Can portable AC unit intake air from inside room?
I have the exact same problem. I have an office with 4 screens, 2 servers, an xbox and it gets HOT.
What I did, which I think is ingenious, is that I put the intake under my desk where the servers are clustered into a tight knight group of heat emitting devils. When the AC kicks on, it sucks the hot air right out of the computers and cools the condenser and shoots it outside.
So for me running it on inside air makes it nice, yes it sucks in air from the hallway but the hallway and other room air is super cold, it's just my room that stinks.
As far as humidity goes I could care less I'm in CA and humidity is low. It may be running less efficient, but I don't see how sucking out hot air from my computers and blowing it outside is any worse than sucking in 120 degree Bakersfield air.
Maybe I'm missing something, but this setup works good for me bludshot.