Question about the 2-10 rule and roof peak

[rumme]

If a person makes sure their chimney is at least 2 foot higher then any part of the roof 10ft away, but that still doesnt rasie the chimney above the roof peak, should the draft still be adequate enough in all situations { including windy days } to run the woodstove and not encounter any smoke coming into the home ? ?

its supposed to...avoid crossdrafting weird windshit. 10-2 -3ft above roof

this is exactly what I was thinking...

the fact that I only experience smoke thru my woodstove and in the house, on windy days, might mean I am experiencing severe cross drafting due to the fact I am not at the 2-10 rule....

I do not think a uninsulated chimney is the source of my smoke problems , becuase if it was, I would think I would experience smoke problems on non windy days, when its very cold out , and that isnt the case so far.

I do recongize that having my chimney uninsulated, is causing condensation...which is evident by the water that drips out of my cleanout trap door , at the bottom of the chimney, when I have the woodstove running.

 

[rumme]

one other point...out here in the boon docks of arkansas, many people do not run insulated chimneys. I have a good friend who has a very half ass setup with his woodstove, running thru his window. He is only using single wall steel chimney, and has had it this way for 3 years. He told me he NEVER has any smoke problems , even on windy days. This is yet a little more evidence that my problem may not be because of a uninsulated chimney.

 

[chunkyal]

I think it's more likely the chimney diameter that's giving you problems - not sure what I'm basing that on - a vibe?

To my way of thinking - smaller equally faster, faster equals hotter, hot air rises, hotter air rises faster, insulated chimney equals hotter, etc.
Also explains why you might have more problems on warmer days - less temperature differential. (hotter/colder being relative terms - hot air on rises if surrounded by colder air - therefore the colder the surrounding air the "hotter" the hot air is.

This makes sense in MY head - hope its not complete nonsense.

So I still think an extra, smaller pipe inside your existing 8x8 is the answer. Building codes are usually fairly conservative so I would think it strange that the part of the code you did come close to satisfying would be the cause of your problems.

That said - an extra 3' is cheaper/easier. If you do that first and it still doesnt work...

Also do you have some sort of cap? I could see than an open "bucket" would catch more wind than one with a lid.

 

[rumme]

I think you misunderstood my post..

I am not having smoke problems on warm days...

only windy days ....


I gave the example of the windy day at 40 degrees and having smoke problems

to the

20 degree day and no wind..with no smoke problems, as evidnece that my smoke problems may not be directly associated with a unisnulated , cold chimney.


I think I am gonna try one of two things...


keep the chimney exaclty like it is, but add a Versa stack wind cap { about $100 } ..which are suppose to solve problems associated with wind...

or, go ahead and pruchase another 3-4 ft of steel chimney and attach it to the existing chimney...which will get me at the 2-10 rule...

the versa stack option is a bit more expenisve, but less labor involved....


I realize that this napolean 1900p is suppose to have a 6x6 chimney....but my 8x8 chimney was all I could get at the time..and it seems to work, as long as the wind isnt strong. Also, when I spoke to a napolean representative/ sales person, they didnt say that going from a 6" stove pipe to a 8x8 chimney, was unheard of....they did say that trying to go from a 8" stovepipe to a 6 " chimney would be unacceptable..which I already knew

 

[Peter B.]

rumme:

Consider this... I lived for five years in a converted machine shed on a friend's farm not far from where I live now. I had a single 3' section of Class A pipe to get me through the roof... straight shot. Above the Class A, I used single wall black pipe, with more than enough height to pass the 'rule'.

Typically, in cold weather, I never had a problem (perhaps surprisingly). On mild days, fall and spring, when the wind was from a different 'quarter' than usual, I'd get uncontrollable backpuffing.

I found only one chimney cap design that helped... but I can't remember enough about it to describe it.

I never solved the backpuffing problem completely... just lived with it. I'm all but convinced now (twenty years on) if I'd used entirely Class A pipe above the roof, the chimney would have retained enough *HEAT* to overcome the windy day problem.

Now, I have a chimney that's '80%' proper... Class A for most of the length... and *only* Class A on the exterior portion. In most of twenty years, I've NEVER had a problem with wind related backdrafting/backpuffing.

My point is that you can continue to do everything (mostly) wrong if you like... and cite the neighbor's success with through-the-window installs... but you ain't likely to get what you want without (somehow) insulating that stack... inside or out.

I'm not to code either... but at least what I have works well for me.

Peter B.

-----

 

[PunKid8888]

Sounds like a lot of little problems are creating a bigger problem. I think if you only eliminate one issue with your set up, you will only see a little improvement, but I think fixing most or all the issues will give you the result you want.

