The pellets or wood pellets
Called pellets or wood pellets depending on the region, they are made in “granulators” from sawdust (generally sawmill waste), it is the most “fashionable” method of heating with wood today.
For the anecdote, their origin is (despite what one thinks) already "old" because their birth goes back to the end of the Second World War in America. Indeed; millions of tons of sawdust and millions of pallets made or accumulated during the United States' war effort had to be "disposed of".
Their height is 6 or 8 mm in diameter and their length to 1 3 times their diameter (see standards Pellets).
Contrary to what one might think their cohesion is achieved only by sintering (mechanical compression): there is no glue type binder or any other additive!
Their humidity is less than 10%, their manufacture therefore requires rigorous drying but this is obviously not the only step. To learn more about the manufacture of pellets, here is the diagram of a pellet or wood pellet manufacturing plant.
The pellets are generally sold "standardized" but remember to ask your supplier for it because it is not systematic. Indeed; in 2009, neither in France nor in Belgium, there was compulsory standardization for manufacturing and selling pellets, but this will evolve with Europe in the coming years in order to guarantee constant quality to consumers. The pellets are delivered either in bulk for pellet boilers via a blower truck (requires a specific storage silo with pellets) Or bag (usually of 15 kg) more convenient for pellet stoves.
There are (at least) 2 big advantages compared to wood logs: the production of ash is very low and their use is "automatable", we thus find the comfort of use of fuel oil! The interested reader will read this very complete dossier on the Heating with pellets by realization and presentation of the pellet boiler or visit our forum on wood heating.
The main disadvantage of pellets is that you have to equip yourself with a special Pellet device which can generally only burn pellets. Pellets can nevertheless burn in a log stove as long as logs or logs are burned at the same time.
Price and energy equivalent wafers
One ton of pellets is equivalent to approximately 500 liters of fuel oil and the storage volume is around 3 to 4 times the volume of fuel oil.
Here too the prices are very variable, they can be equivalent to fuel oil or be 50% cheaper, it depends on the period! The attentive reader will watch with attention theComparative price developments Pellets in "real time" since 2006.