The pellets are obtained by pressing wood sawdust, as the "gluing" is done in a natural way and without the need or presence of impurities - just at high temperature, the lignin contained in the wood melts and "glues" the wood particles. The coniferous wood has a very high lignin content from other tree species, so when it is said that some pellets are entirely beech, from sunflower straw, the truth is slightly concealed.
There are 2 types of pellets - for domestic and for industrial needs. The domestic ones are classified into 2 quality classes - Class A1 - with the strictest restriction of ash content, and Class A2, and the industry ones are classified into Class B.
These norms (standards) determine the following percentage of ash by classes and by descending order:
Class A1 - ≤ 0.7;
Class A2 - ≤ 1.5;
Class B - ≤ 3.5.
Important: Any manipulation and speculation with classes: A , A , etc., is ridiculous because these are energy efficiency classes for household appliances, but not classifications of pellets.
