That's because the only thing coming out of the mechanical device is a bit of water vapor.
Two people on this thread sent me a Freepmail about the blu e-cigs I'm using. I tried two different ones before blu and dumped them. The best thing about blu is the hard case that looks like a hard case pack of cigs. You keep that hard case charged and when you leave the house take it with you as it has a charged cig in there and extra cartridges. With that, you won't run out of a cig when you leave the house. Take a charged one with you plus this hard case and that's two charged you have when you go somewhere.
When you are out and your cig goes dead, take the charged one out of the case and put the spent one in the space inside the case and it will recharge - that's because you had the case charged before you left the house. So you have a recharger with you to keep charging a cig.
My son and I went out to the hill country of Texas and I had no trouble keeping a cig charged since I had the case that kept charging one while I was “smoking” the other one. I took the cord that charges the hard pack so when we were in a hotel, I plugged in the hard case so it was ready the next day to keep charging a cig when I used up the other one. I hope this description makes sense to you as to how to use that hard case.