Technical glossary
Biomass boiler vocabulary
Concise factual definitions to understand pellets, Class 5, modulation, seasonal efficiency and energy grants.
- Pellet boilerWood pellet boiler · Chaudière à granulés
- Biomass boiler with automatic feed of wood pellets (ENplus A1 pellets). Tatano offers pellet boilers from 15 to 3,000 kW, energy class A++, with 1:4 modulation. Common synonym: wood pellet boiler.
- Pellet insertPellet fireplace insert · Insert à pellet
- Closed firebox fitted into an existing fireplace, burning pellets or logs, with a water heat exchanger to supply radiators or underfloor heating. Tatano Kalorino KS pellet inserts cover 15–30 kW, combining radiant room heat with an integrated hydraulic circuit.
- Wood boilerWood-fired boiler · Biomass wood boiler
- Biomass boiler burning wood in the form of logs, wood chips or pellets, depending on the model. Tatano manufactures wood boilers from 15 to 3,000 kW, compliant with EN 303-5 Class 5 and EcoDesign. Generic term covering logs, wood chips and pellets.
- Solar thermal panelsSolar panels · Solar collectors · Solar thermal
- Roof-mounted collectors that convert solar radiation into heat for domestic hot water or supplementary space heating. Tatano offers forced- or natural-circulation solar systems that can be coupled with any biomass boiler via a buffer tank.
- Solar storage tankSolar water heater · Solar DHW tank · Solar cylinder
- Water tank (typically 200–500 L) heated by solar thermal panels to produce domestic hot water and/or supplementary space heating. Coupled with a Tatano pellet boiler or wood boiler via a buffer tank — solar takes over in summer.
- Wood pelletsPellets · Pellet
- Cylindrical fuel 6 mm in diameter, made by compressing residual sawdust without chemical binders. Net calorific value (NCV) ≈ 4.8 kWh/kg, moisture < 10%.
- ENplus A1
- European certification for top-quality wood pellets (NCV ≥ 4.6 kWh/kg, ash ≤ 0.7%, moisture ≤ 10%). The standard required by most modern domestic boilers.
- Wood chipsWoodchips · Forest chips · Cippato
- Fuel shredded from forest or sawmill wood. Quality standard: ISO 17225-4. Particle size 3-50 mm, moisture 20-35%. More economical than pellets, but requires a larger silo.
- LogsFirewood · Split logs
- Split and dried wood, 33-50 cm long, ideal moisture < 20% (2 years of drying). NCV 4.2-4.5 kWh/kg for hardwood species (oak, beech, hornbeam). The cheapest fuel per kWh when sourced locally.
- EN 303-5 Class 5Class 5 · Classe 5
- European standard defining the highest performance class for solid-fuel boilers ≤ 500 kW: efficiency ≥ 87%, CO emissions ≤ 500 mg/m³, particulates ≤ 40 mg/m³ (at 10% O₂). A condition for energy grant eligibility in BeLuxFr.
- EcoDesign ErPRegulation 2015/1189 · Ecodesign
- European Regulation 2015/1189, mandatory since 2020 for every solid-fuel boiler placed on the EU market. Sets minimum thresholds for seasonal efficiency (ηs ≥ 75% for pellets) and emissions.
- Energy Label ErPEnergy label
- European Regulation 2015/1187 requiring the A+++ → G energy label to be visible on every boiler product. Modern pellet boilers reach A++; log boilers A+.
- Seasonal efficiency (ηs)Seasonal efficiency · ηs
- Average efficiency measured over a full heating season, including start-up, shutdown and part-load losses. More representative than nominal efficiency. A Tatano Class 5 boiler typically reaches ηs 88-93%.
- 1:4 modulationModulation · Modulation range
- The boiler's ability to adjust its output between 25% and 100% of its nominal output. Avoids short on/off cycles that degrade efficiency and service life. A 30 kW boiler with 1:4 modulation operates between 7.5 and 30 kW.
- Buffer tankHydraulic buffer · Buffer · Thermal store
- Water tank (typically 500-2,000 L) that stores the heat produced by the boiler and releases it to the heat emitters. Essential for log boilers, strongly recommended for pellets. Also enables solar thermal coupling.
