Progress Hybrid damper questions

[John Lehet]

Is there a way to shut off the secondary air in this stove? I would much prefer a true cat stove control unless I really needed a ton of heat.

Aside from the secondary air being designed in, I’m not positive the cat doesn’t get overwhelmed by lots of smoke from a near full firebox this size without flame. I don’t burn it smoldering very often at all. Maybe my opinion on this is just biased by my installer (a sweep who is a Woodstock geek, working in the area local to the shop) and some other stuff I’ve read. Including the manual, which has the “night burning mode” suggested at the first big mark short of closed. I shut it down way more than that (ideally if I can get minimal secondaries at the top of the stove).

My sense of the intent of the design of the stove is that in general the flames do most of the burning work, and the cat cleans up whatever gets past them and then in the early coaling stage or any smoldering later into coaling. It seems to want to burn generally pretty hot and fast and put that heat into the stone. It seems pretty far from a pure cat stove in that regard, though with the ability to hold coals and keep heat in the stone I think overall it works out about the same.

My situation might be influenced by my very strong chimney draw. I don’t get long fires like a Blaze King or maybe even a Fireview at all, but the end result is a long period of heating and an easy reload on hot coals.

I might be completely wrong and there are people completely happy and getting good results running this stove more often without flame!

 

[tsh2002]

Aside from the secondary air being designed in, I’m not positive the cat doesn’t get overwhelmed by lots of smoke from a near full firebox this size without flame. I don’t burn it smoldering very often at all. Maybe my opinion on this is just biased by my installer (a sweep who is a Woodstock geek, working in the area local to the shop) and some other stuff I’ve read. Including the manual, which has the “night burning mode” suggested at the first big mark short of closed. I shut it down way more than that (ideally if I can get minimal secondaries at the top of the stove).

My sense of the intent of the design of the stove is that in general the flames do most of the burning work, and the cat cleans up whatever gets past them and then in the early coaling stage or any smoldering later into coaling. It seems to want to burn generally pretty hot and fast and put that heat into the stone. It seems pretty far from a pure cat stove in that regard, though with the ability to hold coals and keep heat in the stone I think overall it works out about the same.

My situation might be influenced by my very strong chimney draw. I don’t get long fires like a Blaze King or maybe even a Fireview at all, but the end result is a long period of heating and an easy reload on hot coals.

That would make sense to me too. I have seen issues with low smoldering fires as well with extra creosote buildup in my flue with my BK, so when I start a new load in either stove, I open the damper up all the way with the bypass open (usually when the temp is below where that cat would be active), and give it about 15-20 minutes to get a decent fire going or when the stovetop temp reaches 350 or so, then damper it down and and close the bypass. Based on my research and experience, this will burn off any residual moisture and get things heated up and cat active. Since doing this the flue has stayed clean. I also don't try to open the damper past halfway with the bypass closed either, in order not to push smoke past it too quickly.

Compared to the BK, the PH definitely does not burn as low (damper all the way "closed") and doesn't get the long burn times that the BK can do. Even at the lowest damper setting, the PH still has a fair amount of airflow from my experience, but like you said that also provides more heat for the burn cycle and I think that helps keep the secondaries active. I too have a tall stack since the PH is in the basement.

 

[Todd]

I’m not an wood stove engineer but the cat in the PH is just about twice the size of the Fireview cat and the firebox is only about 1 cu ft larger so I’m assuming the PH cat could handle a full smoldering load. I just thought it would be interesting to see how it would perform as a true cat stove and if it could be dialed down for a lower BTU output and longer burn. I think it would be nice if you could switch those secondaries on and off but I doubt the EPA test methods would allow it.

 

[John Lehet]

I’m also definitely not a woodstove engineer, but I wonder if on account of the secondary air if there is in general greater volume and velocity of exhaust gas going through the cat and so the cat has a tougher job. I’d imagine that if exhaust is going faster there is less dwell time of smoke over metal. On the other hand exhaust gas might be hotter and have more oxygen in it to support catalytic reaction. No idea, just tossing out complexity.

 

[DBoon]

I have a Woodstock Keystone with a 27' vertical double-wall chimney pipe. I can tell you from smoke observations from my chimney that there are conditions in which smoke blows past the cat and is unburned - when draft gets too high from burning too much small wood in the stove too quickly, very cold outside, too fast a start, etc.. Even with a pipe damper smoke blows past the cat (it is not steam). I've learned what not to do to mitigate that, but it might still happen for 10 minutes of a burn now and again. It's not a stove issue - it's a chimney/draft issue.

 

[John Lehet]

I have also smelled a bit of smoke with my Progress at times. Just a bit. With the old Jotul there was usually absolutely zero smell, unless I messed up and it was pretty bad. “Oops, better go in and get it hotter!” With the Progress I have smelled just a hint when everything should have been burning perfectly and the cat hot enough. Most other times zero. I think it was cold in those times I smelled it, but it’s been cold here most of the time lately.

 

[Todd]

Yes there are times when the cat doesn’t have enough time to burn all the smoke. Time, temperature and turbulence all play a roll. This is why cat stoves are most efficient at lower burn rates. I think all these hybrid stoves were designed to burn cleaner at higher burn rates with the help of the secondary baffles and tubes. This all helps with the EPA tests that are burned at a low, med, and high burn rate then averaged together to get an overall efficiency and emissions number. I know looking at the Fireview EPA test results there is a huge difference between the low and high burn rates.

