Chimney O2 Levels on EPA Phase 2 stoves

[TMonter]

I was wondering if Corie or anyone else had some hard data on the O2 levels exiting EPA phase 2 stoves. I'm trying to come up with a basic spreadsheet on energy content versus moisture content versus excess air for modern wood stoves.

I figured Mike & Corie might have the most data in this area but anyone else is welcome to post what they have.

I was figuring most stoves operate with about 60-100% excess air above stoichiometric.

 

[Corie]

O2 levels in stack gas.........


Between 8% and 15% roughly, depending on burn rate (remember this is with Douglas Fir test loads).

 

[TMonter]

O2 levels in stack gas.........

Between 8% and 15% roughly, depending on burn rate (remember this is with Douglas Fir test loads).

Wow so 65% to 220% excess air at a wood moisture content of 25%. That's a pretty big range to work with. I didn't realize excess air levels were that high.

 

[TMonter]

Excess air does not = O2.

Air only has ~20.9% O2 by volume, slightly less for wet air. To get chimney O2 levels of 8-15% (by mass) you need between 65% and 220% excess air to get that O2 content when firing wood with 25% moisture.