Has Anybody Tried A Wider Temp Range?

Discussion in 'OWB's and Gasification Boilers' started by amateur cutter, Sep 30, 2021.

  1. amateur cutter

    amateur cutter

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    So I've been thinking, and before anybody says it I will, that's never good when I think.:loco: :crazy: Is there any advantage such as cleaner burn, wood savings, or any other advantage to say a 20 degree on/off burn than the typical 10 degree? I'm thinking 170 to 190 instead of 180. Pros/cons please & thank you.
     
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  2. lukem

    lukem

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    I run 160 to 180. Dirtiest part of the burn is startup and shutdown so, in theory, this cuts it in half over a 10 degree deadband.

    Con is your fire my go out under light heating load
     
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  3. Eric VW

    Eric VW Moderator

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    There’s a lot OWB members here, but I’d like to hear what walt has his set at….?
     
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  4. brenndatomu

    brenndatomu

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    Agreed ^ ^ ^
    190* is kinda pushing it IMO...if you get much overshoot on shutdown, that's getting close to that magic 212* number...and I would think you'd get a lil more overshoot running a 20* swing.
     
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  5. lukem

    lukem

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    My FIL will run 190 on his during a big cold snap, but it doesn't get much downtime with the square footage he's heating. If it got a little too spicy and shot past there's enough demand to pull the heat right back out of it.
     
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  6. walt

    walt

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    165 to 180 ,when the forced draft shuts off at 180 it will climb to 185 or 190. I have had mine set this way for twenty years. When I first installed my stove I messed with the temps but I don't think you gain anything.
     
  7. amateur cutter

    amateur cutter

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    Thanks for the input, I may try the 160-180 route. I'm looking for less coal build up during our lackluster temps in winter. If it goes out I'll bump it back up. I get tired of shoveling coals out to make room when it's 35ish degrees for days on end. My heat load is azz backwards needing more during the day than at night. The boiler is oversize for the sq footage, but I need the extra for the shop during the day with doors up & down. Nighttime the load drops off & this cycle leads to a bunch of idle time that causes huge coal build up. I may need to start putting up way more Pine to burn the Oak loads down too. I had two weeks last Feb. that I needed good hardwood, the rest of the year I could've burned shoulder wood & been fine.
     
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  8. brenndatomu

    brenndatomu

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    A nice bed of coals won't make the heat you need...even at night?
    Ironic that the new gasifiers need a good coal bed to work right.
     
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  9. lukem

    lukem

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    My boiler loves a good coal bed. Can't have too much.
     
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  10. amateur cutter

    amateur cutter

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    At night it will, during the day when I need a good load & hot burn for heat recovery I sometimes end up having to load an extra time or two to keep water temps up. That's what I'm trying to get away from, it seems stupid to me too, but I can't figure it out. It might be the boiler design itself. I think the damper door should be way wider. Dunno.
     
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  11. brenndatomu

    brenndatomu

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    Yeah, sounds like some SS wood earlier in the day might be the ticket...
     
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  12. Rope

    Rope

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    My boiler is a Central Boiler classic 5036 and I run 180*-190* and burn spruce, I only get deep coal beds when it's -45 or colder. Could it be because I am pulling draft hard? I am talking 12" deep bed, it takes about 1.5 to 3 hours to burn that down when it cold. Right now we are high teens for the low and high twenties for the high and not building a deep coal bed but we are loading the boiler 1/5 to 1/4 full.
     
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  13. lukem

    lukem

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    Coaling happens when you have really high burn temperatures and parts of the wood gas off and burn faster than other parts. That makes sense why it happens at super cold temperatures...you are probably running the boiler near full capacity and getting a hotter burn going.

    There isn't much you can do about it other than mix in some harder and softer wood together or load more frequently to try to vary the rate of burn.
     
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  14. moresnow

    moresnow

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    I am not a boiler officiando. By any means. I do wonder however. Could you run the shop temp up higher overnight to encourage demand on the boiler. Would that help reduce your coaling? May seem like a waste but if you are shoveling out coals to make room for the next load what's the difference? Additional pine has always worked great for reducing coaling for me also. I could easily use only Pine if it were more widespread around me. Best of luck.
     
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