Stovetop temp: 585° Single wall pipe: 450ish __________________________________ Class A.... At the roof penetration 0° Midway up - 14° Top - 20° Inside cap 67° Outside air temp 15.3° Interesting
I'm thinking he is measuring the outside of the class A pipe. Don't understand how the pipe can read colder than the ambient though.
Did you change the emmisivity?(how the heck you spell it) of the IR temp gun? My IR gun seems to not read correctly just leaving it set how it it is normally.
450 surface temps are really hot. I first read your temperatures as negative 14 negative 20. How can it be zero at the roof?
There is probably some heat escaping at the roof line. Right now my class A on the outside is 7° coming out of the roof and 11° heading up. The cap is 57° new small load just started.
I would say you are running too cold. That 57ºF on the cap means you are getting condensation inside your chimney pipe. Condensation = creosote in my way of thinking. The outside of a class A is almost meaningless since it is well insulated from the inner pipe but the cap is reflecting the "real" flue temperature.