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wood burning stoves

Nightmare woodstove smoke! I am stumped... 21 feet of flue, can't get a draft.

joe fish

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posted 3 years ago

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Update, I have to run around today (I try to go to 'town as little as possible, ha!"

I'm considering picking up another 3' of stainless pipe. And I have ordered two different styles of down draft prevention caps. Both the Vacu-stack style recommended earlier. And a wind-directional style that will face a sheild towards the wind.

I'm excited to try both styles. I was able to get them quite affordably so I decided this is important enough to me to really give these things a shot. I will post/update with my testing here! Now I hope this becomes one of those venerated old posts, people find value in a decade later!

joe fish

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posted 3 years ago

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Another update!

This is when I begin to feel like a *real* idiot. I have a Vacu-Stack cap I am ready to put on. I checked the flue with a flash light to see no obstructions several times before making this post. I took me a couple days to rig up a safe way to get back onto the roof (9/12 pitch, covered in snow) And when I finally got up there and removed the old cap I found part of the problem. After getting back on the the ground and inspecting the cap, I noticed, Perhaps this a new saftey thing, but the cap had what looks like a inner spark arrestor and outter bird screen/shield. So from the ground the cap looked fine, no obstructions, but after getting it up close and personal, the inner spark arrestor, which looks to be 1/2" squares was VERY clogged. The only way to see this was to be right up on it and I didn't notice it when I was fussing with it in the late summer. My guess is the cold winds that blow through the cap allowed the perfect environment for the moisture/creosote to stick and layer up. All this build up, occurred in only a partial burning season! Roughly 2 months of use! However the flue pipe has a very small amount of build up, nothing to even really be concerned about it yet. The only way to discover this was to be on the roof and dissemble the cap!

I have removed the offending screens, and put the old cap back on.

I will fire tonight after the house starts to cool off and I install a 3" cold air intake port into a sidewall very close to the stove. I don't plan on plumbing to the stove directly as I want to be abel to stack wood up against the wall, but it will work just the same. Thinking about the air/flow dynamics/draft/leak dynamics I think I am going to put the intake at roughly 5-6' off the ground. My goal is to use it as a bit of a 'passive' damper, It lets the stove intake air, and vent fans intake air, But its not near the roof, or the floor encouraging a natural convection draft.

Its a wind advisory evening tonight, gusts to 30mph+ This is the perfect test to see if my existing FLUE length is adequate to use a cheap chimney cap in a strong wind enviroment.

This is now turning into a cheap $50 cap, vs VacuStack in windy/hillside conditions test

elle sagenev

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John Weiland wrote:I just wanted to be sure from the photos.....is the stove installed in a basement or on a main floor? Thought I recalled something about negative pressure in a basement but can't recall the gist of that notion with respect to woodstove locations. Also, in case the past thread has some relevant information:

https://permies.com/t/32344/Lets-Talk-WOOD-STOVES-Exhaust

Finally, we surely had wind problems that were reduced, but not eliminated, by the style of chimney cap shown below. Hope something here may be helpful!

We have this same one and live in Wyoming where the average wind speed is:

WHP-Blowover.jpg

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Thomas Tipton

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I wouldn't make any other changes other than cleaning or replacing that chimney cap. It's always best to make one change at a time and then evaluate performance so you'll always be sure what change had what effect. My money says you've solved your problem. Though of course there is always room for improvement. Well done!

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joe fish

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posted 3 years ago

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BIG update.

"It's a'Blazin!"

So it looks Like my problems are 95% solved. The outdoor wind has died down, but it is still a bit gusty outside. I did not get a single puff of smoke inside during a overly long lighting procedure. I got impatient and didn't take the time to make a good kindling start.

I will update as I really tweak it, but so far that blockage was the majority of the problem it seems!

John Weiland

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Thanks for the update, Joe, and glad you're running hot again! So far we have been doing well with draft, but I'm glad you shared your experience....I may have to get up there and look at our cap one of these years and make sure it's free of obstructions. Happy heating!

