HUUM DROP 4.5 DROP Series 4.5kW Sauna Heater
The HUUM DROP 4.5 is a 4.5kW wall-mounted electric sauna heater for small sauna rooms from 106 to 177 cubic feet, with the iconic water-droplet form. This listing is the heater only. A UKU control unit and sauna stones are required for operation and sold separately. The DROP 4.5 is the entry model in the HUUM DROP wall-mounted series - the smallest output in the DROP range for rooms from 106 to 177 cubic feet on a single 30A / 10 AWG circuit. No UKU Extension Box is required. The DROP 4.5 delivers the distinctive DROP water-droplet profile and 122-lb stone capacity of the full DROP series in the output appropriate for personal home saunas, apartment saunas, and compact two-person rooms. For a complete installation including control and stones in a single purchase, see the HUUM DROP 4.5STU Package listing at BathingBrands.
The DROP design - water-droplet form, wall-mounted, 122 lbs of stone
The HUUM DROP is one of the most recognised sauna heater silhouettes in contemporary sauna design - a smooth, rounded water-droplet form that mounts on the sauna wall with the pointed end facing downward. Unlike conventional rectangular wall-mounted heaters, the DROP's curved profile reads as a sculptural object in the sauna room rather than an appliance. At 4.5kW for rooms from 106 to 177 cubic feet, the DROP 4.5 carries 122 lbs of 2"-4" (5-10 cm) rounded olivine diabase stones - a generous stone capacity for a small-room wall-mounted heater, providing good thermal mass for sustained steam quality in the compact room it serves. The stone placement video in the documents section below covers the correct method for loading 122 lbs of stones into the DROP basket, which is important for element life and steam performance.
4.5kW - the entry DROP for rooms 106-177 cu ft
The DROP series runs from 4.5kW to 9kW: DROP 4.5 (106-177 cu ft, 30A / 10 AWG), DROP 6 (177-318 cu ft, 30A / 10 AWG), DROP 7.5 (248-389 cu ft, 40A / 8 AWG), and DROP 9 (318-530 cu ft, 50A / 8 AWG). The DROP 4.5 is the correctly sized DROP for rooms at the small end of the HUUM range - personal home saunas, pre-built sauna cabins for one or two people, apartment saunas, and smaller-footprint dedicated sauna rooms. For rooms below 106 cu ft or above 177 cu ft, a different DROP or a different HUUM heater series is appropriate. The Size Your Sauna document below and the HUUM heater calculator at BathingBrands confirm the correct model for a specific room size.
Stone placement matters - follow the Stone Placement Video
Correct stone placement in the DROP basket is important for heating element longevity and steam quality. The DROP's curved basket geometry requires stones to be loaded in a specific pattern that ensures adequate airflow around the elements and even thermal contact across the stone mass. The Stone Placement Video in the documents section below walks through the correct loading procedure step by step. Incorrect stone placement - packing stones too tightly around the elements or loading stones of the wrong size - is one of the most common causes of early element failure in DROP heaters. Use only 2"-4" (5-10 cm) rounded olivine stones as specified in the Stone Requirements document.
4.5kW wall-mounted sauna heater for rooms from 106 to 177 cubic feet. Iconic water-droplet form. Entry model in the DROP series. 122 lbs stone capacity - 2"-4" rounded olivine. No UKU Extension Box required. UKU control (Local Black or WiFi) sold separately. Stones sold separately. Single 30A breaker, 10 AWG wire. 240V / 1-phase. SGS Listed. 5-year warranty (elements excluded). Made in Estonia by HUUM. See DROP 4.5STU Package for complete bundled purchase.
4.5 kW 106 to 177 cu ft Water-droplet wall-mounted form Entry model in the DROP series 122 lb stone capacity 2"-4" rounded olivine stones (sold separately) UKU control sold separately No UKU Extension Box required Single 30A breaker - 10 AWG - 240V 1-phase SGS Listed - made in Estonia 5-year warranty (elements excluded)
Specifications
Electrical
| Power output |
4.5 kW |
| Voltage |
240V / 1-phase / 60 Hz |
| Amperage draw |
18.75 A |
| Circuit breaker required |
Single 30A (standard 2-pole - no GFI/GFCI) |
| Wire gauge |
10 AWG |
| UKU Extension Box required |
No |
| Certification |
SGS Listed |
Room sizing and stones
| Room volume |
106 to 177 cu ft |
| Stone capacity |
122 lbs |
| Stones included |
No - sold separately |
| Stone size |
2" to 4" (5-10 cm) rounded olivine |
| Max temperature |
230°F (110°C) |
Design and installation
| Form |
Water-droplet - wall-mounted |
| Profile |
Rounded, pointed base - mount point up |
| Construction |
Stainless steel |
| Control included |
No - UKU Local Black or WiFi sold separately |
| Origin |
Made in Estonia by HUUM |
DROP series comparison
| DROP 4.5 (this listing) |
4.5kW | 106-177 cu ft | 30A / 10 AWG | 122 lbs |
| DROP 6 |
6kW | 177-318 cu ft | 30A / 10 AWG | 122 lbs |
| DROP 7.5 |
7.5kW | 248-389 cu ft | 40A / 8 AWG | 122 lbs |
| DROP 9 |
9kW | 318-530 cu ft | 50A / 8 AWG | 122 lbs |
Control options (sold separately)
| UKU Local Black |
Wall-mounted digital control - on-site operation |
| UKU WiFi |
HUUM app - iOS and Android - remote preheat |
| UKU Extension Box |
Not required for 4.5kW |
Warranty
| Warranty period |
5 years (elements excluded) |
| SKU |
H1001052 |
What's included
HUUM DROP 4.5kW wall-mounted sauna heater - water-droplet form
Mounting hardware
Installation and operation manual
Required (sold separately): UKU control unit (Local Black or WiFi); sauna stones (122 lbs, 2"-4" rounded olivine - see Stone Requirements). See also: DROP 4.5STU Package for a bundled purchase. Watch the Stone Placement Video before loading stones. A licensed electrician is required. Do not connect to a GFI/GFCI breaker.
