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Could I benefit from a 4" exhaust?

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by Jason Knapp, Jan 29, 2013.

  1. Jason Knapp

    Jason Knapp Member

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    Here's a question...... Could a 4" exhaust on my pellet stove help reduce clinkers? Is there any benefit to a larger exhaust?

    My current setup is: Englander 25ep
    45* elbow connected to
    (2) 1 ft horizontal sections connected to
    cleanout tee connected to
    (1) 3ft vertical rise connected to
    (1) 90* connected to
    (1) termination

    My OAK is 2 or 2.5" aluminum tubing running about 3 ft.
    Comments or suggestion always welcome!:)

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  2. Pelleting In NJ

    Pelleting In NJ Feeling the Heat

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    I don't think the diameter of the flue will have any effect on clinkers : that is a function of the mineral content in the pellets. A larger diameter flue might help with stove efficiency, due to it being less restrictive, thereby allowing a slower combustion blower speed to maintain the same CFM volume as compared to a smaller 3 inch diameter, but this gain might be minimal. I think the bigger advantage is that a 4 inch flue gives you more margin against restriction due to fly-ash build-up : longer flue cleaning intervals.
  3. jtakeman

    jtakeman Minister of Fire

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    Let see what the EVL equals
    45º is 2.5
    2ft horz is 2
    Tee is 5
    3ft Vert is1.5
    90º is 5
    Cap is ?

    EVL looks to be 16+ which is high for 3" pipe. We tend not to go over 15 with 3" But that will cost money to replace. For now I would see if you can either increase the air or reduce the pellet feed to help the clinker issue. That is free and gives you something to do while you scrape up the dough for the new piping.
  4. imacman

    imacman Guest

    Your EVL is marginal at about 16 and normally anything past 15 on a 3" exhaust calls for 4", but you are very close. As Pelleting said above, I don't think it's the stove....probably the pellets.

    What pellets are you burning?

    What are your bottom 3 buttons set at?
  5. Murph

    Murph Proud Grandparent

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    Clinkers are to my understanding caused by silica(sand) in the pellets and happens when the ash fuses with the silica. Bad pellets. Your pipe for three inch is beyond the fifteen foot limit they suggest so you could go up to four inch stock for a better draft.
  6. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    Clinkers = ash (content and amount) + temperature + moisture + time together

    Anything that affects those four items will impact clinker formation.

    For example air flow will impact both temperature and ash time together so a restriction in vent system would also affect clinker formation.

    Normally it is the lack of air flow through the burn pot that has the biggest effect on clinker formation, more air through = more ash out = less time for the temperature to act on the ash causing clinkeritis.

    I have the clinkers to prove it some where in a compost pile.

    I would try other things long before changing the vent out.
  7. Jason Knapp

    Jason Knapp Member

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    The clinkers I dig out of my burn pot every 2 days are EPIC!!!!
    With my Penningtons:( , LFF, 1
    LBA 6
    AOT 1
    I don't want to go too much higher with the LFF if I can help it. Right now my fuel feed is set at 2 or 3 depending how cold it is. I see no benefit to going higher with the fuel feed because Convection air temp really isn't effected
  8. jtakeman

    jtakeman Minister of Fire

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    I would hit the burnpot a couple times a day. Turn it to low and let it settle down. Open the door and swipe the pot. Close the door and turn it back up. Burning on higher settings may also help evacuate the burnpot after stirring. Crank it up for a bit.
  9. Jason Knapp

    Jason Knapp Member

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    I don't want to risk sounding like a moron, but could you clarify your statement? Hit the burnpot, turn it to low, swipe the pot.......etc. Which settings should be higher?
  10. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    Well I have a nice large burn pot on my bucket of parts stove and at one point I was pulling a pot sized clinker out every 8 hours.

    Is all of your combustion air going through your burn pot or is some of it going around the burn pot?

    Is your door and ash pan sealed?

    Is your hopper lid closed and latched with a good seal?
  11. jtakeman

    jtakeman Minister of Fire

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    No not moron, All questions are cool. Thats how ya learn.

