There are two adults in my house who chain vape, and I have yet to notice fog on my windows. I do, however, notice a film that builds up in my vehicle.
Now, I do have two hepa air purifiers in my home so perhaps it DOES help alleviate the issue ... although I'd never considered that as the reason before now.
Fun Fact: My air purifiers stay on an "auto" setting and adjust as necessary to whatever they detect in the air. If I carry a bag of garbage past, it'll kick on. If someone (not me, never me of course) passes gas at one end of the room, it'll inevitably kick on in a few minutes
Just sayin', it's sensitive. But two adults chain
vaping in the same room has never set it off