agree generally with comments on the manometer readings. however, you can have too much flue for a stove, overfiring can result from too much draw. a damper in the pipe was the ususal way to restrict this.
you can probably tell, i have done a fair number of installs in homes, which have different rules i guess. i think where i went wrong in my reading of the ABYC is in the measures for flamable surfaces. what you are saying is by using the thermafiber, you create a non-flamable surface. therefore there is no standoff distance. i was thinking of the 90 degree temperature rise rule of an engineered solution (and the thermafiber was a way to achieve this). this would require equipment i do not have access too. happily it is not needed.
i am well aware that cement board does not meet the requirements. great for mounting tile on though.
i know the theory of how a water deck iron works, and i do not dispute that it would work well if filled with water. perhaps i could combine the ideas and use a 5 inch iron on a 4 inch pipe? i will think about that, but something doesn't seem right about it. i believe the outter diameter of a 5 inch iron is 9 and some inches. you are right about it having some thermal mass. baywood still makes an aluminum one i believe. AL seems a good choice for heat conductivity, though i suppose bronze is tradtional.
lastly, double wall pipe for the exterior. i think this would be a big help and any insulation is good, even double wall with air space as insulation. i was thinking of fabbing up a custom pipe out of SS truck exhaust pipe. it would be nice to take this through the deck (combined with the idea of an oversized deck iron as above) do you know what the insulation is in residential pipe and or a source for?
You could crush up some K-FAC19 and make an insulated pipe filling?
Agree completely about a damper. One will also go through quite a bit of fuel without one! Online manual says don't install a stove without one. The "gas pedal" of the stove....
