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Harman TL 300 Users

Post in 'The Hearth Room - Wood Stoves and Fireplaces' started by cyclone, Oct 5, 2008.

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  1. branchburner

    branchburner Minister of Fire

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    That's what I'd want, too... it's possible it just seems the flue is warmer because so much heat is getting kicked off the back of the stove. We'll see what the numbers say.

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  2. stanleyjohn

    stanleyjohn Feeling the Heat

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    I think that when the AB is activated the stove temp does drop alittle!in my case it seems to be the case.The afterburner was designed to burn wood clean!(not to increase the stove top temp).The big heat up with the AB running will be in the AB chamber itself with alot of that heat going up the flue.
  3. cyclone

    cyclone Member

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    So if you are saying alot of the heat is going up the stove pipe and to the flue; will the blower help pull more heat before it goes up the stove pipe than no blower. Is it an advatage to have a blower on these stoves.
  4. Seasoned Oak

    Seasoned Oak Minister of Fire

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    The area directly above the AB just under the flue exit is bare steel with an warm air channel leading out the top front of the stove, (TL-300)whether you have a blower(and i do have one) or not the room air will come in the bottom and out the top front of the stove just in behind the top load door,the air also circulates around the thick flue collar before it blows out over top of the top load door, i think most of the additional heat that is produced in the AB is radiated into the room, it seem that when the AB is engaged the whole burning process slows down , but the stove still produces a lot of heat due the the extra BTU,s now produced by the burning flue gas. Im going to get anadditional temp gauge and put one on the tp load door and one on the flue pipe just above the stove just to see the effect of the various burning stages.
  5. Seasoned Oak

    Seasoned Oak Minister of Fire

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    Does anyone know how much creosote in the chimney is enough to start a chimney fire? I have some build-up from the last load of wood that burned overnight and im sure the AB was not lit up as in the morning the whole inside of the stove was tarred up as was the flue pipe and the chimney bottom. IT was lust one load of wood though so i don,t think thats enough to cause a Chimney fire.
  6. N/A N/A

    N/A N/A New Member

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    Could not have said it better myself. Yes it may burn hotter in the AB but it still will not produce the amount of BTUs the fire box will with a load of wood burning full throttle.
  7. branchburner

    branchburner Minister of Fire

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    Well, I guess I'm agreeing that more heat may be going up the flue since it is nearer to the AB. But I don't think you get fewer BTUs w/ the AB engaged. You should get more, cause you're burning smoke. Let me be clear, I'm talking about BTUs per pound of wood, not per hour. I have no doubt you can get more heat in an hour burning full throttle, but I think that's because you are going through more wood.
    My stove top drops about 100 degrees when I start to burn smoke. I bring her to 650, make sure I have some coals, engage AB, then cruise at 550. Even though the stovetop temp drops, the back of the stove is now kicking wicked heat, and the burn rate of my splits is slower.
    Now, I am running an Oakwood, not a tl300, so there may be a difference in that alone. When I get some time I'll write down some temps and get a little more scientific about it.
  8. uptrapper

    uptrapper New Member

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    Here is my totally unscientific opinion, keep in mind that this is the first year I am burning a wood stove so please correct me if I'm wrong. I care about how warm my house is not how much heat goes out the pipe or how hot the stove is(to a certin extent, don't want smoke rolling out the chimney). If I put a half load of wood in my stove on a 20 degree night (thats as cold as it has gotten hear this year so far) and don't use the ab the fire will be out in the morning with very few coals left, the house will be about 65 in the morning. If I use the AB and aprox the same amount of wood filling the stove half full the house will be 72 in the morning and lots of coals left. Looking at those facts I would have to say my stove puts out more BTU's/ hour with the ab on. My stove pipe temps drop more than the stove top after putting it in ab, which would lead me to belive less heat is going up the pipe. Further more I sit right in front of the stove when I am getting it up to temp, and about 5 seconds after the bypass damper is closed I get a very noticable increase in temp on my face. The TL-300 is my first stove ever so I don't have any expirence with anything else and am still trying to figure out the perfect way to burn but its pretty easy for me to see that if I run the ab I get more heat for the same amount of wood.

    BTW I want to thank everyone for posting on this tread I have enjoyed reading all the posts and hope it keeps going all winter.

    Mike
  9. branchburner

    branchburner Minister of Fire

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    Well said! Makes perfect sense - I think when I feel that extra heat it seems to be coming from the flue because of its proximity to the AB. I was going to buy another thermometer to put on the flue and compare to my stovetop temps. It's taken me over 24 hours to realize it might be possible to simply pickup the one I have and move it the necessary 18 inches. Excuse me while I go hit myself in the forehead with my maul.
  10. Seasoned Oak

    Seasoned Oak Minister of Fire

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    Im sure most of the heat from the AB is transfered to the room as the air channel in the back of the stove that exits out the top of the stove blowing forward surrounds the AB chamber. While most of the BOttom part of the AB is insulated refractoy material to contain the High temps. the top half is bare steel, the blower pushes air through this air channel so i would say the blower is more effective when the AB is engaged than otherwise.
  11. branchburner

    branchburner Minister of Fire

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    Figured out what was going on as far as my perceived flue temp:
    1. damper open, full air to start fire and build heat
    2. damper open, low air to slow fire and build coals
    3. damper closed, full air to engage AB
    4. damper closed, low air to extend burn

    When I closed the damper on step 3, I was getting a small (very small, and very brief) increase in flue temp since I was jacking the air. That would drop a bit even before step 4, and when I pulled back all the way on primary air the flue temp dropped like a rock.
    Efficiency delivered as promised.

