I noticed that there is space for the vapor to get out. How does the vapor stay inside the chamber if it can easily escape?
In a standard convection vaporizer, the weed is placed next to a heating element with some space in between. When you inhale, you draw air over the heating element, and then that heated air passes over the ganj, vaporizing the THC en route to your lungs. If you're not actively inhaling through the tube, there will not be any vapor produced.
It's one of the things that I don't like about the Iolite. Unlike other vapes, the herb is constantly in contact with a chamber that is heated up to vape temps. You can smell the vape from the stem even when you're not drawing so the bud is constantly being cooked. With other vapes, you can just take the heat source away from the vape between hits and your bud stays fresh. Not so with the Iolite.