So for the last 23 years or so I’ve burned in non-cat stoves, and I’ve managed to have zero creosote in my chimney(s). Burn hot. A lot of heat went up the chimney in those stoves too.
Now I’ve got a hybrid stove, which burns even cleaner and should send less stuff up the chimney. EPA rates this Progress Hybrid at .5g/hour or something, while my old Jotul was over 5g/hour. But this efficient beast captures a lot of the heat out of the flue gas. Like right now with a small load of wood and probably more catalytic combustion than flame-heat, I’ve got temps just over 200F on the single wall pipe a bit above the stove, according to the IR thermometer. The brick chimney above, going through the bedroom (with liner) used to be warm to the touch, sometimes pretty warm, with the Jotul. Now those bricks are never warm, even though I’m now burning 24/7. I only burned in daytime with the tube stove but those bricks got warm by bedtime. Obviously the flue and chimney is way cooler than it was, even when I’m burning hot in cool weather. Now it’s mild weather.
When I was stove shopping I went to a local stove shop, and the sales woman was trying to sell me a Lopi Answer. I was suggesting I’d want a bigger firebox. She said I’d have creosote in the chimney if I burned smaller fires in a big stove. I said, “But the catalyst should take care of all that. If the cat’s firing, there’s nothing to make creosote.” She said nope, don’t do it. On the one hand I thought she was wrong, but on the other hand I wondered. She runs a stove shop after all. I’m just one guy with a lot of non-cat experience and very little catalytic burning in all my years of wood burning. Was she right? Or maybe sometimes sort of right?
So today I’m doing just what she told me not to do. And the Progress Hybrid is probably far more efficient than most stoves at sucking heat out of a small fire and not sending it up the chimney.
I’m experimenting how to burn this stove in milder weather. Even in cold weather I do pretty long burn cycles all the way down through coaling for a while before re-loading. In milder weather I’ve been mostly doing the same kind of thing but with smaller loads, like 8 pounds of wood and then very long coal-time, just enough coals to re-kindle. Though I also find I can keep a pretty low fire continuously in mild weather with small loads on catalytic burn, shut pretty far down, just a bit of flame and the stove top 300 to 350F. I can’t see anything coming out of the chimney except when the bypass is open, except steam early in the fire.
Recent appearance of Ray and his Heat-Maxx or whatever also got me wondering. I wouldn’t think of cooling this flue down any more. No, I will not do that. But how low is too low given my current setup? If there are basically no hydrocarbons after the cat, then what would make creosote?
I guess I’ll see come chimney cleaning time…
Now I’ve got a hybrid stove, which burns even cleaner and should send less stuff up the chimney. EPA rates this Progress Hybrid at .5g/hour or something, while my old Jotul was over 5g/hour. But this efficient beast captures a lot of the heat out of the flue gas. Like right now with a small load of wood and probably more catalytic combustion than flame-heat, I’ve got temps just over 200F on the single wall pipe a bit above the stove, according to the IR thermometer. The brick chimney above, going through the bedroom (with liner) used to be warm to the touch, sometimes pretty warm, with the Jotul. Now those bricks are never warm, even though I’m now burning 24/7. I only burned in daytime with the tube stove but those bricks got warm by bedtime. Obviously the flue and chimney is way cooler than it was, even when I’m burning hot in cool weather. Now it’s mild weather.
When I was stove shopping I went to a local stove shop, and the sales woman was trying to sell me a Lopi Answer. I was suggesting I’d want a bigger firebox. She said I’d have creosote in the chimney if I burned smaller fires in a big stove. I said, “But the catalyst should take care of all that. If the cat’s firing, there’s nothing to make creosote.” She said nope, don’t do it. On the one hand I thought she was wrong, but on the other hand I wondered. She runs a stove shop after all. I’m just one guy with a lot of non-cat experience and very little catalytic burning in all my years of wood burning. Was she right? Or maybe sometimes sort of right?
So today I’m doing just what she told me not to do. And the Progress Hybrid is probably far more efficient than most stoves at sucking heat out of a small fire and not sending it up the chimney.
I’m experimenting how to burn this stove in milder weather. Even in cold weather I do pretty long burn cycles all the way down through coaling for a while before re-loading. In milder weather I’ve been mostly doing the same kind of thing but with smaller loads, like 8 pounds of wood and then very long coal-time, just enough coals to re-kindle. Though I also find I can keep a pretty low fire continuously in mild weather with small loads on catalytic burn, shut pretty far down, just a bit of flame and the stove top 300 to 350F. I can’t see anything coming out of the chimney except when the bypass is open, except steam early in the fire.
Recent appearance of Ray and his Heat-Maxx or whatever also got me wondering. I wouldn’t think of cooling this flue down any more. No, I will not do that. But how low is too low given my current setup? If there are basically no hydrocarbons after the cat, then what would make creosote?
I guess I’ll see come chimney cleaning time…
