The sP20-in is designed and manufactured in Belgium, at the heart of Europe, out of conviction and commitment to quality. With exceptional efficiency, near-zero emissions and a voluptuous flame sculpted by patented technology, the sP20-in brings together the pleasure of fire, performance and architectural integration.
Wood pellets are a fuel made by compressing sawmill waste, sawdust and wood shavings. This process produces small, very dry and dense cylinders with a high calorific value. Pellets require no glue or binder: the compressed lignin from the wood ensures their cohesion.
For the sP20-in, use only ENplus A1- or DINplus-certified pellets, 6 mm diameter. Using non-certified pellets may cause fouling problems and will void the warranty.
To burn, pellets need air. The sP20-in is designed to be connected directly to an external air supply, independent of the building's indoor air. This is the recommended solution, and mandatory in high-energy-performance buildings. The air inlet duct has a diameter of 60 mm, for a maximum length of 5 m and no more than 4 bends of 90°. The air intake is via the back or base of the pre-housing casing and must be planned from the very start of construction.
If the insert is not directly connected to outdoor air, a minimum cross-section of 30 cm² must open near the appliance, from a ventilated cavity, basement or the outside. This is naturally the case in houses built before 1980 that have not been retrofitted with insulation.
Combustion generates exhaust gases leaving the insert at over 250 °C. These gases must be evacuated through a flue able to draw them naturally out of the building. The ideal flue is vertical, thermally insulated, with a round cross-section and a smooth interior wall. The standard outlet diameter of the sP20-in is 80 mm.
The sP20-in produces flue gases at a relatively low temperature, the flue must be fully insulated to limit condensation risk and optimise draw. An uninsulated external flue is not acceptable. In the case of an existing chimney, a stainless steel liner is essential.
The sP20-in's combustion chamber heats exclusively by natural convection and radiation. Radiation comes from the heat of the flames, the glass and the burner, you feel a pleasant warmth comparable to sunlight. Convection draws room air in through the base of the insert, heats it via a heat exchanger, and releases it naturally back into the room. This system eliminates the need for a blower, which, combined with the upward pellet feed, makes the appliance particularly quiet.
The sP20-in was designed with longevity in mind. With regular maintenance, it will operate for many years. The insert slides on its wheeled chassis: all parts subject to replacement are accessible without removing the surround. The sober, timeless design of the sP20-in, available in StûvBlack matt, is also a factor of durability.
A pellet insert fire offers a much higher efficiency than a traditional open fireplace (approximately 15%) or a first-generation wood insert (approximately 70–75%).
The sP20-in exceeds the requirements of the EcoDesign 2022 standard. It emits nearly 1,000 times fewer fine particles than an open fire and 240 times fewer than a previous-generation appliance.
Electrical consumption during normal operation is 0.024 kW.
Thermostatic modulation and time programming also reduce pellet consumption.
Heating output, recess dimensions, noise level, integration capacity, maintenance, customisation, these are the criteria to discuss with an approved installer.
Output: ensure correct sizing. Your installer will calculate this based on the volume to be heated and the building's insulation level.
Architectural integration: the sP20-in fits in a recess of 560 to 585 mm wide, 1,870 mm high and 470 mm deep. An extension can reach 2,800 mm. Compatible with existing Stûv s30-in recesses.
Acoustic environment: no blower, no pellet drop noise, no clicking : thanks to the upward pellet feed.
Autonomy: the 18 kg hopper guarantees several hours of continuous heating. The front-loading door is accessible at chest height.
Ecology: the sP20-in meets and exceeds the EcoDesign 2022 standard (EN 16510-1 & EN 16510-2-6:2022). ENplus A1 pellets are carbon-neutral over their lifecycle.
Maintenance: the insert slides on its chassis : all replaceable parts are accessible without removing the surround. Stûv guarantees spare parts availability for 10 years.
For optimum use of the sP20-in, pellets must meet precise criteria for size, moisture content and ash content. Source pellets labelled ENplus A1 or DINplus, 6 mm diameter.
It is also essential to generate as little dust as possible during transport and storage. Avoid crushing the bags, keep the pellets in their original bag and store them in a dry place.
For more advice and information on standardised quality standards, consult our blog article.
To keep your pellet insert fire in good condition, carry out simple maintenance tasks every day and a more thorough cleaning once or twice a week. Leave the annual service to an approved professional.
Once or twice a week: remove the ash and clean the combustion chamber thoroughly with a vacuum cleaner.
Annually: have an approved Stûv professional sweep the flue and check the condition of seals, moving parts and the air intake duct.
After 2 or 3 seasons: a thorough service with seal replacement is recommended.
If a component needs replacing, spare parts are available from your installer and require no removal of the surround.
Consult our network of approved dealers and installers closest to you.
Your Stûv dealer carries out the installation, the first lighting, the airflow calibration, mandatory after each transport, and provides after-sales service.
Quality warranty: the sP20-in is designed and manufactured in Belgium. Every appliance is factory-tested before shipping.
Performance warranty: certified to EN 16510-1 & EN 16510-2-6:2022. Technology covered by four international patents: EP 2304319, JP 5390603, US 8.904.944 and US 8.826.899.
After-sales: spare parts available for 10 years. Free warranty extension when you register via the Stûv Pellets app within 30 days of installation.
