HUUM Hive Flow LS Wood-Fired Sauna Heater

The HUUM Hive Flow LS Wood-Fired Sauna Heater is designed to deliver outstanding efficiency while significantly reducing environmental impact. Its advanced combustion system is engineered so that approximately 75% of the heat produced by firewood is transferred directly into the sauna, instead of being lost through the chimney. In practical use, this efficiency allows you to enjoy four sauna sessions using the same amount of wood that would typically provide only three.

At the core of the Hive Flow LS is HUUM’s patent-pending airflow and combustion technology, developed to optimize heat utilization and minimize emissions. Carbon monoxide output is limited to 346 mg/m³, compared to more than 1,000 mg/m³ commonly found in comparable wood-burning sauna stoves. Particulate emissions are reduced to just 25 mg/m³, placing the Hive Flow LS among the cleanest-performing heaters in its class.

This controlled heat circulation also enables exceptionally short safety clearances. The Hive Flow LS requires only 150 mm of distance from combustible materials, far less than the typical 200–500 mm. Even heat distribution across the stove body prevents localized hot spots, allowing for compact and flexible installation options.

Built for durability and consistent performance, the stove features a 5 mm thick steel top and 3 mm thick side panels, ensuring structural strength and uniform heat release. The Hive Flow weighs 67 kg, while the LS version weighs 73 kg, and it supports up to 150 kg of sauna stones, with the option to add an additional 35–40 kg using the external stone cage.

The large stone mass stores heat efficiently, allowing for long, gentle steam sessions that continue for more than 30 minutes after the fire has gone out. This creates a soft, balanced sauna atmosphere rather than sharp or aggressive heat.

A large glass furnace door enhances both function and atmosphere, allowing you to enjoy the natural movement of the flames and adding a warm, fireplace-like ambiance to the sauna experience.

The Hive Flow LS meets and exceeds strict environmental requirements, fully complying with Germany’s BImSchV Stufe 2 standard and European Commission Regulation 2025/1185 for solid fuel local space heaters. These certifications confirm its position as a forward-looking and environmentally responsible wood-burning sauna stove.

The LS (loading side) configuration allows the stove to be fired from an adjacent room, keeping the sauna interior clean while improving convenience and safety.

Additional configurations are available, including the HIVE Flow Mini and Mini LS, weighing 54 kg and 59 kg respectively and holding 105 kg of stones. With the optional stone cage, these models can accommodate up to 40 kg of additional stones.

Stove Details

• Power Output: 9.8 kW

• Recommended Sauna Room Size (Minimum): 282 ft³ (8 m³)

• Recommended Sauna Room Size (Maximum): 635 ft³ (18 m³)

• Stone Capacity: approx. 330 lb (150 kg)

• Unit Weight: 160 lb (73 kg)

• Heater Dimensions:

  • Height: 34.8 (884 mm)

  • Width: 20.7 (526 mm)

  • Depth: 27.8 (706 mm)

• Maximum Firewood Length: 11.8 (300 mm)

• Flue Diameter: 4.5 (114 mm)