Good afternoon from England
Just bought myself a bullet smoker and i am not too clear on temperature control.
Will having the top vent full open increase or lower temperature ?
What kind of bullet smoker do you have?
You normally want to have the top vent open all the way.
To answer your question though, closing dampers lowers the temp and opening them up increases the temp.
Depending on what you have, you should have vents around the bottom. Start adjusting those first and if you have to, make small adjustments to the top if you end up closing all the bottom vents.
For each adjustment, wait 10-15 minutes for the smoker to settle down.
It's also much easier to start closing off vents as the smoker gets to 200°F / 93°C. Then you can make the adjustments to get the smoker to 225-250°F / 107°C.
In other words, it's easier to bring the smoker up to a temp than down to a temp.
Saw 'em on eBay - looks like a quality piece. Congrats!
Any pictures of the fire ring/bowl where the charcoal goes?
I also have a Q Pro, And have never closed the top vents
The top vent should remain would always open during smoking, Temperature control is done with the lower vents.
As has been mentioned here, open hotter ,Close is cooler