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eko new (to the us) draft fan

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by taxidermist, Jul 9, 2009.

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  1. Tony H

    Tony H New Member

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    Has anyone taken a look at disassembling the unit and installing the inducer into the existing double wall pipe ?
    I have a T right off the back of the boiler and then straight up and out so adding the EKO inducer unit would require me to cut a new hole in the roof of the shed and that's just not practical.
    I also looked at another unit that can mount in the vertical on/into the existing duct from Tjernlund that looks like it would work.
    Any thoughts ?

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  2. Hydronics

    Hydronics Feeling the Heat

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    Can you take out a length of the double wall and install the damper vertically there after your 90? The one I have from New Horizon for the EKO 60 has a 8.5" inlet and a 6" outlet. Based upon the way it's made it wouldn't work to try and fit it in a double wall pipe.
  3. Medman

    Medman Feeling the Heat

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    Or install on back of boiler, then Tee, then two 45* sections to get back to original pipe. I don't see why the draft inducer wouldn't work in the vertical position, though.
    It is not practical to disassemble, as the fan housing is welded together.
  4. Hydronics

    Hydronics Feeling the Heat

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    Medman,
    Does your inducer have a 6" outlet also?
  5. Medman

    Medman Feeling the Heat

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    Yes, the same as others. On the EKO 25 the 8 inch flange is loose on the back of the boiler. I detailed how to fill this gap.
  6. pybyr

    pybyr Minister of Fire

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    The Tjernlund and other "cut a hole in the side of the flue pipe and install a paddle/pusher wheel" types always under-impressed me, both in terms of seeming flimsy and costing a lot for what they actually are.

    I keep thinking that if I can find the right steel-bladed fan that's a bit under 8 inches in diameter, it'd be interesting to put a T on the back of the boiler, with the middle of the T on the boiler, one side of the T headed to the flue; then put a cap on the other end of the tee- with a shaft running through to mount the bladed fan inside the T on the "exhaust" side. There'd need to be a reasonably tight fit on the shaft where it goes through the cap and into the T, and ideally, the electric motor driving the fan could be on standoffs to give air clearance to minimize heat transfer from wood exhaust to the motor. This'd just be for a boost when loading wood, to minimize smoke spill. Having the fan in the path of the regular flue flow, when the fan blades are not spinning, would probably have some impacts on draft, but hopefully not too significant. Just need to keep my eye out for an approx 6 - 7 inch diameter steel bladed fan, which I have not come across yet.
  7. Tony H

    Tony H New Member

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    The situation is the shed is not very tall or very deep. from the top of the T it's 18" to the roof and from the back of the T it's 24" to the back wall of the shed and the pipe is 6" so there has to be a reducer as well.
    I thought about going out the back of the shed but besides EKO saying not to it would also cut right across my access to all the piping on that wall. What is the length of the damper ? Could it fit in the 18 vertical space with an adapter ?

    After looking back over some of the earlier posts it appears the length is 13.5 " so that gives me 4.5 " to adapt and attach the inducer in a vertical space.
    Does that sound correct and installable to those of you with units installed ?

    Thanks



    Note: build the next shed bigger alot bigger !
  8. easternbob

    easternbob Member

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    I just installed a Tjernlund draft inducer for my EKO 25, a few days ago. I used RTV where the flange screws into the stove pipe, seems like a tightish conection. I fire it up the next day and so far it seems to work great. My boiler is in a outside building so I was never super concerned about smoke, but now there was no smoke when I was loading. I even opened the door a few mins after loading an arm full of small branches and no smoke. I'm not running it all the time, I wired a toggle switch next to the controler, I click that on, open the by-pass, then slowly open the door, no smoke. I did notice that it was really pulling a draft when starting, I'll have to watch the stack temp. as I think it could get up there quick.
    Bob
  9. Hydronics

    Hydronics Feeling the Heat

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    Tony H,
    It should fit between there. How close will you be to combustible wood framing though? I'd use cement backer board on the wood to protect it from stack heat.
    I know what you mean about making the shed bigger. I'm pouring another slab tomorrow to make the wood/boiler building bigger.
  10. Tony H

    Tony H New Member

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    No worries with framing, the shed is all metal. Guess I better get an order in for that inducer before they are all sold.
  11. Tony H