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Abe Coley

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The mystery has been solved!!!

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Pete Arthur

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Took tooo long to read all the replys.

So, you light the stove in the basement.

you throw some towels in the dryer in the basement.

and go upstairs to start the fish fry, and turn on the vent hood.

and go to the john/head and turn on the bath exhaust fan.

and look at the nice night thru your wonderful skylights.

I have had to explain to numerous costomers the "power" of exhaust fans, about ten times that of stovepipe draft.

The only thing that beats an exhaust fan for vacu sucking air out of a house, is a leaking gasket on a skylight.

The tighter the house the worse the effect.

If you have smoke coming out of the joints of the pipe, you have a mechanical vacuum being drawn on the
whole house air system. The stove is fine.

These are the big offenders of sucking your air:

clothes dryer
furnace (combustion air drawn from inside)
vent hood of stove
bath fan
leaky skylight gasket, because roofers only care if the water gets in, not if the air gets out. Especially in multi story homes.

Douglas Alpenstock

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Awesome! I have heard of spark screens causing clogs before, and worse, CO problems for unsuspecting residents. Now that you know it's there, regular inspection will (obviously) be on your list. With the stove you have now, you will hopefully have cleaner burns and less buildup.

joe fish

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Pete Arthur wrote:Took tooo long to read all the replys.

So, you light the stove in the basement.

you throw some towels in the dryer in the basement.

and go upstairs to start the fish fry, and turn on the vent hood.

and go to the john/head and turn on the bath exhaust fan.

and look at the nice night thru your wonderful skylights.

I have had to explain to numerous costomers the "power" of exhaust fans, about ten times that of stovepipe draft.

The only thing that beats an exhaust fan for vacu sucking air out of a house, is a leaking gasket on a skylight.

The tighter the house the worse the effect.

If you have smoke coming out of the joints of the pipe, you have a mechanical vacuum being drawn on the
whole house air system. The stove is fine.

These are the big offenders of sucking your air:

clothes dryer
furnace (combustion air drawn from inside)
vent hood of stove
bath fan
leaky skylight gasket, because roofers only care if the water gets in, not if the air gets out. Especially in multi story homes.

You are absolutely correct, interestingly this wasn't in my case, the house is very tight but my trouble was with zero vents/fans running and even a door wide open. I believe what happened was the flue-spark arrestor was so gunked up and I didn't notice, that the stove was over powering the ability for the stack to dump the exhaust to atmosphere.

It is now working, Very well, with just that taken care of. I will be updating regularly!

joe fish

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posted 3 years ago

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Overnight update.

Basically flawless operation. I am going to report back in a week or so. I wouldn't mind trying out the vacu-stack however I am excited to see how well the cheapo-o cap performs in high wind conditions.

Douglas Alpenstock

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joe fish wrote:... I am excited to see how well the cheapo-o cap performs in high wind conditions.

My experience is that the caps designed to go with the insulated stack system generally do okay in windy conditions. I think I've only seen a blowback once or twice in 20 years.

joe fish

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Douglas Alpenstock wrote:

joe fish wrote:... I am excited to see how well the cheapo-o cap performs in high wind conditions.

My experience is that the caps designed to go with the insulated stack system generally do okay in windy conditions. I think I've only seen a blowback once or twice in 20 years.

Yeah I am curious to see how this goes!

You really in zone 3b? What does that growing season look like!?

John Weiland

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joe fish wrote:

Douglas Alpenstock wrote:

joe fish wrote:... I am excited to see how well the cheapo-o cap performs in high wind conditions.

My experience is that the caps designed to go with the insulated stack system generally do okay in windy conditions. I think I've only seen a blowback once or twice in 20 years.

Yeah I am curious to see how this goes!

You really in zone 3b? What does that growing season look like!?

