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Comment by daneel_w | Hacker News Reader

> " Because this design of stove burns at relatively high temperature, it yields more complete combustion and emits lower levels of particulate."

This doesn't sound right to me, because there's heavy soot production whether hot or cold stove. Are you sure it's not just because a large masonry stove (and its long chimney) has a lot more surface for soot and particulate to stick on compared to e.g. a tiny portable one?

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Soot is amorphous carbon; that will absolutely be burned at higher temperatures (given sufficient oxygen). You might be thinking of ash, which consists mostly of inorganic residue (although even there you'll see carbonates at low temperatures and metal oxides at higher temperatures).

But when we talk about burning wood cleanly we're really talking about smoke -- and that's almost entirely organics (including large amounts of carbon monoxide, methane, and VOCs) which will combust given sufficient heat and oxygen.

Not too much soot should be produced in well designed burning. Which includes sufficient input of oxygen. Ofc, also the material burned matters. Only untreated wood and with right moisture level. The emissions increase with both too wet and too dry wood.

How does too dry wood result in higher particulate emissions?

It burns too fast. I'm not entirely certain of mechanism, but it could break up and vaporize faster than wood with bit higher moisture content. The whole process comes back to sufficient supply of oxygen.

If you have a decent masonry stove, good airflow and dry firewood then most of the particles will simply burn. Once the stove is hot enough, the smoke will ignite and most of that soot is converted into heat and energy.

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