Several weekends ago now, we got a delivery of the stuff that’s going to keep us warm this fall: compressed sawdust bricks. A pallet of these things is supposedly equivalent to a cord of firewood; we split our pallet with another friend here on the island who’s also planning on heating with wood once it gets cold.
Our delivery came via forklift, with an extra pallet on top. We used this as a base to stack them on when we unloaded them under the house.
There are several brands of compressed-hardwood-sawdust bricks; the fellow who delivered ours swears by Canawick, so that’s what we ended up with. They come wrapped in 12-packs, each brick about the size of a normal clay brick, but taller and stumpier.
The most surprising thing about these little guys is how much they weigh. Each brick is quite hefty, a couple of pounds I’d say. The whole pallet was nearly a ton — 1900 pounds, I think.
We had been planning on getting firewood delivered, but everyone we talked to here on the island who heats with wood swears by the bricks. They are sawdust, compressed at high heat and pressure into a form, with no binders or fillers, so they are quite energy-dense. They are supposed to burn quite hot, clean, and even, and they take up a lot less space than cordwood, which is part of the appeal here on the island, I suspect, since it’s expensive to bring vehicles and freight over on the boat. If you can get a season’s worth of fuel delivered in one load — or if you can deliver a season’s worth of fuel to several island homes in one go — so much the better.
One of the interesting things about these compressed-sawdust bricks is how they are marketed: as “bio-bricks,” environmentally-friendly woodstove fuel. The idea here is that they make use of an existing industrial by-product (sawdust form sawmills), and thus are not causing extra waste; also they are made from a renewable resource. I was pleased to discover that they aren’t bound together with any chemicals or adhesives (when I originally heard about them, I was picturing something like those Dura-Flame logs you can buy at the grocery store), so they don’t release anything worse into the air than wood would. They burn hotter, with fewer particulates, and seem to be a much more efficient and fully-burning fuel than cordwood. My one question that has remained unanswered is how much additional energy is required to manufacture them, and to what other uses is this sawdust usually put?
So far, the Canawick bricks have performed very well in the woodstove. Their uniform size makes it very easy to stack them and start a fire, and to keep it going. They produce little ash, so there’s not much to clean out from the woodstove. This makes me believe we’re getting a pretty efficient burn. And we go through them pretty slowly, which is good, as that means we won’t have to get another delivery for a while — this set will last us a long time. Of course, it hasn’t been super chilly here yet, so we’ll see how we feel once we’re heating the house more consistently. But for now, we’re pretty happy with our purchase, especially on a rainy day like today.