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Pondering an insert installation, with a few possible issues

Post in 'The Hearth Room - Wood Stoves and Fireplaces' started by Bluemaxe, Mar 3, 2013.

  1. Bluemaxe

    Bluemaxe New Member

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    I've recently begun revisiting using the fireplace in my house, which is located in an addition that protrudes 18 feet off the rear of the 2 story portion of my home. It is a fairly well constructed masonry fireplace built at an angle in the far corner of the room that is extended by the addition, the underside of which is not insulated and the ceiling is vaulted making the whole room very difficult to heat with the installed supplemental electric heat. My grandparents rarely used the fireplace in their tenure in the home due to various breathing issues in their golden years, but the price of oil has me looking for a solution to at least supplement the existing oil fired forced air.

    The addition was built in the 80's and the fireplace and chimney are in good shape (perhaps a good cleaning is in order) with no real damage, and from reading and research I've decided that an insert is most likely the safest and cleanest way to bring it back to life. I am considering a few possible solutions to the loss issues created by the fact the addition was built on top of some large pilings instead of a foundation by undermining and creating a crawlspace, and perhaps lowering the ceiling and increasing the insulation as well, but the most perplexing part so far comes from my research on the various inserts available.

    The majority of the ones I've researched state that the minimum chimney height should be 15'. on this I am assuming they measure chimney height from the top of the appliance, not the hearth? Either way the chimney is not the required 15 feet. from the hearth it is 8 feet inside (including the assumed portion within the roof), and 5 feet outside for a total of 13 ft. if you deduct the appliance height from that, it obviously falls well below the minimum chimney height specification. In addition to that I measured from the chimney to the house's second story portion and with the large soffit that overhangs, it is hardly the required 10 foot distance diagonally, but scrapes by if you measure directly to the wall.

    In many of the drawings I have seen, they specifically label such an arrangement as less then ideal for draft. I have found a chimney extension at extendaflue.com that appears to be a neat and easy (also cheaper then a mason) solution to extending the chimney roughly 4 feet on a 12" x 12" flue. I'm not sure if in conjunction with installing a new stainless liner this is a good/safe way to go? This extension looks like it is of good quality.

    The other issue I have come across, is on the inside of the front of the fireplace, at the front of the hearth, with a significant protrusion at an angle, is a cast iron air intake vent. the vent runs almost the entire length of the inside of the fireplace, and would interfere with any insert laid directly on the inside of the fireplace floor. With that said, i really like the clean look on an insert that has a shroud around it, but I'm not sure what to do to deal with this vent.

    Being the house is fairly tight, and the chimney is where it is located and not very long, as well as possibly being code required, It seems like having an intake is a good idea, but I cant see how it won't interfere with most inserts that have a fan located at the bottom, either from combating the output of the fan, reducing the intake capability by enclosing it or blowing on it with the fan, or just obstructing it with the insert in general. The hearth is also exactly 16", which would make coming out of the fireplace any farther then the face of it require some more modifications. Any ideas or product recommendations on this would be greatly appreciated.

    The last concern I have, when installing the chimney liner, the damper is undoubtedly less then 6" which is what most appliances i was looking at require, is using an oval liner acceptable, maybe just in the area that goes through the damper? Cut the metal and knock out a little brick? I am not in a position right now to take a few pictures of the situations, but I could if need be to better understand anything.

    Any help would be greatly appreciated. I'm Looking forward to participating in such a great resource for fireplace information.

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  2. chimneylinerjames

    chimneylinerjames Feeling the Heat

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    As far as the liner goes, if you can keep it round thru the damper area that would be ideal. Especially in your case when you are already a little short and possibly too close to another part of the house, I would do everything possible to increase draft. That means keeping it round and installing insulation around the liner. If you can safely connect a pipe to the liner to extend it higher, that would even be better. But just make sure that pipe is insulated, if not it will build up with creosote extremely fast.
    WoodpileOCD likes this.
  3. Bluemaxe

    Bluemaxe New Member

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    Thanks for your reply, I was thinking keeping it round was best, probably will require a little modification around the damper, but once its all installed I don't see ever wanting to go back, and that is really the only reason not to take a little off of it. The extenda-flue apparatus I was looking at was available insulated and had a mounting setup that allowed it to be connected to the liner directly fairly painlessly as well as a fancy patented way of attaching it that looked well secured, I suppose for some its a bit pricey but the visual appeal of it seemed nice too. I guess I forgot the idea of extending a chimney just with insulated stainless smokestack. Is there an ideal interface for that? I guess I'm not sure how to attach it well secured to the chimney, and what limit freestanding in length could be attained? I would really like to extend the chimney one way or another even if maybe it had to be adding some bricks, It was never really used consistently, and I fear the lack of height will cause me draft issues, or make for a smokey upstairs if the wind was wrong.
  4. mellow

    mellow Resident Stove Connoisseur

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  5. rkofler

    rkofler Burning Hunk

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    I was just looking for something like this. Is it possible to add more than 18"? I was thinking like 3ft.
  6. begreen

    begreen Mooderator Staff Member

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    Extend-a-flue will get the job done. They are well-made, by our very own webmaster.
  7. mellow

    mellow Resident Stove Connoisseur

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    I do believe you can link them together to make it higher, with 2 together that would give you 3 feet, at that kind of height you might want to do a brace for it.
  8. chimneylinerjames

    chimneylinerjames Feeling the Heat

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    Those are not the best for wood stoves. That pipe will be extremely cold, the smoke will condensate extremely bad and block up faster than you could imagine. Use an insulated pipe.
  9. mellow

    mellow Resident Stove Connoisseur

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    Yep, I would for sure insulate that, I think you could use rigid liner insulation and cut it down to 18".

    [​IMG]
  10. Bluemaxe

    Bluemaxe New Member

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    I think Ill go with the extend-a-flue, It really looks clean and ads the most length the cheapest and easiest. I didn't realize it was created by the webmaster LOL, that actually makes it more appealing, that someone with that kind of interest and experience in stoves thought it up. I'm in Eastern CT and I was reading up on building code and insurance thoughts, that is going to be a factor as well here. No takers on how to solve the issue I'm going to have with the intake vent in my way? I was hoping someone would have maybe had this issue and came up with something, or compromised in what type of insert was used? I plan eventually to go to a local stove store, they have been around forever, If code requires i guess ill have them install it or recommend someone too, I just want to get an idea of what to expect.
  11. mellow

    mellow Resident Stove Connoisseur

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    Post a picture of the vent, most of the time these can be removed to allow access to the flat concrete/brick surface below.

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