Overview
EN ISO 17225-3:2021 - "Solid biofuels - Fuel specifications and classes - Part 3: Graded wood briquettes" (CEN/ISO) defines fuel quality classes and specification rules for graded wood briquettes. The standard covers briquettes made from:
- forest, plantation and other virgin wood (1.1)
- by‑products and residues from the wood processing industry (1.2)
- chemically untreated used wood (1.3.1)
Thermally treated briquettes (e.g., torrefied briquettes) are explicitly excluded. EN ISO 17225-3:2021 is intended to support clear trading, procurement and appliance compatibility for residential, small commercial and public building heating applications.
Key Topics and Requirements
- Fuel quality classes: Defines property classes (notably A1, A2, B) with A1 representing low-ash, low-nitrogen virgin wood, A2 slightly higher ash/N, and B allowing certain industrial residues and untreated used wood provided they do not contain heavy metals or halogenated organic compounds from preservatives/coatings.
- Specified properties: Requires declaration or verification of key fuel properties such as moisture, ash content, calorific value (net calorific value), particle density, length/diameter, and chemical elements (e.g., sulfur, chlorine, nitrogen, minor elements).
- Sampling and analysis: Sampling, sample preparation and test methods are referenced to established ISO standards (e.g., ISO 18135, ISO 14780, ISO 18134‑1/2, ISO 18125, ISO 16994, ISO 16948). Producers can use previous measured values, calculated typical values or perform laboratory analysis (simplified or reference methods).
- Producer/supplier responsibilities: The standard stresses accurate, transparent declarations of raw material origin and fuel properties. Where chemically treated raw materials are used, origin and any treatments must be clearly described.
- Dimensional and physical requirements: Specifies briquette geometry and particle density standards to ensure appliance compatibility.
Applications and Who Uses It
- Manufacturers and suppliers: To classify products, set quality control and provide compliant product declarations for trade.
- Heating equipment manufacturers and installers: To verify fuel compatibility with stoves, boilers and fireplaces and ensure appliance performance and emissions targets.
- Test laboratories and certification bodies: For sampling and laboratory testing against referenced ISO methods.
- Specifiers, purchasers and regulators: For procurement specifications, building code compliance and environmental reporting.
- Typical applications include residential stoves, room heaters, small commercial heating and boiler systems where higher fuel quality is required due to limited flue-gas cleaning and simpler appliance controls.
Related Standards
EN ISO 17225-3:2021 is essential for clear, reliable fuel specifications, supporting trade, quality assurance and safe, low‑emission use of graded wood briquettes.