    Instead of turning off the stove and doing the cleaning. During a run you can turn the stove down to low and let it settle down. It will be just barely burning. Now grab your tool you that you have to clean the burnpot. Quickly stir the ash in the pot where the clinker forms. Close the stove door and turn it back up. Hope this helps.

    I don't know what stove you own, But what I posted is basic info for most units. Post your stove and maybe someone can post some tips. We usually ask the members to put the stove model in their signature so we don't need to ask.
  12. Don2222

    Don2222 Minister of Fire

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  13. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    It is called pot scraping or stirring the pot or fire, it will break up the not quite hard clinker and allow the air flow to remove it from the burn pot.
  14. Jason Knapp

    Jason Knapp Member

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    2009 Englander 25 EP.

    Smokey, I tried the dollar bill trick with all of the gaskets and they all seem to have a good bit of drag. I also straightened out the burn pot and cradle, because it was slightly warped. I bought the stove used, so I don't know the last time the gaskets were replaced.
  15. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    Even though you straightened the burn pot and cradle out there may be a small leak past the burn pot

    You might want to get a length of flat window gasket, pull it straight to thin it out and then place that under the lip of the burn pot.

    I haven't attempted to burn Penningtons in a number of years. The ash level was rather high the last time, but I can't speak about now.

    Also make certain your stove is in the correct mode.

    ETA: I don't know what you have done in the way of cleaning but I will suggest that if the places inside the stove are filling up with a lot ash it is not helping matters at all. There was one person this fall who thought there was no way his stove could have enough ash in it having only burned 25 or so bags. When he finally opened up his ash trap they were well over half full, seems the ash was having a convention.in just about the worst possible spot.
  16. DexterDay

    DexterDay Guest

    Definitely try another pellet. Penningtons are marginal. At best.

    Also. A used stove needs cleaned from Intake to Exhaust and ALL PASSAGES internally in-between.
  17. Jason Knapp

    Jason Knapp Member

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    Smokey and Dexter, I had questioned my stoves operability a few months ago. You guys and many others were very helpful. I cleaned this stove inside and out, I bought brushes to reach all of the areas, Itap the rear wall with a rubber mallet and vacuum everything. I removed the exhaust blower, brushed and cleaned and vacuumed that too. I also brushed and vacuumed the exhaust pipe. I continue this anal retentive level of cleaning (with the exception of the blower removal) once a week.

    And Dex, I only have Penningtons because they came with the stove. I can pretty much bet I would NEVER get these pellets after this!!!
  18. Jason Knapp

    Jason Knapp Member

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    Please clarify "correct mode"
  19. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    Various England stoves have controllers that have multiple burn programs on them the selected program setting is called the mode.

    Talk to England, except for multi-fuel stoves this setting is rarely if ever mentioned in the manuals.
  20. imacman

    imacman Guest

    Jason, I see in your signature you have some Barefoots coming? If so, wait to see how those burn before making any more drastic changes.
  21. Jason Knapp

    Jason Knapp Member

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    Will do!
    I was on Englanders website last night. They had another method for checking air leaks. I used a grill lighter and slowly traced around the gasket areas while the stove was running. At a few spots, the flame from the lightet got sucked into the stove meaning I have a leak....... I guess the dollar bill trick isn't all that accurate! Time for new gaskets. This combined with better pellets should make a difference.
  22. smwilliamson

    smwilliamson Minister of Fire

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    You can easily push 18-20 EVL with and Englander without too much of a performance issue, though I will caution you to have replacement vac line hoses cause yer exhaust will be hot.
  23. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    The dollar bill test requires all 8 places to be fine for it to pass. The lighter test can also detect certain air washes (not that air washes haven't been known for being too large and to cause problems).
  24. pell it

    pell it Feeling the Heat

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    My air wash has a length of 1/2" rope gasket residing in it now. Window stays clean just as long as without it. (pellet dependent). Convection temps are @25* higher with it!!!!! Not that I am suggesting anyone else try it.

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