The quality class of pellets indicates the raw material used to produce them. According to the UNI EN ISO 17225-2 standard, there are three classes of pellets certified by ENplus, namely A1, A2 and B.

Each of them identifies the combination of wood or wood waste used in the production process: at a higher level (i.e. A1), a certain type of raw material will correspond to a combination of different products.

The ENplus A1 class indicates pellets produced exclusively from hardwood or coniferous logs or from chemically untreated woodworking by-products and residues.

The best quality pellets, obtained using only one raw material, are characterized by a percentage of ash (i.e. inorganic components that do not produce energy) equal to 0.5% – 0.7%. This means that, in addition to a high calorific value, pellets produce less residue by halving the consumption and vice versa, thus increasing the efficiency of the heating system.

The ENplus A2 class includes raw materials combined with each other, such as whole trees without roots, by-products and residues of chemically untreated wood processing, forestry residues and tree trunks. Also in this case, the ash content present in the A2 class pellets does not exceed 1%, the difference being that the fuel quality is slightly lower than in the A1 class.

This does not mean that the product is of poor quality, but simply that for its production, different materials can be used, making it cheaper to buy fuel.

ENplus Class B includes raw materials, by-products and chemically untreated woodworking residues from forests, plantations and other virgin wood, to which used wood that does not contain any chemical components is added, so the wood products will be recycled.

The ash content of Class B pellets can reach 2%, increasing the inorganic content of the product, but this does not mean that the pellets do not guarantee their natural functionality, but are cheaper than products of Class A1 and A2.