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barometric damper?

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by bjwme, Nov 29, 2008.

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  1. bjwme

    bjwme New Member

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    i recently had a new yorker wc-90 wood boiler added on to my oil burning system. my plumber said that he had to put in a barometric damper because it is now code. he also said that he never used to put one on wood boilers that he installed until it was code. my question os do i really need it? i have some creosote build up around the damper and i think it is lowering my flue temps. should i take it out or maybe temporarily seal it off so that i could still be in appliance if i ever got inspected? what do you guys think? i think it might be causing some of the creosote build up in my stove pipe. thanks

    bryan

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  2. pybyr

    pybyr Minister of Fire

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    The topic of barometric dampers on solid fuel appliances and codes regarding any of these seem to have generated more mythology and conspiracy theories than anything that I can recall since the ads in the late 1970s that said that for a mere $100 that you mailed to someone for something you could bolt under your car's hood, you could pee in your car's gas filler, and drive 1000 miles, but that the car and oil companies had cooked up a plot to prevent anyone from realizing this :0

    I beat my head against this more than a little after hearing a dozen arguments and deciding that I would not sleep well until I really got to the bottom of something that let me draw my own, comfortable conclusions

    wish I could spend some time to do a "sticky" on these topics, but I am busy being way behind on my own install while juggling the rest o'life.... so here's the quick and dirty

    basically, as long as your flue draws, and the barometric damper is really set up right in relation to the specifications of the manufacturer of your appliance (and just because someone for hire put it in does not mean that that's the case) there is nothing, overall, inherently bad about it

    the role of a barometric damper is to make sure that the fire does not go up the chimney too fast (before you extract maximum feasible energy) under atmospheric conditions (which vary tremendously depending upon a huge array iof many entirely ndependent variables of what is going on inside and outside a structure) when the chimney is "pulling hard"-- but to also make sure that the fire still goes up the chimney at a reasonable and reliable rate when the outdoor and indoor conditions cause the chimney to draw less well.

    no commies or bureacrats were involved, as best I can tell, in noticing that such automatic regulation of chiimney draft was a good thing for efficiency and safety

    it was considered a bad and even dangerous thing, though, on old very-low tech coal and wood devices that were so poorly regulated (on air and fuel inputs) that they might overrun the chimney and "Spill" combustion nyproducts out a barometric damper

    but modern appliances are not that crude

    and in any event, no matter what anyone does on including or skipping a barometric damper, you should invest in a _really_ good Carbon Monoxide detector -- because even without a barometric damper, if something goes haywire, you don't want to find out by waking up with a severe headache, just barely in time, in a house full of smoke from a back-drafting chimney ( I found that out the hard way once, some years back,on a system that had no barometric damper :) the absence, at the time, of a barometric damper on my old wood hot air furnace did not cause the problem, but having one in place would not have made it worse, and might have been less likley to cause it than my old manual butterfly stack damper that suddenly "met" a huge change of outdoor atmospheric pressure, due to a chance in weather, while I was asleep )
  3. Hansson

    Hansson Feeling the Heat

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  4. ssupercoolss

    ssupercoolss Member

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    heres my take on the baro after a little experimenting. i have the same boiler. i cover the baro with foil. 2 reasons....with the baro uncovered, and my draft around .04 set with a manometer, i could feel a breeze in between the baro and the crawlspace, where it apparantly draws its air from. it also made my flue temp run on the cold side, i didnt like that. and, i guess this is actually the third thing, one time i came down to find wood in the firebox but no fire, and that was with it uncovered. i have a feeling it idled for a while, and instead of pulling air through the firebox and keeping the fire going, it just pulled air in through the baro, and left my fire to go out. there is also the thought that a baro would also give a chimney fire plenty of air. i think the baro contributes to the creosote issue, but covering it wont make the creosote go away. i dont know about yours, but mine does idle quite a bit. i am probably a little anal, i run a brush through everything about every 2 weeks.
  5. bjwme

    bjwme New Member

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    thanks for the replies. futureboiler, i took everything apart this weekend and brushed the chimney and cleaned my stove pipe. my chimney was clean and the only part of my stovepipe that had any build up was around the baro damper. i think i am going to try and cover it for a while and see how it goes. thanks for the help
  6. ssupercoolss

    ssupercoolss Member

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    my flue pipe from the boiler to the chimney had the most buildup on it. thats not really where i expected it to be. but like i said, my boiler idles quite a bit.
  7. CowboyAndy

