About
Architecture
Seven modules that configure to site, climate, and use.
A modular sauna system — designed as a fixed set of components that adapt to any site. Outdoor units are produced in a numbered edition of 2,100, then production closes. Indoor installations are bespoke, designed to the architecture, manufactured without limitation.
The configuration is determined during the design phase based on location, use case, climate, electrical supply, and water access.
Design
Morten Bo Jensen
Groundwork Studio, Copenhagen
Formerly 16 years Chief Designer at leading Danish design brand
Manufacturing
KOERNER Saunabau
Albstadt, Germany — est. 1949
First sauna manufacturer in the DACH region.
Third generation, handcrafted production.
Materials
Natural wood strips
Bench, back wall, and cladding in 30 x 30 mm natural colour wooden strips. Interior warmth, tactile surface.
Wood planks
Floor in 100 mm wide natural colour wooden planks throughout cabin and changing room.
Black painted strips
Exterior and changing room bench in 30 x 30 mm black painted wooden strips. Matching cabin aesthetic.
Frameless glass
Load-supporting glass slabs. Panoramic wall with sliding glass door and black handle. Left or right side option.
Powder-coated steel
Black steel wrapped bottom rim on all modules. Steel guard on swimming bridge. Steel frame on changing room entrance door.
Slate roof
Double side pitched slate roof on main sauna module.
Stainless steel 316L
Shower hardware, marine-grade corrosion resistance.
Module System
Seven modules
Configure to site, climate, and use.
Dimensions
3300 x 2200 x 2500 mm (L x W x H)
Interior
Bench and back wall: 30 x 30 mm natural colour wooden strips. Floor: 100 mm wide natural colour planks.
Glass
Frameless load-supporting glass slabs. Sliding glass door with black handle, left or right side option.
Heater
Sauna heater specified to cabin volume during design phase. Curated selection — the use case determines the stove.
Roof
Double side pitched slate roof
Exterior
Black painted 30 x 30 mm wooden strips. Powder-coated black steel wrapped bottom rim.
Capacity
4-6 persons (outdoor). Indoor scaled to architecture.
Electrical
400V three-phase. Wattage specified to cabin volume.
Edition
Outdoor: numbered 0001-2100. Indoor: bespoke.
Dimensions
1500 x 2000 x 300 mm (L x W x H)
Structure
Powder-coated black steel stairs and guard (left or right side option)
Deck
100 mm wide natural colour wooden planks
Rim
Powder-coated black steel wrapped bottom rim
Installation
Bolted to foundation or dock. Waterside placement.
Dimensions
1500 x 2000 x 2500 mm (L x W x H)
Interior
Bench and back wall: 30 x 30 mm black painted wooden strips. Floor: 100 mm wide natural colour planks.
Skylight
Flat mounted skylight
Storage
Powder-coated black steel locker shelving with mounting storage for M4
Hooks
Powder-coated black steel hooks
Door
Recessed in protruding powder-coated steel frame. Clad with black painted 30 mm strips, black handle.
Exterior
Black painted 30 x 30 mm wooden strips. Powder-coated black steel wrapped bottom rim.
Heating
Via M4 thermal module mounted in locker shelving (optional)
Dimensions
Site-dependent. Mounted in M3 locker shelving.
Hardware
Mining hardware (current generation)
Power draw
3,500 W (typical configuration)
Heat output
3,500 W thermal. 100% electrical-to-thermal conversion.
Daily output
84 kWh heat / day (continuous operation)
Electrical
230V single-phase. Dedicated circuit.
Network
Ethernet or WiFi. Mining pool connection and monitoring.
Sound
Soundproofed enclosure within M3 locker shelving
Note
Optional. Configured per site based on thermal demand, electricity cost, climate.
Dimensions
500 x 100 x 2000 mm (W x D x H)
Material
Stainless steel 316L, marine-grade
Mount
Wall-mounted to cabin or changing room exterior
Supply A
Water hose connection
Supply B
Plumbed installation with mixer valve
Drainage
Surface to ground or plumbed to waste
Dimensions
600 x 300 x 1500 mm (W x D x H)
Construction
Matching exterior cladding
Seal
Weather-sealed, ventilated
Dimensions
1500 x 2000 x 2500 mm (L x W x H)
Construction
Insulated basin, watertight inner shell
Capacity
Single person full immersion
Fill
Manual hose fill or plumbed supply with overflow drain
Drainage
Bottom drain to waste or ground soak-away
Water treatment
Chemical-free configurations available. Specified during design phase.
Outdoor
One of twentyonehundred
2,100 units. Then production closes.
A complete sauna installation for private or commercial sites — delivered and assembled on location. The cabin, changing room, and storage form the core. Swimming bridge, shower, cold plunge, and thermal module extend the configuration. Each unit receives a production number (0001-2100) stamped into the hardware.
Bespoke. Agreed after design phase.
