I also think a very large majority of people on this planet are tired because of an unknown deficit of vitamines and minerals like Omega 3, Zink and Vitamin D
I never ate much meat but I do eat fermented-only dairy. I got my bloodwork done and I am iron deficient. I am taking the bisglycinate salt which is completely unnoticeable on my stomach. I'll have it retested after a course of 5000mg elemental iron equivalents (about a month). My mood noticeably improved after checking and correcting my blood vitamin and iron levels.
V in HVAC is for "ventilation" and although home AC unit might not provide it itself, I'd be surprised if there really wasn't any. Unlike AC, V is mandated by law in many jurisdictions.
The ones I know suck air out of the building (well, really, create a mild low pressure), and rely on fresh air getting in elsewhere (for example through dedicated intakes around windows in apartments.)
Vitamin D deficiency is well known enough it should stand up to the simple concern trolling done by people who demand a source like every post must be an academic journal.