Wood-Burning Sauna Stove Package, 8.5kW The HUUM HIVE Flow Mini Sauna Stove Package comes complete with the HIVE Flow Mini Sauna Stove and Sauna Stones. Its innovative design ensures that 75% of the heat from the firewood directly heats your sauna rather than escaping through the chimney. It stands out as one of the most efficient and environmentally sustainable heaters for sauna rooms from 212 to 494 cubic feet (CF).