Chimney For Wood Stove Up-Date

up side down "Stable 2 position" - NASA

I think someone mentioned this on your last thread. I used the 6" triple walled insulated pipe. Since you have an existing chimney, you could probably go with the less expensive double walled stuff. It works great. The pipe sections just twist together and lock. The pipe I got has a lifetime quarantee.

http://www.duravent.com/Index.aspx

What should really be done is to improve heat production from a stove and to burn all the creosote in the fire/stove itself so that it cannot distill out where it shouldn't, eg. in the chimney.

Creosote deposits can cause awful chimney fires, which can spread.

Feeding it out of the house still hot into the environment has been found to ruin the air quality for a large area around the source. A study in Austria a few years ago found that it only needed one house to burn wood and generate smoke, for the whole village to suffer bad air quality.

Smoke is 100% very fine micro particles that when ingested into the lungs cannot all be expelled, ask any smoker!!! Have you ever seen pictures of a smoker's lungs? UGH!!

In some areas of Europe in the next few years, a $7000 "scrubber" will have to be bought, installed and regularly cleaned on any wood burner chimney to remove these particles, where the stove has not been government certified as "clean-burning". Which is about 99.9% of the ones over 2 years old at this time......

As it will be mounted externally on the chimney (eyesore?), it means power has to brought to the chimney, it has to handle the weight and wind load, which could even mean that a chimney must be rebuilt, a further cost.

It will in fact be cheaper to buy a modern certified clean burning wood/pellets stove...not forgetting the health side for anyone within a mile or so.....

I am sure that there are clean burning wood stoves available in all modern countries, and don't forget that for the same heat output they burn far less wood.....

Furthermore, wood must be seasoned (dried) for at least two years (longer is better!) to reduce the creosote production and dramatically increase the temperature of burning....this is actually how a pellets stove works, dry pellets, usually guaranteed to be below 8% water, a small handful of pellets burning at one and the same time and relatively huge amounts of heat being produced....consistently, not up and down like most wood stoves.

I value my work/play hours such that even if I was young enough to cut and gather wood (I did it till 2006, when I stumbled onto clean burning pellets), it would still be far more expensive than buying pellets.....

I spend only about $200-$300 a year on pellets, even if I devalued my private work hours to say $25 per hour, I would not be able to gather cut and split enough wood for a winter in those few hours!!!! I had to go at least 4 times a year, with a tractor and a few friends (I supplied beer, sausages and marshmallows - extra cost, also a time waster!) for a 10 hour working day, come back totally exhausted for the next two days.

Then I would have to stack the wood and keep it away from rain and snow, while allowing the wind to blow through to dry it out.....keeping track of the date the wood was cut and stored....

Weighing everything up I am more than happy to buy my fuel (pellets) and burn them in a Government certified clean burning stove, which will also help my health a little I believe!!!

Plus I can earn $200-$500 per 8 hour day online in about the same time....so no comparison, AND the air about my house is CLEAN!!! (Or at least I am not contributing to the fine particle problem and its renewable CO2, not fossil fuel!!)

I only use pellets to produce vast amounts of warm air in the house, but if I needed a hew heating system, I would convert from Gas (in a backyard tank) to a full pellets burning system.....

Think about it all carefully!!! Best of luck.

What I forgot to add was this:-

What you should also be doing is finding a way to extract the heat in the exhaust gases and bring it into the house, but this will increase creosote production on unclean smoke. Swedish houses of long ago ran the chimney pipes around the room before exiting, as do Austrian houses of the same period.

I am in the planning stage of a warm air collection system from the chimney gases to improve the heat in my lounge, which is at the same level as the pellets stove and is hardly heated by it as its in the kitchen. I originally wanted to do this for the heating water circuit, but decided against it.....more complicated and needs an extra water pump to work correctly.

But my pellets stove has only between 130° - 200°C exhaust temperatures (it goes into Eco mode at 200°C), with a very small volume of exhaust gas. Some wood burning stoves are sending smoke at 300° - 500°C up the chimney in comparatively huge volumes of gas.....what a waste!

