1000watts draws a lil over 9amps at 120volts, so on a 15amp circuit that only leaves a few amps to use safely. Using just the fan motor on a window ac and not the compressor wont draw much over an amp and should be fine with the 1000, but why use an ac unit just for the fan instead of a fan? Also you are allowing yourself to potentially overload the circuit with the flip of a switch on the ac unit.
But what really concerns me and makes it impossible for me to give you an answer that i would back is, you described it as a 15amp wire and the 2nd plug on the 15am breaker. Wire is not commonly described by the ampere, it is the gauge/#conductors, and i am yet in my long career to see a breaker with plugs, a breaker is the black switches in your homes electrical panel and plugs would commonly refer to the receptacles in the walls around your house, surge strip, ect. A 15amp wire would be #14gauge, 12 is 20, 10 is 30, and so on.
So if you have for-say a 14/2 romex wire running from your houses electrical panel on a 15amp breaker to a 15amp duplex receptacle by your tent then yes you would be ok to max it out. But if you have a strip or ext cord or something like that plugged into a receptacle on your homes wall and not knowing what else is on that circuit than no, i would be hesitant to run anything high draw if i weren't home.
I know alot of ppl run the 1000w digital ballast at 120v but if you wanna do it cheaper, safer, and put less amps on your circuit than run them at 240v if possible, your ballast would also need to be a multi-tap.
