HUUM Steel Sauna Heaters

STEEL brings HUUM’s modern pillar aesthetic to tight spaces. The narrow, upright basket lets you place the heater closer to benches or glazing while maintaining the soft, even steam that a large stone mass provides. Choose STEEL Mini 4 for small rooms that need a wall mount or step up to STEEL 6, 9, and 11 for medium rooms that benefit from a floor-standing tower.  

All HUUM sauna heaters use the same control system. This control system is called UKU. In all HUUM sauna heaters, there will be an external control panel for controlling the sauna.
HUUM allows the UKU to be installed inside the sauna room, as long as their specific instructions regarding the placement are followed. However, it's more common to install your control panel right outside the sauna, where it doesn't get exposed to heat and humidity.
HUUM offers an additional feature to all UKU controls that allows you to control the sauna remotely through an app on your phone.

HUUM STEEL comes in four configurations across two formats: wall-mounted STEEL Mini 4 and floor-standing STEEL 6, 9, and 11. The slender tower profile stays consistent while higher kW models add element power inside the basket. The bigger your sauna, the greater the kilowatt rating you will need.  

Here are the electrical specs when you wire your STEEL sauna heater with 240 V:

• STEEL Mini 4 kW for sauna rooms sized 124–212 ft³. This model draws 14.58 A, requires a 20 A circuit breaker, and uses 12 AWG wire.  
• STEEL 6 kW for sauna rooms sized 212–353 ft³. This model draws 25 A, requires a 30 A circuit breaker, and uses 10 AWG wire.  
• STEEL 9 kW for sauna rooms sized 318–530 ft³. This model draws 37.5 A, requires a 50 A circuit breaker, and uses 8 AWG wire.  
• STEEL 11 kW for sauna rooms sized 353–600 ft³. This model draws 43.75 A, requires a 50 A circuit breaker, and uses 6 AWG wire.  

1. Calculate your room volume in cubic feet.
2. Adjust for cold surfaces such as glass, tile, and stone to maintain warm-up speed and steam quality.
3. Consider insulation for outdoor cabins.
4. If you are between models, choose the larger firebox for faster heat-up and better recovery between water ladling.

Use our Sauna Heater Size Calculator to confirm the right model for your room.

HUUM STEEL is the right choice if you want soft, even löyly from a compact tower with the flexibility to run hotter when you want a more intense session. The vertical stone column gives you stable temperatures and generous steam without taking over your floor plan. Pick STEEL Mini 4 for small rooms that benefit from a wall mount or move to STEEL 6, 9, or 11 for medium rooms that need a floor-standing unit. Pair with UKU Wi-Fi for scheduling, remote starts, and added safety features.  

Have questions about sizing, wiring, or controls? Contact us and our US-based sauna experts will walk you through every step of purchase and installation.