Put an end to my brown glass!

[recppd]

I've read numerous posts on here and have yet to figure out why some stove glass browns up, and why some doesn't. My Jotul Kennebec is one of those with an "air wash" system that SIMPLY DOESN'T WORK! The stove works great, and the heat is excellent, but once you turn the air down below 50-60% the glass starts to brown up - mostly at the bottom. I changed the gaskets this year, but still no improvement. I've tried to figure out why this is happening and have come up with some questions for those of you with more experience...

1) Would thicker glass panels make a difference?
2) Does anyone make a "double-pane" replacement panel that would lessen the "brown" effect?
3) Is the browning being caused by the glass being the coolest surface, or from air infiltration around the glass gaskets?

I really would love to find a solution to this annoying problem

 

[Roospike]

As i dont have the experience with the Jotul Kennebec .........I can throw out a few things.
#1 How dry is your wood is always the first question.
#2 Its a New stove is it not ?
#3 Can you normally burn wood at 1/4 or lower damper setting regardless of how the glass looks ?

We'll have to have some other Jotul Kennebec owners as to there input of the said stove.

 

[BrotherBart]

Are you loading the wood with splits sideways fireplace style or straight in front to back. If front to back the glass will smoke up every time because the gases come out the end of the splits. When you turn the primary air down there isn't anything to blow it away from the glass.

Except in a PE Summit of course. Smoke would not dare to stick to the glass of a Summit.

 

[Roospike]

O' how i wish it was true BB ................

recppd , how is your glass look in compared to this picture ?
http://i9.photobucket.com/albums/a97/Roospike/FOURM/P.jpg

This is about the worst it gets for me over 1 week of burning with out cleaning and thats at Fall weather buring as well.

 

[BrotherBart]

O' how i wish it was true BB ................

recppd , how is your glass look in compared to this picture ?
http://i9.photobucket.com/albums/a97/Roospike/FOURM/P.jpg

Same places the Sierra smoked up when they were front to back. The air comes down the glass but takes a turn for the middle of the fire before it falls across the whole window.

And by the way, I hate being reminded how good that damned stove of yours looks!

 

[adrpga498]

Roos , you may want to turn those splits around as BB suggested. Seems kinda dark to me in the corners. But otherwise very nice.

 

[recppd]

As i dont have the experience with the Jotul Kennebec .........I can throw out a few things.
#1 How dry is your wood is always the first question.
#2 Its a New stove is it not ?
#3 Can you normally burn wood at 1/4 or lower damper setting regardless of how the glass looks ?

We'll have to have some other Jotul Kennebec owners as to there input of the said stove.

1) I burn both cordwood and compressed logs (8-10% moisture) with pretty much the same results. Compress logs keep the glass cleaner for longer periods of time though. They also burn much hotter.
2) Stove is in its third season
3) I can when there is a pretty HOT fire already going. By HOT I mean stove top temps in the 600's.

 

[recppd]

O' how i wish it was true BB ................

recppd , how is your glass look in compared to this picture ?
http://i9.photobucket.com/albums/a97/Roospike/FOURM/P.jpg

This is about the worst it gets for me over 1 week of burning with out cleaning and thats at Fall weather buring as well.

That's how my glass looks after a couple of hours! I just thought of something though...

I have a cold air kit installed on my insert. Could the cooler air be causing the problem?

 

[Roospike]

O' how i wish it was true BB ................

recppd , how is your glass look in compared to this picture ?
http://i9.photobucket.com/albums/a97/Roospike/FOURM/P.jpg

This is about the worst it gets for me over 1 week of burning with out cleaning and thats at Fall weather buring as well.

That's how my glass looks after a couple of hours! I just thought of something though...

I have a cold air kit installed on my insert. Could the cooler air be causing the problem?

Good question , I dont have the outside air kit so i cant answer from one view point to the other.

Roos , you may want to turn those splits around as BB suggested. Seems kinda dark to me in the corners. But otherwise very nice.

Pacific Energy says to load the stove as to front to back and thats how i have run it so far and going to try it the other way this winter a few times.
Again , the picture of my glass is worst case i have had and by no means is this normal to be this dark.

O' how i wish it was true BB ................

recppd , how is your glass look in compared to this picture ?
http://i9.photobucket.com/albums/a97/Roospike/FOURM/P.jpg

Same places the Sierra smoked up when they were front to back. The air comes down the glass but takes a turn for the middle of the fire before it falls across the whole window.

And by the way, I hate being reminded how good that damned stove of yours looks!

Sorry brother man , I thought we had talked about you painting your stove "whorehouse red" ;-)

 

[recppd]

Forgetting how the splits face, let me ask this question...

