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.
rumme said:
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.
