wood stove good or bad?

[Jens]

Since this is a woodstove thread, I thought I wouldn't waste new thread space with this simple question.  What are the big dangers to having the exhaust go up the unlined chimney after exiting the woodstove?  I ask, because as soon as we can afford it, we will be getting a full liner, but for the time being, am I just, "playing with fire" to use just a short section of stovepipe going into the bottom of the chimney?  Sure would be nice to go ahead and start burning.  We have been making small fires in the firebox, I keep a very close eye on how high the flames are getting as I am a bit paranoid, and I know that with a stove less heat goes up the chimney.  Are chimney fires as big a concern due to the reduced flue temperatures? 

[Redoverfarm]

Jens I am not real sure what you are calling an unlined Chimney.  Is there clay or just parged block.  The biggest problem with the older flues is that the parging and the mortar would give out in time and create gaps between the blocks.  With just stove exhaust I doubt there would be a problem but if a flue fire would develope I doubt that the block could withstand that amount of heat .  It is not uncommon for people to exhaust a wood stove into a fireplace chimney.  In fact that is all an insert is. A stove w/o legs and a heat shield to block off the rest of the opening.  A modern stove eliminates alot of the flammable gases which were once sent up the flue by re-burning them.  So I guess alot just depends. 

[Jens]

It is just brick.  I am not sure what the original intended purpose was, coal, wood, I don't know, I just know that it has no clay liner.  The mortar is in decent shape when examined from the outside.  The wood stove I got is this one, http://pasurvivalprods.tripod.com/waterford.html.  I would assume that the gasses would be pretty well spent, but I wonder if enough heat would go up the flue that chimney fires would be very common.

[MountainDon]

How old is it?

One thing to remember with a brick chimney is they creosote up faster than an insulated metal chimney. If you did have a bad build up of creosote and made a hot fire it's possible you could end up with a run away chimney fire.

My parents old house had brick chimneys; dated from the turn of the 20th century. They quit using the living room fireplace sometime in the 1960's as a chimney inspection showed some sort of problems.

[glenn kangiser]

course, almost the whole place is non-combustible material...I bet you've tried a time or two?

Not a problem, Jens... If I catch the place on fire the 1" wood is rated at about a 1 hour fire wall.  That means we have about an hour before the wood burns through and the dirt on the roof caves in and puts the fire out.  The beams and girders should be good for 4 or 5 hours.

Sassy wants me to fire the stove up right now.

[Jens]

The house was built in 1930.  The chimney appears to be fairly clean inside.  10x10" flue, unlined.  Would a single wall stainless flex liner have major drawbacks?  Enough to really worry about?  I can get one for $175, vs. $400 for double wall.  Alternatively, like I was saying, I could just use the chimney for now, but like I said, kinda worried about chimney fire.  Is the exhaust hot enough to worry about that all the time, or just when you really have it roaring?  This stove has secondary air, and combustion baffle.  I'd rather not have to borrow money to get a liner in...getting cold though, and gas ain't getting any cheaper.

[Redoverfarm]

Well there has been a lot of discussion about wood stoves and their preformance.  I thought I would post a video of my stove in the "after burner" mode.  Excuse the background noise as the television was on. 

[MountainDon]

It is a difficult combination of lighting to get the stove itself to be visible as well as seeing the fire really well. Always fun to play.

Looks like a lot of heat.

[glenn kangiser]

Some low clearance wood stoves - the 1440 was reviewed by http://www.kk.org/cooltools/index.php

http://www.morsoe.com/us/Products/Stoves/

Not exactly cheap - the reviewed one had 7" clearance.

[cordwood]

I have flue fires all the time! I can get easily 1' of flame rolling around the rain cap that is 12' above the fire box. Fire in the flue is not the problem with most flue/chimney applications it's the creosote that weeps between the joints to an area not intended for for fire or flames.

I will NEVER use an unlined brick/rock chimney again. It is almost impossible to be certain that wet creosote has not oozed through the cracks and in the attic area or wall space. The fire just follows the trail like gunpowder in a western movie. Metal pipe can do the same thing if it gets rusted out OR the joints are UPSIDE DOWN! The male ends need to go DOWN to prevent hot flaming tar from running down the outside of the pipe and creating the "Lava flowing down the mountain" look!

