The Wall Series, 6kW, Sauna Heater, Stainless Steel The Wall 6kW home sauna heater from Harvia features a polished stainless-steel exterior and an illuminated, built-in, top-mounted control that can be configured on the right or the left side of the unit. Harvia's The Wall electric sauna heater is engineered to power home sauna rooms up to 282 cubic feet (CF). Requires a minimum of 44lbs of stones, sold separately. Direct rock-to-heating element contact For sauna rooms up to 282 cu. ft. Requires a minimum of 44lbs of stones (1 box-AC3000)Please note that each natural stone is unique in shape and size. We recommend purchasing an additional box of sauna stones to allow you to choose the highest quality of stone for fit, form, and function. Please note that each natural stone is unique in shape and size. We recommend purchasing an additional box of sauna stones to allow you to choose the highest quality of stone for fit, form, and function.