Cozy Heat O Wood-Burning Sauna Stove – 12 & 18 kW

A calmer silhouette around a hard-working firebox. The O wraps the Cozy firebox in a clean cylindrical mesh. It reads softer than a square cage and puts the natural texture of the stones at the center of the room.

Cozy builds structural-steel firebox walls about 67% thicker than a typical standard-stove wall, then joins them with clean, precise welds. It is made for years of real fires, not dressed up for a showroom.

Size it from the finished room

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

Use finished dimensions. Add about 4 cu ft per square foot of glass, tile, brick, concrete, or other uninsulated surface. Multiply a massive-log room by 1.5. Between sizes? Call before ordering.

Keep the whole ritual in one room

The firebox faces the sauna, keeping the flame in view and avoiding a wall penetration. Protect the floor and leave room for wood, service, and loading.

High efficiency without a fussy fire

Combustion air enters in three paths, including secondary air above the fuel. Cozy says the design uses about 25% less wood than comparable heaters; 40% occurred only in ideal tests. The manual reports 73.9% efficiency for the 12 family and 81.3% for the 18 family. The practical difference is just as important: load dry wood, light the kindling, regulate the air, and add a couple of pieces as needed. There is no specialist firing routine to learn.

The O carries 243–353 lb of exposed stone. That reserve stores heat and gives water a broad surface for steam, but it is a specification to plan around rather than the reason to choose the stove.

Before the stove arrives

• Minimum side clearance to combustible material: 6.7 in for 12 kW; 9.1 in for 18 kW.
• Rear clearance: 9.1 in. Front clearance: 19.7 in.
• Clearance above the stove: 44.5 in for 12 kW; 52.8 in for 18 kW.
• Required chimney draft: 12 Pa. Minimum smoke-flue cross-section: 12.2 sq in.
• Stones, chimney, and any required floor or wall protection are sold separately.

Cozy builds these steel heaters in its Estonian facility. The U.S. warranty is 24 months. European EN 15821 and BImSchV Stage 2 documents do not replace local code review. The current manual below controls installation and stone loading.

Want us to check the room math or chimney plan? Call or text (844) 565-1113 with the finished dimensions.