Understanding Keystone Burn Times

[fox9988]

Couple more questions.
1) Is your stove top or rear vented?
2) Do you have a stove pipe thermometer? It would tell you how much heat is going up the chimney and not in the house.

 

[fox9988]

@Todd has a lot of KS experience and great advice. Hopefully he will weigh in.

And @Woody Stover.

 

[radtechrad]

Couple more questions.
1) Is your stove top or rear vented?
2) Do you have a stove pipe thermometer? It would tell you how much heat is going up the chimney and not in the house.

It is rear vented. I'm having the chimney upgrade to a class A superpro by selkirk. Right now it is an uninsulated flex liner. The chimney runs through a framed "fake" fireplace, so I can't take a temperature on the stove pipe.
I did take a temperature reading on the T which is approx. 1 foot from the stove. I took the temp when the stove top was 600+. The T measured around 300F.

Also, I'm now running the stove at a 0 setting. I was told not to do this because I would promote a smoldering fire that lacked the air needed to circulate the smoke to the cat. Of course I've got flames going at 0.5 so, I'll see what happens at 0.
I sure hope I can dial this stove in.

One thing that is a bit frustrating is the old cat I had which my chimney sweep said was damaged never produced any smoke. I still had all the problems mentioned in this thread though. It was a ceramic cat which I replaced with a metal one.
I asked Woodstock if they've had any problems with the metal ones. They said they should work well. Still, I wish I hadn't thrown the old damaged cat away. I also discarded the metal housing thinking I wouldn't need it anymore. Bad move on my part.

Thanks for all the follow up replies. I'm not very knowledgeable when it comes to wood stoves. You and the other posters have been a great help!

 

[fox9988]

I did take a temperature reading on the T which is approx. 1 foot from the stove. I took the temp when the stove top was 600+. The T measured around 300F.

From the T should be fine. 300F sounds fine with a 600F stove top, doesn't sound like you are waisting heat.

I have never used a ceramic cat but most that have changed to a new stainless steal are happy. My SS works great and doesn't smoke.

It is normal to see some steam from the chimney early in the burn. It is white and dissipates quickly unlike smoke.

 

[danimal1968]

It is rear vented. I'm having the chimney upgrade to a class A superpro by selkirk. Right now it is an uninsulated flex liner. The chimney runs through a framed "fake" fireplace, so I can't take a temperature on the stove pipe.
I did take a temperature reading on the T which is approx. 1 foot from the stove. I took the temp when the stove top was 600+. The T measured around 300F.

Also, I'm now running the stove at a 0 setting. I was told not to do this because I would promote a smoldering fire that lacked the air needed to circulate the smoke to the cat. Of course I've got flames going at 0.5 so, I'll see what happens at 0.
I sure hope I can dial this stove in.

One thing that is a bit frustrating is the old cat I had which my chimney sweep said was damaged never produced any smoke. I still had all the problems mentioned in this thread though. It was a ceramic cat which I replaced with a metal one.
I asked Woodstock if they've had any problems with the metal ones. They said they should work well. Still, I wish I hadn't thrown the old damaged cat away. I also discarded the metal housing thinking I wouldn't need it anymore. Bad move on my part.

Thanks for all the follow up replies. I'm not very knowledgeable when it comes to wood stoves. You and the other posters have been a great help!

This isn't directly related to your post but since you indicate you're new with the stove, here is a video the guys from Woodstock posted a while back that covers the process of them starting up a Keystone from a cold start.

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[radtechrad]

From the T should be fine. 300F sounds fine with a 600F stove top, doesn't sound like you are waisting heat.

I have never used a ceramic cat but most that have changed to a new stainless steal are happy. My SS works great and doesn't smoke.

It is normal to see some steam from the chimney early in the burn. It is white and dissipates quickly unlike smoke.