Also flue fires don't require a large fire to get started, DUST can cause a flue fire very easily!

[MountainDon]

The male ends need to go DOWN to prevent hot flaming tar from running down the outside of the pipe and creating the "Lava flowing down the mountain" look!

Just to make this perfectly clear, because when I first read that my mind was still working on a mental image of the insulated chimney pipe.

The double wall insulated pipe I have worked with over the years is always installed with the male connector end pointing up, the female socket down. The female inner wall overlaps the joint of the inside to prevent leaking through the joint.

However, it is correct that the black pipe that connects between the stove and the insulated chimney, is installed with the male connector end facing down and inside the upper female end of the next pipe down the chimney.

If one is using factory made chimney pipe and related parts it would take some extraordinary effort to assemble all the parts of the chimney with any parts oriented incorrectly.

I've never seen flames coming out of a chimney cap and hope I never do. That doesn't seem right to me. 

[Jens]

My Mom's boyfriend Mike, is a retired fire fighter.  He told me that he has seen many chimney fires.  They would usually get there after the chimney was not burning any more.  He also said that it doesn't make a difference if it is the double, triple, or single wall, they all melt just the same and must be replaced after a chimney fire.  They have been running stovepipe inside their chimney for the last ten years, with no problems, and he wouldn't take a chance (any more than just using wood heat, or power tools) with their house.  They couldn't afford double wall at the time, so they just make sure to keep it clean, and inspect for rust, which is a very common problem, I guess. 

The house we had with a wood stove in California, had only stovepipe all the way up and through the ceiling.  So did the other three houses on the property.  We would clean ours out with a hot burn once in a while.  A little cardboard, aspen, or a tightly rolled paper bag of planer shavings works well.  It would get rid of the creosote build up.  Maybe there were fires sometimes, don't know!  Not saying its smart, just saying...

[cordwood]

 My brother in-law argued with me over the orientation of the pipe saying I was putting mine upside down till the night his started dripping flaming creosote onto the floor and that pretty much convinced him, The pictures of him covered in white dust from the fire extinguisher I bought them for Christmas helped too!!

If it gets cold enough again and I get someone to walk me through posting pictures I will show you the flaming cap trick!!! I don't by any means recommend anyone doing this but because I installed this in MY house and I maintain it and have been heating this way for thirty years or so I feel very comfortable with my situation,.......However my wife of over twenty years does not always share my slightly off center sense of security. Considering all the broken bones (100+) I feel every time the weather changes I guess her worries may have a certain degree of merit

[Alasdair]

Anyone come across one of these before? I'm thinking of buying it second hand. (The price is right!)
It is CSA approved and has the stickers to prove it but is not a brand I have heard of. Google turned nothing up so I was wondering if anyone had come across one before.



The Legend reads "MacGregor" what the significance of the kangaroos is I don't know....

[Jens]

look more like deer than kangas to me.  looks like a nice quality stove though.

[Alasdair]

I was sure that was a joey in her pouch there ... 

[Woodswalker]

Sorry to be late getting in on this discussion, but feel my 30+ years of wood stove heating experience might be of some help.  The first 10 yrs I heated with a Vermont Castings stove vented into a fireplace chimney (circa '30 house) that did have a clay flue.  Had one chimney fire while at work (spouse home) that taught me the critical importance of yearly chimney cleaning.  Firefighters came in like gang-busters and broke into an attic access to see if structure was starting to burn.  Luckily, the clay liner contained the fire, and they didn't turn on the hoses.  I would NEVER, NEVER vent a wood stove into an unlined flue.  Jens, I think a single-wall, flexible stainless liner would work OK, if inspected and cleaned often.  There are companies out there that can place a long tube bladder into the chimney, inflate it, and then pump refractory cement into the space between the bladder and the bricks.  Makes a very good flue that will last a long time.  Probably pretty expensive tho.  Personally, I would not use single-wall steel pipe inside the chimney because of the numerous joints involved.