fabio.gel wrote:
If your boiler is set on hardwood, do not change especially (if you have access to the admin code of the motherboard to change the settings).
I had done the test on my old pellet stove that is set on softwood, poor combustion result and much too much ash.
Correct: the quantity of oxygen necessary for complete combustion actually depends on the PCI (roughly speaking, the PCI is the number of bonds -CC- and - C - H) of a fuel. So the more there are of these bonds to "crack" and the more it will be necessary to "stick" of oxygen atoms on these covalent bonds ...
So a fuel with a higher "dry" PCI therefore requires more O² [NB: if the PCI drops due to humidity, this has no effect; it is therefore the PCI of the perfectly dry fuel that must be considered].
The "ratio" between the pellet feed screw and the control of the combustion air feed fan must then be changed.
The sign: a "blackening" at the level of the burner (elsewhere, the deposition of a black feurage of C particles is inevitable) sign of incomplete combustion (and greater releases of toxic CO!)