If the pipe are in backwards as You say (female end up) then the creasote should not be leaking out (this may be the reason it was put in this way). However I would think that the smoke would be coming out the joints.

oilcan13

I wonder if the creosote seals the gap after a few days of running?

Actually, all the stoves that I have ever had, the chimney is under a slight lower pressure than the air in the house as the smoke escapes it tries to "pull" more after it. The so called "chimney effect".

Even my pellets stove has an "artificial" lower pressure in it as a vacuum pump sucks the smoke out of the burner to make sure any leaks go in, not out!! A safety feature.

I've always wondered how you can have a chimney fire if your using an air tight stove that is already set for minimum air for combustion to control the fire box. How can it burn in the chimney, if it can barely burn in the fire box ?

I use a damper to control air flow through the stove. The stove itself, (wood), isn't air tight. The creosote is far more flammable and hotter burning than the wood, once it gets going. It will suck air through any small opening in the stove to keep itelf going, turning the stove box into a vacuum chamber. Even my damper doesn't have a tight enough fit to starve a chimney fire of air.

I put a inline catalytic converter six inches above the stove, then a Magic Heat powered heat exchangers two feet above that and have been running that for the last 15 years. I use it in my shop about four hours to six a day during the winter, so far no problems.

I was thinking of the catalytic converter route also.

Haven't done any searches on them as after market add ons. where did you get yours and what did it cost?

Joe

Hi Joe, It's been too long ago and I looked on the unit, there was no name. It does still work as when it get going there is very little smoke. Here's the way I've been doing it, but remember I want fast heat for a short time.

Load the fire box starting with yellow southern pine, top that with oak and hickory. Both very well seasoned, at least a full year.

I cheat and use diesel fuel as a starter, not poured on, but wetting a rolled up heavy card paper, 1" dia by six inches.

The Magic Heater turns on first, maybe 15 minutes, the stove fan turns five minutes later.

By then the chimney temp is hot enough to close the catalytic converter.

The shop temp usually is around 55 degrees to begin and rises very quickly. (40 x 40) I checked it but forgot so I'll guess right now, 30 minutes to 65 degrees.

After a couple of loads, I usually let it die slow and it's good till quitting time. Which is pretty early for this old man, 3:00/4:00

There's some here.

I might consider Charlie's method out in my shop..............Concrete floor in metal building, not in my stick built house though. I only burn seasoned hardwood. I don't use a catalytic converter, but at least a couple of times a week, with the stove full of nice hot wood, I'll open the damper completely and slightly open the ash slide on the front and let it rage hot for about 3-4 minutes. It sounds like a jet. I check the stove pipe every year...............no signs of creosote buildup yet. It's been 7 years.

I did find something, don't know if they are the same manufacturer." NU-TEC flue gas thermometer", catalyst active @ 600, self cleaning at 1,000, over-heat at 1,500. Wonder if that thing is supposed to taper from one end to the other, lol, might be time for a new one.

This talk of catalytic converters implies the particulates that form creosote are burned just like surplus gasoline is burned in an automotive catalytic converter.

If this is true what about designs like the 'rocket stove' which claims to perform this action and effectively recover the heat from the exhaust ( chimney) pipe?

A friend recently brought this design to my attention so I am still studying it to see if claims are valid and true.

Up-Date to this up-date.

The original was the three layer 8" pipe that had buildup really bad, of course 90% of what is beig burned is pine doesn't help much. I was cleaning the cumney weekly and it was a cresotey gooy mess. anyway over the summer I slid inside the 8" a 6" pipe, with spacers at each joint to keep it centered, I then filled the spce between the 6" and the 8" with the vermiculite insulation.

Been using this setup for 3 or 4 weeks now, The outer layer never even gets above ambient temp now, before it would get warm and even sometime too hot to touch, not enough to start a fire or anything like that in temps but you couldnt keep yur hand on it more than a few seconds or so, Now it stays at room temp totally.

And the inside of the chimney no goo at all, been checking weekly, havent brushed it down yet all there is,, is a fine layer of dust that is 100% dry and if you touch it,,, it falls off, it is un measureably thin coatng. so keeping that innermost layer as hot as possible has stopped th cresote buildup totlly so far.

