The Brand Story
HUUM: A Grandson of Estonian Stove Builders Redraws the Sauna Heater
Siim Nellis grew up around sauna stoves the way other children grow up around cars. His grandfather, Paul Nellis, was a stonemason who built sauna stoves by hand in Estonia. His father built them too. When Siim started a sauna webshop in the late 2000s, he could see something his family's trade had never needed to think about: the world outside Estonia wanted saunas, and much of it wanted them powered by electricity rather than firewood. The heaters on offer were metal boxes that did their job and looked like it. He thought a sauna heater could be something you wanted to look at, and he went to his garage to prove it.
Chapter 1 · Three generations
A family trade meets a new market
HUUM describes its founder as a third-generation sauna stove maker, and the company's identity still rests on that inheritance. In the traditional Estonian sauna, the stove is the center of the room and the stones are the heart of the stove. A well-built heater holds heat in a deep mass of rock, and when water hits that rock the steam that rises is soft and lasting rather than sharp and brief. Siim wanted to keep that feeling while building an electric heater that could ship anywhere, install in a modern home and stand on its own as an object.
For years the work was mostly tinkering. He built and rebuilt prototypes in his garage, learning what electric elements, steel and stone would and would not do together. The engineering was coming along. The look was not.
Chapter 2 · 2011 to 2012
The students who drew the Drop
In 2011 Siim reached out to the Estonian Academy of Arts and asked its design students to imagine a sauna heater that was both functional and beautiful. One student's concept stood out: a rounded, open form that cradled a large pile of stones in plain view. The design was finalized in 2012 and given a name that matched its shape, DROP.
The round body was more than styling. HUUM explains that the shape lets the heater carry an unusually large load of stones while using less metal, which is exactly what produces the gentle, long steam of a traditional stove. It took roughly two more years, applications for European development funding and a search for the right manufacturer before the first heaters were ready for production. In 2015 the DROP won a Red Dot design award.
Chapter 3 · 2014
A sauna you can start from your phone
The heater solved one problem and revealed another. The sauna remote controls on the market, Siim felt, were stuck in the past, wired with network cables and run from dated web pages. A friend introduced him to Henrik Ling, who became HUUM's chief technology officer. The pair began with a Raspberry Pi prototype, moved to electronics designed in-house, added a cellular connection and later Wi-Fi, and went through about five versions before they had something that could be manufactured.
The result was UKU, a smart sauna control system introduced in 2014. It let owners set time and temperature and switch the sauna on remotely, so the stones could be hot by the time they got home. Later updates brought lighting and humidity control into the same app. UKU's function and design earned their own Red Dot award in 2021, and HUUM products have also received the European Product Design Award.
Chapter 4 · Listening to customers
From one heater to a family
As the brand traveled, customers began asking for things the DROP was never meant to be. Buyers in Germany wanted a rectangular black heater that would sit quietly in a minimalist room. The oldest players in the sauna trade asked whether HUUM would make a wood-burning stove. The company's customers came to include private homeowners, public sauna operators and short-term rental hosts, each with a different idea of what a sauna should be.
The answers became new product lines, each carrying the same stone-forward idea in a different body. HUUM has also used its craft beyond the showroom: in 2022 it helped start Saunas4Ukraine, an effort to supply Ukrainian soldiers with ten mobile laundry and sauna trucks.
The Lineup
What HUUM builds today
HUUM builds electric sauna heaters, wood-burning sauna stoves and the smart controls that run them, designed in Estonia and sold worldwide, with a dedicated U.S. site at huumsauna.com. HVAC365 carries a broad selection of the range:
- Electric sauna heaters: the Cliff and Cliff Mini series, including a compact 3.5 kW Cliff Mini for small rooms and a 6 kW Cliff, and the CORE series, rated up to 10.5 kW and offered with black, alder, aspen, thermo-aspen or customizable wood exteriors.
- Heater packages: Cliff and Cliff Mini heaters paired with the UKU control, so the heater and its controller arrive as a matched set.
- Sauna controls: digital controls for on/off, time and temperature, and Wi-Fi versions in black and mirror finishes that run from a phone.
- Wood-burning sauna stoves for owners who want the crackle of a real fire.
- Sauna accessories: lighting kits, textiles and cushions, and buckets, ladles and thermometers for the ritual of throwing water on the stones.
Heater sizing depends on the room's volume, its insulation and how much glass or bare stone it has, so the kilowatt rating should always be matched to the specific sauna, and electric heaters should be wired by a licensed electrician on a dedicated circuit.
At a Glance
HUUM by the numbers
- Home country
- Estonia
- Founder
- Siim Nellis
- Chief technology officer
- Henrik Ling
- First heater
- DROP, design finalized 2012
- Smart control
- UKU, introduced 2014
- Design awards
- Red Dot 2015 (DROP), Red Dot 2021 (UKU)
- Product focus
- Electric heaters, wood stoves, sauna controls
Questions
Frequently asked questions about HUUM
Where is HUUM from?
HUUM is an Estonian sauna heater company. It was founded by Siim Nellis, a third-generation sauna stove maker whose grandfather and father both built sauna stoves.
What is HUUM known for?
HUUM is known for open, stone-heavy electric heaters such as the DROP, Cliff and CORE, which hold a large mass of stones for soft, lasting steam, and for its UKU smart sauna control.
What is the HUUM UKU control?
UKU is HUUM's smart sauna control system, introduced in 2014. It sets time and temperature, can start the sauna remotely through an app, and in later versions also manages lighting and humidity.
Has HUUM won design awards?
Yes. The DROP heater won a Red Dot award in 2015, the UKU control won a Red Dot award in 2021, and HUUM products have also received the European Product Design Award.
Does HUUM make wood-burning sauna stoves?
Yes. Alongside its electric heaters, HUUM makes wood-burning sauna stoves, a line it developed after traditional sauna customers asked for one.