    Tony H New Member

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    Order is in should be here in about a week got the whole deal , inducer , speed control, and gasket for my EKO 40. My gasket has been pretty good but I figured it would be good to have one on hand.
  12. markpee

    markpee New Member

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    Some of you have mentioned a barometric damper - for those with this, does it help suck smoke up the chimney when you open the door? I don't have one on my unit, nor do those that posted pics here. What would be the purpose of the damper at this point? I like the damper idea, but all of my chimney piping is 8" - I'm not in the mood for making a big change.
  13. stee6043

    stee6043 Minister of Fire

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    I don't think you could run the fan and a baro-damper at the same time/on the same boiler. Not unless you manually close the damper before you turn on the fan. Otherwise I'm pretty sure the damper would simply open up when the fan kicked on preventing you from "overdrafting" your boiler. But in effect this would be eliminating the benefit you gain from the fan.
  14. Hydronics

    Hydronics Feeling the Heat

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    Stee,
    This will work as long as you put the damper on the discharge of the inducer. The inducer is hinged & weighted so that it will open as pressure is reduced (draft) inside the tee. Set up this way the inducer will increase pressure at the damper.
    Just for the sake of complicating things -smile-: the inducer is actually acting based on the differential pressure inside (draft) and outside (atmospheric). Life's too easy if we don't complicate things....
  15. taxidermist

    taxidermist Minister of Fire

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    No it does not help to suck the smoke out. It makes the draft in the chimney less so it is not sucking the heat up the chimney. It also lets you get a better tune to your boiler. If your a motor head it works like this..... You set your timing on your car at idle when you rev your motor the timing does not change unless you have tha vaccume advance hooked up. so there for you lose performace.

    Watch video!!!!

    Rob
  16. stee6043

    stee6043 Minister of Fire

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    I was basing my guesses on someone putting the damper below the T coming out of the back of the boiler (pre inducer). I've seen this a few times now. In this orientation I'm rather confident it wouldn't work....
  17. Gooserider

    Gooserider Mod Emeritus

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    I don't remember just how it was set up, but I do distinctly remember when I was up at the Maine Woodsman show, Eko / PAXO had their mobile trailer there with a boiler burning - and it had both a BD and an inducer on it. I thought the BD was below the "T" and the inducer above it, but I could be remembering wrongly. At any rate, there certainly wasn't anything coming out of the BD when the inducer was running.

    My own guess (which does contradict the above) is that if the inducer is between the boiler and the BD then there shouldn't be a problem with the BD supplying the feed to the inducer instead of the boiler. However in that setup you would want to make sure that the chimney was always pulling more draft than the inducer could provide, or else you would have a risk of the exhaust coming out the BD instead of going up the chimney.

    OTOH, it might not make a lot of difference if the inducer is pulling part of it's air through the BD. Remember the BD only opens to supply air IN EXCESS of what it is set for - the rest is going to come from the boiler... Thus if the BD is set for 0.4"WC and the inducer is making 0.6" then 0.4" is going to come through the boiler, and only the remaing 0.2" will come through the BD. (Remember the inducer is a relatively gentle air mover, it isn't like you were putting a shop-vac in line with the chimney...) My understanding of how one is supposed to use the inducer, is that it only gets used when lighting off a fresh load, or when openning the top door for loading. In both cases you are supposed to have the bypass flap open, which will result in the boiler draft resistance being close to zero, so most, if not all the supply to the inducer should come from the boiler, regardless of whether there is a BD present or not, as long as the BD is properly set.

    Gooserider
  18. Hydronics

    Hydronics Feeling the Heat

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    It should work either way but putting the BD on the inlet of the inducer would waste some of the energy.
  19. Gooserider

    Gooserider Mod Emeritus

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    IMHO it would waste energy ONLY if the inducer is pulling more air into it than the boiler can supply without giving more resistance than the setting on the BD. If the boiler resistance is less then the air will come in via the boiler and the BD will stay closed. If the boiler resistance is greater, then some of the air will come through the boiler, and the BD will open just enough to supply the difference - but is this really a problem??? If it is, wouldn't it be a simple matter to either increase the setting on the BD, or turn down the speed on the inducer?

    Note that at least in theory, it wouldn't be at all difficult to create an electromagnet or motorized way to force the BD to close when the inducer was operating. That there doesn't seem to be such a product commonly on the market would suggest to me that it probably isn't seen as being needed...