 

[John Lehet]

All winter I've burned either bigger loads or smaller loads on serious coal beds. Stove top goes to 400 or over, secondaries. Now it's often milder, and I'm feathering in the stove with the mini split (the mini split can't keep up at this time of year with all the cold distant parts of the house pulling heat away). I'm finding that a small load (10 pounds of wood) in a lukewarm stove seems to do just fine for a purely catalytic burn, or primary flames + cat. Right now I've got some ghost flames, stove top about 325. I haven't seen or smelled any smoke from the chimney with this fire (I keep checking). Haven't had any secondaries this burn. Seems like a small catalytic fire is just fine. Started it from the coals of last night's load, 13 hours ago.

This warm stove along with the mini split (not struggling) will coast along until evening when I load it up. There will probably be enough coals to start the fire just fine. It's a good stove.

 

[BKVP]

All,

I spoke with the owner of Woodstock Soapstone this week. I mentioned some feedback on combustor availability was on this site.

He said "you can tell them we are 100% caught up and have lots in stock".

He's a true friend as many of you know.

BKVP

 

[John Lehet]

Now it’s a bit of shoulder season starting, and in my house a big fire in the Progress is overkill. When I was shopping for this stove, I had a conversation with Lorin at Woodstock and asked about this very thing. She said, ‘Just make smaller fires!” I was wondering about that, but now I’m doing it. It works great. It’s a whole different thing though, like a different stove.

So to get a bit of heat in here to go along with the mini splits and have a nice warm radiating body in the room, I’m using sticks. From my own wood cutting, I always cut up all branches down to twigs when I fell a tree, so I have a lot of sticks.

I had been putting them on coals under splits at every reload just to get rid of them, but now I’m having fires with just the sticks. It is perfect. At about 6 pounds of sticks I can get it just hot enough at the end of flaming to get the cat hot enough, and then that will clean up the end of flaming -> smoldering coaling phase. No smoke out of the chimney. Also little or no smoke out of the chimney during vigorous flaming.

It’s perfect.

 

[Todd]

Now it’s a bit of shoulder season starting, and in my house a big fire in the Progress is overkill. When I was shopping for this stove, I had a conversation with Lorin at Woodstock and asked about this very thing. She said, ‘Just make smaller fires!” I was wondering about that, but now I’m doing it. It works great. It’s a whole different thing though, like a different stove.

So to get a bit of heat in here to go along with the mini splits and have a nice warm radiating body in the room, I’m using sticks. From my own wood cutting, I always cut up all branches down to twigs when I fell a tree, so I have a lot of sticks.

I had been putting them on coals under splits at every reload just to get rid of them, but now I’m having fires with just the sticks. It is perfect. At about 6 pounds of sticks I can get it just hot enough at the end of flaming to get the cat hot enough, and then that will clean up the end of flaming -> smoldering coaling phase. No smoke out of the chimney. Also little or no smoke out of the chimney during vigorous flaming.

It’s perfect.

Have you had the opportunity to fill the stove full and burn it low and slow yet, or do you think that would be too much heat?

 

[John Lehet]

In the winter I’d load it pretty full and shut it almost all the way down, or sometimes all the way down. With the hybrid design it’s not reliable that secondaries won’t light off no matter how far I shut it down, if there’s a strong draft and the wood is dry. And in fact I prefer to burn it that way, with flame. Lately with less draft, and often tossing in a less dry split I’m finding it hard to get secondaries before I go to bed sometimes, so I do get a catalytic smolder overnight sometimes. It doesn’t seem to matter in terms of the temp or the coal bed in the morning. Wood burns up, room is 70 - 72, thick bed of coals with or without flame. With all the soapstone to buffer, it’s hard to tell if the output of the stove at any point is any different. I assume there are differences in where the stove gets hot. The cat will heat the top of the stove, while flames will heat the sides of the stove as well. But over 8 hours it all comes out in the wash I think.

 

[Leeks]

FYI, you can add a small piece of aluminum foil to the slot of the stovetop thermometer that Woodstock provides so that it can indicate peak overnight temperatures. The pointer pushes it around. Crude but it works.

 

[DBoon]

FYI, you can add a small piece of aluminum foil to the slot of the stovetop thermometer

Done this myself. Works pretty good on my Woodstock cat stove. Didn't work so well on the Lopi Answer with the blower (foil blew away, often enough).

 

[John Lehet]

I might have to revise my comments on low and slow with the progress. This winter had been so cold. Strong draft, and I always had a deep bed of coals. Running in the higher 20s, starting the cold stove, no bed of coals — it’s a completely different stove, just a very different personality. This morning I can do low and slow with flames, or not flames. I haven’t measured my draft in the warmer weather. I still have the Meyer manometer. I’ll have to check it.

 

[DBoon]

Running in the higher 20s, starting the cold stove, no bed of coals — it’s a completely different stove, just a very different personality.

I find that starting a cold (to the touch) soapstone stove takes a bit of work. My cold-start burns are always small loads with small pieces just to get a coal bed started for the next load.

 

[Todd]

My cold starts consist of larger logs with kindling and fire starter in between. Kind of a kindling sandwich. Works well for me.