air conditioning

So I picked this a/c unit up at an auction a few days ago $40, runs great, not loud, even has a dehumidifier setting, I plan to use it in a detached garage grow, I have a lot more head space in there, my only problem was lack of cooling. Then I got this thing, it has a vent on the rear to expel...

I just got a new 1000 watt MH air cooled, I'm running with my Appolo 300 watt LED. It's at like 90. Degrees now I want to turn on my other 600 watt MH but I'm scared that will make it hotter, I use a crappy duct fan from Home Depot, I'm getting a hydro farm 6inch fan soon, will that take care of...