16tonBEAN

Much obliged, Glenn!

DennisG, your hood design with 24" height seems more reasonable than the one I was considering - 22"w x 16"d x 48" h. I need to look into hood design some more. By the way, where did your chimney pipe come from?

Glen, Thanks for the info, and I will definitely test the wind first as you suggest. The distance I'm referring to is from the top of the side draft hood to the chimney cap. If I use one of the hood designs I have found on the net, that would mean I would have only 3 feet of pipe on the inside, then 5 feet more chimney pipe on the outside to get to a point where I'm 4 feet above the ridge. Maybe the tall hood is not a good choice, I don't know. I've been looking at several side draft hood designs and am trying to decide which to use, but my biggest issue is where to get pre-fab double wall chimney pipe or for that matter single wall interior stove pipe 12" in diameter. Or do you make your own? I have found Dura-Vent pipe, but it's expensive. Thanks

Well I think I've worked out a solution to use a side draft hood and my existing forge unit - appreciate the advice. I'm having issues locating chimney pipe in my area. Any opinions on 12" Simpson Dura-Vent double-wall class-A chimney pipe the whole way up - from forge to cap? (except the expense). I really only need 7' of pipe to get 4' above the ridge pole, but a lot of people seem to think that 10' of chimney is kind of the magic number for a large side draft hood.

Ok great, thanks for the replies! Yes, I see now that side draft is better and I should make the 12" chimney, side draft work somehow. Thing is I bought a forge unit from Centaur forge awhile back, and that design has the open hood with 8" pipe opening. None of it is installed yet, though, and the framing for the shop is happening this week, so I have a chance to make it better. I will try to figure it all out today - hopefully with some modifications, I can make the forge work with side draft? I don't have much metal work experience yet.

Hi. I've read many threads concerning chimney pipe diameter for a coal forge. I am new at blacksmithing and am currently in the middle of shop construction and still am unsure what chimney diameter to use. My roof will be asphalt shingles on a half-inch deck - no ceiling. The problem is that I already have a forge hood with an 8" opening, but from what I've read, a 12" chimney pipe is preferable. Now is the time to decide on the 12" chimney pipe, but hate to waste the hood. Any ideas? (At this point I have to stick with the steel pipe chimney instead of masonry).