Well, it's good to know the metal cats are not problematic. I just placed some thin gasket material on top of the gasket in the ash door. A temporary fix just to tighten things up. I did an incense test and the stove is no longer drafting through the ash bin
I'm going to wait for the stove to drop to 300F. Gonna re-load....wait.....engage the cat and set the draft between 0 and 0.5 depending on the flames. Hopefully the stove is now very tight. Then I'm gonna time the stove from the initial burn stage until it returns to 300F.
I think this scenerio (no draft, proper settings and waiting for the stove to go through an entire burn CYCLE) should give me a better idea of what I'm dealing with.

Thanks again for the help.
I think I'll call it a night, and hopefully...enjoy the heat AND long burn times.

Take Care

 

[radtechrad]

This isn't directly related to your post but since you indicate you're new with the stove, here is a video the guys from Woodstock posted a while back that covers the process of them starting up a Keystone from a cold start.

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For more detailed information, see our cookies page.

Accept third party cookies

Thanks for the video! This should be helpful

 

[fox9988]

If you haven't yet, you can try the incense test on the stove body also. Anywhere the soapstone meets cast.

 

[Highbeam]

300F sounds fine with a 600F stove top, doesn't sound like you are waisting heat.

Careful now, that's 300 on the outside of the tee so 600 degree smoke temps. That's quite high. My BK runs 400 degrees smoke temps. He's shooting heat up the stack.

 

[Jo191145]

I did replace the cat. It is a new design (all metal and not ceramic) Bought it from Woodstock. But, I think you put your finger on my issue. I'm just running it full out expecting too much heat from it AND long burn times. The only physical problem I see is some draw from the ash bin door. I did an incense test over the exterior and saw incense smoke being drawn into this area. The other thing that I don't understand is smoke coming from the chimney. I thought cat stoves burned smoke. Anyway, I'll re evaluate my burn times by letting the stove cool to 300F and measure my time from initial burn to 300F. Thanks for your observations and advice.

I read somewhere the metal cats should fire off at lower temperatures than the ceramics. Maybe someone with knowledge could chime in on that.
There's lots of advice not just here but all over the web on how to get your cat fired up. I won't discount the validity of that advice but my stove seems not to need all that work. If I have a decent amount of coals I can just stuff it full, shut the air down to nothing and wait. It'll fire up the cat in about 5 minutes without doing the normal preburn. Once the cat is going it heats the baffle which ignites the off gases floating around in the firebox. Sort of just opposite of the normal recommendation without charring up all the wood for nothing. YMMV
I don't always do it this way but I do try different things looking for Nirvana. I have found mine actually lights off better closed down instead of wide open. As someone else mentioned too much air not only cools the cat but allows smoke/fuel and heat to go up the chimney.

Another useful term I recently learned on this forum is "envelope". This stove might not be capable of heating my entire house under all weather conditions but by allowing it to do its thing efficiently I'm still adding heat to the envelope. Now instead of trying to get those stones red hot I attempt to run it efficiently and let my wood furnace idle to take up the slack when it gets into the teens or less. I think that's as close to Nirvana as I'll get with this stove. It's warmer inside than most winters and I'm still using less wood to achieve it.

 

[radtechrad]

I read somewhere the metal cats should fire off at lower temperatures than the ceramics. Maybe someone with knowledge could chime in on that.
There's lots of advice not just here but all over the web on how to get your cat fired up. I won't discount the validity of that advice but my stove seems not to need all that work. If I have a decent amount of coals I can just stuff it full, shut the air down to nothing and wait. It'll fire up the cat in about 5 minutes without doing the normal preburn. Once the cat is going it heats the baffle which ignites the off gases floating around in the firebox. Sort of just opposite of the normal recommendation without charring up all the wood for nothing. YMMV
I don't always do it this way but I do try different things looking for Nirvana. I have found mine actually lights off better closed down instead of wide open. As someone else mentioned too much air not only cools the cat but allows smoke/fuel and heat to go up the chimney.

