OekoTube Outside Electrostatic Chimney Filter for Wood-Fired Saunas
OekoTube Outside Electrostatic Chimney Filter for Wood-Fired Saunas
If you operate a wood-fired sauna and have received a written smoke complaint or a letter from a state environmental agency, this is the equipment that addresses it. The OekoTube Outside is a chimney-top electrostatic precipitator from OekoSolve, a Swiss manufacturer that has built fine-dust separators for wood-firing systems since 2006. It mounts at the flue outlet and removes particulate matter from the exhaust before it leaves the stack.
How it works
A high-voltage electrode suspended in the center of the flue imparts an electrical charge to the fine particles carried in the exhaust stream. The charged particles migrate to the grounded flue wall and adhere there, rather than exiting the chimney as visible smoke. Because the mechanism is electrostatic rather than filtration, there is no media to replace and no measurable increase in flue resistance — draft is unaffected. Accumulated dust is removed with a conventional chimney brush during normal sweeping.
Wood smoke opacity is the specific problem this solves. In most wood-fired sauna operations, visible emissions are concentrated in the first several minutes after lighting, before the firebox reaches steady-state temperature. That startup window is where opacity limits are typically exceeded, and it is where an electrostatic precipitator does the most work.
Specifications
- Particulate removal: 70–95%, independently tested (OekoSolve published figure)
- Appliance rating: wood-firing appliances under 50 kW
- Chimney diameter: 130–300 mm (5.1″–11.8″), round or rectangular
- Maximum flue gas temperature: 400 °C (752 °F) at the point of installation
- Power draw: 30 W maximum, under 1 W standby
- Electrical connection: standard appliance plug — no dedicated circuit or special wiring required
- Maintenance: brush-cleaned during routine chimney sweeping; no consumable filter media
- Origin: designed and manufactured by OekoSolve AG, Switzerland
What's included
- OekoTube Outside electrostatic precipitator unit
- 8″ chimney T-section
- Electrode assembly and flue temperature sensor
- Control box with mounting hardware
- OekoSolve installation manual and technical literature
Installation requirements — read before ordering
The tube must be installed vertically. The electrode is flexible and supported at one end only. Mounted horizontally, it contacts the flue wall, grounds out, and the unit will not function. This is a hard constraint, not a recommendation.
Short chimneys can still be accommodated. On trailer-mounted and low-stack installations where vertical clearance for the full assembly is limited, the electrical control box can be mounted perpendicular to the flue and supported by a strap running to the sauna structure rather than hung off the T-section. The box weighs 5–7 lb and will not support itself off the T-section alone. This configuration carries a secondary benefit: with the control box off the flue, its electronics are no longer exposed to flue-wall temperature. We confirmed this approach directly with the North American distributor before deploying it in the field.
Typical installation is approximately half a day and covers mounting the unit, installing and aligning the electrode assembly, fitting the temperature sensor and cover, and completing a startup review. Third-party installers in our network have quoted this work at roughly $750 where chimney access is normal. Roof or chimney repair, outlet installation, permits, and lift or scaffold access are separate.
Compatible with
Any wood-burning sauna stove under 50 kW venting through a 5.1″–11.8″ flue, including the IKI Mini, IKI Original, HUUM HIVE Wood, HUUM HIVE Flow, Harvia Legend, Harvia Pro and Harvia Duo. Confirm your flue diameter, available vertical clearance and measured flue-outlet temperature before ordering — we will do this with you.
We'll decide together in your consult
- Flue diameter, geometry, and T-section fit
- Measured flue gas temperature at the outlet against the 400 °C limit — this matters on high-output stoves
- Vertical clearance and whether a perpendicular control-box mount is required
- Electrical access at the stack and whether an electrician is needed
- Freight, installer coordination, and scheduling around your firing schedule
- Documentation for your local air-quality authority
A note on compliance
Wood smoke opacity is regulated at the state level, and thresholds and measurement methods vary — Texas, for example, is administered by TCEQ. This equipment reduces particulate emissions; it is your agency, not the manufacturer and not us, that determines whether a given installation meets a given standard. We will help you document what was installed and why. We will not tell you it guarantees an outcome we cannot measure on your site.
Schedule a consultation with an advisor to confirm fit, freight, and installation for your specific stove and chimney.
