Harvia 5050 Series, 40kW, Wood Burning Stove The Harvia 50 SL black wood burning sauna stove is the king of large heaters. Designed for large sauna rooms from 706 to 1766 square feet. A large amount of stones ensures consistent heat even in large sauna rooms with the ability for large amounts of steam. Required sauna stones 264 lbs (6 boxes) sold separately. Features Wood Burning Stylish black color Floor Mounted Even heat in a large sauna 40kW Steel