Another useful term I recently learned on this forum is "envelope". This stove might not be capable of heating my entire house under all weather conditions but by allowing it to do its thing efficiently I'm still adding heat to the envelope. Now instead of trying to get those stones red hot I attempt to run it efficiently and let my wood furnace idle to take up the slack when it gets into the teens or less. I think that's as close to Nirvana as I'll get with this stove. It's warmer inside than most winters and I'm still using less wood to achieve it.

I agree that achieving "Nirvana" means compromise. This stove simply will not heat my entire home (probably due to layout) but will certainly warm most areas and keep other areas very comfortable. This being achieved by running the stove efficiently. I admit my situation is more human error than problems with the stove itself. Will keep experimenting. Thanks for the reply

 

[radtechrad]

Careful now, that's 300 on the outside of the tee so 600 degree smoke temps. That's quite high. My BK runs 400 degrees smoke temps. He's shooting heat up the stack.

My chimney sweep will be installing a new class A chimney tomorrow. Will ask him about the high smoke temps. Thanks Highbeam

 

[fox9988]

Careful now, that's 300 on the outside of the tee so 600 degree smoke temps. That's quite high. My BK runs 400 degrees smoke temps. He's shooting heat up the stack.

Yes, that is high for a low draft setting. I only see a flue temp like that at high draft settings (2).

 

[fox9988]

My chimney sweep will be installing a new class A chimney tomorrow. Will ask him about the high smoke temps

Don't be surprised if your sweep has no idea.

I read somewhere the metal cats should fire off at lower temperatures than the ceramics

Correct.
WS recommends charing the wood before engaging the cat to rid the wood of it's moisture which is very hard on a cat. So I do.

 

[Tenn Dave]

Well, it's good to know the metal cats are not problematic. I just placed some thin gasket material on top of the gasket in the ash door. A temporary fix just to tighten things up. I did an incense test and the stove is no longer drafting through the ash bin
I'm going to wait for the stove to drop to 300F. Gonna re-load....wait.....engage the cat and set the draft between 0 and 0.5 depending on the flames. Hopefully the stove is now very tight. Then I'm gonna time the stove from the initial burn stage until it returns to 300F.
I think this scenerio (no draft, proper settings and waiting for the stove to go through an entire burn CYCLE) should give me a better idea of what I'm dealing with.

Thanks again for the help.
I think I'll call it a night, and hopefully...enjoy the heat AND long burn times.

Take Care

At stove top of 300* that keystone should still be giving off plenty of heat into the room. I usually don't reload my Progress Hybrid until the stove top falls below 200*. But what really dictates when I reload is the room temperature. When it falls to the lower limit of my comfort zone (71*), I reload.

 

[begreen]

Part of the issue here is the home. True log houses are of entirely different construction than stick built. In extreme cold logs can be more conductive to cold than a well insulated wall. There are so many variables from home to home that the same stove may perform quite differently in different environments.

 

[Highbeam]

My chimney sweep will be installing a new class A chimney tomorrow. Will ask him about the high smoke temps. Thanks Highbeam

Fox is right, the sweep is most likely ignorant about flue temps, expected cat flue temps, efficiency, and how they correlate. The Sweep will likely think that higher is better since low temps promote creosote. Really, a properly functioning cat will eat the smoke and letting out any extra heat is taking heat away from the home. Ideal flue temps are just high enough to prevent condensation.

 

[Jo191145]

Part of the issue here is the home. True log houses are of entirely different construction than stick built. In extreme cold logs can be more conductive to cold than a well insulated wall. There are so many variables from home to home that the same stove may perform quite differently in different environments.

Without a doubt. And no two log makers are the same. Some of the worst designed log homes are right in my area. The design consisted of two flat logs mated with a 1/4" compressed paper spline between them set in grooves. I would hope the original design called for a nice flexible caulk to be used but it was rarely done. In all the log homes I've chainsawed through I'd guesstimate two had caulking along those splines. The rest of those paper splines rotted out within a few years once water got in that far. If water gets through air does.
Bad design and shady construction makes some drafty houses.

