or when it has sagged under its own weight. Sagging will reduce resistance to heat flow in the upper part of a sauna cabin where the heat is highest.
Isoholz provides highly efficient thermal insulation from day one, insulation that will last for decades.