- AugerFeed auger · Screw conveyor
- Helical mechanism that carries pellets or wood chips from the silo to the combustion chamber. A wear part checked at the annual service. Variable speed to match the fuel flow to the output required.
- MaPrimeRénov'Prime Rénov · MPR
- French energy renovation grant distributed by ANAH. Since 01/01/2026, a biomass boiler is no longer eligible as a single measure: only within a whole-home renovation (rénovation d'ampleur). Still available: CEE, 5.5% VAT and éco-PTZ.
- Buildings ProgrammeProgramme Bâtiments · Das Gebäudeprogramm
- Swiss subsidy programme for energy renovation, funded by the CO₂ levy and administered by the cantons. Replacing a fossil-fuel heating system with a wood boiler is subsidised depending on the canton (e.g. Vaud M-03: CHF 8,500; Geneva: CHF 3,000 + 50/kW). The application must be filed BEFORE the works.
- Thermal kWThermal kilowatt · kWth
- Unit of a boiler's instantaneous output. 1 kW = the capacity to produce 1,000 W of heat continuously. A 150 m² BBC (low-energy) house typically needs 9-12 kW, an average renovation 18-25 kW.
- Useful kWhUseful kilowatt-hour
- Thermal energy actually delivered to the home (after losses). Allows fuel costs to be compared for the same delivered output. Pellets ≈ 7.7 cents per useful kWh in Luxembourg in 2026.
- NCVNet calorific value · Lower heating value
- Quantity of heat released by the complete combustion of 1 kg of fuel, without recovering the condensation heat of the flue gases. ENplus A1 pellets: 4.8 kWh/kg; dry hardwood logs: 4.2 kWh/kg; wood chips at 30% moisture: 3.5 kWh/kg.
- Particulate matter (PM)PM2.5 · Fine particles · Dust
- Fine solid particles suspended in combustion flue gases, measured in mg/m³ or mg/Nm³. EN 303-5 Class 5 caps them at 40 mg/m³.
- Nm³Normal cubic metre
- Cubic metre of gas measured under standard conditions (0 °C, 1,013 hPa). Unit used to normalise pollutant concentrations in flue gases regardless of actual dilution.
- Heat exchangerExchanger
- Component that transfers thermal energy from the combustion flue gases to the heating water circuit. Its cleanliness directly determines efficiency — hence the mandatory annual maintenance.
- InsertFireplace insert · Closed firebox
- Closed cast-iron or steel firebox fitted into an existing fireplace or a masonry surround. Tatano Kalorino KS inserts produce room heat (radiation) and hot water for radiators (integrated heat exchanger).
- Thermo-fireplaceHydraulic fireplace · Water-jacketed fireplace
- Insert variant fitted with a water heat exchanger so that the appliance can be connected to the central heating circuit. Suits homes that want to keep the look of a fireplace while supplying all the radiators.
- Boiler roomPlant room · Technical room
- Room dedicated to the boiler, its fuel silo, its circulating pumps and its hydraulic buffer. Must comply with strict rules on ventilation (air inlet/outlet), fire resistance and accessibility for maintenance.
- CogenerationCHP · Combined heat and power
- Simultaneous production of heat and electricity from the same fuel. Available from a few hundred thermal kW for Tatano industrial sites. Raises overall energy efficiency above 80%.
- District heating networkDistrict heating · Heat network
- Centralised heat production (0.5-3 MW biomass boiler plant) distributed to several buildings through a network of insulated pipes. Typical applications: new neighbourhood, business park, multi-unit residential complex.
Grants
In Germany, replacing a heating system with a biomass boiler (pellets, logs, wood chips) in an existing residential building is subsidised by KfW (programme 458, Federal Funding for Efficient Buildings).
KfW 458 — heating grant for private individuals (BEG EM)
Base grant of 30 % of eligible costs, plus bonuses depending on the situation (climate speed, household income); up to 70 %, or 80 % with the income bonus. Eligible costs capped at €28,000 for a single-family house.
- EXISTING residential building; apply to KfW BEFORE work starts
- Supply or service contract signed with a condition precedent or subsequent
- Climate speed bonus (16 %) when replacing a gas or biomass heating system at least 20 years old; it decreases from 01/02/2027
- Income bonus (40, 30 or 10 %) for owner-occupiers depending on taxable household income
Information checked on October 14, 2026.
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