Top vent wide open and the bottom vent needs to be open as well. Gotta have oxygen to combust.
I also have a question when using amps. I bought the expandable tube. I used this 1 time this summer in my propane smoker. I lit the end like it said and waited about 7 minutes, blew out the flame and stuck it inside my smoker. I came back to check on it about an hour later and notice that it burned out (no smoke). I want to use this to smoke cheese so I am wondering would I have to keep the door cracked and the top vent opened to keep the air flow so the pellets do not burn out? I have seen the mailbox trick but just did not want to have to do it unless it is necessary to smoke cheese.