Never seen a venturi smoker so all I can offer is... Are your vents open for proper air flow?
I use the
A-Maze-N Pellet smoker. Just set it in the smoker, light one end with a torch, and close it up. I have gotten up to 10.5 hours of cold smoke from a single fill, before refilling and allowing to burn in the other direction. Easy Peasy...
It follows the normal air flow of the smoker, bottom vent open, top vent open. The warm smoke naturally rises exiting the chimney and is refreshed with fresh air from below.
Wish I could be of better assistance.....
