ThermaSol Lumaria Indoor Glass Sauna Cabin (2-5 Person)

The Light Comes In. Everything Else Stays Out.

Most saunas ask you to disappear into a dark wooden box. The Lumaria does the opposite - it surrounds you with glass and pulls the whole room in.

A panoramic, floor-to-ceiling glass front turns this into something closer to a solarium than a sweat box: light pours across brushed Tyrol wood walls, the black-trimmed glass frames the view like a window you can sit inside, and the corner layout tucks into a room without ever feeling enclosed. You don't retreat into the Lumaria. You open a door, step in, and the day keeps going around you - just warmer, slower, and entirely yours.

Inside, the materials do the talking. Brushed Tyrol wood, left raw the way real sauna wood should be, warms and deepens with every session and carries that unmistakable cedar-and-heat character. The thermo-aspen benches stay smooth and comfortable even at full temperature, and they're built to resist moisture and stay true season after season. The 9kW Harvia Virta builds a deep, even heat - up to 194°F - held steady by multi-layer wood-fiber insulation, while full-spectrum LED lighting glows from beneath the benches and behind the backrest, shifting the mood from bright and clear to low and golden with a remote. The Harvia Xenio touchpad lets you set a delay start, schedule the week, and pre-heat from your phone through the MyHarvia app, so it's ready the moment you walk in.

This isn't a unit you hide in the basement. It's a piece you build a room around - and because it arrives as pre-finished panels rather than a flat-pack kit, it goes together in clear phases over a weekend with two to four people, no crane and no contractor, then sits right on your existing level, water-resistant floor. A quiet, glass-walled fixture of a home where wellness isn't somewhere you go, but somewhere you live.

Choose Medium for an intimate two-to-three-person retreat, or Large for a four-to-five-person room, each with a left- or right-corner layout selected at order.

• Panoramic, floor-to-ceiling glass front - a solarium-style indoor sauna, open and light-filled, never cramped
• Brushed Tyrol wood interior, left raw and untreated, with smooth thermo-aspen benches and backrest - a material that ages beautifully with the room
• 9kW Harvia Virta heater (up to 194°F) with Harvia Xenio Wi-Fi control + MyHarvia app
• 12-hour delay start and weekly scheduling - pre-heat on your terms
• Full-spectrum LED lighting under benches and behind the backrest, with remote, for personalized mood lighting
• Multi-layer wood-fiber insulation for efficient, consistent heat
• Two sizes: Medium (2-3 people) and Large (4-5 people); left- or right-corner layout
• Transparent tempered glass with black-trim/enamel frame; interior aspen handle, exterior matte black
• Pre-finished panels assembled in clear phases - a weekend project for two to four people, no crane
• Sits on your existing level floor; can be disassembled and relocated
• Requires a dedicated 240V/40A circuit and a 4.3" vent ducted to the outside - plan placement accordingly
• Included: sauna stones, control, sensor, 2 headrests, and wood platform

Sauna use isn't right for everyone. Consult your physician before use, especially if you are pregnant or have a heart condition, high or low blood pressure, or any cardiovascular or other medical concern. Begin with shorter, lower-heat sessions, hydrate, avoid alcohol before use, don't exceed ~30 minutes, and supervise children. Use only clean water on the stones. Install indoors in a dry, climate-controlled space, keep the vent connected and unobstructed, and leave benches uncovered in use.

• Free shipping in the continental US; cost quoted by location
• Delivered via flatbed trailer with on-site offloading, ~12-13 weeks; notified ~2 weeks ahead
• Assembly is a guided, multi-phase build (walls, benches, ceiling, glass) - plan on two to four people and a weekend, using common tools (drill with cross-head and torx bits, level, ladder, rubber mallet)
• The tempered-glass panels require careful two-person handling during install - the edges can shatter on a hard knock, so the glass goes in last and slow
• Plan your space - clearances differ by size:
  • Medium: cabin 67"w x 87"d x 83"h; minimum assembly clearance 91"w x 107"d x 95"h
  • Large: cabin 87"w x 87"d x 107"h; minimum assembly clearance 110"w x 110"d x 95"h
  • Both: a room ceiling height of at least 8', and a 2" air gap between the unfinished cabin sides and adjacent walls
• Ventilation: the sauna requires a 4.3" vent connected to a duct that leads outside the wall cavity, to carry warm, moist air away from the structure. This affects where the Lumaria can go - choose a room where that duct run is possible
• Sits directly on existing level, water-resistant flooring (concrete, ceramic tile, vinyl, or laminate)
• Electrical (heater, control, lighting) is wired during assembly; the heater requires a dedicated 240V, 40-amp circuit installed by a licensed electrician (lighting 110V). All electrical work must be done by a licensed electrician

Download the ThermaSol Lumaria specification sheet (PDF)

By size

Shared across both sizes

Is the Lumaria an indoor or outdoor sauna?
Indoor. It's designed to sit inside a dry, climate-controlled space on an existing level floor, with a panoramic glass front that blends into modern interiors.

What sizes does it come in, and how many people does each seat?
Two: Medium seats two to three (67" x 87", 40 sq ft interior), and Large seats four to five (87" x 87", 53 sq ft interior). Both use a corner layout with a left- or right-hand entrance chosen at order.

How much room do I actually need?
More than the cabin footprint. The Medium needs a minimum assembly clearance of 91" x 107" x 95" tall; the Large needs 110" x 110" x 95" tall. Both need a room ceiling height of at least 8' and a required 2" air gap between the unfinished cabin sides and adjacent walls.

How hard is it to assemble?
It's a guided, multi-phase build rather than a flat-pack chair. Plan on two to four people over a weekend, with common tools - a drill, level, ladder, and rubber mallet. The panels are pre-finished and the joints are pre-drilled, so it goes together in a clear sequence, but the tempered glass goes in last and needs careful two-person handling.

Does it need ventilation?
Yes. The Lumaria requires a 4.3" vent connected to a duct that runs outside the wall cavity, which carries warm, moist air away from the structure and protects it long-term. Choose a room where that duct run is possible - it's worth confirming before you order.

What electrical setup does it need?
The 9kW Harvia Virta heater needs a dedicated 240V, 40-amp circuit; the lighting runs on 110V. All electrical work - heater, controller, and LED wiring - must be completed by a licensed electrician, and is done during assembly.

Does it need a special floor?
It sits directly on existing level, water-resistant flooring - concrete, ceramic tile, vinyl, or laminate. If your floor doesn't qualify, an alternative base may be needed.

Can I control it from my phone?
Yes - the Harvia Xenio control offers a 12-hour delay start, weekly scheduling, and Wi-Fi control through the MyHarvia app, so it's hot when you want it.

What's the warranty?
The sauna structure carries a 1-year limited warranty against manufacturing defects from completion of installation. The Harvia heater, Xenio control, and power box are covered for 5 years in residential use (stones and heating elements, 1 year). To keep coverage valid, the sauna must be installed by a certified electrician and registered within 15 days of purchase. Full terms at thermasol.com/pages/warranty.

What's included?
Sauna stones, the control and temperature sensor, two headrests, a wood platform, and MyHarvia app access. Optional accessories (pail and ladle, cushions, aromatherapy, decorative stones, timer) are available.

Can I move it later?
Yes - it's freestanding and can be disassembled and relocated.