From an old thread:The big bang
Originally posted by Smokenque:
There was a good description of a "bang" by a fireman on either this forum or one of the others I've signed up for.
It might have to do with partially burned fuel that is in the atmosphere of the smoker. This, as I understand, is early on in the smoke.
The inside of the smoker is controlled in how much oxygen is allowed inside, creating a lot of smoke rather than fire. I've had this inadvertently happen when I opened the box early on, like about the 30 minutes that jimbie mentioned. That inrush of oxygen, reacting with the rich smoke caused the wood to ignite and created mini fireball. I only cracked the door and after the flash, boom.. the door was sucked closed.
While I don't know the technicalities of it.. there can be a mini explosion that you might not hear when grease or smoke ignites causing a big puff. When that is finished, fresh oxygen filled air is pulled in the holes to replace that air that expanded and blew out the holes and gaps around the door. That large amount of oxygen can cause a bigger bang or pop.
Most incidences I've heard about are usually in the early stages of a new smoker. After a bit of time, the smoke residue seals enough of the gaps to minimize the intrusion of air, other than was designed into the unit.