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

For rooms that want the stove to stand tall. The SW climbs higher than the other Cozy cages and opens a wide wave of visible stone. The 18 kW model carries the line's largest specified stone load, 397 lb, for buyers who want the stone column to define both the look and the session.

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.

Make room for the tallest family

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

Use finished dimensions. Add 3.94 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 SW carries 265–397 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.
• Minimum finished room height: 76.7 in for SW 12; 87.1 in for SW 18. These totals use the stove height plus the manual’s required overhead clearance, rounded up.
• SW 18 stove weight: 209 lb without stones; 606 lb with the nominal stone load, before chimney and protection.
• SW 18 top flue outlet: 4.49 in diameter. Confirm the connection with your chimney installer.
• 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.

SW 18 ceiling note: the manual and dimension drawing also print a smaller total room height. The SW 18 stove height plus the manual’s stated overhead clearance requires 87.1 in when rounded up. Use the larger requirement and have your installer resolve the document discrepancy with Cozy before installation.

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 and exact drawings below control installation and stone loading.

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