Do epa stoves burn creosote?

The goal is to burn the smoke with whichever method involved. Burn tubes or catalyst. In either case there is always some smoke emissions but markedly reduced. The temperatures in the chimney is frequently lower than non-epa stoves, but if burning practices are good there shouldn't be nearly the buildup either.

Without good burning practices (mostly burning wet wood) temperatures don't reach optimal, and the secondary burn method efficiently is greatly reduced and then you have lower temperatures in the chimney with more smoke so theoretically the creosote buildup could be worse.

If the wood is dry and the cat takes off appropriately buildup shouldn't be a problem.

If you cut the wood this year and need to burn it this winter that is what you have to do. It may have extra moisture content than is ideal, and it may lead to more buildup than you have had in the past. You'll need a moisture reader to know for sure.

The two year old oak could even still have some moisture problems. Or maybe it is fully seasoned (hopefully) by now.

Regardless, you burn what you have to to stay warm.

If there is buildup, it just means you may have to be extra-vigilant and sweep the chimney more frequently until you get an adequate seasoned wood supply up.

I did find the IS to be very tolerant (less picky) of moisture in the wood than my secondary-only stove. I also ran it lower/slower during a long shoulder season and my chimney and stove pipe still looked good. Maybe some more than I used to have but again, I ran it low on purpose. Overall I am totally comfortable with yearly cleanings. I'd probably stretch it further if it took me more than 15 minutes to do.

JA600L said:

This is a dumb question, but do epa stoves actually burn creosote before it becomes solid? Is that one of the gasses that light off the secondaries? My curiosity is because a more efficient stove is going to send less heat up the chimney right? Does that put you in danger of building creosote at a low burn rate (with cat/ secondaries lit)? Thanks for any thoughts.

Click to expand...

actually its not a dumb question at all. to be simplistic about it , "smoke" is simply wood that aint burnt yet. stack gasses for the most part are also unburned fuel
the thing about creosote is that its not just the amount of smoke being exhausted by the stove, creosote is formed when the products of incomplete combustion are not completely evacuated by the chimney then allowed to mix with moisture at a temperature below 211F.

one of the things to remember when it comes to the issues with creosote in "smoke dragons" is that the methods people used to try to get longer burn times out of them ended up being the biggest cause for excessive creosote buildup. with an old pre-epa unit the only thing one could do to slow the burn time down to achieve an overnight burn was to deny air to the primary fire. this does a couple things in an old unit which you do not typically get with a modern stove.
1. lower stack temps, since there is no secondary burn in an old tech stove the incomplete burn created by denial of primary air results in a cooler fire and lower stack temps.
2. the amount of smoke created by this type of fire results in an exteremely incomplete level of combustion.

so you are putting a lot of fuel in the stack and also running a lower stack temp allowing moisture which IS a byproduct of woodburning even with seasoned wood (though much worse with wet wood) the rapid building of creosote will happen. this starts to reduce the diameter of the flue as this stuff layers up, now the dangerous part of this is that when you reduce diameter you increase temperature in the exhaust stream. so once enough concentration is present add a hot fire and boom, there you go to a chimney fire.

the real advantages of a modern unit stem from not only the ability to burn a much higher percentage of the stuff which usually creates creosote but in doing so burn in such a way as to create higher exhaust temps with lower volume of flow. this is the big difference. a modern stove is designed in such a way as to deny a larger portion of primary air (as with the old tech) while at the same time , introducing secondary air downstream if you will from the primary fire. this allows a slow burn which would normally plug up a chimney with the reburn after the fire which not only burns away the largest portion of unspent fuel, but also BOOSTS exhaust temperature to maintain stack temps above the creosote zone. so, you get the "long burn times" without plugging up your chimney and polluting the air.

the added bonus (and really where the boosted efficiency comes into play is this) you are producing a "hot fire" output, with a "slow burn" fire. simply releasing more energy from the fuel at a slower pace.

hope this helps ya!

I urge you to get an inexpensive moisture meter. I doubt seriously that one-year cut wood (or two-year cut oak) is sufficiently dry for an EPA stove. YMMV...but at least you'll know.

There are non-cats and cats as the most common technologies out there today. There have been some attempts at a "hybrid" but they are really just cat stoves for this discussion which is concerned with low burn and creo accumulation. Just about any stove, burned at full throttle with good fuel, will burn relatively cleanly.

The non-cats burn cleanest in my experience. So much air is pushed into the firebox during all levels of combustion that the burn is never oxygen starved. The non-cat tech is not well suited for long and low. The only way to lower the surface temps of a non-cat is to reduce the fuel load since reducing primary air settings simply transfers that same flow of air to the secondary burners.

The cat stove is well suited for long and low, best designs are capable of longer and lower while maintaining cat ignition. These stoves use a catalytic combuster to eat that unburnt fuel and no extra air source. They are not lean burners and minimal air passes through the system at low burn.

I suppose this could become a cat vs. non-cat post so I'll wrap it up for the OP. The modern stoves burn most of the creosote but enough of it passes by along with water that you need to be sure that flue temps stay up high enough to assure that condensation of the water/creo does not occur until the exhaust exits the flue.

The IS is a very clean burning stove. It's low setting higher than some cat stoves so it seems to burn more cleanly.