    Gooserider
  20. Hydronics

    Hydronics Feeling the Heat

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    It's not a problem provided there is adequate draft after the BD opens to prevent smoke out the door if that's your goal. The BD setting should be based on the desired draft under normal operation. If you set it up with the BD on the inducer's discharge none of this is an issue & you can turn down the speed to where it's only enough to prevent smoke out the door. The inducer won't pull air needlessly through the BD. This will minimize energy usage, granted, it's minimal.
    If you intend to operate the boiler with the inducer running you wouldn't want to do this as it makes the BD ineffective unless chimney draft is greater than the inducer's. If that's the case, the inducer wouldn't be needed in the first place.
  21. Gooserider

    Gooserider Mod Emeritus

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    The more I think abou this, the more I feel that having the BD on the discharge side of the inducer is a BAD idea... As you said, if the chimney is drafting more than the inducer is pushing, then the inducer wouldn't really be needed. OTOH, if the chimney is drafting LESS than the inducer, then the inducer is going to be positively pressurizing the chimney on it's discharge side, meaning that smoke will potentially come out any openings, and BD's do NOT seal air-tight when closed...

    OTOH if the BD is on the intake side of the inducer, along with the boiler, then any positive pressure on the inducer discharge side should be no problem, as long as the rest of the chimney is properly sealed. The inducer will help to ensure that the chimney on the intake side is definitely under negative pressure, thus reducing the odds of any smoke coming out the BD.

    Gooserider
  22. Hydronics

    Hydronics Feeling the Heat

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    If draft is less than inducer pressure you could potentially get a whiff of smoke out the 1/32" opening but this could ONLY happen when loading & nothing compared to what would be rolling out the loading door without an inducer.

    Fortunately, if you install one you're free to set it up however you may choose... It will probably work well either way.
  23. pybyr

    pybyr Minister of Fire

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    Here's another $0.02 on the topic of mixing draft inducers and barometric dampers;

    for intro to my comments below, I have a B.D. on my Econoburn and believe that they can be a positive (even important) part of system efficiency _if_ set up properly (right setting for proper draft); I also have nothing against decent quality draft inducers- in fact, I may want to try one at some point.

    But one thing to factor in is that, in my experience (and from what I have heard from others, too), gasifiers seem to send more/ finer ash dust into the flue than many other wood-burning heat units. I don't think that's any reason to avoid a gasifier (I would much rather have dust in the flue than creosote) However, barometric dampers are _far_ from a tight seal even when "fully shut." I would want to keep an eye on whether dust could come out the damper when the draft booster is running, and/ or also whether more dust would accumulate in the damper to be waiting to be ejected rather stunningly if you ever get a "puffback" (which gasifiers will occasionally do, especially with someone who is new to the learning curve). When I was still getting the hang of starting and re-loading, I got a few puffbacks that did blow some fine ash out of the B.D.

    As I said, none of these things are any reason not to put in a damper or an inducer-- just some things to keep an eye on.
  24. sfriedri

    sfriedri New Member

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    Have any of you with the new draft fan tried using it on its own as the only source of draft during normal operation of the EKO? I have an EKO40 and am wondering if it would be possible to use the draft inducer fan to basically convert the EKO into a negative draft unit. The draft inducer fan could be hooked up to replace the standard draft fan on the front of the boiler, so that the controller turns it off and on and regulates the speed. You could then have a DPDT switch to turn the fan to full power for loading.

    For those of you with the fans installed it would be easy to do a temporary test - just disconnect the front draft fan and turn on the draft inducer fan. The only challenge is that you will not be able to open the bottom door to check the gassification, since this would just cause the fan to pull air through the open door rather than through the gassification nozzels. The only way you could check the boiler was firing properly would be the stack temperature.
  25. pybyr

    pybyr Minister of Fire

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    I think that what you're describing is intriguing in concept, but even speaking as someone who frequently disregards "don't try this at home" I think you'd run into some complications that may make it far beyond 'diminishing returns.'

    The downdraft gasifiers with blowers on the air input have separate and at least partly adjustable orifices to control ratio of air into the primary firebox and the refractory's air channels.

    I tend to think that balancing those would become different and more complex if you completely change to a flue-side-suction configuration. I also tend to doubt that the EKO-type flue-sideinducer has anywhere near the "mojo" that the forced-draft-inlet blower does.

    Add all that up and I think you'll get a system that is more complex and does not perform as well. Again, I'm an experimenter who rarely leaves well enough alone... but it seems as if-- unless you are just out of other things to play with-- you're better off either using and enjoying as-is or swapping the unit out for a unit that has been comprehensively engineered to run off of a flue-side fan.

    I'll be happy to hear that I am wrong if you try this and make it work.
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