I won't speak for Douglas A. directly, but can confirm that based on the 'winter shade' (

.... kidding! ) he throws down our way (4b) from the Canadian prairies, I'd say 3b sounds about right. And I will echo his observations on the Vacu-Stack style of caps.....greatly reducing back-draft. We will get a chance to see both sides of the effect starting this evening with relatively high south winds that will hit the opposite side of the house from the stack, thereby creating that "giant sucking sound" (in the words of past presidential candidate Ross Perot) until tomorrow when it turns to the north. Predicted winds as of now are to be around 45 - 47 mph from late Sunday afternoon through the evening. Really hope not to be disturbed in slumber by that back-draft smoke. Glad to hear the stove is still in the spirit of giving.....!

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Ben Zumeta

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I had such a weather vane chimney cap at my old place, and it was one of the few things I never had to fix. The chimney was on the short side, so maybe it helped because a draw was only a problem during atmospheric inversions. It looks in the second photo like that may be happening but it’s hard to tell. You’d probably already have identified this as the problem.

I am no expert, just a longtime wood stove user and person who likes to speculate about stuff I have no business talking about. I suspect that elbow is a part of the problem. This is even though RMHs obviously have lots of bends, but they are also engineered and sized specifically to get a good draft.. My understanding of the physics of ventilation is that flow rate is restricted by 50% with every 90deg bend (it’s relative to the shortest diameter in the bent section). The fatter elbow is meant to compensate for this, but I suspect heat stratification in it is causing an eddy to form, creating the loss of draft your are seeing. Maybe it’s the just photo, but it looks like you could almost make a straight pipe work on that chimney, or at worst have a much lower degree of bend. I’d bet other factors are also at play, because plenty of people have serpentine chimneys. Perhaps you could measure the chimney temps above, below, and around the elbow to confirm or eliminate this as a possibility.. Just my 2c, this does seem puzzling.

48A65CBC-F41E-4C1E-8D90-4B54D958A140.jpeg

This is all just my opinion based on a flawed memory

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Douglas Alpenstock

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Ben Zumeta wrote:I had such a weather vane chimney cap at my old place, and it was one of the few things I never had to fix. The chimney was on the short side, so maybe it helped because a draw was only a problem during atmospheric inversions.

Ben, I used one of those on a little cabin, with a crappy short uninsulated chimney fed by a crappy little wood stove. It made a big difference in the draw. These work.

Douglas Alpenstock

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joe fish wrote:You really in zone 3b? What does that growing season look like!?

Yep, 3b at best. Orbital mechanics gives us a short growing season, but it's an intense season with massively long hours of sunlight. People didn't settle here for the mild climate; they came because given half a chance we can feed half the world. Cheers mate!

John Weiland

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Alas, my wishes went unfulfilled. We are now under a blizzard warning and the winds currently from the north are a sustained 33 mph and gusting to 40. So I'm noticing a bit of smoke smell in the air.....not enough to be considered 'smoky', but not welcomed all the same. Current temperature is 9F (-13C) and it will be below 0 F in the morning. It appears Murphy's Law is at work here as I have the first scheduled appointment in town for several months in the morning and am supposed to be at said appointment by 10 am. If they post-pone, it will be a great relief,.....otherwise it will be a cold dark morning on the tractor pushing the snowdrift out of the drive in that 'brisk' northern breeze! :-/

“The most important decision we make is whether we believe we live in a friendly or hostile universe.”― Albert Einstein

joe fish

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John Weiland wrote:Alas, my wishes went unfulfilled. We are now under a blizzard warning and the winds currently from the north are a sustained 33 mph and gusting to 40. So I'm noticing a bit of smoke smell in the air.....not enough to be considered 'smoky', but not welcomed all the same. Current temperature is 9F (-13C) and it will be below 0 F in the morning. It appears Murphy's Law is at work here as I have the first scheduled appointment in town for several months in the morning and am supposed to be at said appointment by 10 am. If they post-pone, it will be a great relief,.....otherwise it will be a cold dark morning on the tractor pushing the snowdrift out of the drive in that 'brisk' northern breeze! :-/

Run the stove a little hotter/harder? Can you add another section of pipe?