 

[Woody Stover]

300 on the outside of the tee so 600 degree smoke temps. That's quite high. My BK runs 400 degrees smoke temps.

Yes, that is high for a low draft setting. I only see a flue temp like that at high draft settings (2).

If his setup is like mine (sounds like it is,) with a stainless tee, the only thing I can do is lay the surface meter on the tee snout, about 6" behind the flue collar. That's gotta be reading higher than the recommended placement 18" above the flue collar, so maybe he's not blowing too much heat up the stack. I just shot the top and bottom of the tee, right behind the flue collar; Top 247, bottom 140, so I think my tee flue temp readings may well be skewed high. Not sure where you have your meter, Highbeam, or if you have a probe (or both. I would, nerd that I am.) I do know the Princess is top-vent only...

 

[Woody Stover]

After slowly warming up the stove to catalytic temperatures (300F stove top temp) I load the stove full of 16-18" seasoned oak hardwood....It's been drying for approx 18 months.

1300 sqft home...It's a manufactured log home with drafty windows.

Everything I'll offer is based on my experience with dry wood. Echoing danimal1968, the chances of your Oak being dry are slim. Maybe my Oak is useable after 18 months if that included 2 summers, the tree was dead-standing for several years before I cut it, and I split it medium-small and stacked it single-row in a windy spot. You may have to supplement with Bio-bricks unless you have some non-Oak, lighter, faster-drying woods like soft Maple, Cherry (or White Ash that was dead-standing.)
The 'stone should handle that 1300 if you can tighten up the envelope. Get that window film and maybe some of these if you have wooden door jambs. (Don't press the vinyl bulb to the door real tight, just touch the door.) http://www.homedepot.com/p/MD-Build...Weatherstrip-Kit-69938/205545482?N=5yc1vZc3dy

Can you explain "slowly warming up the stove?" From a cold start, I load top-down, burn it in, cut the air in a couple steps, then close the bypass. I might be looking at 45 min. or so. Loading on a coal bed, maybe 30 min. If you try to heat the stove top to 300 before closing the bypass, you are burning a lot of the load away, something you don't want to do with a small box. Since the stove top lags so far behind what the fire box is doing, I use the cat probe for ramp-up, and to tell me when to close the bypass. I doesn't read the true cat temp since it doesn't reach over the cat, but it tells me the conditions in the top/rear of the fire box. I run it up to about 1000 with medium flames in the box, cutting air as the load takes off. Then I cut the air to hold the probe at 1000 for 10-15 min. You could also experiment with your flue meter and do essentially the same thing. The probe is easier for me to see, so I use it. Since my stove is in front on the fireplace and it's hard to see the face of the probe, I bent a paper clip around the bolt head and I can see it and the thermo pointer by looking over the top back of the stove. IIRC, I was lighting off the cat in the Keystone with about 170 stove top.

No, the flames don't extinguish. Usually I see "normal flames" burning albeit darker in color, and I see what I would describe as an aurora of flames.

This sounds like my stove set on 1 to 2. There should be no flames on 0, the wood should smoke/off-gas and the cat burns that for heat. I would recommend you try a burn on 0 and see if that helps.

Yeah, you should be able to snuff the flames, and may well be able to do that with the ash door fix...I don't think your stack is real tall, where other small leaks could feed a lot more air. These stoves like to run on the low end to burn clean. I can burn a little flame with no smoke, but if you need more output, you gotta do whatcha gotta do. Tighten that place up, until you can run low.

I won't discount the validity of that advice but my stove seems not to need all that work. If I have a decent amount of coals I can just stuff it full, shut the air down to nothing and wait. It'll fire up the cat in about 5 minutes without doing the normal preburn.

WS recommends charing the wood before engaging the cat to rid the wood of it's moisture which is very hard on a cat.

