Imperial Pipe and How to Vent

Since I am back working on the greenhouse coal project(little bit of a hiatus). I was pricing out piping and trying to keep this project on a low budget, I found Imperial Pipe. Any one use them? The second question I is it possible just to run the stove pipe up and connect to the chimney pipe above the greenhouse so I am not building a masonry chimney .

Yes, inside the greenhouse you could use plain black or cheaper still galvanized single wall pipe, connected to insulated double wall pipe above. Support and bracing would have to be worked out.

cheaper still galvanized single wall pipe

I don't know if thats a good idea, I remember reading that galvanized pipe should not be used for some reason, but I could be wrong..

grumpy wrote:

cheaper still galvanized single wall pipe

I don't know if thats a good idea, I remember reading that galvanized pipe should not be used for some reason, but I could be wrong..

Excessive heat could start to vaporize the zinc. Every old coal burner or furnace I have seen had galvanized many years old. Wood could over heat it but coal with a stove not over fired should be no problem. Black is a better radiator though.

The stovepipe manufactures don't recommend galvanized for solid fuels. Overheat it once and it will rust quickly.

Galvanized flue pipe works very well on stokers.

With a coal fire, exhaust gas temperatures are probably low enough to not cause any off-gassing of galvanized pipe. However, it only takes one instance of loading too much too quickly to get the pipe really hot and anyone near it is in serious trouble. It's not worth the risk. It's also in contradiction of NFPA 211, I believe.

Talk to welders about welding galvanized. They'll tell you how miserable the gases can make you.

Thank you all, I totally forgot about Nfpa 211. I will be staying away from the galv. metal pipes and sticking to the black pipe.