Charles Robertson

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Hope this may help. Been heating with and installing wood stoves for 50+ yrs. Currently Jotul Combi 4 (shop), Jotul 118 (house). Before you spend a lot of money, 3 actions-make sure chimney cap spark arrestor is clean not hindered. Move stove and run straight pipe to double wall. Remove elbow and check for draft. Check stove interior for any possible blockage of draft and air intake systems. Heat shield at riser and tread.
Realize you have probably already tried this. Just thought I'd mention them.
Burning, smoking paper at open insulated stack to check for draft. I feel your pain Have not had your problem with any of my stoves or the ones I have installed. Wish you much luck. I do not see a problem but I did not like that elbow.
Al Robertson

Ben Zumeta

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That reminds me, our current wood stove came with our new place, and it had some broken parts I didn’t know about. These greatly increased our draft difficulties until fixed, and was a bit of a face palm moment when I figured it out. I was cursing my incompetence at fire building despite having done so when it counted in snow and freezing rain in the wilderness many times. It turns out I can in fact build a fire, I am just an idiot in other ways.

The metal piece attaching the handle to masonry of the flue damper, and that opening/closing the recombustion channels, had rusted off. It could still move the thing if it caught just right with the broken handle, but it made it easy enough to think the thing was wide open or fully closed when we were in fact doing virtually nothing different, and it was just slightly open or fully closed at an inappropriate time, causing smoke back or inefficient heating. The perforated pipe (is that called the heat exchanger?) at the top of the burn chamber were also rusted out. When we took the chimney apart to clean and inspect, we did so for the stove as well and realized we’d have to replace these parts and doing so worked well.

This is all just my opinion based on a flawed memory

Trev Ortex

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Have you tried it without the chimney cap? The chimney cap exit should be at least 1.5 times the cross sectional area of the chimney pipe or it will restrict flow - most aren't big enough. Also a spark screen alone can restrict the gas flow 50% easy. I'd put money on the cap being the main problem. One other situation I have seen like that where no one else could figure it out was the insulation inside the twin wall stove pipe was soaking wet, it happened because the pipe had been installed upside down.
Hope that's some help.

Vortex Stove

John Weiland

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joe fish wrote:

John Weiland wrote:Alas, my wishes went unfulfilled. We are now under a blizzard warning and the winds currently from the north are a sustained 33 mph and gusting to 40. So I'm noticing a bit of smoke smell in the air.....not enough to be considered 'smoky', but not welcomed all the same. Current temperature is 9F (-13C) and it will be below 0 F in the morning. It appears Murphy's Law is at work here as I have the first scheduled appointment in town for several months in the morning and am supposed to be at said appointment by 10 am. If they post-pone, it will be a great relief,.....otherwise it will be a cold dark morning on the tractor pushing the snowdrift out of the drive in that 'brisk' northern breeze! :-/

Run the stove a little hotter/harder? Can you add another section of pipe?

The first photo below shows the north side of the house with the stack....it exits the house on the main floor and rises quite high above the roof soffit before being capped above the supports. It's about 20- 25 ft from the ground to the soffit, so a fair and wobbly distance to the top of the stack. Not sure it would be worth the extra 3 ft of pipe..?? Running the stove hot does improve the situation....but eats wood that much more quickly. :-( In the end, it's operating so much better than in the original config that a small bit of backdraft during extreme weather is tolerable.

The stack for the Rocket Heater prototype placed in one of the outbuildings is shown in the second photo.....I've decided this falls into the "Tim Burton School of Chimney Design" :-) Note the stack exiting the building near ground level, then using the gutter to anchor the stack just below the cap. Both stove and stack (class B piping) working well this winter.