I think the moisture isn't as much an issue if you have the steel cat, but I don't want a lot of unburned smoke going through it. I figure creosote will stick to the catalyst surface, then burn off but the ash will be stuck; It's not gonna blow right out by mouth, like fly ash does. I wanna see that cat glowing in less than a minute when I close the bypass. It may be that the 201 is capable of lighting off like that due to different cat setup and air routing, but I don't think my Keystone or Fireview can light off without burning in the load. I can't see how much wood could be gassing, just tossing it in and closing the bypass...

True log houses are of entirely different construction than stick built. In extreme cold logs can be more conductive to cold than a well insulated wall.

More conductive? You know how that's supposed to work? I figured they would be good insulation. My problem is that wind gets behind the logs and sucks the heat away from my non-gypsum wallboard. It's like an inch of concrete-type stuff, sucking the heat out of the room, then the wind blows it away. I figured that if I can get the chinking in good shape, and where logs butt up to the chimney, etc, it would be pretty good. The wind also blows inside through any breach in the wallboard; Outlets, window frames, etc.

 

[begreen]

A 6" log according to this article has a value of R=1.0 per inch or R=6. But if the log is round it's max R value is only at its thickest point and diminishing toward the top and bottom. Just like in conventional stud built structure a large portion of the heat loss is through thermal bridging. Studs directly conduct heat to the outside envelope of the house through thermal bridging in spite of insulation in the stud cavities. This heat loss can be prevented by an insulation wrap on the exterior or by a staggered stud wall construction, which is a double 2x4 wall with the studs offset. This later technique is how my BIL built his house in NY. He heats all 2100 sq ft with 2 cords or less wood, even during last year's winter.

http://inspectapedia.com/structure/Log_Home_Insulation.htm

 

[Woody Stover]

All this talk about incense had me thinking, "I oughta seal that air leak I know about, put the Keystone back in, and see if I can find any more leaks. Plus, the incense might trigger a flashback; That could be fun..." Then I thought that instead of switching stoves in the middle of winter, with no backup heat, maybe I could just rig up the vacuum cleaner to the flue outlet and simulate the draft. Might be hard to exactly duplicate the real thing, but I bet I could get close by feeling how much air was being sucked in the door...
Another thing; The air leak is in the right vertical seam, and looking inside the stove, I can see a thin white line where the creosote has burned off the soapstone.

 

[begreen]

Maybe wirebrush it clean and goober the gap up with some furnace cement to get you through the winter?

 

[Woody Stover]

A 6" log according to this article has a value of R=1.0 per inch or R=6. But if the log is round it's max R value is only at its thickest point and diminishing toward the top and bottom.

Aw, man, now I guess I gotta just shrink-wrap the whole house. Seriously, I've got a lot of leaks yet to fix...it's all about slowing down the transfer of heat, if I can't stop it. That's awesome that your BIL is heating that kind of space with that little wood. That's probably about what I burn for 1000 sq.ft.

Maybe wirebrush it clean and goober the gap up with some furnace cement to get you through the winter?

Although it doesn't have the arse of the Keystone, I'm getting by on the Dutchwest. If night temps go into the mid-teens, I have to fire up the blower to hold room temp at 70. But when I don't need the blower, I gotta back out the bolts that hold the convection block-off plates in place and swivel them out of the way, to allow more air to move through the stove jacket unassisted. I won't need the blower for another couple of weeks, it looks like. I guess I'll go ahead and see if I can find more leaks in the Keystone, then tear it down and rebuild it over the summer, go the whole nine yards. Either that seam didn't quite get enough cement at the plant, or it was loosened in transport....we'll see.
But I am pulling my SIL's identical Dutchwest today, and doing just that, seam-gooberin', along with a complete re-gasketing and sweep-down of the chimney. Dis is da shizzle, right here. Like furnace cement, but thinner to squeeze in all those tight seams, and hopefully hold better and longer.

 

[begreen]

BIL built the house in the early 1980's. They have been saving year round ever since.