The HUUM HIVE 12STUX Package is a complete sauna heater package for large sauna rooms from 424 to 636 cubic feet, including the HIVE 12kW floor-standing heater, UKU sauna control with wood case (Local or WiFi - selected at checkout), UKU Extension Box, and 528 lbs of rounded olivine diabase sauna stones (16 boxes). The X in the model name designates that the UKU Extension Box is included - it is a required component for all HUUM heaters over 11kW and is not sold separately for this package. Everything needed to operate the HIVE 12 arrives together. The HIVE is a fundamentally different heater from HUUM's wall-mounted DROP series: it is a floor-standing unit with a beehive-inspired open cage design, a 22" diameter cylindrical form, and a stone capacity of 528 lbs - more than four times the DROP's 122 lbs - making it the appropriate choice for the large sauna rooms that the DROP series cannot serve.
HIVE vs DROP - floor-standing vs wall-mounted, and why it matters for large rooms
The DROP series (4.5kW through 9kW) is wall-mounted and covers rooms up to 460 cubic feet. The HIVE series begins at 12kW and covers rooms from 424 cubic feet upward - the two series overlap slightly, but the HIVE is the appropriate choice for rooms approaching and exceeding 500 cubic feet. The reason is not just output: a large sauna room requires not only more heat but more thermal mass in the stone load to sustain temperature and produce consistent steam throughout long sessions or back-to-back use with multiple bathers. The HIVE's 528-lb stone load provides thermal mass comparable to a large traditional wood-burning stove, and its open beehive cage design maximizes airflow through the stone mass for even, efficient heating. The floor-standing format means the HIVE stands directly on the sauna floor rather than being mounted to the wall, which also allows it to be partially embedded into a sauna bench for custom installations.
The beehive design - open cage, maximum airflow, direct stone contact
The HIVE is inspired by the form of a wild beehive - an open, structured cage of stainless steel fins that holds the stone mass while allowing air to circulate freely through the full stone volume from multiple directions simultaneously. This open cage geometry produces two outcomes: the stones are heated more evenly because air circulates through the entire mass rather than only from the heating elements at the base, and the steam produced when water is ladled is softer and more evenly distributed because the water contacts stones at multiple temperature levels within the pile rather than only the hottest stones at the top. The HIVE's pre-installed air tunnel reinforces this: it speeds up heating by approximately 25% by directing airflow more efficiently through the stone mass and also extends the life of the heating elements by reducing the thermal stress of the warm-up cycle.
Dual 30A circuit - two separate breakers required
The HIVE 12kW requires two separate 30A circuit breakers and two runs of 10 AWG wire - a dual-circuit electrical installation that differs from the single-circuit requirements of the DROP series. Total draw is 50A across the two circuits. The UKU Extension Box (included in this package) is the component that manages this dual-circuit configuration and connects the two heater groups to the single UKU control panel. A licensed electrician must plan and install the dual-circuit wiring before the HIVE can be connected. The UKU Extension Box dimensions are 7"W x 4"D x 10"H (178 x 101 x 254 mm) and it mounts on the wall outside the sauna room.
528 lbs of stone - pallet delivery and setup
The 528 lbs of rounded olivine diabase stones included in this package (16 boxes) represent a significant weight and volume that changes the delivery and installation process from smaller heaters. The HIVE 12 package ships on a wooden pallet and requires a scheduled delivery appointment - it does not deliver as a standard parcel. The stones are loaded into the HIVE cage following the stone placement procedure shown in the Stone Placement Video in the documents section below. Correct stone placement in the HIVE is important for element life and steam quality - the Stone Requirements document provides the specifications for stone type, size, and loading pattern.
Complete 12kW floor-standing sauna heater package for large rooms from 424 to 636 cubic feet. Includes HIVE 12kW heater, UKU control with wood case (Local or WiFi - select at checkout), UKU Extension Box (required for 12kW - included), and 528 lbs of rounded olivine diabase stones (16 boxes). Beehive-inspired open cage design - maximum airflow through full stone mass. Air tunnel pre-installed - 25% faster heating, extended element life. 528 lbs stone capacity - more than 4x the DROP series. Floor-standing - stands on sauna floor or embeds into bench. Dual 30A breakers + dual 10 AWG wire required. 240V / 1-phase. Max 230°F. SGS Listed. Ships on wooden pallet - scheduled delivery. 5-year warranty (elements excluded). Made in Estonia by HUUM.