Stack1.JPG

Stack2.JPG

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richard corbin

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Spent 10 years as an installer in the central valley and the two biggest problems I always encountered was the flue was less than 2 feet higher than anything within 10 feet .I see a tree in one photo and you are on the backside of the roof from the wind. those two items create a lot of down pressure to the flue .Raie the flue above that 2 and 10 rule and add a directional cap.

Richard McNew

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I have used a wood stove for many years and I have learned that the top of the stack has to be higher than the highest part of the roof. Also some professionals say the taller the stack the better and for every 90 degree bend you lose 3 feet of hight. I've learned that a plain flat cap about 5 inches above the top is sufficient, mine is home made using an 8 inch square peace of sheet metal with 3 peaces of 1 inch metal strips attached together with screws to the top of my stack. It's mostly to keep out the rain. If there is not enough air flow coming into the room where the store is it will definitely smoke back. If there is no restrictions in the stack you can try to open the vent that controls the air flow into the store for a few minutes before you open the door. I'm thinking that something is not right in the store itself. Good luck I hope you can solve the problem soon.

Kelly Pridgen

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Not sure if this has already been stated.

Location of the stove’s air source relative to wind direction can make a difference.

Cracking open a window/door on the windward side of the house will create positive pressure inside and improve draft.

If opening is on the leeward side, will create negative pressure inside which will reduce draft. If strong enough can pull smoke into house.

Mark Grindahl

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With the height of the trees pictured I think you will need more pipe. I installed a stove this fall and even though I was 2' higher than the closest roof section I still had smoke. One more three foot section took care of it.

Marty Gass

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I have the same stove installed in a newer manufactured stove. Drafted poorly and smoked terribly until I put a length of flex pipe from the cold air feed to the outside. On the bottom rear of the stove , where your register rod slides in and out, there is a box. Mine had a 2" round outlet. I used 2" automotive exhaust flex pipe to get cold air from the outside. On the exterior wall I used a screened dryer vent. It was necessary to use PVC couplers to mate the pipe to the vent. Before opening up to outside air the stove was horrible to light . Had to use fire starter etc. It also caused oxygen loss to the home causing me to awake in the night struggling to breathe. Now it's lights fast and simply and heats a 1600 sq ft area with no problem. I'd also try to simplify the way you shift your flue pipe. Hope this information is helpful.

See Hes

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There are so many reasons that an answer is not easy to find:

These kind of ovens were in Germany until 1970 (ish) in every household.
They are starting like an old steam engine and as more you fumble around with the air supply or even open close the Glass Door at start as more Smoke you will get at the room.

These beasts need a soft start by meaning.

First you have to heat up the pipe by loosely stuffing a few times some newspaper in the bottom where you can reach this pipe from the oven.
Burn a few stuffings until you hear the pipe howling...
If the pipe is hot enough start the oven as usual.

These type ovens are also sensible if there are gaps between the parts and the fire cradle

If you are at the foot of a mountain...
Make it a benefit and hang some hams in the room for 8 hrs a day as if the wind comes falling from the mountain the fall winds could build up more pressure than the oven is capable to build up.

My Parents and Grandparents started them without much fuzz about a little smokey burp into the room but I remember that they lit the starter media (Newspaper and small wood) after they had pre-heated the pipe with newspaper a few times and as soon the fire was on, the door got closed.

In modern times the only right way forward is to come back to nature.

Bob Herman

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Hello i dont know if this would help your problem ..but i used stainless pipe clamps that came with the stainless pipe at the sections of pipe

Crispin Pemberton-Pigott

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Greetings

I confess at the beginning I am a stove designer.

The leak between the chimney sections when you "do anything" is a key indicator that you have positive pressure inside the upper chimney created by the local environment and positive pressure at the bottom created by the buoyancy of the hot exhaust. Otherwise the leak would not occur. The pressure inside the chimney would should always be negative compared with the room(s).

