Steam Hood c/w Preheater (stack size?)

[Pibster]

My 2'x3' steam hood is coming together. Just wondering how big I should make my vent pipe. Would a 6x6 square be too small? I will be putting a damper inside and the hood will sit tight to the pans.

[Pibster]

I ended up bending a 6x6 square pipe. That's almost as much area as a 7" round so I'm thinking it should be plenty.

[Treetapper]

I am using an 8 " round on a 2.5 x 4 hood with a preheater, on the flue pan. It exits at the cupola.
Have a good season.

[maple flats]

yes 6x6 should be good. Have a good season!