Complete package - control + ext box + 528 lbs stones 12 kW 424 to 636 cu ft Floor-standing - not wall-mounted Beehive-inspired open cage design 528 lb stone capacity - 16 boxes included Air tunnel pre-installed - 25% faster heat-up UKU Extension Box included (X in model name) UKU Local w/Wood Case or UKU WiFi - select at checkout HUUM app - iOS and Android (WiFi variant) Dual 30A breakers - dual 10 AWG - 240V 1-phase Ships on wooden pallet - scheduled delivery SGS Listed - made in Estonia 5-year warranty (elements excluded)
Specifications
Electrical
| Power output |
12 kW |
| Voltage |
240V / 1-phase / 60 Hz |
| Total amperage draw |
50 A (25A per circuit) |
| Circuit breakers required |
Two separate 30A breakers (no GFI/GFCI) |
| Wire gauge |
Two runs of 10 AWG |
| UKU Extension Box |
Required - included in this package |
| Certification |
SGS Listed |
Room sizing and stones
| Room volume |
424 to 636 cu ft |
| Stone capacity |
528 lbs (16 boxes) |
| Stones included |
Yes - 16 boxes rounded olivine diabase |
| Stone size |
2" to 4" (5-10 cm) rounded |
| Max temperature |
230°F (110°C) |
Physical
| Diameter |
22" (560 mm) |
| Height |
29.5" (750 mm) |
| Heater weight |
44.1 lbs |
| Construction |
Stainless steel open cage |
| Mounting |
Floor-standing (or bench-embedded) |
| Air tunnel |
Pre-installed - 25% faster heat-up, extended element life |
| Origin |
Made in Estonia by HUUM |
Control options - select at checkout
| UKU Local w/Wood Case |
Digital control with thermo-ash wood enclosure - on-site |
| UKU WiFi |
Adds HUUM app remote preheat and scheduling |
| App |
HUUM app - iOS and Android (WiFi variant) |
| UKU Extension Box |
Required and included - 7"W x 4"D x 10"H |
HIVE vs DROP comparison
| HIVE 12kW (this listing) |
Floor-standing | 424-636 cu ft | 528 lbs stones | Dual 30A |
| DROP 9kW (largest DROP) |
Wall-mounted | 318-460 cu ft | 122 lbs stones | Single 50A |
| Stone capacity |
HIVE carries 4x more stone mass than DROP |
| UKU Extension Box |
Required for HIVE (12kW+) | Not required for DROP |
Delivery and warranty
| Delivery method |
Freight on wooden pallet - scheduled appointment |
| Warranty |
5 years (elements excluded) |
| Design inspiration |
Wild beehive - open cage form |
What's included
HUUM HIVE 12kW floor-standing sauna heater - stainless steel open cage
UKU sauna control with wood case (Local or WiFi - selected at checkout)
UKU Extension Box (required for 12kW - included)
Rounded olivine diabase sauna stones - 16 boxes (528 lbs)
Air tunnel (pre-installed on heater)
Installation and operation manual
Optional accessories (sold separately): HUUM HIVE safety railing (recommended), reflector panels (allow closer wall installation), HIVE embedding flange (for bench mounting). A licensed electrician is required for all electrical connections.
Why the HUUM HIVE 12STUX Package stands out
528 lbs of stone - massive thermal mass
At 528 lbs (16 boxes), the HIVE 12 carries more than four times the stone mass of HUUM's DROP series. This thermal mass is what enables the HIVE to sustain consistent temperature and steam quality through long sessions and back-to-back use - the stone load stores enough heat to continue producing soft, even steam long after the elements have cycled. For rooms from 424 to 636 cu ft and any commercial or high-intensity use, this thermal mass is the correct specification.
Open beehive cage - airflow through the full stone mass
The open stainless steel cage allows air to circulate through the entire 528-lb stone load from multiple directions simultaneously. Stones throughout the pile - not just those adjacent to the elements - are heated evenly. When water is ladled, it contacts stones at multiple temperature levels, producing a softer, more layered steam than a heater where only the top-surface stones are ladled. The beehive cage geometry is the engineering that makes this possible.
Air tunnel pre-installed - 25% faster heat-up, longer element life
The HIVE air tunnel directs airflow more efficiently through the stone mass during the warm-up cycle, reducing the time to reach bathing temperature by approximately 25% and reducing the thermal stress on the heating elements. The tunnel is pre-installed on the heater in this package - no separate installation required. It also means the effective stone load with the air tunnel in place is optimized for the 424-636 cu ft room range specified for this package.
