OK, so I know this topic has been beaten down, but I just wanted to let some know before they do something they might regret. I brought $120 to go get some of those compressed sawdust blocks, and the dealer (who knows me well and knows what stoves I have) tells me I can't have them because Jotul recommends against burning them. It would seem my insert (550 C Rockland) relies on some moisture in the wood and burning those compressed blocks with no moisture at all can easily create an overfiring situation. I remember someone saying that to me a long time ago but I must have forgotten it. Anyway, the moral of the story is check with your stove manufacturer before burning them as its a possibility you can create an unsafe situation. JS
I've used them in my Jotul, but not loaded to the gills. I've mixed with splits as well. I have not used them a lot, just here and there a few times with no issue.
What they are trying to convey is that a full stove load of compressed blocks is too much- runs to hot- used in conjunction with wood splits, particularly if your fuel is a bit wet yet works just fine. I would not completely load my stoves with store bought 2x4's either for the same reason- but you never see the stove MFG's comment on that possibility( some due caution about construction scraps though). Yet there people that routinely over fire their stoves with that type of fuel. 3 or4 of the 2x6x4 compresed blocks tightly stacked together works just fine. Obviously the stove chamber would hold more and I never use the ones that have a wax binder in them. I and many others have recommended using them with less than adequately dried wood splits ( the standard seller "seasoned" type, which mostly means seasoned with bar oil and 2 stroke fumes). In a couple months the woe is me, new wood burner, wet wood, no or poor heat output crowd will start to post about problems and you will read the above suggestion many times. People across the big pond have been burning peat bog blocks for centuries ( mother natures version of compressed material).
Agree with WS and Swags, Ive never used them solo, only with a portional load of splits with it. I've had overfiring problems in the past in my Oslo so I can imagine what a full load of blocks would do if not under supervision. I bought a bag at the tractor supply just to try them out. They burned hot along with splits but nothing worth picking up more for. Maybe special situations may permit having them on hand.
Brian did a test last winter with the IS loaded full of those. I think the stove burned for a month. So, I think it depends on the stove.
I'm thinking the operator and stove condition (gaskets) has more to do with the overfires than the fuel itself.
