Minimizing Creosote with an Older Stove and a Masonry Lined Flue

[spirilis]

The secondary combustion/downdraft mode on the Defiant doesn't seem to work for us as I never hear that dull rumble everyone talks about and there's plenty of visible smoke coming out the chimney when I do it, but I noticed it does burn consistently (the fire doesn't just go out) and slows/moderates the heat output when I do it. I don't think the Defiant's entire combustion chamber gets hot enough for a thoroughly efficient burn when I'm burning such a small load of wood (approx. 12lb worth) even though the griddle gets so hot. I would never dream of burning more wood than that because the load I use right now already gets the place too hot.

PS- I observe the temps using an infrared thermometer, and the "flue temp" is the pipe's surface temperature taken just 1 inch beyond the oval-to-round adapter coming out the back of the unit.

It must be tough burning those bricks inside the cavernous Defiant. 6 highly compressed bricks weighing a total of 12 pounds sitting in the middle of a big stove designed to hold 65 pounds of cord wood up to 24" long. Your griddle top gets hot because the heat rises to it, but those bricks are a long way away from the face and those sides. Have you tried using more bricks and closing the air down almost all the way? You can close the secondary flap down a bit as well. Seems to me this might give the same heat into the room but burn cleaner due to higher internal combustion temps.

I'm going to pick up a couple sleeves of those bricks to experiment with. I'll try 6 in my smaller stove and see what they do, then try 8-10 and see if I can't keep the same heat output by varying the air a bit. I'll also see if I can get a secondary burn going with them. I like the idea of doing away with a some of the cord wood, even if it costs me more money. I have plenty of room to stack 2-3 pallets at a time in my basement.

It might be worth a try and I'll see if it works, but I know past experiments with that resulted in me opening the side door to see a dark, semi-glowing smoldering pile of bricks. However several things have changed since last year so I'll give it a shot.