How many of you burn in the very center of your stove? I think most of us, right? The reason I ask is because the outer corners of the glass are the first to brown up, and that would make sense if the heat was centered in the stove. If any of you folks have one of the digital laser thermometers (awesome invention!) then you can attest to my next discovery. I've found that when measuring the temps on top of my insert I can get readings as much as 200 degrees cooler on the outer edges versus those directly in the center. That's significant! My Jotul is cast, and I don't know if that matters. Perhaps steel stoves transfer heat more evenly?

 

[Roospike]

As i dont have the experience with the Jotul Kennebec .........I can throw out a few things.
#1 How dry is your wood is always the first question.
#2 Its a New stove is it not ?
#3 Can you normally burn wood at 1/4 or lower damper setting regardless of how the glass looks ?

We'll have to have some other Jotul Kennebec owners as to there input of the said stove.

1) I burn both cordwood and compressed logs (8-10% moisture) with pretty much the same results. Compress logs keep the glass cleaner for longer periods of time though. They also burn much hotter.
2) Stove is in its third season
3) I can when there is a pretty HOT fire already going. By HOT I mean stove top temps in the 600's.

Damn , I'm kinda at a loss. 3 years experence with the stove , low moisture fuel and runing good fires.
How about taking a can of compressed air ( like computer air cleaner ) and blowing in the air inler of your stove.
#1 Has you stoves glass always been this way from new?
#2 You said cord wood .......what kinda of wood?
#3 Is the glass much worse when burning in the Fall and Spring vs the cold of winter ?
#4 Are you burning 24/7 or other ?

 

[BrotherBart]

I think the splits burn so much more efficiently front to back with the air running between them that I never worried about some crud on the glass.

I am in a hurry to see what a little dude on the new stove does. Right in the middle of the front there is a little "tower" connected to the primary air channel. It has a .38 caliber size hole in it aimed right at the middle of the firebox. That and the airwash is how the primary air comes in. I suspect with a little draft the wood in front of that hole is going to do some burning. I'll include a pic of it when I put some together.

 

[recppd]

As i dont have the experience with the Jotul Kennebec .........I can throw out a few things.
#1 How dry is your wood is always the first question.
#2 Its a New stove is it not ?
#3 Can you normally burn wood at 1/4 or lower damper setting regardless of how the glass looks ?

We'll have to have some other Jotul Kennebec owners as to there input of the said stove.

1) I burn both cordwood and compressed logs (8-10% moisture) with pretty much the same results. Compress logs keep the glass cleaner for longer periods of time though. They also burn much hotter.
2) Stove is in its third season
3) I can when there is a pretty HOT fire already going. By HOT I mean stove top temps in the 600's.

Damn , I'm kinda at a loss. 3 years experence with the stove , low moisture fuel and runing good fires.
How about taking a can of compressed air ( like computer air cleaner ) and blowing in the air inler of your stove.
#1 Has you stoves glass always been this way from new?
#2 You said cord wood .......what kinda of wood?
#3 Is the glass much worse when burning in the Fall and Spring vs the cold of winter ?
#4 Are you burning 24/7 or other ?

1) Yes
2) Mostly oak and maple, with some elm mixed in. Very seasoned and dry.
3) Hmmm...I've never really noticed any difference between seasons
4) This time of year it's mostly 12-16 hrs. /day. Come winter its 24/7.

 

[Roospike]

Forgetting how the splits face, let me ask this question...

How many of you burn in the very center of your stove? I think most of us, right? The reason I ask is because the outer corners of the glass are the first to brown up, and that would make sense if the heat was centered in the stove. If any of you folks have one of the digital laser thermometers (awesome invention!) then you can attest to my next discovery. I've found that when measuring the temps on top of my insert I can get readings as much as 200 degrees cooler on the outer edges versus those directly in the center. That's significant! My Jotul is cast, and I don't know if that matters. Perhaps steel stoves transfer heat more evenly?

I normally burn in the center and or towards the back away from the glass.
When first lighting your stove and the wood starts to smoke before being chared i notice now matter where the wood is at that the smoke goes up .......then rolls off the front glass all the way down .......back into the fire then up with the flames. ( new load / full open draft )

Another point to the stove being a different temp in say the front to the stove ............
With a front air wash system you are always drawing fresh air into the front of the stove and through the bottom air inlet and around the top and down the front air wash system , that being said would suggest that the front of the stove where the air was is being run should be cooler.

 

[suematteva]

When you are burning at 600 does the glass clean up at all or stay the same?

 

[BrotherBart]

Forgetting how the splits face, let me ask this question...

