Harvia WHP270 Insulated Smoke Damper for Steel Chimneys, Stainless or Black

The Harvia WHP270 insulated damper plate makes a Harvia steel chimney better suited to sauna buildings heated through the winter. Closing the damper after the fire has burned down retains heat in the sauna room instead of letting it escape up the flue. The CE-marked damper meets fire-safety requirements and installs in any Harvia WHP steel chimney.

Features

• Insulated damper plate retains sauna heat after firing
• Best choice for saunas used year-round, especially in winter
• CE marked — meets fire safety requirements
• Installs with all Harvia steel chimneys
• Stainless steel (WHP270SP) or black (WHP270SPM) finish
• Limited 2-year warranty (consumer use); limited 1-year warranty (commercial use)

What’s Included

• Insulated steel smoke damper
• Installation instructions

Specifications

Compatibility

Fits all Harvia WHP steel chimneys, including the WHP1500 / WHP1500M chimney kit and WHP500 / WHP1000 extensions.

Planning note: Harvia’s WHP steel chimney system installs vertically only and is designed for wood-burning sauna stoves in standalone outdoor sauna buildings. Keep at least 4″ (100 mm) of clearance between the insulated outer casing and any combustible material, and confirm your installation with your local building authority before you build.

Good to Know

Why add a damper to a sauna chimney?

An open flue keeps pulling warm air out of the sauna long after the fire dies down. Closing the insulated damper once the embers are fully out traps that heat, so the sauna stays warm longer and uses less wood — most valuable in winter.

When is it safe to close the damper?

Only after the fire is completely out with no glowing embers. Closing a damper on a live fire can push carbon monoxide into the sauna room — always err on the side of leaving it open.

Which finish should I choose?

WHP270SP is stainless steel and WHP270SPM is black; both are functionally identical. Match the finish of your chimney.

Designing a Harvia Chimney System

Every part on this page belongs to Harvia’s modular WHP steel chimney system: a 115 mm (4.5″) smoke path inside a 220 mm (8.6″) insulated casing, assembled with slot-and-lock joints. Here is how a complete system comes together:

1. Start with the chimney. For pitched roofs, the WHP1500 kit (1500 mm chimney plus rain cap, tilted rain flange, smoke pipe, and ceiling lead-through set) is the core of the system. For flat roofs and barrel saunas, the WHP1000500 package bundles the chimney with the symmetric roof kit.
2. Connect the stove. Bridge the stove collar to the insulated chimney with 115 mm WZ smoke pipes (20 cm, 50 cm, or 1 m). Add the WZ115030SP damper plate at the stove to control draft while firing, a WZ115120 reducer where pipe sections step down, or the WZ115155 adapter if you are transitioning to 6″ US Class A pipe.
3. Reach your height. Add WHP500 (500 mm) or WHP1000 (1000 mm) extensions. Stay within Harvia’s limits: 5.0 m (16.4 ft) total chimney height, no more than 2.0 m (6.5 ft) above the last support, lateral supports every 3.0 m (9.8 ft).
4. Go through the roof. Choose the roof kit that matches your roofline — WHP-AS for tilted/pitched roofs, WHP-ASSYM for flat roofs and barrels. Replacement rain collars: WHM22 (tilted) and WHM24 (symmetric). Add a snow barrier above the chimney where sliding snow can load the flashing.
5. Seal and control. The WHM25 vapor barrier restores the vapor-tight layer where the chimney passes the sauna ceiling; the WHP270 insulated damper closes the flue after the fire is fully out so the sauna holds its heat.
6. Finish the stove side. Stone-filled covers — WL300 for Legend stoves, WL300PC for Cilindro — absorb radiant heat from the smoke pipe and significantly reduce its required safety distances.

Key clearances and rules: vertical installation only; 100 mm (4″) from the insulated casing to combustibles; 500 mm (stainless) or 375 mm (black) from non-insulated smoke pipe unless shielded; designed for wood-burning stoves in standalone outdoor sauna buildings. Confirm your plan with your local building authority — and if you would like help speccing the system, talk to us; we design these daily.

Shop the Complete Harvia Chimney System

1. Start with the chimney

• WHP1500 Chimney Kit, 1500mm (stainless or black) — the system core
• WHP1000500 Complete Chimney Package for flat roofs & barrel saunas

2. Connect the stove

• WZ Smoke Pipes, 115mm (20 cm / 50 cm / 1 m, stainless or black)
• WZ115030SP Stove-Side Damper Plate (draft control while firing)
• WZ115120 Reducing Pipe (joins mismatched pipe sections)
• WZ115155 Adapter, 4.5″ Euro to 6″ USA (hybrid Class A transitions)

3. Reach your height

• WHP500 Chimney Extension, 500mm
• WHP1000 Chimney Extension, 1000mm

4. Go through the roof

• WHP-AS Roof Accessory Kit for tilted / pitched roofs
• WHP-ASSYM Roof Accessory Kit for flat roofs & barrel saunas
• WHM22 Replacement Rain Collar, tilted roofs
• WHM24 Replacement Rain Collar, flat roofs & barrels

5. Seal and control

• WHM25 Chimney Vapor Barrier (seals the ceiling penetration)
• WHP270 Insulated Smoke Damper (retains heat after firing) (this page)

6. Finish the stove side

• WL300 Smoke Pipe Cover for Legend stoves (cuts clearances)
• WL300PC Chimney Cover for Cilindro stoves (cuts clearances)