
HUUM Steel 9: a 9 kW floor heater for saunas from 318 to 529 cubic feet
The HUUM Steel 9 is a floor standing electric sauna heater made in Estonia, rated at 9 kW for rooms from 318 to 529 cubic feet. The stainless steel column measures just 12.6 inches square and 38 inches tall and weighs 33 pounds. It can sit within a few inches of the wall, taking up very little floor space for the room it heats. An internal air duct brings the sauna up to temperature up to 25 percent faster. The column holds 331 pounds of stones directly against the heating elements for soft, steady heat and lasting steam.
The box contains the heater and manual. It needs a HUUM UKU control to run, and you add that on the page. Choose the Wi-Fi version and you can start the sauna from your phone. Sauna stones are sold separately, so add the 10 boxes it needs on the page. A safety rail, a reflector panel, an embedding flange, and a bucket and ladle set are optional. Want the control and stones bundled? See the HUUM Steel 9 heater package. The HUUM Steel 9 ships free from My Cozy Outdoors with No Sales Tax (except WY) and the full manufacturer warranty.
FAQ
What size sauna does the STEEL 9 serve?
Rooms from 318 to 529 cubic feet, per the features and specification tabs. It is the middle size in the STEEL series, between the 6kW and 10.5kW floor models, so measure your room volume and match it to the range.
Why does it carry so much stone?
The description credits the well-optimized structure: 331 pounds of rock in a slim 12.6-inch-square column. All that thermal mass is what delivers steadier heat and stronger steam; the ten required boxes are listed in the Required Stones add-on on this page.
How close can it sit to the walls?
The description quotes a minimum safety distance of just 4 inches for the larger STEEL models thanks to the optimized structure. Always confirm the exact clearance for your specific installation in the manual before finalizing the sauna framing.
What control does it need?
A HUUM UKU control, sold separately but available in the Sauna Heater Controls add-on on this page – UKU Local, Wi-Fi, Mirror, or Gold. The Wi-Fi versions connect to the HUUM smartphone app so the sauna can be started remotely.
Is it quick to heat?
The features tab lists up to 25 percent faster heating from the internal air duct. The pattern with this series is a fast climb to temperature, then a long, mild heat sustained by the unusually heavy stone load surrounding the elements.
What are the warranty and electrical notes?
A limited 5-year warranty excluding heating elements, stainless steel build, made in Estonia. The spec table’s amperage row is blank on this page, so a licensed electrician should pull circuit sizing from the installation manual rather than the listing.