Joe

Good thinking. Sounds like the perfect solution..................except the burning pine part. Nothing but hardwood in my stove.

Yeah I know about the pine, But the price is right. When someone built this home. they planted like 100 pine trees all around it, and some I mean like 4 feet from it. messy messy trees needles everywhere. Imagine having to use a lef blower on your roof because the needles end up like 6" thick!

Plus they now have some sort of a bug that is burrowing under the bark and killing them off, ( fine with me) so as they die i have been cutting them down and heating the house with them.

joe

Gotcha. I'd probably do the same. Just open up that damper once in a while and let it scream. You should be able to burn off that creosote as you go.

Hi Joe,

I'm wondering about your original problem with the "cresotey gooy mess". I start a burn with pine bark beetle killed pine and then finish the day with hardwood. I've never had any "gooy mess", but I dry my wood for two years. That dead pine starts out very heavy with water and ends up very light after drying. While you are now keeping the 6" pipe hot enough to prevent condensation I'm wondering if the problem hasn't just moved further up the chimney. Do you have this setup going all the way to the outside and have you checked to see if the is any condensation further up the pipe?

Charlie

yup I went the whole length of the original set up, and about 6 inches past the old top.

The only place where there is the beginning of any buildup at all is that last un insulated 6" of pipe and the chimney cap itself.

I like it!!

From a safety point of view absolutely perfect.

But from an economy point of view, that is wasted energy......better to burn it in the grate and get the max amount of heat out of it. Also less likely a chimney fire or an explosion....

Also, the hot gases, if sent up an uninsulated pipe, can deliver more heat into the house, maybe even on another floor.

In old Scandinavian houses, they might run the stove pipe around 2 or more walls, to get as much heat out of it as possible before expelling the rest.....They knew what they were doing then....

I found this very interesting:-

http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/23809/WRAESNO103.pdf?sequence=1

Showing that a badly designed stove and pipe may be under 20% efficient, whereas a good one may exceed 50%. You would be cutting and carrying half the amount of wood with a good product. Also your supply will be dramatically increased!!!!!

GA.

Or should I say GQ (Good Question!)

Hi Guys! I thought you might be interested in this, I hope it's on topic.

Water Logged Standing Red Oak split into fire wood size.

Start-8#-3.2 oz

13 days-6#13.6oz

17 days-6#10oz

31 days-6#4oz

65 days-5#11.6 oz

1 year -4lb-15oz

That's a lot of water! But I thought you might find it especially interesting on how much it lost in the first month.

All the best!

Was the Hash sign (#) denoting pounds on some lines?

Why not use the "lb" for each and every line, it would make it easier/clearer to read?

Or am I completely off base and those lines with a "#" denoting something else?

Sorry Andy, Yes the # sign designates pounds, sorry, I thought that was common usage.

You may well be correct where you are, but do not forget CR4 is a world wide blog.

For me personally a "#" just indicates the same as "number"...Not a unit type as for instance a pound (lb).

Thanks for clearing that up, I just wanted to be sure. It was interesting to follow the weight changes as the wood dried, though here we recommend drying wood outside, with some sort of covering for rain from above and let the wind blow through from the sides.

Some woods need to dry for 12 months, some for 24 months or more, depending upon when cut and wood type. Moisture meters are cheap here (around US$25 or less) and let you know when a wood can be burnt with least losses due to excess water.

Yes, I checked it is an American thing, if the # sign is in front of a number it means number if behind the number it means pound, I can see how it would have no meaning to you. Sort of like the Navaho wind talkers.

And yes, everything is relative when it comes to drying fire wood, I was just offering a FYI, first hand experience with American red oak, I wasn't trying to write a scientific paper. It was more to show how much water goes up the chimney with poorly dried wood and I don't think there are more than three of us that even care.

You demonstrated that perfectly!

I must admit I was shocked just how much moisture can be in some woods, though you did say it was soaked!!!

UP_DATE

By the way the new lined/insulated chimney is still awesome! not one bit of tarry creosote at all anywhere! just a very thin layer of dust is all that has built up since i did this to this chimney!

Awesome!

Joe