Originally Posted by Master11

No no no. We don't do that. Preconditioned air or APU air only.

Your alleged anecdotal experience is uninformed/uninspired. But this is the internet, and after all, you could be a pilot wife or flight attendant, fanboy/girl, retiree, or even a mechanic (although I'd wager a mechanic would, at the very least, strongly question the illogical process of powering air conditioning packs with hotly compressed air that is only treated to restrict moisture on its way directly to the engine(s)).