I have used these units many years, prior to retiring, and they worked great. We called them "move and cool", or "spot cool units" , and used them for emergency situations in comercial building computer rooms. You need to run a flexible exaust duct, to either the outside, or in my cases, in the ceiling return air system. Also, there is a condensate bucket, that can either be emptied when full, or also run to a drain line. If this is going in your garage, and you are all sheet rocked in, I see no reason why you could not dump the warm condensing air up above the ceiling.
Wayne