UKU Extension Box included - the X in 12STUX
The X in the model name designates that the UKU Extension Box is included. This component is required for all HUUM heaters over 11kW and manages the dual-circuit electrical connection between the two 30A breakers and the single UKU control panel. Without it, the HIVE 12 cannot be connected to any UKU control. Including it in the package removes the need for a separate purchase and ensures all required components arrive together.
UKU Local w/Wood Case or WiFi - select at checkout
The standard UKU Local w/Wood Case is a digital control in a thermo-ash wood enclosure that complements the natural aesthetics of a timber sauna interior. Upgrading to UKU WiFi adds HUUM app remote preheat and scheduling on iOS and Android. For a large 424-636 cu ft sauna room that takes 45-60 minutes to reach temperature, remote preheat via the WiFi option is especially practical - start the session from the app before leaving for the sauna.
Floor-standing with bench-embedding option
The HIVE 12 stands directly on the sauna floor without wall mounting hardware - installation is simpler in that respect, though the dual-circuit electrical requirement must be planned. The HIVE embedding flange (sold separately) allows the heater to be partially inserted into a sauna bench for custom installations where the stove sits flush with the bench level. The optional reflector panels allow the heater to be installed closer to the sauna wall than standard safety clearances.
About HUUM
Made in Estonia - SGS Listed
HUUM HIVE 12STUX. 12kW. 424-636 cu ft. 528 lbs of stone. The complete large-sauna package.
HUUM is an Estonian sauna heater company. The HIVE is HUUM's floor-standing heater series, designed for large sauna rooms and commercial installations where the DROP series's wall-mounted format and stone capacity are insufficient. The HIVE 12STUX Package includes every required component: the HIVE 12kW heater with pre-installed air tunnel, UKU control with wood case (Local or WiFi at checkout), UKU Extension Box, and 528 lbs of rounded olivine diabase stones in 16 boxes. Everything arrives on a wooden pallet via scheduled freight delivery. A licensed electrician is required for the dual-circuit electrical installation. We are an authorized HUUM dealer.
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Complete package - HIVE 12kW, UKU control w/wood case, UKU Ext Box, 528 lbs stones
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12kW, 424-636 cu ft - dual 30A breakers, dual 10 AWG, 240V/1PH
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528 lb stone capacity - 4x the DROP series - massive thermal mass
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Air tunnel pre-installed - 25% faster heat-up, extended element life
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Pallet delivery, scheduled appointment - 5-year warranty (elements excluded)
HIVE vs DROP - choosing the right HUUM series
When to choose the HIVE over the DROP
The DROP series (4.5kW through 9kW, wall-mounted, 122 lbs stones) covers sauna rooms up to 460 cubic feet on single-circuit electrical installations. The HIVE series (12kW and above, floor-standing, 528 lbs stones) begins at 424 cu ft and is designed for rooms where the DROP series cannot provide sufficient output or thermal mass. The overlap between 424 and 460 cu ft is where the choice matters most: a 450 cu ft room with standard wood walls and no cold surfaces can be served by either the DROP 9 or the HIVE 12. For that room, the DROP 9 is simpler to install and requires less electrical work; the HIVE 12 provides significantly more thermal mass and will sustain temperature better through back-to-back sessions. For rooms with glass, tile, or masonry cold surfaces, for commercial use, or for rooms above 460 cu ft, the HIVE 12 is the appropriate choice without ambiguity.
Licensed electrician required. Two separate 30A breakers and two 10 AWG wire runs required. No GFI/GFCI. The HIVE safety railing is recommended. Reflector panels allow closer wall installation. The HIVE embedding flange enables bench installation. All accessories sold separately.
Manuals and Documents
Warranty
5-year limited warranty (elements excluded)
The HUUM HIVE 12STUX Package is covered by HUUM's 5-year limited warranty from the date of purchase. The warranty covers defects in manufacturing and materials under normal use conditions. Heating elements are excluded from the 5-year coverage and carry their own separate warranty period. The warranty does not cover damage caused by improper installation, incorrect dual-circuit wiring, use of incorrect or non-approved stones, operating the heater without the required stone load, or failure to follow HUUM's installation and operating guidelines. A licensed electrician is required for all electrical connections. Do not connect to GFI/GFCI breakers. Proof of purchase from an authorized HUUM dealer is required. We are an authorized HUUM dealer.
