6mm or 8mm refers to the diameter of the pellet. And the general rule is as follows:
6mm Pellets: Stoves and Boilers
8mm Pellets: Boilers only
This in only a general rule, and there maybe a stove that utilizes 8mm pellets, but I have never found one.
Why have different sized Pellets?
Well to start with stoves are generally smaller than boilers, and so are their internal components. So the augur for example that feeds the pellets into the burn chamber is narrower, so can only utilize the smaller diameter pellet (6mm). Boilers on the other hand have a wider augur, so can utilize both 6mm and 8mm pellets.
Advantages / Disadvantages
For the user, utilizing 6mm or 8mm pellets there is very little difference, this is not true for the producer. You can achieve a higher productivity with 8mm pellets than with 6 mm pellets. The simple reason is that the pellet mill finds it easier to compress the material through the wider holes. So in terms of the PelHeat unit if you own a pellet boiler it makes better sense to use the 8mm die plate. Once development is finished we will have productivity figures for different material through the 6mm and the 8mm die plate, with lots of videos and pictures.
Thank you for your interest
