Cozy Heat SW Thru-Wall Sauna Stove Package with Stones

The big decision is the tall through-wall stove. The SW Thru-Wall combines Cozy's tall wave-pattern guard with an extended firebox. You see and water the broad stone field inside while the fire is tended from the adjoining room.

The package uses the same Cozy structural-steel firebox walls about 67% thicker than a typical standard-stove wall and clean, precise welds as the heater-only listing. Its three-path combustion uses about 25% less wood than comparable heaters, while the fire still lights, regulates, and refuels like a familiar wood stove.

Choose the stove before the finish

Every option pairs the exact Cozy Heat SW Thru-Wall heater with the package’s current stone-box count. Split-face stones give the cage a rougher, more architectural texture. Rounded stones make the visible field feel softer. Both choices are olivine diabase; the difference shown here is shape and appearance, not a promise that one produces better steam.

On a phone, swipe the table sideways to compare every column.

The table separates the package box count from the heater’s technical stone load. Stone size and packing change the final weight inside the cage, so follow the exact manual and keep the stove body covered without blocking airflow.

Room size and loading side still come first

Choose 12 kW for an adjusted 212–424 cu ft room or 18 kW for 318–636 cu ft. Add about 4 cu ft for every square foot of glass, tile, brick, concrete, or other uninsulated surface; multiply a massive-log room by 1.5. The firebox passes through a properly built noncombustible wall opening, so wood and ash can stay in the adjoining room.

What the wall opening has to be

Cozy’s manual (section 2.5, Models COZY TW) puts the stove through an opening in a concrete or brick wall no more than 5.9 in thick. The 12 kW needs an opening at least 10.0 in wide and 17.3 in tall measured from the floor; the 18 kW needs at least 12.4 in wide and 18.5 in tall. Combustible material must stay at least 23.7 in from the sides of the opening and 37.8 in above it, and the through-wall extension adds 5.9 in to the stove depth.

What this package does not finish

• Chimney system and roof or wall pass-through components
• Floor and wall protection required by the exact installation
• Local solid-fuel approval and installer review

The current manual and 24-month limited warranty are in Manuals & Documents. Use them before the room is closed up.

Want us to check the room volume and loading side with you? Call or text (844) 565-1113 before choosing the package option.