Why the HUUM DROP 4.5 stands out
Iconic water-droplet form - smallest DROP
The DROP 4.5 delivers the full DROP water-droplet aesthetic - one of the most recognisable contemporary sauna heater silhouettes - in the output appropriate for rooms from 106 to 177 cubic feet. For small personal home saunas, apartment saunas, and compact two-person rooms where the DROP's sculptural wall-mounted presence is the design goal, the DROP 4.5 is the entry point to the series.
30A / 10 AWG - no Extension Box
The DROP 4.5 runs on a single 30A / 10 AWG circuit without a UKU Extension Box - the lightest floor-standing-equivalent DROP circuit (shared with the DROP 6). For small sauna rooms in homes or apartments where panel capacity is a consideration, the 30A / 10 AWG specification of the DROP 4.5 is among the most accessible electrical requirements of any HUUM heater with this stone capacity.
122 lbs of stone - generous for 4.5kW wall-mounted
The DROP 4.5 carries 122 lbs of 2"-4" rounded olivine stones - the same capacity as the DROP 6. At 4.5kW driving 122 lbs of stone mass, the thermal reserve is proportionally high relative to the output: more stone mass at lower output means softer, longer-lasting steam and better temperature stability in the 106-177 cu ft room the DROP 4.5 serves.
Stone placement video - critical for element life
The Stone Placement Video in the documents below walks through the correct method for loading 122 lbs of stones into the DROP basket. Correct stone placement ensures adequate airflow around the heating elements and even thermal distribution through the stone mass. HUUM recommends watching this video before loading stones for any DROP heater installation - incorrect placement is a leading cause of premature element failure.
UKU WiFi - remote preheat for a small sauna
A 106-177 cu ft sauna room at 4.5kW reaches bathing temperature in 15-25 minutes. The UKU WiFi (sold separately) adds HUUM app remote preheat on iOS and Android - start the sauna before leaving work or from the other room and arrive to a ready temperature. No Extension Box required for the 4.5kW DROP. The UKU Local Black provides on-site digital control without app connectivity.
DROP 4.5STU Package - complete bundled option
The DROP 4.5STU Package at BathingBrands bundles the DROP 4.5 heater, UKU control (Local Black or WiFi at checkout), and stones in a single purchase. This standalone listing is for buyers replacing just the heater in an existing DROP installation, or purchasing components in separate transactions. For most new installations, the Package is the more convenient path.
About HUUM
Made in Estonia - SGS Listed
HUUM DROP 4.5. 4.5kW. 106-177 cu ft. Water-droplet form. 122 lbs of stone. 30A circuit.
HUUM is an Estonian sauna heater company. The DROP 4.5 is the entry model in the HUUM DROP wall-mounted series - the iconic water-droplet form in the 4.5kW output for rooms from 106 to 177 cubic feet on a single 30A / 10 AWG circuit. This listing is the heater only. UKU control and stones are required and sold separately. See the DROP 4.5STU Package for a bundled purchase. Watch the Stone Placement Video before loading stones. We are an authorized HUUM dealer.
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4.5kW, 106-177 cu ft - single 30A / 10 AWG, 240V/1PH
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Water-droplet wall-mounted form - iconic DROP design
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122 lbs stone capacity - 2"-4" rounded olivine
- No UKU Extension Box required
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UKU control + stones sold separately - DROP 4.5STU Package also available
DROP standalone vs DROP 4.5STU Package
Standalone heater vs DROP 4.5STU Package - which to order
This listing is the DROP 4.5 heater only. For operation, a UKU control unit and stones are required and sold separately. The DROP 4.5STU Package bundles all three in a single purchase with the UKU IOM, UKU Diagram, and UKU Video included alongside the DROP documents. This standalone listing documents only the DROP heater itself - the installation and stone placement documents below are for the heater. For most new DROP installations, the Package is the more convenient and complete option. Stone specification: 2"-4" (5-10 cm) rounded olivine only. Watch the Stone Placement Video before loading. Do not connect to a GFI/GFCI breaker. A licensed electrician is required for the 30A / 10 AWG circuit.
Manuals and Documents
Warranty
5-year limited warranty (elements excluded)
The HUUM DROP 4.5 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 stone placement, use of incorrect stone size (non 2"-4" stones), operating without the required stone load, or failure to follow HUUM's installation and stone placement guidelines. Watch the Stone Placement Video before loading stones. A licensed electrician is required. Do not connect to a GFI/GFCI breaker. Proof of purchase from an authorized HUUM dealer is required. We are an authorized HUUM dealer.