Key to solving this will be addressing what is going on at the top of the chimney. Wind can easily blow air down a chimney for all the reasons mentioned by others.

I was surprised by the chatter about vane hoods being a problem re durability. These draft inducers are common enough around the world. The rotating (spinning) type are very reliable so why would a swinging one be a problem?

Various static induction or more correctly "eduction" designs have been made going back centuries.

Let's concentrate on your upper installation. It sounds as if everything is fine, but you have positive pressure inside the stack which should not be the case.

In the Russian national standard, they have a different approach to the eternal dimension spec. The 10 feet rule is not applied in the building code. The rule is: take the top of the peak and draw a line at ten degrees down towards the chimney. The stack exit must be above that line. I can't remember if it is one foot above but certainly it must not be below it.

We used that standard when creating an installation manual in Kyrgyzstan and never had draft problems with stoves that were much more efficient than the usual crap. More efficient usually means with a lower gas exit temperate (but not always). So less draft available, but no trouble.

These installation specs are in the building code, not the stove performance standard such as CSA B415.1 which applies in Canada and the USA. (A new update is coming in a couple of months, BTW.)

Explore the 10 degree clearance idea, and see if your chimney would pass the standard applied in most of Eastern Europe and Central Asia.

Second, temporarily remove whatever cap you have to see if it is responsible for creating positive pressure at the top. Maybe it's fine. I haven't used that draft-creating cap in the photo before, but it looks interesting. It has no moving parts. If it doesn't work, send it back for a refund.

Third, regarding the make-up air - try opening various upstairs windows instead of the nearby door. Windward side, leedward side, find out what doesn't work. Ruling things out is as important as finding conditions that work. If it suddenly solves the problem it points to an architecture problem (building layout etc).

Fourth, the comment about trees might be significant. I don't thinl you have a stove problem. You have an architecture problem. If it was me, I'd immediately put on a swinging vaned hood while seeking other solutions.

Fifth, if you raise the top of the chimney, check with the rules about the support and the "vee" of sheet metal that diverts snow around it. It should be able to pass a WETT inspection even if your municipality or insurance company doesn't require it.

Lastly, Permies readers can reach me using crispinpigott at outlook dot com. I can dig out the graphics on the chimney top dimensions and slope. It might be on my website at www.newdawnengineering.com in the library, stoves, Kyrgyzstan. There is an English version somewhere.

Stay well
Crispin

Dennis Barrow

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joe fish wrote:

randal cranor wrote:Howdy,

And is there a spark screen on/in the top cap? Might try without it. I've seen spark screens slow the draft down. To my knowledge, the top of a chimney has to be higher than the peak of the roof. and I'm also not a stovepipe expert.

There is a spark screen, The top of the flue is not above the roof line, but it is more than 10' away from the roof. I could take off the arrestor but it seems like its adding very little resistance.

Joe, I have installed a couple dozen stoves over my life and I believe you need to get the stove pipe above the peak of the roof. I have found that it does not matter much how far from the peak your pipe is, it still needs to be a couple feet above the peak.

That means you will have to install supports for it, but well worth it.

Real funny, Scotty, now beam down my clothes!

Kelly Craig

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On what others say, above, remember that there is a lot of air in the house when you start the fire, so it may look like the fire is burning and on its way at the start. As the fire burns, that air will reduce, absent an air intake. That might cause the fire to act like it does when starting, even after several minutes of run time.

One more thing, the uninsulated pipe is a huge heat sink. It reduces how hot the drafted smoke gets, reducing draw. That is the very concept around which mass heaters are built. They contain the heat of the chimney to allow it to get hotter and burn off more gases, creating better draw.

Trevor Walker

Posts: 58

Location: Ohio

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posted 3 years ago

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Congrats on finding the major issue!!
Sometimes it does take that close look, but you just don't know until you SEE it, right?

Not surprised it helped to remove the gunky screen in the final egress.
But now you have to look out for the barn swallows coming down in roosting weather.

