You can very safely remove the “probably” from your first sentence.

I mean, there is a hard limit on how much info your brain can take in. It’s time. Every hour spent learning one thing is an hour not spent learning everything else.

*Thinnest and yet roughest. Not thick enough to be a barrier, and it can rub you raw to provide an entry point at the same time!

“Sealed” is also a vague suggestion with HVAC. Every ducting join, every piece of equipment, all of it leaks. I shudder to think how much heating/cooling is wasted that way.