Knowing how to choose a good pellet it is very simple; a wrong choice, in addition to decreasing energy saving, could affect the lives of your stove or biomass boiler.
For this you need to know some basics and pay attention to labels and appearance of the pellets.
First test: visual examination of the bags of pellets
- The bag must not contain sawdust on the bottom
This would indicate that the wood flour has not been properly dried, the pellet was kept bad, or for too long and that in the transport has suffered bumps and jolts.
- Excessive rigidity bags
A bag is too stiff when it has been kept in a high humidity environment, causing the pellets to swell.
Examination of the label
- DIN 51731 certified pellets; DIN PLUS; ONORM M7135; PELLET GOLD; EN PLUS
These are the only markings that certify the quality of Pellet
- Warning label
If the pellet is not certified, also the statements on the label often serve little, as they are also indications of the producer.
Visual inspection of the pellet
- Pellet dark
A very dark pellet could have an abundance of slag or bark and porous and voluminous ashes that can clog the brazier cleaning system or ash extraction. This, however, is not always synonymous with a poor product.
- Pellets mixed
A pellet quality could have a mixed blend of materials with different melting points of ash and leave "glassy stones" in the brazier.
- Pellet friable
The pellet that comes in various sizes (friable) disperses unburned parts for heat exchanger, smearing abnormally, and tends to make a "bridge" in the grate, creating poor combustion and poor yields.
Test the pellet to the touch
- Test break
If the pellet is hard to break or become coarse rubbing it with your fingers, then it means it has a low density or a moist dough.
Test the pellet in water
- No flotation
If immersing the pellets in water goes to the bottom, it means that it is a very bad material with low density.
- Nothing crumbling
A good quality pellet immersed in water flakes, creating a rainbow effect on the surface, a sign of the presence of solvents and adhesives in wood flour.
Examination after use
Examination of glass
If after the use of the boiler in skint on the glass doors do not show stains brown, this means that the pellets used was wet.
- Examination of the ash
The ash should appear similar to talcum powder gray. If instead is presented as a non-homogeneous mass which recalls the ash of wood, we are in the presence of a low melting point of the pellets.