OekoTube Outside Electrostatic Chimney Filter for Wood-Fired Saunas
If you operate a wood-fired sauna and have received a written smoke complaint or a letter from a state environmental agency, this is the equipment that addresses it. The OekoTube Outside is a chimney-top electrostatic precipitator from OekoSolve, a Swiss manufacturer that has built fine-dust separators for wood-firing systems since 2006. It mounts at the flue outlet and removes particulate matter from the exhaust before it leaves the stack.
How it works
A high-voltage electrode suspended in the center of the flue imparts an electrical charge to the fine particles carried in the exhaust stream. The charged particles migrate to the grounded flue wall and adhere there, rather than exiting the chimney as visible smoke. Because the mechanism is electrostatic rather than filtration, there is no media to replace and no measurable increase in flue resistance — draft is unaffected. Accumulated dust is removed with a conventional chimney brush during normal sweeping.
Wood smoke opacity is the specific problem this solves. In most wood-fired sauna operations, visible emissions are concentrated in the first several minutes after lighting, before the firebox reaches steady-state temperature. That startup window is where opacity limits are typically exceeded, and it is where an electrostatic precipitator does the most work.
Specifications
- Particulate removal: 70–95%, independently tested (OekoSolve published figure)
- Appliance rating: wood-firing appliances under 50 kW
- Chimney diameter: 130–300 mm (5.1″–11.8″), round or rectangular
- Maximum flue gas temperature: 400 °C (752 °F) at the point of installation
- Power draw: 30 W maximum, under 1 W standby
- Electrical connection: standard appliance plug — no dedicated circuit or special wiring required
- Maintenance: brush-cleaned during routine chimney sweeping; no consumable filter media
- Origin: designed and manufactured by OekoSolve AG, Switzerland
What's included
- OekoTube Outside electrostatic precipitator unit
- 8″ chimney T-section
- Electrode assembly and flue temperature sensor
- Control box with mounting hardware
- OekoSolve installation manual and technical literature
Installation requirements — read before ordering
The tube must be installed vertically. The electrode is flexible and supported at one end only. Mounted horizontally, it contacts the flue wall, grounds out, and the unit will not function. This is a hard constraint, not a recommendation.
Short chimneys can still be accommodated. On trailer-mounted and low-stack installations where vertical clearance for the full assembly is limited, the electrical control box can be mounted perpendicular to the flue and supported by a strap running to the sauna structure rather than hung off the T-section. The box weighs 5–7 lb and will not support itself off the T-section alone. This configuration carries a secondary benefit: with the control box off the flue, its electronics are no longer exposed to flue-wall temperature. We confirmed this approach directly with the North American distributor before deploying it in the field.
Typical installation is approximately half a day and covers mounting the unit, installing and aligning the electrode assembly, fitting the temperature sensor and cover, and completing a startup review. Third-party installers in our network have quoted this work at roughly $750 where chimney access is normal. Roof or chimney repair, outlet installation, permits, and lift or scaffold access are separate.
Compatible with
Any wood-burning sauna stove under 50 kW venting through a 5.1″–11.8″ flue, including the IKI Mini, IKI Original, HUUM HIVE Wood, HUUM HIVE Flow, Harvia Legend, Harvia Pro and Harvia Duo. Confirm your flue diameter, available vertical clearance and measured flue-outlet temperature before ordering — we will do this with you.
We'll decide together in your consult
- Flue diameter, geometry, and T-section fit
- Measured flue gas temperature at the outlet against the 400 °C limit — this matters on high-output stoves
- Vertical clearance and whether a perpendicular control-box mount is required
- Electrical access at the stack and whether an electrician is needed
- Freight, installer coordination, and scheduling around your firing schedule
- Documentation for your local air-quality authority
A note on compliance
Wood smoke opacity is regulated at the state level, and thresholds and measurement methods vary — Texas, for example, is administered by TCEQ. This equipment reduces particulate emissions; it is your agency, not the manufacturer and not us, that determines whether a given installation meets a given standard. We will help you document what was installed and why. We will not tell you it guarantees an outcome we cannot measure on your site.
Schedule a consultation with an advisor to confirm fit, freight, and installation for your specific stove and chimney.