The HUUM DROP 9STU Package is a complete sauna heater package for rooms from 318 to 460 cubic feet, including the award-winning DROP 9kW wall-mounted heater, UKU sauna control (Local Black or WiFi - selected at checkout), and 122 lbs of rounded olivine diabase sauna stones. The DROP 9kW is the highest output model in the DROP series - the top of the range for sauna rooms that exceed what the 4.5kW, 6kW, and 7.5kW models can cover. It shares the same external body dimensions, the same 122-lb stone capacity, and the same water-droplet design as every other DROP model. What changes at 9kW is the electrical requirement: a 50A breaker and 6 AWG wire, and the room coverage that steps up to 460 cubic feet.
9kW - the top of the DROP series for the largest rooms
The DROP series runs from 4.5kW to 9kW across four models with identical external dimensions. At 9kW, the DROP covers sauna rooms from 318 to 460 cubic feet - the range appropriate for large residential saunas, multi-bench installations, and sauna rooms with significant cold surfaces (glass walls, tile floors, natural stone or masonry panels) that increase the adjusted room load beyond what a smaller model can effectively heat. The 9kW model has more heating elements inside the same cage as the 4.5, 6, and 7.5kW versions - the physical size of the basket and the 122-lb stone capacity are identical across all four output levels. For rooms at or approaching 460 cubic feet, the DROP 9 is the appropriate choice within the DROP series. For rooms exceeding 460 adjusted cubic feet, HUUM's STEEL or other higher-output models should be considered.
50A / 6 AWG - planning the electrical installation
The DROP 9kW requires a dedicated 240V/1-phase circuit with a 50A two-pole breaker and 6 AWG wire. This is a heavier electrical specification than the DROP 4.5 and 6 (both 30A / 10 AWG) and the DROP 7.5 (40A / 8 AWG). For new sauna installations where the electrical panel is being planned from scratch, specifying a 50A circuit for the DROP 9 is straightforward. For retrofits where the panel has limited capacity, it is worth confirming available breaker slots and panel headroom before ordering. All electrical work must be completed by a licensed electrician in compliance with local codes. Do not connect to a GFI/GFCI breaker.
122 lbs of stone and UKU control - same specification as every DROP
The DROP 9 carries the same 122-lb stone capacity as every DROP model and the same rounded olivine diabase stone specification: 2"-4" (5-10 cm) rounded stones for dense packing, good water flow when ladling, and soft, consistent steam throughout the session. The 4 boxes of stones included in this package are the correct type and quantity for the DROP 9. The UKU control is included - choose UKU Local Black for on-site digital control, or upgrade to UKU WiFi at checkout for HUUM app remote preheat and scheduling on iOS and Android. Neither variant requires an extension box for the DROP 9kW.
Complete 9kW wall-mounted sauna heater package for rooms from 318 to 460 cubic feet. Includes DROP 9kW heater, UKU control (Local Black or WiFi - select at checkout), and 122 lbs of rounded olivine diabase stones (4 boxes). Top of the DROP series - maximum output in the same award-winning water-droplet body. Same 122 lb stone capacity and body dimensions as all DROP models. Red Dot Award-winning design. Direct stone-to-element contact for even heat. Soft, consistent, long-lasting steam. Stainless steel construction. 240V / 1-phase. 50A breaker, 6 AWG wire. Max 230°F. 2" safety clearance all sides. SGS Listed. 5-year warranty (elements excluded). Made in Estonia by HUUM.
Complete package - control + 122 lbs stones included 9 kW 318 to 460 cu ft Top of the DROP series Red Dot Award-winning design Water-droplet inspired form 122 lb stone capacity - 4 boxes olivine included More stone mass than most wood-burning stoves Soft consistent steam - rounded olivine diabase UKU Local Black or UKU WiFi - select at checkout HUUM app - iOS and Android (WiFi variant) 240V / 1-phase - 50A breaker - 6 AWG Stainless steel - made in Estonia SGS Listed 5-year warranty (elements excluded)
Specifications
Electrical
| Power output |
9 kW |
| Voltage |
240V / 1-phase / 60 Hz |
| Amperage draw |
37.5 A |
| Circuit breaker required |
50 A (standard 2-pole - no GFI/GFCI) |
| Wire gauge |
6 AWG |
| Certification |
SGS Listed |
Room sizing and stones
| Room volume |
318 to 460 cu ft |
| Stone capacity |
122 lbs (55 kg) |
| Stones included |
Yes - 4 boxes rounded olivine diabase |
| Stone size |
2" to 4" (5-10 cm) rounded |
| Max temperature |
230°F (110°C) |
Physical
| Dimensions (W x D x H) |
15.4" x 13.2" x 23.3" (390 x 335 x 590 mm) |
| Heater weight |
24 lbs |
| Construction |
Stainless steel |
| Mounting |
Wall-mounted |
| Safety clearance |
2" all sides |
| Origin |
Made in Estonia by HUUM |
Control options - select at checkout
| UKU Local Black |
Wall-mounted digital control - on-site operation |
| UKU WiFi |
Adds HUUM app remote preheat and scheduling |
| App |
HUUM app - iOS and Android (WiFi variant) |
| UKU Extension Box required |
No - only needed for heaters over 11kW |
DROP series output comparison
| DROP 4.5kW |
106-248 cu ft | 30A / 10 AWG |
| DROP 6kW |
177-318 cu ft | 30A / 10 AWG |
| DROP 7.5kW |
248-389 cu ft | 40A / 8 AWG |
| DROP 9kW (this listing) |
318-460 cu ft | 50A / 6 AWG |
| Body dimensions |
Identical across all four output levels |
| Stone capacity |
122 lbs - identical across all four |
Warranty and awards
| Warranty |
5 years (elements excluded) |
| Design award |
Red Dot Award winner - product design |
| Design inspiration |
Water droplet form |
What's included
HUUM DROP 9kW wall-mounted sauna heater - stainless steel
UKU sauna control (Local Black or WiFi - selected at checkout)
Rounded olivine diabase sauna stones - 4 boxes (122 lbs)
Wall mount bracket and hardware
Installation and operation manual
Optional accessories (sold separately): HUUM safety railing (recommended), HUUM Drip Tray, HUUM Flange D (for bench embedding). A licensed electrician is required for all electrical connections.
