Double D!!
Cigars are hygroscopic, which means simply that they absorb water. I have tried just about all that can be tried. I own 3 humis and 1 coolidor ( not much, by LOWMAN's standards!!! LOL). I keep all of them at 85%-90% filled, it seems to keep my RH constant. I have not add any water to my coolidor in over 8 months, (I also keep my stogies on the dry side), all of my humis keep a constant RH of 64-68 RH. Cigars serve as humidifiers, the more cigars you have in the humi, the better. However I have found that a little room in the humi is better, lets it breathe better
my .02