The HUUM CLIFF 9 is a 9kW floor-mounted electric sauna heater engineered for a specific problem: how do you put a high-capacity heater in a sauna where wall space is tight? The CLIFF's answer is geometry. Where most sauna heaters are wide, boxy units that demand significant clearance from the surrounding walls, the CLIFF is a slim vertical tower - 10.6 inches wide, 10.6 inches deep, and 38.4 inches tall - that requires only 9.45 inches of clearance from walls on the 9kW model. This makes it the logical choice for compact sauna cabins, corner installations, and any room where a conventional heater would compromise bench space or create awkward layout constraints. Despite its slim profile, the CLIFF 9 holds 165 lbs of sauna stones - a generous load that produces the soft, sustained steam that is the mark of a properly loaded sauna heater.
The internal air duct system - 25% faster heating
The CLIFF's slim profile is made possible by an internal air duct system that serves a dual purpose: it is the structural reason the safety distances are reduced, and it is also the mechanism that makes the heater up to 25% faster at reaching temperature than a conventional heater of equivalent power. The air duct draws cool air from the base of the heater, channels it up through the core, and releases it through the top and sides - creating continuous air circulation through the stone mass rather than relying on passive convection alone. This forced internal circulation means the stones heat more evenly from base to top, that the temperature equilibrium inside the heater is reached faster, and that the surrounding wall materials are actively cooled by the moving air rather than receiving static radiant heat. The result is a heater that is simultaneously faster, safer, and more space-efficient than standard electric sauna heaters.
165 lbs of stone capacity - soft, long-lasting steam
The CLIFF 9 holds up to 165 lbs of sauna stones. This is a substantial stone load - significantly more than many compact heaters of comparable footprint - and it is the primary reason the CLIFF produces the soft, gentle, long-lasting steam that sauna enthusiasts associate with wood-fired heating. Large stone mass stores more thermal energy, releases it more slowly, and absorbs more water per ladle without producing the sharp steam burst that an under-stoned heater creates. HUUM designs the CLIFF so that the stones are in direct contact with the heating elements - rather than surrounding a separate heated core - maximising the proportion of heat that transfers directly to the stones rather than radiating from metal surfaces. Five boxes of HUUM CLIFF-compatible stones (33 lbs each, 165 lbs total) are required for proper operation and to maintain warranty coverage; they are sold separately. HUUM recommends rounded olivine-diabase stones in 5-10cm size for the best steam quality and durability.
Red Dot Award design, SGS certified, 230°F maximum
The CLIFF received the internationally recognised Red Dot Product Design Award - a recognition of both its aesthetic quality and its engineering innovation. The natural stone surface surrounds the heater on all sides, making it visually resolved from every angle in the sauna room rather than presenting a visible metal housing. The CLIFF is SGS certified (rather than UL listed), which is relevant to the temperature it can reach: SGS standards allow the heater to achieve up to 230°F, compared to the 194°F ceiling imposed on UL-listed heaters. In practice this means the CLIFF can bring a properly sized sauna room to the high temperatures associated with Finnish sauna tradition - temperatures that UL-listed heaters physically cannot reach. The CLIFF operates on a 240V/1-phase circuit, requires a 50A breaker, and uses 8 AWG wire. A HUUM UKU control unit is required for operation and is sold separately in Local, Wi-Fi, or Glass Wi-Fi configurations.
9kW slim floor-mounted electric sauna heater for rooms from 283 to 460 cubic feet. 10.6"W x 10.6"D x 38.4"H. 35.2 lbs heater weight. 165 lbs stone capacity (5 boxes, sold separately). Internal air duct system - heats up to 25% faster than conventional heaters. Wall safety distance 9.45" (24 cm). Stones in direct contact with heating elements. Removable ribs and prop blocks for precise stone stacking. Premium stainless steel construction with industrial-grade heating elements. SGS certified - maximum 230°F. Red Dot Award winner. 240V / 1-phase, 37.5A, 50A breaker, 8 AWG wire. UKU control sold separately (Local, Wi-Fi, or Glass). Stones sold separately. Optional safety railing and reflector panel available. 5-year warranty. Made in Estonia by HUUM.
