On 02/04/2018 13:14, GB wrote:
On 01/04/2018 18:31, David wrote:

How hot is the smoke likely to be?

If you are cool/cold smoking then you might get away with drainpipe or
soil pipe.

Out of interest, does a chimney work at all with cold smoke? I thought
it needs hot smoke to rise inside the chimney?

Cold smoke is still warmish in the sense of not cold and rises slowly,
it just isn't warm enough to cook whatever is being smoked.

If the chimney is not going to draw, the OP might as well just make a
vent in the wall or leave the door open.

3" mild steel pipe with an old bean can on top cross wise would get my
vote (assuming function is more important than form).

--
Regards,
Martin Brown