COLUMN 02 — Future Sauna
Saunas of the Future, Heated by Hydrogen
For a long time, the heat sources used in saunas have been supplied by wood, electricity, and gas. But now, the fuel itself is beginning to change.
That shift is embodied in a new concept: the Hydrogen Sauna.
This initiative was brought to life through the world's first hydrogen combustion sauna concept model, jointly developed by the Finnish sauna manufacturer Harvia and Japan's leading automotive company, Toyota Motor Corporation.
Behind its creation lies the city of Jyväskylä in Central Finland. The region is home to Cefmof (Central Finland Mobility Foundation), a nonprofit organization dedicated to promoting the adoption and utilization of hydrogen. In collaboration within this region, Toyota and Harvia developed the hydrogen sauna as an innovative heat source aimed at achieving carbon neutrality.
What Is a Hydrogen Sauna?
In traditional saunas, stones are heated in a stove, and water is poured over them to generate steam. In contrast, hydrogen saunas are designed so that the combustion of hydrogen gas itself becomes the heat source, producing heat and water vapor simultaneously.
What is generated during combustion is only water (H₂O)—in the form of steam—and warm air. No carbon dioxide (CO₂) or carbon monoxide (CO) is emitted, and no chimney is required, making it an exceptionally clean system.
As a result, the sauna room naturally fills with soft, moisture-rich steam (löyly), creating a new heat quality distinct from conventional saunas. Sauna stones heated evenly through hydrogen combustion gently warm the space from all directions. The contours of the heat feel softer, while mild steam envelops the air.
Japan Premiere at Japan Mobility Show 2025
This hydrogen sauna was first unveiled in Japan at "Japan Mobility Show 2025," held from October 30 to November 9, 2025, at Tokyo Big Sight. The exhibition booth was titled "H2 LÖYLY LAB – Future Sauna Mobility," attracting attention as a vision of the sauna of the future.
At the exhibition, the clean heat and water vapor generated during combustion, along with its safety features and development background, were introduced through informational panels and staff explanations. A public experience program was also conducted through an advance lottery system.
Bridging Tradition and the Future
Hydrogen saunas aim to recreate the soft heat of Finland's traditional smoke saunas, while evolving toward the use of clean energy that significantly reduces environmental impact.
Depending on how it is used, it can be designed to operate without external power sources or chimney infrastructure—opening possibilities for new sauna experiences in locations where installation was previously impossible.
This technology simultaneously pursues a future vision of harmony with the environment, mobility, and sustainability—without compromising the cultural essence of sauna: the shared joy of fire and heat.
Saunas heated by hydrogen may well represent the next chapter of sauna culture—an emerging experience that deserves to be told as part of the world's evolving sauna story.