How *exactly* is an airtight supposed to work

[turn_n_burn]

I have been trying to solve this question in my own head, and have done hours of research both here and elsewhere, and I just can't quite seem to pin the answer down exactly. I understand that they use gasketed doors and everything, flue included is sealed well. I'm more after how they operate (or are supposed to operate). For example, If someone shut down the primary air completely once the stove was going full bore, would it eventually put the fire out, or would there be some kind of effect where combustion oxygen is drawn down one side of the chimney/flue interior while the smoke goes up the other side of it in parallel? I understand well enough what a traditional damper does, as far as limiting the upward heat loss and keeping more of it in the stove, but I'm not sure how different damper settings would affect the stove (if already preheated/running full bore) once the primary air is completely closed off. Or do you just simply have to let a little primary air in regardless to keep the stove from going out? And lastly, because mostly all I have access to is pine, fir, tamarack, and juniper, is it realistic to expect a 7 or 8 hour burn?

Sorry for the litany of questions there, any insight would be hugely appreciated.

 

[bholler]

I have been trying to solve this question in my own head, and have done hours of research both here and elsewhere, and I just can't quite seem to pin the answer down exactly. I understand that they use gasketed doors and everything, flue included is sealed well. I'm more after how they operate (or are supposed to operate). For example, If someone shut down the primary air completely once the stove was going full bore, would it eventually put the fire out, or would there be some kind of effect where combustion oxygen is drawn down one side of the chimney/flue interior while the smoke goes up the other side of it in parallel? I understand well enough what a traditional damper does, as far as limiting the upward heat loss and keeping more of it in the stove, but I'm not sure how different damper settings would affect the stove (if already preheated/running full bore) once the primary air is completely closed off. Or do you just simply have to let a little primary air in regardless to keep the stove from going out? And lastly, because mostly all I have access to is pine, fir, tamarack, and juniper, is it realistic to expect a 7 or 8 hour burn?

Sorry for the litany of questions there, any insight would be hugely appreciated.

There are no modern stoves that let you shut the air off completely. They are required to allow a certain ammout of air in so people can't smoulder the fire

 

[peakbagger]

Yes if you could seal the firebox you could "black" the stove out. This is not a good thing, if the stove is hot, the stove is still gasifying the wood. but it will not burn until if finds enough oxygen to burn. There is a recent post about a stove having a rapid combustion event which is what happens when a stove is putting out combustion gases with not enough oxygen to burn. Eventually the stove will find enough air and poof. Air tight stoves attempted to control combustion by limiting the oxygen to the stove. Unfortunately using this approach, the stove can put out a lot partially burnt gases up in the air and condense out as creosote. One of the key things that EPA stoves do is install a secondary set of air ports that cannot be shut off. The stove loses some capability to be turned down but the emissions are a lot cleaner. Some folks will cheat and plug these ports and turn their stove back into an air tight. The result can be creosote and increased emissions.