New Smoker questions

Yesterday we cold smoked for the first time. We used a smoke spiral. After leaving it it overnight the results this morning were mixed. The dust was only partially burned so not everything we tried was all done. Now i have a couple of questions :
- must all the air vents only year BBQ be closed or (partially) open (inflow of oxygen for the burning)/
- we packed the dust quit tight in the spiral. is that wise or should it be more loose?

Thanks in advance

Jet & Gert