av8tor
Meat Mopper
I too use my WSM with top vent open but recently have read a newsletter from Harry Woo that he leave the bottom open and controls the draft and temp with the top vent. So this has me scratching my head as Harry has won many championships using his WSM's.
From here
When you open the exhaust vent on the WSM, you allow hot air to leave the pit and this creates a vacuum suction to draw air in from the bottom intakes. Thus, by skillfully manipulating the top vent, you can control your WSM like a pro. Many beginners constantly fiddle with their intake dampers in hopes to maintain a constant temperature with less success than leaving the bottom vents untouched and fiddling with the top vent to control the draft within their WSM. In future articles, I’ll address the mechanics of damper control on the WSM (e.g., old school versus automated blower systems) and the science on dirty smoke, white smoke, clean smoke, blue smoke, sour smoke, etc. For now, just give my technique a try and see if it works for you.
From here
When you open the exhaust vent on the WSM, you allow hot air to leave the pit and this creates a vacuum suction to draw air in from the bottom intakes. Thus, by skillfully manipulating the top vent, you can control your WSM like a pro. Many beginners constantly fiddle with their intake dampers in hopes to maintain a constant temperature with less success than leaving the bottom vents untouched and fiddling with the top vent to control the draft within their WSM. In future articles, I’ll address the mechanics of damper control on the WSM (e.g., old school versus automated blower systems) and the science on dirty smoke, white smoke, clean smoke, blue smoke, sour smoke, etc. For now, just give my technique a try and see if it works for you.