This looks like a stove I used everyday for a few winters.
I prefer the door open just a crack, so it jets air in quickly.
That was the perfect air feed for a fresh hot start, or right after adding a handful of kindling and a couple small logs.

But naturally, the compromise of this design of stove is the best fuel efficiency is a dirtier burn.
One is meant to close the door completely and damp down the air inlet a bit to slow the burn.
Its meant to swirl flame, but not burn particularly quickly, keeping more of the heat for your comfort, rather than send all the heat out the flue.

Peace to you

Ralph Kettell

pollinator

Posts: 290

Location: The Arkansas Ozarks

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posted 3 years ago

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Hi Joe,

You started that the top of the chimney was not above the ridge. In a prior house, I had a chimney that was well above the near part of the roof, but .... it was not above the peak of the house. There was enough turbulence in the roof that when the wind was blowing in certain directions I got horrible backdraft. I increased the height of the chimney and added a screen at the top. Problem solved. Not sure if this is the cause of your problems, but maybe with a try. It also fixed the draft on current house. I added 4 feet and a better cap and voila wonderful draft.

Best wishes with the draft.

Sincerely,

Ralph Kettell

Sincerely,
Ralph

Roger Bradley

Posts: 13

Location: Mid Wales, (dis)UK

posted 3 years ago

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joe fish wrote:Longtime lurker,
You can see it looks windy in the outside picture, Its always like this, not terribly windy, but a gentle flow, that often changes directions. Is this it???

I'm no expert, but have installed a few woodburners, most with unusual configurations! But - To the nitty-gritty:
My logic says that if you have smoke leaking from joints then you have: A) a good updraft, and B) back pressure stopping the smoke emerging from the top of the flue. The flue is clear so the only remaining explanation is that you have a downdraft stopping the heat/smoke exiting properly. You have plenty of updraft or there wouldn't be the pressure to push smoke through the joints. In our barn conversion I had to ensure our flue finished above the ridge to satisfy Building Control. I've not regretted it. In my past researches I have come across numerous mentions of flue finishing above ridge height. BUT - your flue looks to be by the outside wall so extending will clearly require support wires. An alternative would be to reroute the flue so that it exits the roof much closer to the ridge. I can only guess that the prevailing wind causes back-pressure. The photo of the outside appears to show smoke being pushed down and to one side although that isn't clear. The bends are unlikely to be a problem - I have a very similar setup - and the length of flue appears to be giving you a good updraft (smoke leakage at joints = pressure). These conclusions also point to the stove itself being fine.

Unimportant but relevant extras:
In our barn conversion I originally thought to put our woodburner in the corner of the lounge. We had it there initially as we worked through the build - we had one room that was very much like a student bedsit with everything squeezed into it - and the flue was a custom made steel pipe with around 8' of flexy pipe, including some 4' of almost horizontal, to allow the smoke to exit through a narrow (4") ventilation slit in the stone wall. The problem was that it was on the windward side of the barn and there was no other sensible temporary option. So, when the wind blew we would have a lot of problem getting the fire lit without turning ourselves into kippers! Once the flue was warm though, even with the weird flue, it worked fine except for occasional gusts that would push a bit of smoke back. I eventually moved the stove away from the corner and ran the insulated flue through the bedroom and out the roof around 3' from the ridge. This configuration has two 45 degree bends to accommodate a wall and to get the flue a bit closer to the ridge. (I didn't want to build a chimney or try to support a long length of flue sticking out of the roof). It works superbly and we've not had problems with back-draughts even though I have a simple cap on the flue to stop rain ingress. I looked long and hard at all sorts of different cowls but reviews generally pointed to eventual problems with anything that turned. Our barn is in a dip by a river with a big tree-covered hill behind. This causes the wind to eddy in all sorts of directions, some almost in the opposite direction! I feel the problem you are having is the same thing, with wind eddying around the building and roof to give a down-draught exactly where you don't want it.
Down by the river is our "bath-house" - an insulated "shed" with a woodburner in it that gave us a bath/sauna arrangement while we were building. It's so lovely that we still use it every couple of weeks, even though we've got "proper" indoor bath/shower rooms

