Defenders Of Glass
Likewise since it's not hermetically sealed, air is always present. You would have to displace that space with something else, or in the case of insulated windows as you mentioned, remove air with a vacuum.That concept sounds flawed considering there is nothing trapping or sealing that air in. If it was hermetically sealed it would work as an insulation barrier.
For example: we wear sweatshirts for insulation, but they don't require a hermetic seal to function.
Natural convection still takes place, even when insulation is used. A hermetic seal would help, but my main point in the above post really wasn't about the air gap acting as insulation, it was that the sidewalls not directly touching the insert is not really ideal heat transfer. This is one of the reasons why a torched banger at the same floor temperature as an e-nail produces different vapor (additional radiant heat penetration)
Your vape is also a bit different then my example, as it's not being heated from the outside-in like an axial coil, though it is still heating from the bottom which is pretty much what I was saying above. I used to do dabs from a Thermal P (the double walled banger) doing cold starts with a triple jet vapcap torch using only the floor to vape because I didn't have a big enough torch to heat the whole banger. I swear that must have been in 2016/17 before the cold start trend started booming, it was also very quiet this way compared to those big jet engine torches