Installation Requirements
Footprint
Approximately 22 m2 full configuration including all modules.
Foundation
Level concrete pad, screw piles, or timber frame. Prepared before delivery.
Electrical
400V three-phase for heater. 230V for M4 (3.5 kW) if configured. Dedicated circuits, certified electrician.
Water
Optional. Water hose for basic M5/M7. Plumbed supply for installed M5 and continuous M7 fill.
Access
Vehicle access for delivery. Crane where direct placement is not possible.
Permits
Varies by municipality. Confirmed during site review.
Timeline
~8 weeks from confirmed order to installation.
Indoor
The original interior design, modelled to site
Uncapped. Bespoke. Upgrade current sauna installations.
The indoor sauna features the same bench geometry, timber detailing, and material language as the outdoor unit. Each installation is shaped to the space — typically behind panoramic glass, integrated into the architecture of the building.
Suitable for residences, hotels, spas, commercial spaces, and wellness facilities. The M4 thermal module replaces conventional building heating — particularly effective in spaces with continuous thermal demand.
Bespoke. Materials and construction quoted per project. Pricing confirmed after design phase.
Heater System
The stove and the thermal module
Two kinds of heat. One system.
A sauna installation needs two kinds of heat. The sauna heater heats the cabin itself — it brings the room to sauna temperature (80-110 C) and holds infusion stones for steam. The heater is specified to the cabin volume during the design phase.
But the cabin sits inside a larger space. In a commercial building, the surrounding space needs continuous heating. In an outdoor installation, the changing room needs warmth and the cabin needs a warm baseline before the heater takes over. That ambient heat has to come from somewhere.
The M4 is that heat source. It mounts inside the M3 changing room locker shelving. All electrical energy in is converted to heat energy out — warming the changing room and holding the cabin at a baseline so the sauna heater covers only the delta.
The difference: it also mines bitcoin. Same electricity, same heat. Dual output.
Stove Selection
The LYN system accepts a curated selection of stoves. Only heaters that match the design language are included. The use case determines the stove.
Indoor / commercial
KOERNER stove as standard configuration. Integrated into the architecture.
Private outdoor
Other stoves within the LYN selection may be configured. Specified during design phase.
Heater and M4
Sauna heater
Heats the sauna cabin to operating temperature. Finnish sauna, infusion stones, steam. Specified to cabin volume.
M4 thermal
Heats the space around the cabin. Changing room warmth, cabin pre-warming to ~20 C baseline, hot water routing where applicable. Runs continuously or seasonally.
Together
M4 holds the cabin at a warm baseline. The heater covers the delta to sauna temperature — not from ambient. In January without M4, the heater works from -5 C to 80 C. With M4, from 20 C to 80 C. Faster heat-up, better first session.
M4 Technical
Input
Electricity — 3,500 W typical. Same wattage as a conventional electric space heater.
Process
100% electrical-to-thermal conversion. Computation generates heat as byproduct.
Output 1
Heat — 3,500 W thermal into changing room and cabin.
Output 2
Bitcoin — mined continuously while the unit runs. Accumulates in site wallet.
Placement
Mounted in M3 changing room locker shelving (outdoor). Utility area (indoor).
Sound
Soundproofed enclosure. Negligible noise at property boundary.
Network
Ethernet or WiFi from site. Mining pool connection and monitoring.
Hardware life
~4-5 years productive life. Simple swap — same enclosure, new unit.
Custody
Bitcoin mines to a wallet you control. Setup assistance included.
Site Application
Commercial indoor
Runs 24/7 as primary building heating system. Continuous thermal demand means high utilisation. The space needs heat regardless — electricity is a heating cost you pay anyway. Bitcoin is upside. Net heating cost is lower and the site accumulates BTC on its balance sheet.
Private outdoor
Runs seasonally — heating season only, approximately October through April. Heats the changing room and holds the cabin at ~20 C baseline. Without M4 the heater works from -5 C to 80 C. With M4, from 20 C to 80 C. Faster heat-up, comfortable changing room on arrival.
The M4 is optional. Configured per site based on thermal demand, electricity cost, and climate. The site planning tool evaluates each site individually.
Process
From interest to installation
01
Site Review
Submit your site through the planning tool. Location, type, modules, electrical supply, water access, ground conditions. The tool generates a site-specific assessment.
02
Project Page
You receive a project page with your site model, proposed configuration, M4 economics, heater sizing, and open questions. It updates as we work through details.
03
Design Phase
We refine the configuration. Orientation, materials, finishes, heater specification. For indoor: architectural integration. Final pricing confirmed.
04
Manufacturing
KOERNER produces the installation in Albstadt, Germany. Handcrafted, third-generation production.
05
Delivery + Installation
Modules delivered and assembled on site. Foundation and site prep coordinated in advance. Electrical and plumbing by certified local trades. Unit number assigned and stamped.
download pdf · site planning tool
Contact
Julius Schulze-Berge