    CowboyAndy New Member

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    So, what about barametric dampers on a wood oil combo? My brother in law installed mine, and the counterweight was not put on. with no fire, and the oil burner off it is not closed all the way, its always slightly open. is this bad? what is the proper procedure to "tune" it?
  8. ssupercoolss

    ssupercoolss Member

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    you set a barometric damper with a manometer. i think proper operation of a barometric damper is somewhat critical on an oil fired boiler. does the manual give you any insight on this? newyorker recommends .04, and mine was flapping in the breeze too.
  9. CowboyAndy

    CowboyAndy New Member

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    the manual made no mention of it, other than it had to be installed.
  10. pybyr

    pybyr Minister of Fire

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    pros use an official draft gauge (expensive!), but a long time back, somewhere on the web, I saw some instructions where someone did a cheap but effective DIY version where they got the sensitivity of scale for tiny fractions of an inch of water column by putting a piece of clear vinyl tube on an inclined ramp, with a calculated angle and markings so as to get tiny fractions of an inch of reasonably accurate readings, not the rough scale that one would get from a vertical tube

    maybe someone can re-find that- I can't spend the time right now
  11. jpelizza

    jpelizza Member

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    i have a econo 150 first burn 12/21/09.
    so far i don't have a barametric damper installed and i'm not sure what to do after reading this thread. the dealer i bought the boiler from told me i should instal one so i don't lose btus and the draft is regulated better. my draft is decent. when i load would i may get a little smoke for 5-10 seconds tops then its gone and thats usually when i'm loading it after being on idle.

    any thoughts???
  12. pybyr

    pybyr Minister of Fire

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    Econoburn's manual definitely instructs to install one, and when I called the company back during my planning of my install, I had the chance to discuss the topic with VP Mark Odell. He confirmed that it's a good thing to have, and that the old-time fears that a B.D. will allow oxygen into the flue in the event of a chimney fire are not pertinent, in that a properly operated gasifier will not lead to creosote build up in the first place.

    The B.D. will help see to it that the hot combustion gases are not pulled through the heat exchanger fire tubes faster than needed; this gives a better opportunity to extract heat before the hot gases go up the flue = better efficiency.

    You DO need to be sure to adjust the B.D. correctly, and there's no such thing as setting it by eye or instinct; the official pro gauges are not cheap, but do a search on here for "inclined manometer" for some discussions of how to make your own.

    I sometimes temporarily cover my B.D. with foil when first starting a fire during moderate/ rainy weather, as I want all the draft I can get under those conditions to get/ keep things going.

    But in cold weather, and in experimenting with different conditions, watching the in-flue thermometer, my draft gauge (a nice Bacharach MZF that I lucked into a few years ago) and the rate at which the boiler gains heat, I can see a difference when the B.D. is allowed to regulate the draft to specified levels-- the flue temp runs lower, and the boiler heats/ recovers faster after reloading the firebox-- confirming that efficiency is higher.
  13. WRVERMONT

    WRVERMONT New Member

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    My own research into barometric damper or no barometric damper on a wood gasifier has resulted in the following findings: They definitly can enhance the efficiency of a wood gasification boiler. If however, we have a case where we want higher flue temps ...then sometimes a barometric damper would not be the best thing.

    With a properly set Baro, After installation on a system with proper chimney draft, make up air, etc. the temps leaving the chimney are lower. The heat exchange tubes and combustion chamber in the boiler are hotter. The turbulators stay cleaner. There is better combustion and residence time of hot gasses for thermal transfer. My system definity performs better with one. I do disable it at start-up to maximize draft. I would like to design a automatic servo to accomplish this.