How many of you burn in the very center of your stove? I think most of us, right? The reason I ask is because the outer corners of the glass are the first to brown up, and that would make sense if the heat was centered in the stove. If any of you folks have one of the digital laser thermometers (awesome invention!) then you can attest to my next discovery. I've found that when measuring the temps on top of my insert I can get readings as much as 200 degrees cooler on the outer edges versus those directly in the center. That's significant! My Jotul is cast, and I don't know if that matters. Perhaps steel stoves transfer heat more evenly?

Heck my Jotul F3 will run up to 200 degree differences from one side to the other. And the side varies so it isn't a leak. Also the temp varies greatly in checking just a couple of inches one way or the other.

I kind of chuckled when I discovered that wondering how many people were standing smiling looking at their nice six hundred degree thermo reading not realizing the other side of the stove was over 800. And that the mag thermos appear to be at least fifty to a hundred degrees off. Rutland, Candor, Homesaver you name it. I got'em all.

 

[Roospike]

Here is some input on front to back loading and side to side loading of wood and what differences it can make.

http://www.woodheat.org/tips/biglistoftips.htm

 

[adrpga498]

Here is some input on front to back loading and side to side loading of wood and what differences it can make.

http://www.woodheat.org/tips/biglistoftips.htm

Good article, thank you.

 

[Todd]

I've read numerous posts on here and have yet to figure out why some stove glass browns up, and why some doesn't. My Jotul Kennebec is one of those with an "air wash" system that SIMPLY DOESN'T WORK! The stove works great, and the heat is excellent, but once you turn the air down below 50-60% the glass starts to brown up - mostly at the bottom. I changed the gaskets this year, but still no improvement. I've tried to figure out why this is happening and have come up with some questions for those of you with more experience...

1) Would thicker glass panels make a difference?
2) Does anyone make a "double-pane" replacement panel that would lessen the "brown" effect?
3) Is the browning being caused by the glass being the coolest surface, or from air infiltration around the glass gaskets?

I really would love to find a solution to this annoying problem

Woodstock makes a double pane glass. My glass has never turned brown anywhere. Once in awhile I get a couple spots of that white/clear film on the glass, but it either burns off or I can wipe it off.

The previous stoves in this house had brown in the lower corners like yours (Regency & Hearthstone). I tried everything in those old stoves to keep the glass clean and nothing worked except burning hot. Once I turned down the air the airwash just wasn't strong enough to keep glass totaly clean.

I think some air wash systems are better than others, and for them to work you need absolutly dry wood and great draft. It shouldn't matter if the wood is loaded one way or the other the airwash is designed to keep the smoke off the glass.

 

[wg_bent]

I find that when I burn some of my "fatwood" pine the glass get's more brown. Oak will actually clean it up. The hotter the better. Any wood that sizzles will cause cloud up in a heartbeat. Same basic patterns, but on my stove it's the outer edges of the bay windows, and a very minor strip along the bottom of the center window. I do notice that the latch side of the door clouds up more than the hing side. Both pass the bill test, so not leaking air...

The dryer the wood the less this happens to a very large degree, and if hotter fires are run it almost doesn't happen.

I can't say what happens over time since I'm a bit anal on clean glass, so as soon as the load of wood is down to coals and a bit cooler I get out my little door adapter and clean the glass. That's like once a day.

 

[Dunadan]

I get the same thing on my glass if I turn my air down too far for an overnight burn. I also will get it if my splits don't catch well and smoke more than they should. Often times if I catch it right after it happens I can just wipe it off. Otherwise a mixture of ash, dish soap, and water takes it right off.

I also vote for loading split vertically in (north/south) as opposed to horizontally. I almost always get a good burn this way. When I load them east/west more often than not I don't get as good a burn.

 

[Arthur]

We have a one year old Jotul Kennebec, and get some browning of the glass also, though usually just hazed in lower corners. We give it a quick glass clean every couple of days, only burn 24/7 on weekends (when cold), otherwise 12hr burns. Stove uses the outside air intake also. Wood is generally well seasoned. However, our chimney height is at the low end of manufacturer recommended (16ft) with a couple of 30 degree bends in the liner (insulated 6" Simpson Duraliner). Does fine loading it with one door open, but if you open both doors, some smoke spills into the room. So, I think our draft is marginal, which may contribute to the browned glass. Otherwise, we really like the Kennebec.
How high is your chimney? Insulated? Got draft?
As far as a North/ South load vs. East/ West load, the Kennebec firebox is sorta medium sized and rectangular. Takes a 20" split east/ west, but can't get much bigger than 13" north/ south. We generally feed it longways or diagonally (one door open!).
Mike Wilson may have some triangulation on this subject if he's out there still (?).

 

[Todd]

I wonder if the problem with dirty glass is the secondary air intake of most non-cat stoves? Most don't have a way to control it and when you turn down the primary air the secondary takes over and reduces the airwash?