Inputs on poor draft but little creosote?

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Rhone

Minister of Fire
Hearth Supporter
Nov 21, 2005
827
I got a company does full liner installs AND sweeps chimneys to sweep my chimney and see what they find because my draft is terrible. They didn't find anything wrong so, I told them about a possible crimp. They put mirrors to look up the liner and said there's a small one but it certainly is having very little impact on your draft. They also informed me, that if there was a crimp, most likely that spot would be full of creosote and there was hardly any. They also said if draft was affected they would've found more creosote. They only found 1/8" flakes around the ending 5 feet so, they told me it's burning especially clean if that's all there was after 4 cords.

They seemed to think there was minimal creosote for 4 cords, and the wood I burned must've been extremely dry... I know the wood was rather wet. They told me the only thing that could be is that my chimney is simply too short because a crimp would cause creosote in that location or cause more creosote to form later in the liner. With as little creosote as was in there, there isn't a restriction. Is that true a crimp would cause creosote in the location or later? My liner is 16 feet with my chimney ending around 14 feet above, my liner is sticks out a couple feet. Any other ideas or, is that all the symptoms of a short chimney. Smoke pours into the living area on reloads, difficulty in getting a fire going, starting a fire and leaving the door open a crack when I shut the door it can occasionally go out, unusually long burn times. They told me, if it took professionals 2 days to get the current liner in there, I certainly don't want to be taking it out and nothing with the liner appears to be the problem, has to be a short chimney. Your thoughts?
 
14 feet is on the short side for minium preformance levels. Which sounds like you are experiencing. What about addint 3 ft
of class a extending from your liner?. Either that have the expert that Extenda flue guy add his input. What you did was fight threw the process cracking the door getting a real good coal base and when enough heat was generated it finally acted ok. As evidence of cresote or lack there of. You finally burnt enough hot fires to keep the amounts down. This masked the weeken draft issues that you have. Is your linner ovalized threw the dapmer area? does it turn 90 degrees before it makes the verticle rise? You probably have figured out what is not working as well as you would like the extention above your cap will not count in height due to it being exposed and never being heated to enhance any draft. That piece is useless. Now insulated class A would help lenghten the verticle rise and not cool down as quickly

I take it you chimney is exposed to 3 outside walls sounds like a very differcult installation PM me for other suggestion I have
some other ideas
 
No 90's. From the top of my insert it's 6' flex straight up and ovalized through my damper area then it offsets to the right about 20 degrees until it meets with 10' of solid 6" liner of which only 8' is inside my chimney.

My chimney is in the middle of my house but, I think it acts like an outside chimney. Take a look at the included picture before I remodelled that room. This is a 62 house. You see where the brick ends at the mantel and turns into plaster? From my attic I can climb down and actually stand on the top of the brick you see there behind that wall, or any of the 4 walls in there and look up and see my rafters above. Why'd they do that, I don't know. I've been working on that. If you look at this article (broken link removed) top of page 5 it shows you how to "insulate" around your chimney through the attic penetration using sheet metal. That chimney looks pretty nice and has what looks like a 3" gap around it... my chimney has more like a 2 foot gap around it and why I can crawl down and stand behind those walls with my feet on the bricks the mantel is resting on. I won't be able to do that shortly, I've been working on tightening it to a 3" gap and closing the 3" gap with some sheet metal and mineral wool insulation. Has to be better than the 2 foot open gap.
 

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Rhone, maybe I missed this part somewhere, so refresh my memory for me. Is your liner insulated?
 
It isn't insulated, I have an 8x12 flue that makes it impossible to fit insulated liner down it. What I plan on doing is, ripping off my storm collar and packing as much mineral wool as deep as I can. That's about the best I can do.
 
you could fill it with vermiculite. Just make sure your block off plate doesn't have a single little hole in it. Craig said that he did that once and the stuff came pouring out like sand.
 
From what we talked about in PM's, your draft problem seems severe. It should not take you hours to get that thing up to 180* I agree with elk, you chimney hight is marginal, but it seems like more then that. You stove should be at FULL temp within a hours time, and more like 45 minutes. Insulating would help, but like i said it seems like you have a bigger problem then a too short uninsulated chimney. For one, you have a enternal masonry flue, 2nd you have 13 feet. And where i live 13 is marginal, but works, and its lot harder to draft a stove here then it is at sea level.
 
1. I looked at a Clydesdale today and there is no way in the world you could put a stove thermometer on that thing in a location that would give anything but a too low reading. In fact I don't know how you would put one anywhere on it.

2. That masonary has to be soaking up a ton of heat and depositing it in the attic. Especially being open topped as your describe. Dump a load of insulation on it from the top. And then climb down and pull the surround and lay a blanket of rockwool on top of the insert.
 
Other factors.....

on a first floor - in a basement? How many floors above it?
Plenty of combustion air?

To check on these things, open a window nearby about 6 inches and see if the stove acts differently.

In your case, every little thing will help. I don't think insulation will be a miracle, or another foot on top either - But, with both together you are getting there. Some companies make a pourable insulation that isn't as tiny as vermiculite - maybe perlite will be bigger?

As mentioned, I had problem with vermiculite finding it's way out!
 
You stated that your wood was rather wet? I see this as the main problem, unless you also burned well seasoned wood and had the same results?
 
Todd I was thinking the same thing wet wood is never a formula for effecient burning. what fooled me was the chinmy sweeps not
finding more amounts of cresote. Wet wood will add to cresote build up. I PM Rhone with a lot of questions to narrow down his situation. One Craig hit upon the need for enough combustion air or other appliances compeating for it. I does not take much for a minium length chimney to act up.He starts out with the round to oval restriction to begin with. Another thought is a manufacturing defect. blockage of inlet air duet to excessive seam bead or miss alignment of insulation blanket in the secondary burn chamber that blocks the path of exhaust. It could be outside his home a large tree ortaller home next door creating a negative pressure situation.
Rhone did not confirm the 10/2 3 rule for chimney height? It is possible that the olalizing put enough restriction to the draft flow more chimney height is needed., Ontside influences may dictate extending the chimney height. We have to get into a situation that goes like this if it is not these factors then it must be thoses. Got to eliminate possibilities to improve what is not working
 
Rhonemas said:
It isn't insulated, I have an 8x12 flue that makes it impossible to fit insulated liner down it. What I plan on doing is, ripping off my storm collar and packing as much mineral wool as deep as I can. That's about the best I can do.

I believe Vermiculite can be found in a loose form.

That said.

Where does one get loose vermiculite, Rock wool, etc... I looked around in Poughkeepsie, and was unable to find it.
 
They've got it up in the Adirondacks, just ask Eric to shovel up some for you :-). I'm not sure if it's still true, but one used to be able to pick up vermiculite at better garden centers. I'm not sure about it's purity, but it's available on Amazon. Two half-bushel bags for $12.95. Be sure you get pure vermiculite and not a mix. One thing to note is that vermiculite can contain asbestos. They occur naturally together. For safety sake, treat it like it does, even if it doesn't.
 
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