    Damn, I love this stove.
  12. branchburner

    branchburner Minister of Fire

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    Agreed. I don't have a blower but would recommend it for the rear AB models, especially for a hearth stove set up like mine.
  13. stanleyjohn

    stanleyjohn Feeling the Heat

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    Ok another theroy while looking at my stove operation pic in the manual!.there seems to be a air flow chamber that rides from the back of the stove to the top then to the front.When the ab is not being used then alot of the heat is building in the main stove area which heats up the stove top pretty good.When the AB is activated then heat is then drawn down thru the back into the AB chamber causing less heat in main stove area!also this extra burst of heat in the back chamber from the AB is carried from the back to the front by the air flow chamber that causes you to feel extra heat.This is why i feel more heat when the AB is activated and see the stove top temp drop a bit.
  14. cyclone

    cyclone Member

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    I have been doing alot of the steps that have been taken by many of individuals with the TL 300 and similar stoves. I have the TL 300 and noticed when I engage my stove into after burn (nice bed of coals, stove top five hundred) The stove top drops and cruises at 375 for the length of its burn . It also seems what also works for me is the air intake at the second notch. What has been happening though, when the After burner is engaged and I have the long burns the bottom part of the class blackens.

    Is this because of the heats being drawn towards the back and less heat by the Glass???
  15. stanleyjohn

    stanleyjohn Feeling the Heat

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    I also have noticed that my afterburner runs very well with stove top temps around 350 deg.My door glass does get some brownish tint mainly on the bottom sides.This may be because of the low stove temp.I did get the stove hotter later when i put in a few more splits to a peak in the high 500s..So it seems to me that the afterburner will run fine with temps in the 300s!this suits me fine because the stove heat output is plentyful with the fan running.I have noticed that when a good amount of the wood goes into the coal stage then the afterburn shuts down.At this stage of the burn its likely not needed anymore because there is very little smoke left to burn.
  16. Seasoned Oak

    Seasoned Oak Minister of Fire

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    Does anyone know if a wood stove with an AB such as the harman TL-300 is the same tech as those wood gasification boilers? The boilers that i have read about also burn the off gasses and smoke that comes off the wood at high temperature
  17. smokey beaver

    smokey beaver New Member

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    Hey folks new to forum and stove tl300, quick question when you guys speak of starting reburn up does that mean closing damper? thks in advance!
  18. stanleyjohn

    stanleyjohn Feeling the Heat

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    Welcome!! Im guessing that this is a new stove that you got!Before you activate the afterburn there our a few things to do.
    1-Built a good fire with the stove damper open and the air control lever out.(stove fan off if it has one)
    2-When a deep hot coal bed is formed (2 inches) then close the damper and you should hear a sound of air being sucked in the back of the stove!Also no smoke exiting the house.stove should be hot enough to run fan at this point.Afterburn is running now.
    3-Close the air flow control in steps to a point where you stop!depends on your draft.If you close it too much with not too much draft the afterburn will end.
    4-During the coal stage your afterburn will cut off!but thats ok since there is very little more smoke to burn.

    Remember to read the manual and there are other harman users out here that can help!
    Enjoy your stove!I have the TL200 exeption wood insert oad love it! Take care! stan
  19. Seasoned Oak

    Seasoned Oak Minister of Fire

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    How do you know when your AB shuts down? can you see it burning or is it just that you do not hear the rushing air sound.
  20. N/A N/A

    N/A N/A New Member

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    Sometimes I can hear my AB operating and sometimes I cant. So I do not completely rely on that alone to tell if it stalled or is even operating. I pay attention to the stove temps at the connector pipe and stove top. And a quick check of the top of the chimney outside will tell the tail. And if you do have a view of the AB chamber opening you can see if it is operating. Sometimes the wood will block the view.
  21. stanleyjohn

    stanleyjohn Feeling the Heat

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    On my TL200 i can see the afterburner in action thru a window in the afterburner chamber.It has been running very well so far!only stoping when there are more coals than wood to burn.I havent piled in the wood so far! i guess when i do i will not be able to see the afterburn in action because of the wood blocking the view.
  22. Seasoned Oak

    Seasoned Oak Minister of Fire

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    What are your Flue pipe temps when at various stages of startup and after AB is started? I only did a few fires so far ,Im waiting for colder weather so I don.t have to use the lowest setting all the time. My Coal stoker is good when only a litttle heat is needed and it does my hot water too. I know on my last full load of wood the AB did not light as it creosoted up the stove and flue pipe and chimney pretty bad.Im sure i engaged the AB way too soon.So when temps get 40 day and 25-30 night ill give it another try and as i can rarely see the AF (Ill try to stack the wood as to make a tunnel to observe)im going to go by stovetop and flue temps as when to engage the AF. Ill try 550 stove top so at thet temp what would the Flue pipe read before and after engaging the AB?
  23. N/A N/A

    N/A N/A New Member

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    I will light the stove up and often times let it get hot enough for the pipe probe thermometer to read around 1000. It was installed 18 inches up from the top of the stove. The stove top will read around 600. After a good coal bed and the AB is put into action those above temps will usually drop to and around 500 and 350 respectfully with the AB operating. Its not that way all the time, depending on outside weather conditions and the wood used I have had 900 and 550 temps on lowest air setting.
  24. Seasoned Oak

    Seasoned Oak Minister of Fire

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    Isnt 1000 degrees in the stove pipe the Cherry red Zone? I have those magnetic temp gauges, so i expect that it would be a little lower than 1000 with those. I think the Coals is what give the AB the 1100 minumum temp to light off, after it lights off i suspect that it makes enough of its own heat to keep burning. THe owners manual does not say anything about the AB except it does cover the start up procedure, bed of coals,hot fire ect.
  25. MishMouse

    MishMouse Minister of Fire

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    Actually I think 1,000 internal flue temp is a good temp for engaging the ab.
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