Why the HUUM DROP 9STU Package stands out
Top of the DROP series - 9kW for large rooms
The DROP 9kW is the highest output in the DROP range, covering rooms from 318 to 460 cubic feet in the same compact wall-mounted body as the 4.5, 6, and 7.5kW models. For large residential saunas, multi-bench rooms, or rooms with cold surfaces that drive up the adjusted cubic footage, the DROP 9 is the correct DROP model. Rooms exceeding 460 adjusted cu ft require stepping up to HUUM's higher-output range.
122 lbs of stone - same as every DROP model
The DROP 9 carries the same 122-lb stone capacity as the 4.5, 6, and 7.5kW models. With more output driving the same stone mass, the DROP 9 reaches temperature faster and maintains it across larger room volumes. Direct element-to-stone contact throughout the full 122-lb load ensures consistent heat distribution and soft, long-lasting steam even in the largest rooms the DROP series covers.
Same body dimensions as all DROP models
Despite being the highest output DROP, the 9kW is physically identical to the 4.5kW - same 15.4"W x 13.2"D x 23.3"H cage, same 2" safety clearances, same wall bracket. The heater footprint and installation requirements do not change with output level within the DROP series. A larger room requires the same amount of wall space and the same installation procedure as a smaller one.
Red Dot Award design - the same in every room size
The water-droplet form that won the Red Dot Award applies identically to the DROP 9 as to every other DROP output level. The organic rounded body softens the angular interior of a large sauna room and makes the heater a design element rather than a utility appliance on the wall - the aesthetic effect is the same whether the room is 106 or 460 cubic feet.
UKU WiFi option - preheat a large sauna remotely
Large sauna rooms take longer to reach temperature - a 400 cu ft room with a 9kW heater may need 45-60 minutes to reach bathing temperature. Upgrading to UKU WiFi at checkout makes remote scheduling essential rather than just convenient: start the preheat from the HUUM app before leaving work and arrive to a ready sauna, without needing to plan around the warm-up cycle.
50A / 6 AWG - plan the electrical before ordering
The DROP 9kW requires a 50A two-pole breaker and 6 AWG wire - heavier than the lower DROP models. Confirm that the electrical panel has a free 50A slot and sufficient remaining capacity before ordering. All wiring must be completed by a licensed electrician. Do not connect to a GFI/GFCI breaker. The UKU Extension Box is not required for the DROP 9kW.
About HUUM
Made in Estonia - Red Dot Award winner
HUUM DROP 9STU. 9kW. 318-460 cu ft. The top of the DROP series - maximum output, same award-winning design.
HUUM is an Estonian sauna heater company founded on the principle that electric sauna heaters should produce the quality of steam experience associated with traditional wood-burning stoves. The DROP 9STU Package is the complete top-of-range DROP installation: the 9kW heater, the UKU control, and 122 lbs of rounded olivine diabase stones - everything needed for a large sauna room up to 460 cubic feet. The same Red Dot Award-winning form, the same 122-lb stone capacity, and the same direct element-to-stone contact as every DROP model, at the output level required for the largest rooms in the DROP series. We are an authorized HUUM dealer.
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Complete package - DROP 9kW, UKU control, and 122 lbs rounded olivine stones
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9kW, 318-460 cu ft - 240V/1PH, 50A breaker, 6 AWG
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Top of the DROP series - maximum output in the compact DROP body
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122 lb stone capacity - same as all DROP models
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UKU Local or WiFi at checkout - 5-year warranty (elements excluded)
Choosing the right DROP output level
Which DROP is right - 4.5, 6, 7.5, or 9kW?
All four DROP models share the same body, stone capacity, and design. The selection is based entirely on room size and adjusted cubic footage. DROP 4.5kW: 106-248 cu ft, 30A / 10 AWG. DROP 6kW: 177-318 cu ft, 30A / 10 AWG. DROP 7.5kW: 248-389 cu ft, 40A / 8 AWG. DROP 9kW: 318-460 cu ft, 50A / 6 AWG. Adjusted cubic footage accounts for cold surfaces - glass, tile, natural stone, and masonry all absorb heat and effectively increase the room load beyond the raw volume. A 350 cu ft room with a glass wall may have an adjusted load equivalent to 420-430 cu ft. Use HUUM's online calculator or contact BathingBrands for sizing guidance before selecting the output level. For rooms below 318 cu ft, the DROP 7.5 or lower is the appropriate model - the DROP 9 is oversized for small rooms and will not perform optimally at reduced output.
A licensed electrician is required. Do not connect to a GFI/GFCI breaker. The UKU Extension Box is not required for any DROP model (4.5 through 9kW). The optional HUUM safety railing is recommended for all DROP installations.
Manuals and Documents
Warranty
5-year limited warranty (elements excluded)
The HUUM DROP 9STU 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, 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 a GFI/GFCI breaker. Proof of purchase from an authorized HUUM dealer is required. We are an authorized HUUM dealer.
