What Harvia owners say
Public reviews and notes owners sent our team, word for word. Names are shortened to a first name and last initial, or to initials.
★★★★★“The heater and rocks came in a timely manner and were well packed on an individual pallet. The heater was undamaged and works great! Now it’s time to get my sweat on!”
★★★★★“The stove arrived yesterday afternoon in perfect condition. Thank you!!”
★★★★★“I used the new heater last night for the first time. Worked AWESOME. Looks AWESOME! You guys are great, thanks so much”
★★★★★“Man you are awesome and I will keep buying”
★★★★★“Delivery packaging was World Class!!!”
★★★★★“Customer service is ABSOLUTELY AMAZING! Super fast delivery!”
★★★★★“I will recommend your site to other sauna lovers based on the constant communication and follow-through I have experienced.”
The ThermaSol outdoor sauna lineup
The Solaris Medium is the four-to-five-person off-grid sauna in the ThermaSol line. Same Harvia KIP heater and solar-and-battery system as the Solaris Small, scaled up to a square 86 by 86 inch footprint with about 242 cu ft inside.
How the off-grid system works
Rooftop panels feed an onboard battery bank that powers the 3 kW Harvia KIP heater through a CX170 controller. No 240V drop, no chimney, no recurring wood. Heat-up runs 45 to 60 minutes from a fully charged bank. Yield drops in winter and on overcast weeks, which is the trade-off of off-grid; we curate at the build-spec level and would rather you know that up front.
Solar monitoring app
A companion mobile app reports solar yield, battery charge state, and heater status from your phone, so you can check capacity before heading out to a remote site or schedule a session for after a sunny afternoon. The Harvia CX170 controller drives the heater on command once the battery bank has the energy to back it.
Spec sheet
- Footprint: 86 by 86 inches, 97 inches tall; interior about 242 cu ft
- Capacity: 4 to 5 adults
- Heater: 3 kW Harvia KIP; Controller: Harvia CX170
- Cladding: Tile Oak inside and out, Brushed Alder benches
- Glass: solar-tinted panoramic; RGB LED color lighting
- Power: integrated solar with battery bank; Built in Finland by Kirami
Built by Kirami in Finland
Solaris Medium is sold in Europe as the Kirami FinVision® -sauna M Zero. Kirami is a family-run Finnish manufacturer that builds these saunas from start to finish at their own factory in Sastamala, Finland. The FinVision® line carries the Finnish Key Flag Symbol (Avainlippu): the credential that certifies Finnish-designed, Finnish-manufactured, and built from Finnish materials.
The Kirami FinVision® Zero line launched in 2024 as the world’s first fully self-sufficient off-grid electric sauna. Triple-pane argon-filled tempered glass, fully insulated walls, and enclosed tiled benches reduce the sauna’s effective heated volume to about 179 cu ft, which is why a small 3-3.6 kW heater can do the work of an 8-10 kW heater in a conventional outdoor sauna of the same exterior footprint.
Kirami joined the Harvia Group in May 2021, so the heater you choose and the sauna it sits in are now sister-company products engineered together. The integrated LED lighting wires into the Harvia Xenio control panel, which means one controller for heat, time, and ambiance.
Finnish ventilation engineering: fresh air enters through the intake on the heater side wall; spent air exhausts through the vent at the opposite upper back corner. Continuous airflow during a session without the cold drafts that plague poorly ventilated outdoor saunas.
Kirami construction details
Same triple-pane argon-filled tempered glass construction as the Solaris Small, applied across the larger footprint. LED lighting in the backrest; the Harvia CX170 control panel handles heat, timing, and lighting from a single interface. Solar system uses three 410-watt panels and two 25.6-volt lithium battery packs; a full charge typically delivers 2 to 3 hours of bathing or 4 to 5 hours in full sun. A companion Bluetooth app reports panel yield, battery state, and heater status in real time. Kirami’s framing: “modern design and practicality, combining Finnish traditions with sophisticated European aesthetics.”
FAQ
How many people fit?
Four to five adults.
How long does it take to heat up?
About 45 to 60 minutes from a charged bank.
Do I need an electrician?
No. The system is self-contained.
What’s the warranty?
One year manufacturer warranty.
Can it stay outside year-round?
Yes; expect reduced solar yield in deep winter.
What’s the lead time?
Twelve weeks.
Shipping
Free shipping included. Outdoor saunas ship fully assembled via flatbed trailer. A forklift or crane is required at delivery for placement; manual offloading is not recommended due to size and weight. A licensed electrician handles the heater hookup. We notify customers two weeks before scheduled delivery so the site is ready. The path from the truck to the placement pad must be clear and accessible. Pad should be a firm, level surface with slight drainage runoff: concrete, decking, pavers, or compacted gravel.
Planning guides: Delivery and installation checklist
Prebuilt
Brushes, Whisks and Body Care
Vents