What is the best pellet to use?

When you decide to heat your home with a pellet product, you are making an ecological choice that contributes to improving the quality of the air we breathe and provides your family with natural, efficient heat. 
However, always choosing quality pellets is essential for optimal combustion that minimises emissions and ensures the proper functioning of your product's generator. 
In this article you will find out what the criteria for doing so are and what to pay attention to when purchasing.

Let us proceed in order. Pellets are a fuel made from wood, dried and compacted, with a high calorific value, making it a regenerable, clean and efficient resource. 

When we say that pellets are made from wood, we mean that they are made from wood waste such as wood chips and sawdust. This waste, before being processed, undergoes drying, which reduces its internal moisture content. In fact, for maximum heat yield, the moisture content must not exceed a certain threshold, which is why the pellets must be stored in a dry, low-humidity place. After being dried, these wood scraps are compressed mechanically, which is why the pellets are usually in the shape of small cylinders or small ovals. Mechanical compression avoids the use of glues or chemical adhesives. The better a pellet is pressed, the higher its quality. 

Now that we know what we are talking about, let us look at it in more detail.

We have already mentioned something, but now let's get down to specifics: what should we look at when choosing which pellets to buy? What are the criteria to consider before making a purchase that is, in any case, an investment for our home and our winter?

The ENplus® quality mark
First of all, always check that the pellets you are buying are of certified quality. Buying a quality pellet guarantees the proper functioning of your appliance and clean combustion. The mark that certifies the quality of pellets on an international level is ENPlus®, the only one that is controlled throughout the entire supply chain. 
Therefore, make sure that the bag of pellets you are buying bears the ENPlus® mark and the identification code of the certified company, which consists of the initials of the country and a progressive certification number. You should also find the quality class A1 and the ISO 17225-2 standard, the reference for ENPlus quality classes, indicated.

Another thing to know, and which characterises quality pellets, is the diameter of the pellets, which must be 6 or 8 millimetres.
Pay attention to these aspects to ensure that you are purchasing a fuel of certified quality and that the generator of your product works properly.

Ash and calorific value

As pellets burn, they leave behind a residue, or ash. The amount of ash in the pellet is another key criterion for your choice, because it affects emissions and the corrosion and durability of the pellet stove, which you want to last as long as possible and in the best possible condition. Look for an ash level of less than 0.7% on a dry basis, which is usually found in A1 pellets. This will guarantee you lower costs on ordinary and extraordinary stove maintenance. 

The value of the ash level goes hand in hand with another fundamental criterion: the calorific value, i.e. the energy that can be obtained by converting a unit biomass under standard conditions. We are talking about an output of between 4.7 and 4.8 kWh/kg. Watch out for the numbers!

The right essence 
The last step, after looking at all these 'technical' aspects, is the essence. Or, to put it very simply, the type of wood from which the pellet is made. 

Among the essences already used are beech (which has a very high and better-than-average yield but consumes more and tends to produce greater residues) and fir, which has a slightly lower yield but somewhat lower ash and consumption. Spruce and beech are not the only types of wood species available when it comes to pellets. We speak here of softwood species (spruce, larch, fir, alder, poplar, maritime pine) and hardwood species (beech, ash, oak, birch, maple, locust, chestnut). So-called soft materials burn more easily, wear out quickly, have a fixed residue of around 12% and therefore have a low heat output. So-called hard materials, on the other hand, develop a constant but less intense thermal heat, tend to last longer but are somewhat more difficult to ignite. 

You must bear in mind, however, that other variables also affect performance, such as the type of system and the quality of the pellets, which we discussed above. A good compromise must be sought between all these elements. To achieve this, it may be advisable to go for mixed pellets, created from a selection of both beech and fir, or by testing with your own pellet stove.
 

As you will have understood if you have come this far, the choice of pellets to buy is an important aspect. Always choose quality pellets certified ENPlus® class A1, to be sure that the product you are buying comes from a controlled supply chain, from the raw material to delivery to the end consumer. Furthermore, as we have emphasised, a quality pellet, stored properly in a closed, dry place, allows optimal combustion and proper operation of your appliance's generator.