 

[rumme]

sounds like 2' extension would do the trick to test i''d jam a piece of cheap pipe into chimney,plug corners with fiberglass & test the 10-2 rule= cheap & sounds like would be conforming with the local style

I actually like your idea..and your sarcasms..LOL...

 

[rumme]

rumme:

Consider this... I lived for five years in a converted machine shed on a friend's farm not far from where I live now. I had a single 3' section of Class A pipe to get me through the roof... straight shot. Above the Class A, I used single wall black pipe, with more than enough height to pass the 'rule'.

Typically, in cold weather, I never had a problem (perhaps surprisingly). On mild days, fall and spring, when the wind was from a different 'quarter' than usual, I'd get uncontrollable backpuffing.

I found only one chimney cap design that helped... but I can't remember enough about it to describe it.

I never solved the backpuffing problem completely... just lived with it. I'm all but convinced now (twenty years on) if I'd used entirely Class A pipe above the roof, the chimney would have retained enough *HEAT* to overcome the windy day problem.

Now, I have a chimney that's '80%' proper... Class A for most of the length... and *only* Class A on the exterior portion. In most of twenty years, I've NEVER had a problem with wind related backdrafting/backpuffing.

My point is that you can continue to do everything (mostly) wrong if you like... and cite the neighbor's success with through-the-window installs... but you ain't likely to get what you want without (somehow) insulating that stack... inside or out.

I'm not to code either... but at least what I have works well for me.

Peter B.

-----

the chuimney cap wasnt the Versa stack ?

 

[Peter B.]

the chuimney cap wasnt the Versa stack ?

Can't recall... but it was for single wall 6" round pipe.

I really think you want to insulate your steel chimney somehow... if you insist on retaining it.

You really shouldn't be trying to 'beat the Devil' here, but finding a solution that works, is safe, and comparatively trouble free.

Peter B.

-----

 

[rumme]

the chuimney cap wasnt the Versa stack ?

Can't recall... but it was for single wall 6" round pipe.

I really think you want to insulate your steel chimney somehow... if you insist on retaining it.

You really shouldn't be trying to 'beat the Devil' here, but finding a solution that works, is safe, and comparatively trouble free.

Peter B.

-----

in the near future, I plan on bricking around it, so it will match the outside of our brick house...but this option is not feasable right now, due to weather, wetness and money.....so im trying to do a quick fix for the wind/ smoke problems...I still find it difficult to believe that the smoke problems are mostly associated with a uninsulated chimney .....all indications are it is asscoated primarily with wind...

 

[rumme]

even though my setup is not exactly to codes...I do consider it to be quite safe from a fire point of view...

my horizontal section has at least 1/2 " rise per foot

the outside chimney is 20 " away from my outside brick wall..

my roof is a non combustable metal roof

I have used proper stainless steel / insultaed wall thimble for connection of stovepipe to chimney..


etc...



I fully admit that not having the chimney insulated, is not the best choice, and allows for condensation/ water to drip from the cleanout....but I can deal with that issue later, when the weather is more appropriate. The backpuffing of smoke into my house, on windy days , and alleviating it for now ,is my primary focus at this point in time.

I will report back with my results.

 

[rumme]

i JUST ordered a versa stack wind resistant chimney cap...for $100....

im gonna try using this first...and keeping my chimney height where it is currently at. This method is a bit more expensive then just adding 3- 4 ft more chimney, but it will be less labor involved...

 

[rumme]

i JUST ordered a versa stack wind resistant chimney cap...for $100....

im gonna try using this first...and keeping my chimney height where it is currently at. This method is a bit more expensive then just adding 3- 4 ft more chimney, but it will be less labor involved...

if it dont plug with creosote

possible...but I doubt it. I burn fully aged cedar/ ash/ ..some of which is over 7 years aged...I dont burn any cardboard or trash...and if needed, I can easily clean the chimney out via the cleanout at the of my chimney....

I know you wanted me to try the other route, using PVC pipe and fiberglass...but my wife wont let me :}

 

[KeithO]

So rumme

When you burn your stove on those windless days, have you observed what happens to the smoke from your stack ? You apparently have an EPA compliant Napoleon stove, so it seems a mystery why you should get any smoke at all, especially with your 7 year seasoned wood. But I digress... I guess everyone gets a little smoke right at the time they re-light the stove, particularly from cold. I have to assume you are not talking about smoke all the time, when burning in windy conditions, because then you have a much more serious wood burning problem.