    So many different systems out there, it's hard to generalize to much with this. I think if conditions are good a barometric is realy smart.
  14. bjwme

    bjwme New Member

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    After using my boiler for the second season I do think the b.d. makes my boiler more efficient. The only problem I have is the b.d. is right before my pipe hits the chimney and I do get some creosote build up there but my chimney stays clean. I was thinking of putiing a tee where my stove pipe 90's to go into the chimney or basically replacing the 90 with a tee and putting the b.d. there so it would not be inline with the flue gasses. Would the b.d. still function as it should? I was hoping if I did it this way i wouldnt have as much creoasote build up around the b.d. I guess I am asking if the barometric dampner will work at any point in the stove pipe
    Thanks
  15. WRVERMONT

    WRVERMONT New Member

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    It seems to me that it will still acomplish it's function if used in a T as you suggest. I'm sure the dynamics of flow are changed some..but may work fine?. The best way to find out I guess would be to try it? I know it is recomended to install the B.D. close to the boiler(18" if possible)
  16. pybyr

    pybyr Minister of Fire

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    I'd be hesitant to use a Tee in that configuration/ location- reason being, that if weather patterns create a momentary condition where the chimney draft 'stalls', you've got flue gas coming up the boiler flue pipe meeting the Tee where the B.D. suddenly becomes the path of least resistance- at the very point that the pipe and chimney flue meet- creating an increased potential for some flue gas to spill out of the B.D. I believe (though this is supposition on my part) that this may be one of the reasons that the B.D. is recommended to be as near the combustion appliance as possible.

    I did put my B.D. in via a Tee right near the flue/chimney intersection, but in order to address the above concern, the B.D. in on a piece of pipe that's an "offshoot" that drops about a foot vertically from the Tee, and then goes around an elbow so that the B.D. is still mounted in the proper/ necessary alignment with its face vertical and its pivot horizontal. The reason for this downward extension is to make the B.D. less of an appealing path for any spill, by creating some "stack rise" between the B.D. and the flue pipe/ chimney intersection. So far so good.

    Like WRboiler, I intend to have a 'temporary override' for the B.D. for some conditions, but have decided that rather than anything electromechanical, I'll probably just install a hinged sheetmetal outer cover, with the hinge at the top of the B.D. opening, so that a thin cable lifts the cover under normal operation, but the weight of the cover shuts itself when the cable is allowed to go slack.

    Do be very sure to install any B.D. in the proper vertical/horizontal alignment, and to set it up using some instrumentation capable of accurately measuring draft. Anyone who claims to be able to distinguish tenths or hundredths of an inch of water column draft by eyeball or instinct is, in my opinion, emitting the element bolognium.
  17. Gooserider

    Gooserider Mod Emeritus

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    I've seen those, and while I don't have a link, I was able to write up my own version in another thread, along with a QCAD drawing of the concept - I've also now stuck it in the "Tidbits" sticky...

    Gooserider
  18. pybyr

    pybyr Minister of Fire

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    Great description in the sticky, Goose, and here is another link back to a description of how to DIY one

    http://www.hearth.com/econtent/index.php/forums/viewthread/35739/#379845
  19. laynes69

    laynes69 Minister of Fire

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    If your tube has a 1" rise in 10" then every .1 up the tube would be .01" on draft right? Or thats the way I took it.
  20. peakbagger

    peakbagger Minister of Fire

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    A frined of mine had a long term radon issue in his basement. He didnt want to install a dedicated sub salb ventilation system and fan so he plumbed the inlet to the barometric damper down to the floor and that cut down his radon smaples enough that he got down below the action level.
  21. tbsdolmar

    tbsdolmar New Member

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    I had a WC130 before I got my Biomass. I had the damper in a tee off the first elbow. My pipe went straight up off the back of the boiler. This worked perfect for mine.
  22. Gooserider

    Gooserider Mod Emeritus

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    That's what the math would say... I'd probably go with a lower rise than 1 in 10 given that you want such a low number, as .1" would be tough to measure - if one did 1 in 25" then it would be 1/4" horizontal per 0.01" of rise, which would be easier to measure...

    Gooserider
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