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Which burn pot/feed system has the highest efficiency?

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by Stovensen, Mar 14, 2013.

  1. Stovensen

    Stovensen Burning Hunk

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    According to this Ecotec website (link below) they claim that their patented pellet burner should have an efficiency as high as 90-95 % and that all other principles have a lower efficiency due to the fact that the pellets are not "allowed" to burn totally, since they are somehow turned into flying embers too soon by the violent dropping action. Especially the top feeders should be bad in this respect. The horizontal feeders like the Harmans and the Englanders most likely have higher efficiencies.
    Does anybody know the exact efficiencies for these particular brands?
    OK, when I compare the max. efficiency of 78% on my old Whit to the 90-95% claimed on the Ecotec burner we must conclude that a lot of fuel is wasted in my old Whitfield. Also, the heat exchanger is outdated and this contibutes to the overall bad efficiency.

    Note: Ecotec is a Swedish stove manufacturer and not to be mixed up with the Italian Ecoteck stoves.

    Link to Ecotec, Sweden:

    http://www.ecotec.net/

    On the photos below we see illustrations of the three basic principles that we're dealing with:

    Bottom, horizontal and top feeding.

    The patented Ecotec burner is the only true bottom fed type. From reading here on Hearth.com I've learned that the Harmans and to some extent the Englander pellet stoves are horizontal feeders, and that all the others ( the majority ?? ) are top feeders.
    Questions is: Why do so many manufacturers stick to top feeding when it's obvious that this principle has a much lower burn efficiency?
    And the tendency of auger jams is such a huge subject in itself that I won't mention it here.

    Note: the Ecotec burner on the picture is from one of their pellet furnaces, but the Ecotec Tyr pellet stove has the same burner installed. It can be studied in the owners manual linked to below
    http://www.ecotec.net/pdf/Engelska/Tyr_instrbok-07_E.pdf



    Fødeprincipper generelt.jpg 1-s2_0-S1364032103001242-gr7.jpg BioLine%2020%20liten.jpg

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  2. heat seeker

    heat seeker Minister of Fire

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    Embers that are blown out of the burn pot still give off heat, so it's not wasted.

    Burning efficiency is not the be-all and end-all - there's the efficiency of the heat exchanger, and other factors to consider.

    And, I'm not so quick to believe the company's hype. They're blowing their own horn. If it was so great, others would be copying it, or coming up with their own versions.

    This thing looks pretty complicated, and I wonder if it's a servicing nightmare. There's lots to be said for simplicity, even if it's not the most efficient.
    SmokeyTheBear likes this.
  3. john193

    john193 Minister of Fire

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    Interesting, i used to own a Harman XXV (bottom feeder) and according to the manufacturers site, it is 79% efficient, my Quad is a top feeder and they claim 81 to 83% efficiency? How are top feeders obviously less efficient? As "heat seeker" said, dont be so quick to believe the hype, and there are a lot of efficiency components to consider. I compared the two models above because they are both owned by the same company - presumably using the same standard of efficiency measurement.
    heat seeker likes this.
  4. iceguy4

    iceguy4 Minister of Fire

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    my pb 105 claims 86%...i have to believe its close based on flame size. ash and exhaust temp....observations
  5. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    There is at least one top feed pellet stove that doesn't eject the fuel or ash. Ash is removed under the fuel bed by augers. So feed type really doesn't need to be a limit.
  6. DexterDay

    DexterDay Guest

    There is combustion efficiency and stove efficiency.

    Combustion efficiency on most stoves is close to 100%. Now how the stove extracts that heat? That's a different efficiency #.
    jtakeman, schoondog and SmokeyTheBear like this.
  7. ironpony

    ironpony Minister of Fire

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    I seen "bottom feeder" and thought we were going to talk about lawyers.............................
    tjnamtiw and SmokeyTheBear like this.
  8. SmokeyTheBear

    SmokeyTheBear Minister of Fire

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    Funny I always thought they were top feeders as in sharks going for chum.
    DexterDay likes this.
  9. tjnamtiw

    tjnamtiw Minister of Fire

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    DexterDay and the others are correct. Ecotec is talking 'burner efficiency', not whole stove efficiency. Smoke and mirrors and because of that, I wouldn't trust them without more feedback from users. Why is it obvious to you that top feeders are less efficient? I can burn for days with very little ash accumulating meaning everything else was turned to heat or byproducts. Therefore, 'burner efficiency, which you were discussing, is quite high. Now heat exchanger efficiency, as I have preached in the past, leaves a LOT to be desired sadly.
    DexterDay likes this.
  10. Stovensen

    Stovensen Burning Hunk

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    This text below from the Ecotec web site must have gotten me hypnotized... now whouda thunk that I could be a victim of that so easily;sick

    "They're blowing their own horn"

    "Smoke and mirrors"

    I just love these expressions...;lol Hearth.com is a true gold mine for foreigners like me who want to learn natural language. You know at school we were only taught standard english.

    Oh, and another thing that has happened to me from reading/partycipating ( parti..sp? ) here: I've become interested in brewing my own beer. From what I read it shouldn't be so difficult. Some hardware must be acquired, some reading must done, and if questions turn up, I know where to get assistance.


    Ecotec efficiency.jpg
    heat seeker likes this.
  11. smwilliamson

    smwilliamson Minister of Fire

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    The Tyr can also burn stickwood
    Stovensen likes this.
  12. tjnamtiw

    tjnamtiw Minister of Fire

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    I know what you mean about learning the slang of another language. In college I was talk a French expression for 'let's go'. Year later (many years :( ) I had to chance to use it with some French dignitaries who were visiting my company. Unfortunately, I never learned that the true meaning was 'Get the hell out of here'!!!!! oooops.....
    Stovensen likes this.
  13. heat seeker

    heat seeker Minister of Fire

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    Stovenson, thank you for being a good sport!
    (And, it's "participating".)
    Stovensen likes this.
  14. Lake Girl

    Lake Girl Minister of Fire

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    I thought insurance salesmen:p

    Did I miss it in the brochure or was there not a lot of information of heat exchanger, etc?
    SmokeyTheBear likes this.
  15. Stovensen

    Stovensen Burning Hunk

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    LOL...:p I'm sure the Canadian and French members on here will helps us through such a situation in the future.
  16. Stovensen

    Stovensen Burning Hunk

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    Thanks, Heat seeker, it must have been the talk of beer in the next sentence that made me somehow favourize the "party" word;)
    SmokeyTheBear likes this.
  17. Lake Girl

    Lake Girl Minister of Fire

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    Did anyone notice the "burn pot" angle on the illustrations? The top feed on the Elena drops the pellet into the burn pot from a distance of approximately four inches from the bottom of the burn pot. There is no angle on the burn pot as shown in the illustration...
    heat seeker and Stovensen like this.
  18. Stovensen

    Stovensen Burning Hunk

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    Thanks for noticing, Lake Girl. You're absolutely right. The illustration below is more correct. Especially 'c' the top feeder is more correctly illustrated here:

    Principper for pillefødning.jpg
    DexterDay likes this.
  19. stoveguy2esw

    stoveguy2esw Minister of Fire

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    stoves are tested here for efficiency to meet or exceed a minimum standard, the manufacturer has the option of "default" versus obtaining a "true' rating. default is 78% with pellet stoves for certification. some manufacturers will go ahead and have the "true" rating done but its quite a bit more expensive and really doesnt benefit anyone. we select default for our units when tested which is why they all show 78% efficient. the units actual efficiency is going to be higher than that on each unit though we do not know what it actually is. i suspect in the low to mid 80's anyway.

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