The woodburner here has 2x3' uninsulated flue sections and works brilliantly. It heats a tank of water in an hour or so and we can enjoy a hot "bathroom" to raise a gentle sweat, even with snow on the ground outside. It is a relatively "Heath-Robinson" affair using an old bath rescued from a skip, water from a tank catching land-drain run-off high on the hill behind, and a second-hand insulated hot water cylinder. (Safety note - the cylinder doesn't feed a tap as that could cause explosive pressure - the outlet is a simple pipe into the bath. I have a gate-valve in place of the hot tap and that allows cold water into the bottom of the tank and that, in turn, pushes the hot out the top and down into the bath! All great fun, and very simple. This is the second iteration of bath-house after the first had a fire - mice must have nested too close to the uninsulated flue going through the roof and then we had no hot water cylinder - the woodburner back boiler just heated a bath full of water. That took three hours so gave the nesting material time to ignite. Cautionary warning - use insulated flue, or make sure that nothing unwanted can come in contact with the flue.

Tog.
Pitiful is the one who, fearing failure, makes no beginning. -- Hindu Saying

Lesa NeSmith

Posts: 6

Location: Witch Well, Arizona

posted 3 years ago

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Roger Bradley wrote:

joe fish wrote:Longtime lurker,
You can see it looks windy in the outside picture, Its always like this, not terribly windy, but a gentle flow, that often changes directions. Is this it???

I'm no expert, but have installed a few ...

~~~~~
I WOULD LOVE to know more about your bath set up. We have a cold windy challenging winter for a couple months where I am. I have gravity fed water, which freezes up in the winter...I have an rustic 3 season shower toilet set up that I want to upgrade. I'm allergic to propane so truly want to use wood for heat as well as the water.... (I do not, however, want to highjack this thread - which has helped me tremendously with my backdraft issues up on my hill - perhaps Moosage Me?)

joe fish

Posts: 29

Location: Zone 5A New Hampshire

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posted 3 years ago

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Lesa NeSmith wrote:

Roger Bradley wrote:

joe fish wrote:Longtime lurker,
You can see it looks windy in the outside picture, Its always like this, not terribly windy, but a gentle flow, that often changes directions. Is this it???

I'm no expert, but have installed a few ...

~~~~~
I WOULD LOVE to know more about your bath set up. We have a cold windy challenging winter for a couple months where I am. I have gravity fed water, which freezes up in the winter...I have an rustic 3 season shower toilet set up that I want to upgrade. I'm allergic to propane so truly want to use wood for heat as well as the water.... (I do not, however, want to highjack this thread - which has helped me tremendously with my backdraft issues up on my hill - perhaps Moosage Me?)

Hey Lesa, So you are trying to use wood heat to prevent a water line from freezing? Do you have pictures? Even more details?

Crispin Pemberton-Pigott

Posts: 22

posted 3 years ago

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I have an update on the chimney termination above the roofline.

I wrote that I would find the installation manual for Kyrgyzstan which cites the updated Russian national building code (I think 2016 or so).

It is not "one rule for all". Please see the attached schematic.

+++++++++++++
Within 1.5m of the ridge, it should be 0.5m above the ridge.
Within 3m of the ridge, same level as the ridge.
More than 3m from the ridge, at a line descending 10 degrees from the ridge.
+++++++++++++

Of course there is no problem to be higher than any of these values.

Crispin

Chimney-termination.JPG

Crispin Pemberton-Pigott

Posts: 22

posted 3 years ago

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This is the general case installation guide (not showing the particulars of the passage through a floor or ceiling).

Crispin

Chimney-through-roof.JPG

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