ThermaSol

ThermaSol is the premium American sauna and steam brand under the Harvia Group, the Finnish heater and wellness conglomerate listed on the Helsinki exchange. The outdoor cabins on this page are built by Kirami in Sastamala, Finland, on the same FinVision production line that supplies Kirami’s European dealers. The indoor cabins are built in the United States. Every cabin ships with a Harvia heater. We carry the full ThermaSol catalog: ten outdoor cabins, four indoor cabins, and Nordic Misty modular add-ons.

The heritage

ThermaSol was founded in 1958 in California by David Altman, who designed the first electric residential steam shower for a Park Avenue apartment. The company moved to Round Rock, Texas in 2014. In July 2024, Harvia Group acquired ThermaSol for $30.4 million, gaining access to ThermaSol’s distribution network of roughly 2,500 plumbing wholesale, kitchen and bath, and design dealers across North America and Europe. The sauna lineup we sell here launched on that same channel as Harvia’s American premium play.

Built in Finland by Kirami

The ten outdoor cabins in this catalog are produced at Kirami’s factory at Villilantie 2, Sastamala, Finland. Kirami opened a dedicated Sauna Factory in November 2020 with approximately 32,000 square feet of heated production space, adjacent to the wood-fired hot tub line Kirami has run for thirty years. Harvia acquired Kirami in May 2021 for EUR 7 million plus an EUR 4 million earnout. The FinVision line carries the Finnish Key Flag Symbol (Avainlippu), the credential that certifies a product as Finnish-designed, Finnish-manufactured, and built from Finnish materials.

The Kirami connection is visible in Kirami’s own image archive: file names follow the pattern kiramibyharvia_kir-XXXX.png across the FinVision production line. Five of our outdoor cabins map directly to Kirami’s catalog: Nordic Misty Small (FinVision S Misty), Nordic Misty Medium (FinVision M Misty), Nordic Dawn (FinVision M Dawn), Solaris Small (FinVision S Zero), Solaris Medium (FinVision M Zero). The other five (Vue, Ombra, Spectra, Fortis, Vera) are additional configurations of the same production line, branded for the American premium market with different glass treatments and exterior wood species. The Ombra ships under Kirami’s internal working name “Velden XL” in non-US markets.

Awards and recognition

Solaris (S Zero / M Zero): Named to TIME’s Best Inventions of 2025 as the world’s first fully self-sufficient off-grid electric sauna.

Vue: 2026 LUXE RED Award and Hospitality Design Awards finalist for its 34-millimeter mirrored thermal glass facade.

The outdoor catalog (built in Finland by Kirami)

Nordic Misty Small: 2 to 4 people, modular system with optional lounges, terraces, pergolas, and changing rooms.

Nordic Misty Medium: 4 to 5 people, same modular system, 9 kW Harvia Virta or Legend 240 wood-burning heater.

Nordic Dawn: 4 to 5 people, full-front double-glazed argon window, heat-treated Finnish pine, 9 kW Harvia Spirit.

Solaris Small: Off-grid solar sauna, 2 to 3 people, triple-pane argon glass, integrated rooftop and wall solar panels.

Solaris Medium: 4 to 5 people, same off-grid solar system.

Vue: 3 to 4 people, Mirror+ glazing transparent by day and mirrored by night, 9 kW Virta.

Ombra: 4 to 5 people, flagship outdoor, IPE Lapacho wave-pattern cladding, natural skylight, private dressing lounge, 10.5 kW Virta.

Spectra: 3 to 4 people, Thermally Modified Tyrol panels, STEICO insulation, Firestone EPDM roof, 8 kW Virta.

Fortis: 3 to 4 people, eave-style roofline, brushed Tyrol facade, 8 kW Virta.

Vera: 2 to 3 people, smallest outdoor footprint (63 by 87 inches), dual mirrored Parsol glass walls, 8 kW Virta.

The indoor catalog (built in the USA by ThermaSol)

Aalto: Named for Finnish architect Alvar Aalto. 3 to 4 people, Brushed Tyrol walls, RGB color-therapy LEDs, 9 kW Virta.

Astra: 3 to 4 people, disciplined glass-panel front for primary baths, 9 kW Virta.

Lumaria Medium: 2 to 3 people, panoramic transparent glass front, 9 kW Virta.

Lumaria Large: 4 to 5 people, same construction in a larger footprint.

Why we carry ThermaSol

The American premium sauna market has been culturally Finnish for years, but most cabins arriving in American backyards have been built in Estonia (Auroom) or Germany (Klafs). The ThermaSol lineup closed that loop: the outdoor cabins are now built in Finland, by a Finnish manufacturer, with Finnish heaters, and shipped through a 2,500-dealer American distribution network. There is no other premium American sauna brand with this combination of provenance and reach.

Every cabin in this catalog ships with free shipping, a Harvia heater pre-wired at the factory, and access to our Bens-on-site installation program when scheduling aligns. We carry the full lineup, we know the construction in detail, and we will tell you the trade-offs (Solaris winter solar yield, forklift logistics, lead times) before you order rather than after.

Frequently asked questions

Are ThermaSol outdoor saunas really made in Finland? Yes. The ten outdoor cabins on this page are built at Kirami’s factory in Sastamala, Finland, on the same FinVision production line that supplies Kirami’s European customers. Final delivery and installation happen in the United States.

Who is Kirami? Kirami is a Finnish wood-fired hot tub and sauna manufacturer founded in 2001, based in Sastamala. Harvia Group acquired Kirami in May 2021. Kirami opened a dedicated Sauna Factory in November 2020 and has been shipping FinVision cabins to European dealers ever since.

What is the warranty on a ThermaSol outdoor cabin? The Nordic Misty Small and Medium carry a 2-year warranty. The other outdoor cabins (Nordic Dawn, Solaris Small/Medium, Vue, Ombra, Spectra, Fortis, Vera) carry a 1-year warranty. Heaters carry the standard Harvia 1-year warranty. Indoor cabins carry a 1-year warranty.

Does ThermaSol still sell steam generators? Yes. ThermaSol’s original product line is residential steam generators and steamhead systems. The sauna cabin lineup is a 2024 launch and runs alongside the steam catalog. We focus on the sauna cabins on saunamarketplace.com.

Is the ThermaSol indoor line also Finnish-built? The indoor cabins (Aalto, Astra, Lumaria Medium/Large) are built in the United States by ThermaSol. They ship as components for on-site assembly rather than as the fully-assembled outdoor modules.