If you observe a cold fire burning outside in the open, like someone burning their leaves on the ground in late fall, you will see that at first the smoke rises straight up. As the smoke rises, it is cooling and soon it reaches a point where it is no warmer than the air around it. It is plainly visible that at that height the smoke can rise no more and then spreads out in a horizontal direction. Now at this point you are probably wondering what this has to do with your wood burner and install. It is actually connected. In order to avoid breathing the combustion products that come out of your chimney, the goal of a successful chimney design is to deliver the flue gasses to a height above the roof line, with sufficient heat that they will on their own be able to rise clear of the structure and be swept away by the prevailing wind.

In your case, while the single wall pipe is obviously capable of delivering the flue gasses to roof height, it is entirely possible that by the time they get to the top, they are in fact almost as cold as the surrounding air. So instead of rising up away from the structure, they may in fact come out horizontally. Now add some wind coming over the ridge of the roof, and it is going to bring that smoke (why smoke anyway ?) down to a level that you are going to be breathing it. Rain caps are quite effective at stopping wind from reversing draft (it has been measured, not armchair engineering), and only cost about $30, but the adapter onto your pipe will be an interesting job. And as others have mentioned, the vanes on the rain cap are prone to collecting creosote, and that is a fact too. Probably 80% of creosote deposited on my system is on the rain cap, but compared to having rain infiltrating my system, I'll take the cap and clean it any day.

The same "too short, too cold" chimney and fire issue is the reason why outdoor boilers are being banned in one state after another, since the smoke (from a cold fire with too little air) spreads out horizontally just above the ground at the perfect height to be ingested by others central heating system air intakes.

I think you misunderstood my post..

I am not having smoke problems on warm days... only windy days ....

I gave the example of the windy day at 40 degrees and having smoke problems to the 20 degree day and no wind..with no smoke problems, as evidence that my smoke problems may not be directly associated with a uninsulated , cold chimney.

 

[rumme]

I would imagine, if the wind is able to backdraft into the chimney, down it, and into the woodstove itself, while there is wood burning, that this would create smoke in and of itself, by smothering the fire .

Ive had my stove running all day today..no wind...and no smoke entering my house. ...but its not very windy out.

If the vacu stack solves this problem, then I will know it was almsot entirely a wind related issue and I would hope this info may help others in the future.

 

[North of 60]

So rumme

When you burn your stove on those windless days, have you observed what happens to the smoke from your stack ? You apparently have an EPA compliant Napoleon stove, so it seems a mystery why you should get any smoke at all, especially with your 7 year seasoned wood. But I digress... I guess everyone gets a little smoke right at the time they re-light the stove, particularly from cold. I have to assume you are not talking about smoke all the time, when burning in windy conditions, because then you have a much more serious wood burning problem.

If you observe a cold fire burning outside in the open, like someone burning their leaves on the ground in late fall, you will see that at first the smoke rises straight up. As the smoke rises, it is cooling and soon it reaches a point where it is no warmer than the air around it. It is plainly visible that at that height the smoke can rise no more and then spreads out in a horizontal direction. Now at this point you are probably wondering what this has to do with your wood burner and install. It is actually connected. In order to avoid breathing the combustion products that come out of your chimney, the goal of a successful chimney design is to deliver the flue gasses to a height above the roof line, with sufficient heat that they will on their own be able to rise clear of the structure and be swept away by the prevailing wind.

In your case, while the single wall pipe is obviously capable of delivering the flue gasses to roof height, it is entirely possible that by the time they get to the top, they are in fact almost as cold as the surrounding air. So instead of rising up away from the structure, they may in fact come out horizontally. Now add some wind coming over the ridge of the roof, and it is going to bring that smoke (why smoke anyway ?) down to a level that you are going to be breathing it. Rain caps are quite effective at stopping wind from reversing draft (it has been measured, not armchair engineering), and only cost about $30, but the adapter onto your pipe will be an interesting job. And as others have mentioned, the vanes on the rain cap are prone to collecting creosote, and that is a fact too. Probably 80% of creosote deposited on my system is on the rain cap, but compared to having rain infiltrating my system, I'll take the cap and clean it any day.

The same "too short, too cold" chimney and fire issue is the reason why outdoor boilers are being banned in one state after another, since the smoke (from a cold fire with too little air) spreads out horizontally just above the ground at the perfect height to be ingested by others central heating system air intakes.

I think you misunderstood my post..

I am not having smoke problems on warm days... only windy days ....

I gave the example of the windy day at 40 degrees and having smoke problems to the 20 degree day and no wind..with no smoke problems, as evidence that my smoke problems may not be directly associated with a uninsulated , cold chimney.

OK Rumme I think what a few of us are saying here is that since your install has everything batting against it, the wind aint gonna help. THUS YOUR EXPERIENCE.